Update August 2018

Myocardial infarction (MI) arising from obstruction of the coronary circulation engenders massive cardiomyocyte loss and replacement by non-contractile scar tissue, leading to pathological remodeling, dysfunction, and ultimately heart failure. This is presently a global health problem for which there is no effective cure. Following MI, the innate immune system directs the phagocytosis of dead cell debris in an effort to stimulate cell repopulation and tissue renewal. In the mammalian adult heart, however, the persistent influx of immune cells, coupled with the lack of an inherent regenerative capacity, results in cardiac fibrosis. Here, we reveal that stimulation of cardiac lymphangiogenesis with VEGF-C improves clearance of the acute inflammatory response after MI by trafficking immune cells to draining mediastinal lymph nodes (MLNs) in a process dependent on lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1). Deletion of Lyve1 in mice, preventing docking and transit of leukocytes through the lymphatic endothelium, results in exacerbation of chronic inflammation and long-term deterioration of cardiac function. Our findings support targeting of the lymphatic/immune cell axis as a therapeutic paradigm to promote immune modulation and heart repair.

PURPOSE: Pancreatic cancer is the fourth cause of death by cancer worldwide. Lymph node (LN) involvement is known to be the main prognostic factor. However, lymphatic anatomy is complex and only partially characterized. The aim of the study was to study the pancreatic lymphatic system using computer-assisted anatomic dissection (CAAD) technique and also to update CAAD technique by automatizing slice alignment. METHODS: We dissected three human fetuses aged from 18 to 34 WA. 5-microm serial sections of duodeno-pancreas and spleen blocks were stained (hematoxylin-eosin, hematoxylin of Mayer and Masson trichrome), scanned, aligned and modeled in three dimensions. RESULTS: We observed a rich, diffuse but not systematized lymphatic network in the peri-pancreatic region. There was an equal distribution of LNs between the cephalic and body-tail portions. The lymphatic vascularization appeared in continuity from the celiac trunk to the distal ends of its hepatic and splenic arterial branches parallel to the nerve ramifications of the celiac plexus. We also observed a continuity between the drainage of the pancreatic head and the para-aortic region posteriorly. CONCLUSION: In view of the wealth of peri-pancreatic LNs, the number of LNs to harvest could be increased to improve nodal staging and prognostic evaluation. Pancreatic anatomy as described does not seem to be compatible with the sentinel LN procedure in pancreatic surgery. Finally, we are now able to offer an alternative to manual alignment with a semi-automated alignment.

The glymphatic system is a glial-dependent waste clearance pathway in the brain, in place of lymphatic vessels, dedicated to drain away soluble waste proteins and metabolic products. Specifically, the glymphatic network serves as a “front end” for waste clearance, and is connected downstream to an authentic lymphatic network, associated with dura covering the brain as well as cranial nerves and large vessels at the skull exits. The anatomical and functional interconnections between these two networks are not completely understood. Several key physiological processes have been identified that control glymphatic transport function and waste clearance from brain. In this review, we aim to provide an overview and discussion of the concept behind the glymphatic system, current evidence, and controversies, while specifically focusing on the consequences of aging and evidence of its existence in human brain. Discovering novel strategies for optimizing and maintaining efficient brain waste clearance across the lifespan may in the future prove to be important for preventing cognitive decline and sustaining healthy aging.

The paper describes the extension of a previously developed model of pressure-dependent contraction rate to the case of multiple lymphangions. Mechanical factors are key modulators of active lymphatic pumping. As part of the evolution of our lumped-parameter model to match experimental findings, we have designed an algorithm whereby the time until the next contraction depends on lymphangion transmural pressure in the contraction just completed. The functional dependence of frequency on pressure is quantitatively matched to isobaric contraction experiments on isolated lymphatic segments. When each of several lymphangions is given this ability, a scheme for their coordination must be instituted to match the observed synchronization. Accordingly, and in line with an experiment on an isolated lymphatic vessel segment in which we measured contraction sequence and conduction delay, we took the fundamental principle to be that local timing can be overridden by signals to initiate contraction that start in adjacent lymphangions, conducted with a short delay. The scheme leads to retrograde conduction when the lymphangion chain is pumping against an adverse pressure difference, but antegrade conduction when contractions occur with no or a favourable pressure difference. Abolition of these conducted signals leads to chaotic variation of cycle-mean flow-rate from the chain, diastolic duration in each lymphangion, and inter-lymphangion delays. Chaotic rhythm is also seen under other circumstances. Because the model responds to increasing adverse pressure difference by increasing the repetition rate of contractions, it maintains time-average output flow-rate better than one with fixed repetition rate.

The lymphatic vasculature act as the drainage system for most of our tissues and organs, clearing interstitial fluid and waste and returning them to the blood circulation. This is not the case for the central nervous system (CNS), which is devoid of parenchymal lymphatic vessels. Nevertheless, the brain is responsible for 25% of the body's metabolism and only compromises 2% of the body's mass. This high metabolic load requires an efficient system to remove waste products and maintain homeostasis. Well-described mechanisms of waste clearance include phagocytic immune cell functions as well as perivascular fluid flow; however, the need for active drainage of waste from the brain is becoming increasingly appreciated. Recent developments in lymphatic vascular biology challenge the proposition that the brain lacks lymphatic drainage or an equivalent. In this review, we describe the roles of the glymphatic system (a key drainage mechanism in the absence of lymphatics), the recently characterized meningeal lymphatic vessels, and explore an enigmatic cell population found in zebrafish called mural lymphatic endothelial cells. These systems may play important individual and collective roles in draining and clearing wastes from the brain.

The etiopathogenesis of infantile haemangioma has not been well understood, and it is accepted that angiogenic mediator dysregulation is the main contributor to the abnormal haemangioma capillary formation. The role of NDRG1, a hypoxia-inducible protein; FOXOs, which are tumor suppressor proteins; and the mTOR complex 2 pathway in infantile haemangioma have not been studied yet. The purpose of this study was to investigate NDRG1 and FOXO1 expression in the infantile haemangioma and the correlation of these proteins with proliferation and involution. Primary endothelial cells were obtained, with parental agreement, from 12 infantile haemangioma patients during surgery; 6 patients had proliferating infantile haemangiomas and 6 had involuting IHs. We compared the infantile haemangioma tissues and primary endothelial cells with human vein endothelial cells using microarrays, real-time PCR, Western blotting and immunohistochemical staining. Our data indicated that FOXO1 expression was downregulated in proliferating infantile haemangioma tissue. We found that the expression of NDRG1, a molecule upstream of the FOXO1 pathway, increased during haemangioma proliferation. NDRG1 knockdown decreased haemangioma endothelial cell proliferation and downregulated c-MYC oncoprotein levels. Our findings suggest that NDRG1 positively regulates haemangioma proliferation. FOXO1 dysregulation plays an important role in infantile haemangiomas pathogenesis.

BACKGROUND AND OBJECTIVE: Vascularized omentum lymphatic transplant (VOLT) for treatment of lymphedema has become popular because of no risk of iatrogenic lymphedema and abundant lymphatic tissue. However, perfusion to the omentum can be difficult to assess clinically. The purpose of this study was to clarify the incidence and degree of ischemia in the omentum. METHODS: A retrospective study was conducted to review indocyanine green perfusion findings on patients undergoing VOLT. Patients were placed into 4 categories based on the percentage surface area of omentum that was ischemic: normal, less than 25%, between 25% and 50%, and greater than 50% ischemic. Spearman correlation was performed to determine whether an association exists between prior abdominal surgery and the presence of ischemia. RESULTS: Twenty-six patients underwent VOLT for treatment of extremity lymphedema. Twelve (46.2%) patients had normal perfusion, 8 patients (30.8%) had less than 25% ischemia, and 6 patients (23.1%) had 25% to 50% ischemia. Prior abdominal surgery was not significantly associated with the presence of ischemia. CONCLUSIONS: Normal flap perfusion is a requisite for successful VOLT harvest. However, over half the patients had some degree of abnormal perfusion irrespective of prior abdominal surgery. Indocyanine green angiography is an important tool in ensuring a healthy lymphatic reconstruction.

Objective To investigate whether lymphoedema in a Chinese family showed the hereditary and clinical characteristics of Milroy disease, an autosomal dominant form of congenital lymphoedema, typically characterized by chronic lower limb tissue swelling due to abnormal lymphatic vasculature development, and to perform mutational analyses of vascular endothelial growth factor receptor ( VEGFR)3. Methods Individuals from a three-generation family affected by congenital lymphoedema were clinically assessed for Milroy disease. Mutation analysis of VEGFR3 was performed using DNA from family members and healthy controls. Results Out of 20 family members, eight were diagnosed with hereditary lymphoedema. Mutation analyses revealed a novel mutation site for c.3163 G>A, resulting in a p.1055D>N mutation in the second tyrosine kinase domain of VEGFR3, which was present in affected individuals only (absent in all unaffected family members and 130 healthy controls). Computed functional analyses showed the mutation may lead to structural alterations with a probability of 0.99999 of being disease causing. Conclusion A novel mutation associated with Milroy disease was identified in a Chinese family, expanding our knowledge of VEGFR3 gene function and providing a potential molecular target for treating hereditary lymphoedema.

The study of lymphangiogenesis is an emerging science that has revealed the lymphatic system as a central player in many pathological conditions including cancer metastasis, lymphedema, and organ graft rejection. A thorough understanding of the mechanisms of lymphatic growth will play a key role in the development of therapeutic strategies against these conditions. Despite the known potential of this field, the study of lymphatics has historically lagged behind that of hemangiogenesis. Until recently, significant strides in lymphatic studies were impeded by a lack of lymphatic-specific markers and suitable experimental models compared to those of the more immediately visible blood vasculature. Lymphangiogenesis has also been shown to be a key phenomenon in developmental biological processes, such as cell proliferation, guided migration, differentiation, and cell-to-cell communication, making lymphatic-specific visualization techniques highly desirable and desperately needed. Imaging modalities including immunohistochemistry and in situ hybridization are limited by the need to sacrifice animal models for tissue harvesting at every experimental time point. Moreover, the processes of mounting and staining harvested tissues may introduce artifacts that can confound results. These traditional methods for investigating lymphatic and blood vasculature are associated with several problems including animal variability (e.g., between mice) when replicating lymphatic growth environments and the cost concerns of prolonged, labor-intensive studies, all of which complicate the study of dynamic lymphatic processes. With the discovery of lymphatic-specific markers, researchers have been able to develop several lymphatic and blood vessel-specific, promoter-driven, fluorescent-reporter transgenic mice for visualization of lymphatics in vivo and in vitro. For instance, GFP, mOrange, tdTomato, and other fluorescent proteins can be expressed under control of a lymphatic-specific marker like Prospero-related homeobox 1 (Prox1), which is a highly conserved transcription factor for determining embryonic organogenesis in vertebrates that is implicated in lymphangiogenesis as well as several human cancers. Importantly, Prox1-null mouse embryos develop without lymphatic vessels. In human adults, Prox1 maintains lymphatic endothelial cells and upregulates proteins associated with lymphangiogenesis (e.g., VEGFR-3) and downregulates angiogenesis-associated gene expression (e.g., STAT6). To visualize lymphatic development in the context of angiogenesis, dual fluorescent-transgenic reporters, like Prox1-GFP/Flt1-DsRed mice, have been bred to characterize lymphatic and blood vessels simultaneously in vivo. In this review, we discuss the trends in lymphatic visualization and the potential usage of transgenic breeds in hemangiogenesis and lymphangiogenesis research to understand spatial and temporal correlations between vascular development and pathological progression.

Flavonoids, present in fruits, vegetables and traditional medicinal plants, show anticancer effects in experimental systems and are reportedly non-toxic. This is a favorable property for long term strategies for the attenuation of lymph node metastasis, which may effectively improve the prognostic states in breast cancer. Hence, we studied two flavonoids, apigenin and luteolin exhibiting strong bio-activity in various test systems in cancer research and are readily available on the market. This study has further advanced the mechanistic understanding of breast cancer intravasation through the lymphatic barrier. Apigenin and luteolin were tested in a three-dimensional (3-D) assay consisting of MDA-MB231 breast cancer spheroids and immortalized lymph endothelial cell (LEC) monolayers. The 3-D model faithfully resembles the intravasation of breast cancer emboli through the lymphatic vasculature. Western blot analysis, intracellular Ca(2+) determination, EROD assay and siRNA transfection revealed insights into mechanisms of intravasation as well as the anti-intravasative outcome of flavonoid action. Both flavonoids suppressed pro-intravasative trigger factors in MDA-MB231 breast cancer cells, specifically MMP1 expression and CYP1A1 activity. A pro-intravasative contribution of FAK expression in LECs was established as FAK supported the retraction of the LEC monolayer upon contact with cancer cells thereby enabling them to cross the endothelial barrier. As mechanistic basis, MMP1 caused the phosphorylation (activation) of FAK at Tyr397 in LECs. Apigenin and luteolin prevented MMP1-induced FAK activation, but not constitutive FAK phosphorylation. Luteolin, unlike apigenin, inhibited MMP1-induced Ca(2+) release. Free intracellular Ca(2+) is a central signal amplifier triggering LEC retraction through activation of the mobility protein MLC2, thereby enhancing intravasation. FAK activity and Ca(2+) levels did not correlate. This implicates that the pro-intravasative contribution of FAK and of Ca(2+) release in LECs was independent of each other and explains the better anti-intravasative effects of luteolin in vitro. In specific formulations, flavonoid concentrations causing significant anti-intravasative effects, can certainly be achieved in vivo. As the therapeutic strategy has to be based on permanent flavonoid treatment both the beneficial and adverse effects have to be investigated in future studies.

BACKGROUND: Lymphedema is a common and debilitating complication following cancer treatment with surgical lymph node excision and radiotherapy. Currently there are no curative treatments for lymphedema. Animal models that intended to replicate the disease have been inadequate, making a troublesome transition from experimental therapeutic studies into the clinic. It is therefore imperative to establish an experimental animal model that can reliably replicate clinical lymphedema. METHODS: To discover the optimal method of lymphedema induction, surgical lymph ablation and irradiation or silicone splint emplacement were combined in 8 experimental groups (n = 4). In total, 32 mice served in this study and were followed for 8 weeks after surgery. Outcomes included micro-computed tomography hind limb volumetry, lymphatic clearance measured with technetium Tc 99m (Tc) human serum albumin lymphoscintigraphy and lymph vessel ectasia quantified with LYVE-1 immunohistochemistry. RESULTS: All trialed models but one resulted in only transient lymphedema or lasting lymphedema with adverse morbidity. Combined surgical lymph obstruction with 2 fractions of 10-Gy irradiation successfully induced lasting lymphedema without adverse events. Over the 8 weeks' follow-up, limb volumes were significantly increased at all time points (P < 0.001), lymph drainage was impaired (P < 0.001), and lymph vessels were ectatic (P < 0.001), when compared with the unoperated limbs. CONCLUSIONS: The presented model of acquired lymphedema is a reduction and refinement of previous works and can transpose to future observational and interventional studies. In addition, it is shown how Tc-HSA lymphoscintigraphy can quantify lymphatic clearance, which can prove insightful in therapeutic studies aiming to enhance lymphatic drainage.

Significance: Growth of distinctive blood vessels of granulation tissue is a central step in the post-developmental tissue remodeling. Even though lymphangiogenesis is a part of the regeneration process, the significance of the controlled restoration of lymphatic vessels has only recently been recognized. Recent Advances: Identification of lymphatic markers and growth factors paved the way for the exploration of the roles of lymphatic vessels in health and disease. Emerging pro-lymphangiogenic therapies use vascular endothelial growth factor (VEGF)-C to combat fluid retention disorders such as lymphedema and to enhance the local healing process. Critical Issues: The relevance of recently identified lymphatic functions awaits verification by their association with pathologic conditions. Further, despite a century of research, the complete etiology of secondary lymphedema, a fluid retention disorder directly linked to the lymphatic function, is not understood. Finally, the specificity of pro-lymphangiogenic therapy depends on VEGF-C transfection efficiency, dose exposure, and the age of the subject, factors that are difficult to standardize in a heterogeneous human population. Future Directions: Further research should reveal the role of lymphatic circulation in internal organs and connect its impairment with human diseases. Pro-lymphangiogenic therapies that aim at the acceleration of tissue healing should focus on the controlled administration of VEGF-C to increase their capillary specificity, whereas regeneration of collecting vessels might benefit from balanced maturation and differentiation of pre-existing lymphatics. Unique features of pre-nodal lymphatics, fault tolerance and functional hyperplasia of capillaries, may find applications outreaching traditional pro-lymphangiogenic therapies, such as immunomodulation or enhancement of subcutaneous grafting.

The hyaloid vasculature constitutes a transitory system nourishing the internal structures of the developing eye, but the mechanism of vascular regression and its cell biological characteristics are not fully understood. The present study aimed to reveal the specificity of the hyaloid vessels by a systematic immunohistochemical approach for marker substances of myeloid cells and the extracellular matrix (ECM) in neonatal mice. Macrophages immunoreactive for F4/80, cathepsin D, and LYVE-1 gathered around the vasa hyaloidea propria (VHP), while small round cells in vascular lumen of VHP were selectively immunoreactive for galectin-3; their segmented nuclei and immunoreactivities for Ly-6G, CD11b, and myeloperoxidase indicated their neutrophilic origin. VHP possessed thick ECM and a dense pericyte envelope as demonstrated by immunostaining for laminin, type IV collagen, integrin beta1, and NG2. The galectin-3(+) cells loosely aggregated with numerous erythrocytes in the lumen of hyaloid vessels in a manner reminiscent of vascular congestion. Galectin-3 is known to polymerize and form a complex with ECM and NG2 as well as recruit leukocytes on the endothelium. Observation of galectin-3 KO mice implicated the involvement of galectin-3 in the regression of hyaloid vasculature. Since macrophages may play central roles including blocking of the blood flow and the induction of apoptosis in the regression, galectin-3(+) neutrophils may play a supportive role in the macrophage-mediated involution of the hyaloid vascular system.

The study examined the effect of bone marrow multipotent mesenchymal stromal cells and their products secreted into the conditioned medium on uterine microcirculatory bed in Wistar rats during chronic inflammation. The parameters of blood and lymphatic microcirculation in the uterus changed in various directions in relation to the administration routes of biomedical cell product, which is important when the cell therapy is employed in the treatment of inflammatory-degenerative alterations in the lesser pelvis organs.

Alterations in the intestinal lymphatic network are pathological processes as related to inflammatory bowel disease (IBD). In this study, we demonstrated that reduction in inflammation-induced lymphangiogenesis ameliorates experimental acute colitis. A soluble and stable angiopoietin-1 (Ang1) variant, COMP-Ang1, possesses anti-inflammatory and angiogenic effects. We investigated the effects of COMP-Ang1 on an experimental colonic inflammation model. Experimental colitis was induced in mice by administering 3% dextran sulfate sodium (DSS) via drinking water. We determined body weight, disease activity indices, histopathological scores, lymphatic density, anti-ER-HR3 staining, and the expression of members of the vascular endothelial growth factor (VEGF) family and various inflammatory cytokines in the mice. The density of lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and VEGFR-3-positive lymphatic vessels increased in mice with DSS-induced colitis. We observed that COMP-Ang1-treated mice showed less weight loss, fewer clinical signs of colitis, and longer colons than Ade-DSS-treated mice. COMP-Ang1 also significantly reduced the density of LYVE-1-positive lymphatic vessels and the disruption of colonic architecture that is normally associated with colitis and repressed the immunoregulatory response. Further, COMP-Ang1 treatment reduced both M1 and M2 macrophage infiltration into the inflamed colon, which involved inhibition of VEGF-C and D expression. Thus, COMP-Ang1, which acts by reducing inflammation-induced lymphangiogenesis, may be used as a novel therapeutic for the treatment of IBD and other inflammatory diseases. KEY MESSAGES: COMP-Ang1 decreases inflammatory-induced lymphangiogenesis in experimental acute colitis. COMP-Ang1 improves the symptom of DSS-induced inflammatory response. COMP-Ang1 reduces the expression of pro-inflammatory cytokines in inflamed colon. COMP-Ang1 reduces the expression of VEGFs in inflamed colon. COMP-Ang1 prevents infiltration of macrophages in a DSS-induced colitis model.

Background: The morphologic and histologic behavior of lymphatic vessels in lymphedema has not been well analyzed using laboratory animals. The purpose of the present study was to elucidate the regeneration process of lymphatic vessels after acute lymphedema in a rat model. Methods: The acute lymphedema was induced by an amputation and a replantation surgery on a rat hind limb. Recovery of lymphatic flow was traced using fluorescent lymphography with dye injection. The morphology and number of lymphatic vessels were immunohistochemically detected and quantified in both superficial and deep layers. Results: The swelling was the most severe, and the number of lymphatic vessels in the superficial layer was significantly and maximally increased on postoperative day 3. Backflows and overflows were also detectable in the superficial layer on postoperative day 3. The number of lymphatic vessels had decreased but remained significantly higher than that in the controls on postoperative day 14, when the swelling decreased to the levels in the controls. In contrast, the number of lymphatic vessels in the deep layer showed a tendency toward increased numbers; however, it was not statistically significant on postoperative day 3, 7, or 14. Conclusions: We have obtained solid evidence showing the differential potency of lymphatic vessels between the superficial and the deep layers after temporal lymphedematous induction. Further analysis of lymphedematous responses in animal models could provide new insights into the challenges associated with the clinical treatment of lymphedema.

BACKGROUND: Vascularized lymph node transfer (VLNT) has recently received attention as a potential surgical treatment for lymphedema. Despite good results in some series, the mechanism and benefits of VLNT have yet to be fully understood. This study aimed to investigate the re-establishment of drainage into transferred lymph nodes following VLNT in a rat model. METHODS: Seven rats underwent VLNT. The operation performed on each rat consisted of two parts. First, the left groin lymph node basin with superficial epigastric vessels was harvested as a free flap. Second, the flap was re-attached in the left groin of the rat via end-to-end microvascular anastomoses. Anastomosis patency was assessed immediately post-op and at the time of animal sacrifice. The rats were evaluated for re-establishment of lymphatic flow into the transplanted nodes at 1 month intervals for at least 6 months post-op. This was accomplished non-invasively by injecting the rats in their flanks with fluorescent indocyanine green (ICG) which was detected using a PDE infrared camera. RESULTS: Anastomoses were patent in all 7 rats immediately postop. No ICG uptake was seen in the transplanted lymph node basins in the first 2 months post-op in any of the rats. In 5 of 7 rats, however, ICG uptake was demonstrated in the transplanted lymph node basin by 6 months (average 13 weeks). CONCLUSIONS: We report uptake of ICG in 5 of 7 rats at an average of 13 weeks following lymph node transplantation, consistent with the re-establishment of lymphatic drainage into the transplanted nodes.

Postzygotic mutations of the PIK3CA [phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha] gene constitutively activate the PI3K/AKT/mTOR pathway in PIK3CA-related overgrowth spectrum (PROS) patients, causing congenital mosaic tissue overgrowth that even multiple surgeries cannot solve. mTOR inhibitors are empirically tested and given for compassionate use in these patients. PROS patients could be ideal candidates for enrolment in trials with PI3K/AKT pathway inhibitors, considering the “clean” cellular setting in which a unique driver, a PIK3CA mutation, is present. We aimed to assess the effects of blocking the upstream pathway of mTOR on PROS patient-derived cells by using ARQ 092, a potent, selective, allosteric, and experimental orally bioavailable and highly selective AKT-inhibitor with activity and long-term tolerability, currently under clinical development for treatment of cancer and Proteus syndrome. Cell samples (i.e., primary fibroblasts) were derived from cultured tissues obtained from six PROS patients [3 boys, 3 girls; aged 2 to 17 years] whose spectrum of PIK3A-related overgrowth included HHML [hemihyperplasia multiple lipomatosis; n = 1], CLOVES [congenital lipomatosis, overgrowth, vascular malformations, epidermal nevi, spinal/skeletal anomalies, scoliosis; n = 1], and MCAP [megalencephaly capillary malformation syndrome; n = 4]. We performed the following: (a) a deep sequencing assay of PI3K/AKT pathway genes in the six PROS patients' derived cells to identify the causative mutations and (b) a pathway analysis to assess the phosphorylation status of AKT [Ser473 and Thr308] and its downstream targets [pAKTS1 (Thr246), pRPS6 (Ser235/236), and pRPS6Kbeta1 (Ser371)]. The anti-proliferative effect of ARQ 092 was tested and compared to other PI3K/AKT/mTOR inhibitors [i.e., wortmannin, LY249002, and rapamycin] in the six PROS patient-derived cells. Using ARQ 092 to target AKT, a critical node connecting PI3K and mTOR pathways, we observed the following: (1) strong anti-proliferative activity [ARQ 092 at 0.5, 1, and 2.5 muM blunted phosphorylation of AKT and its downstream targets (in the presence or absence of serum) and inhibited proliferation after 72 h; rapamycin at 100 nM did not decrease AKT phosphorylation] and (2) less cytotoxicity as compared to rapamycin and wortmannin. We demonstrated the following: (a) that PROS cells are dependent on AKT; (b) the advantage of inhibiting the pathway immediately downstream of PI3K to circumventing problems depending on multiple classes a PI3K kinases; and (c) that PROS patients benefit from inhibition of AKT rather than mTOR. Clinical development of ARQ 092 in PROS patients is on going in these patients.

Mouse podoplanin (mPDPN) is a type I transmembrane sialoglycoprotein, which is expressed on lymphatic endothelial cells, podocytes of the kidney, and type I alveolar cells of the lung. mPDPN is known as a platelet aggregation-inducing factor and possesses four platelet aggregation-stimulating (PLAG) domains: PLAG1, PLAG2, and PLAG3 in the N-terminus and PLAG4 in the middle of the mPDPN protein. mPDPN overexpression in cancers has been reportedly associated with hematogenous metastasis through interaction with the C-type lectin-like receptor 2 of platelets. We previously reported a rat anti-mPDPN monoclonal antibody clone PMab-1, which was developed by immunizing the PLAG2 and PLAG3 domains of mPDPN. PMab-1 is very useful in flow cytometry, western blot, and immunohistochemical analyses to detect both normal cells and cancers. However, the binding epitope of PMab-1 remains to be clarified. In the present study, flow cytometry, enzyme-linked immunosorbent assay, and immunohistochemical analyses were utilized to investigate the epitope of PMab-1. The results revealed that the critical epitope of PMab-1 is Asp39 and Met41 of mPDPN. These findings can be applied to the production of more functional anti-mPDPN monoclonal antibodies.

Immunogens carried in lymphatic fluid drain via afferent vessels into regional lymph nodes and facilitate the efficient induction of appropriate immune responses. The lymphatic system possesses receptors recognizing hyaluronic acid (HA). Covalent conjugates of small-molecule TLR7/8 agonists with HA are entirely devoid of immunostimulatory activity in vitro. In murine models of immunization, however, such conjugates traffic to lymph nodes, where they are 'unmasked', releasing the small molecule TLR7/8 agonist from the carrier polysaccharide. The resulting focal immunostimulation is manifested in potent adjuvantic effects with negligible systemic exposure. The efficient delivery of immunogens has been a major challenge in the development of subunit vaccines, and enhancing targeted delivery of immunogens to secondary lymphoid organs might be a promising approach for improving vaccine efficacy, as well as safety.

Incomplete delivery to the target cells is an obstacle for successful gene therapy approaches. Here we show unexpected effects of incomplete targeting, by demonstrating how heterogeneous inhibition of a growth promoting signaling pathway promotes tissue hyperplasia. We studied the function of the lymphangiogenic VEGFR3 receptor during embryonic and post-natal development. Inducible genetic deletion of Vegfr3 in lymphatic endothelial cells (LECs) leads to selection of non-targeted VEGFR3(+) cells at vessel tips, indicating an indispensable cell-autonomous function in migrating tip cells. Although Vegfr3 deletion results in lymphatic hypoplasia in mouse embryos, incomplete deletion during post-natal development instead causes excessive lymphangiogenesis. Analysis of mosaically targeted endothelium shows that VEGFR3(-) LECs non-cell-autonomously drive abnormal vessel anastomosis and hyperplasia by inducing proliferation of non-targeted VEGFR3(+) LECs through cell-contact-dependent reduction of Notch signaling. Heterogeneity in VEGFR3 levels thus drives vessel hyperplasia, which has implications for the understanding of mechanisms of developmental and pathological tissue growth.

BACKGROUND AND PURPOSE: Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current treatments for bAVM are all associated with considerable risks. There is no safe method to prevent bAVM hemorrhage. Thalidomide reduces nose bleeding in patients with hereditary hemorrhagic telangiectasia, an inherited disorder characterized by vascular malformations. In this study, we tested whether thalidomide and its less toxic analog, lenalidomide, reduce bAVM hemorrhage using a mouse model. METHODS: bAVMs were induced through induction of brain focal activin-like kinase 1 (Alk1, an AVM causative gene) gene deletion and angiogenesis in adult Alk1-floxed mice. Thalidomide was injected intraperitoneally twice per week for 6 weeks, starting either 2 or 8 weeks after AVM induction. Lenalidomide was injected intraperitoneally daily starting 8 weeks after AVM induction for 6 weeks. Brain samples were collected at the end of the treatments for morphology, mRNA, and protein analyses. The influence of Alk1 downregulation on PDGFB (platelet-derived growth factor B) expression was also studied on cultured human brain microvascular endothelial cells. The effect of PDGFB in mural cell recruitment in bAVM was explored by injection of a PDGFB overexpressing lentiviral vector to the mouse brain. RESULTS: Thalidomide or lenalidomide treatment reduced the number of dysplastic vessels and hemorrhage and increased mural cell (vascular smooth muscle cells and pericytes) coverage in the bAVM lesion. Thalidomide reduced the burden of CD68(+) cells and the expression of inflammatory cytokines in the bAVM lesions. PDGFB expression was reduced in ALK1-knockdown human brain microvascular endothelial cells and in mouse bAVM lesion. Thalidomide increased Pdgfb expression in bAVM lesion. Overexpression of PDGFB mimicked the effect of thalidomide. CONCLUSIONS: Thalidomide and lenalidomide improve mural cell coverage of bAVM vessels and reduce bAVM hemorrhage, which is likely through upregulation of Pdgfb expression.

Background: Early diagnosis of girls with Turner syndrome (TS) is essential to provide timely intervention and support. The screening guidelines for TS suggest karyotype evaluation in patients presenting with short stature, webbed neck, lymphoedema, coarctation of aorta or >/ = two dysmorphic features. The aim of the study was to determine the age and clinical features at the time of presentation and to identify potential delays in diagnosis of TS. Methods: Retrospective data on age at diagnosis, reason for karyotype analysis and presenting clinical features was collected from the medical records of 67 girls with TS. Results: The mean age of diagnosis was 5.89 (+/-5.3) years ranging from pre-natal to 17.9 years (median 4.6 years). 10% were diagnosed antenatally, 16% in infancy, 54% in childhood (1–12 years) and 20% in adolescence (12–18 years). Lymphoedema (27.3%) and dysmorphic features (27.3%) were the main signs that triggered screening in infancy. Short stature was the commonest presenting feature in both childhood (52.8%) and adolescent (38.5%) years. At least 12% of girls fulfilled the criteria for earlier screening but were diagnosed only at a later age (mean age = 8.78 years). 13.4% of patients had classical 45XO karyotype and 52.3% of girls had a variant karyotype. Conclusion: Majority of girls with TS were diagnosed only after the age of 5 years. Short stature triggered evaluation for most patients diagnosed in childhood and adolescence. Lack of dedicated community height-screening programme to identify children with short stature and lack of awareness could have led to potential delays in diagnosing TS. New strategies for earlier detection of TS are needed.

BACKGROUND: Chronic lymphoedema (CLE) is a burdensome disease of multiple causes leading to significant reductions in health-related quality of life (HRQoL). A specific method to assess HRQoL is the Freiburg Life Quality Assessment for lymphedema (FLQA-L), which consists of 92 items. OBJECTIVES: To develop and validate a short form of the FLQA-L with improved psychometric properties and feasibility. METHODS: The FLQA-L validation data were re-analysed by patients and experts. The application of factor analysis enabled the exclusion of lower load items. An optimized short version of the questionnaire (FLQA-LS) with 33 items was generated and tested in a validation study on patients with different forms of CLE. RESULTS: n = 348 patients with CLE of the upper or lower extremities were included (mean age 57.3 years, range: 24–89, 90.8% female) and data from n = 301 could be analysed. 42.8% of the patients suffered from secondary lymphedema, 23.6% from primary lymphoedema, 9.5% from lipoedema and 24.1% were diagnosed with lipo-lymphoedema. Lower extremities were mostly affected (64.4% of the patients presented with leg involvement and 17.5% with both arm and leg impairment). The FLQA-LS showed good internal consistence with high Cronbach's alpha in the subscales and in the global scale, between 0.79 and 0.94. Regarding convergent validity, a good correlation was found with the general HRQoL questionnaire EQ-5D (r = 0.72, p < 0.001). CONCLUSIONS: FLQA-LS is an improved version of the FLQA-L questionnaire for chronic lymphedema. It demonstrated validity and feasibility and can be easily used in clinical practice and research studies. This article is protected by copyright. All rights reserved.

BACKGROUND: Breast lymphedema is a common issue after breast cancer surgery but remains understudied because it is difficult to be quantified. Untreated breast lymphedema may lead to severe form of delayed breast cellulitis. Supermicrosurgical lymphaticovenular anastomosis is one option for the treatment of breast cancer-related lymphedema but has not been described for the treatment of breast lymphedema. METHODS: This report presented a rare case of male breast lymphedema secondary to axillary lymph node dissection for the treatment of a forearm melanoma. Deep lymphatic vessels and adjacent venules were individualized under high magnification in the periareolar area. Six lymphaticovenular anastomoses were performed using supermicrosurgical techniques. A clinical examination and a volume assessment under magnetic resonance imaging were used to assess the efficiency of surgery. RESULTS: Postoperative outcome was uneventful. The patient was followed-up during 1 year. Swelling relief was clinically significant 3 months postoperatively. The pinch test reduction was 2 cm after 12 months. The breast volume reduction rate was 47.2%. CONCLUSIONS: Supermicrosurgical lymphaticovenular anastomosis may be efficient for the treatment of postoperative breast lymphedema, even in male patients.

Primary childhood lymphoedema is a rare disorder, attributed to constitutional lymphatic system abnormality(ies), with familial, syndromic and nonsyndromic forms, associated or not with known gene mutation(s).(1,2) Lymphoedema treatment for adults is based on complete decongestive physiotherapy, comprised of an initial intensive phase, to reduce volume that includes low-stretch bandaging, manual lymph drainage, exercises and skin care, followed by a maintenance phase, essentially based on wearing an elastic garment.(3) Recommendations addressing upper limb lymphoedema after breast cancer, exclusively for adult women, were extrapolated to primary lymphoedema. For children, conservative nonsurgical management requiring parents' commitment is not consensual and differs according to the team; some teams developed new surgical techniques.(1,4-6) Low-stretch bandages are the cornerstone of therapy to reduce lymphoedema volume in adults but no specific data on children are available. We retrospectively analysed a large cohort of children with primary lower limb lymphoedema treated with low-stretch bandages This article is protected by copyright. All rights reserved.

Chylous ascites (CA) is a rare form of ascites that results from the leakage of lipid-rich lymph into the peritoneal cavity. This usually occurs due to trauma and rupture of the lymphatics or increased peritoneal lymphatic pressure secondary to obstruction. The underlying etiologies for CA have been classified as traumatic, congenital, infectious, neoplastic, postoperative, cirrhotic or cardiogenic. Since malignancy and cirrhosis account for about two-thirds of all the cases of CA in Western countries, in this article we have attempted to reclassify CA based on portal and non-portal etiologies. The diagnosis of CA is based on the distinct characteristic of the ascitic fluid which includes a milky appearance and a triglyceride level of >200 mg/dL. The management consists of identifying and treating the underlying disease process, dietary modification, and diuretics. Some studies have also supported the use of agents such as orlistat, somatostatin, octreotide and etilefrine. Paracentesis and surgical interventions in the form of transjugular intrahepatic portosystemic shunt (commonly known as TIPS), peritoneal shunt, angiography with embolization of a leaking vessel, and laparotomy remain as treatment options for cases refractory to medical management.

RATIONALE AND OBJECTIVES Findings and Postnatal MR: This study aimed to describe prenatal and postnatal imaging features and outcomes of neonates with neonatal lymphatic disorders (NLDs). MATERIALS AND METHODS: An institutional review board-approved search of the radiology database for patients with NLD identified five patients. Inclusion criteria include prenatal imaging (fetal magnetic resonance [MR] imaging and ultrasound) and postnatal three-dimensional T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) and dynamic contrast-enhanced MR lymphangiography within 6 months of life. Chart review was undertaken to evaluate morbidity and mortality. RESULTS: Prenatal finding of “nutmeg lung” or fetal pulmonary lymphatic disorder was identified in all five patients on fetal MR imaging, and in four of five patients on fetal ultrasound. Postnatal dynamic contrast-enhanced MR lymphangiography demonstrated abnormal lymphatic flow to the lungs in four of five patients, but absent in the single patient with coexisting hypoplastic left heart syndrome (HLHS). Dermal backflow was seen in one patient, also the only patient with prenatal body wall edema. Three patients with lymphatic flow to the lungs only were classified as neonatal chylothorax. The patient with dermal backflow and perfusion to the lungs was diagnosed with central lymphatic flow disorder (CLFD). The HLHS patient with normal lymphatic perfusion maintained the HLHS diagnosis. Of the five patients, the patient with CLFD and the one with HLHS expired because of respiratory distress. CONCLUSIONS: NLDs can be recognized on prenatal and postnatal imaging and may be primary, as in neonatal chylothorax or CLFD, or secondary. In this small series, “nutmeg lung” was present in all patients. Prenatal imaging demonstrates that body wall edema may correlate with postnatal dermal backflow, which, in our small cohort, carried a poor prognosis.

Context: By promoting the recirculation of tissue fluid, the lymphatic system preserves tissue health, aids in the absorption of gastrointestinal lipids, and supports immune surveillance. Failure of the lymphatic system has been implicated in the pathogenesis of several infectious and inflammatory diseases. Thus, interventions that enhance lymphatic circulation, such as osteopathic lymphatic pump treatment (LPT), should aid in the management of these diseases. Objective: To determine whether thoracic duct lymph (TDL) mobilized during LPT would alter the function of macrophages in vitro. Methods: The thoracic ducts of 6 mongrel dogs were cannulated, and TDL samples were collected before (baseline), during, and 10 minutes after LPT. Thoracic duct lymph flow was measured, and TDL samples were analyzed for protein concentration. To measure the effect of TDL on macrophage activity, RAW 264.7 macrophages were cultured for 1 hour to acclimate. After 1 hour, cell-free TDL collected at baseline, during LPT, and after TDL was added at 5% total volume per well and co-cultured with or without 500 ng per well of lipopolysaccharide (LPS) for 24 hours. As a control for the addition of 5% TDL, macrophages were cultured with phosphate-buffered saline (PBS) at 5% total volume per well and co-cultured with or without 500 ng per well of LPS for 24 hours. After culture, cell-free supernatants were assayed for nitrite (NO2-), tumor necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10). Macrophage viability was measured using flow cytometry. Results: Lymphatic pump treatment significantly increased TDL flow and the flux of protein in TDL (P < .001). After culture, macrophage viability was approximately 90%. During activation with LPS, baseline TDL, TDL during LPT, and TDL after LPT significantly decreased the production of NO2-, TNF-alpha, and IL-10 by macrophages (P < .05). However, no significant differences were found in viability or the production of NO2-, TNF-alpha, or IL-10 between macrophages cultured with LPS plus TDL taken before, during, and after LPT (P > .05). Conclusion: The redistribution of protective lymph during LPT may provide scientific rationale for the clinical use of LPT to reduce inflammation and manage edema.

Background & objectives: India is a signatory to the 1997 World Health Assembly resolutions on lymphatic fila- riasis, and other neglected tropical diseases, and supports global elimination of lymphatic filariasis by 2020. The global programme to eliminate lymphatic filariasis (GPELF) has two main components, viz. interrupting transmission of LF through mass drug administration; and managing morbidity and preventing disability. Consorted efforts by the Public Health Department in Tamil Nadu state (India) for elimination of LF was launched in the year 1997 concentrating on both the components of the programme. The data on the prevalence of filarial morbidity and its entire management at present is based on manual reports and registers maintained by the field functionaries. To overcome the constraints in the manual reporting, an attempt was made to develop a web-based reporting system with different modules and user-friendly interface. Methods: The Vellore and Thiruvannamalai districts were selected as a study area. The study was conducted between 2011 and 2014, which revealed that the entire morbidity management was based on the manual formats. Constraints in the present manual reporting were analysed. PHP and MySQL tools were used to generate user friendly modules. Feedback was collected from field functionaries at different health centre levels, on the adequacy in the modules and effectiveness of the web-based reporting system. Results: The online reporting modules facilitated data entry at the health subcentre level itself. Analysis and retrieval of data was facilitated at all other levels in the public health system. The modules also covered details of surgical interventions, ex-gratia payments and other benefits extended to the lymphoedema patients by the Government. Interpretation & conclusion: The usage and feedback of the web-based reporting system appeared very encouraging and reliable, indicating that it can be implemented in health programmes for disease management. This web-based user-friendly online reporting system can contribute largely to achieve the goals of the GPELF; specially after MDA is withdrawn.

RATIONALE AND OBJECTIVES: To investigate the clinical feasibility of CT lymphangiography (CTL) in primary intestinal lymphangiectasia (PIL) by comparison with intraoperative enteroscopy (IOE) during exploratory laparotomy. MATERIALS AND METHODS: Eleven PIL patients (F/M, two/nine, age range 10–37 years) were recruited in this study, and they were performed IOE during exploratory laparotomy for suspected serious lymphatic-intestinal leakages. All the patients were performed CTL before surgery, and the imaging data were reviewed by two radiologists separately. CTL assessments included intestinal lesions, edematous lesions, intestinal and mesenteric lymphangiectasia, lymphaticabdominal leakages, lymph fluid reflux, lymphangioma and abnormal lymphatics in other area. The intestinal lymphangiectasia and lymphaticintestinal leakages were confirmed by histology and IOE. RESULTS: For CTL, (1) nine intestinal wall thickening; (2) eight ascites, complicated with four pleural effusions, (3) eight intestinal and mesenteric lymphangiectasia, (4) six lymph fluid reflux (5) one lymphatic-abdominal leakage, (6) two lymphangioma. While for IOE, intestinal lymphangiectasia has been confirmed in all patients, including five segemental and six diffusive lesions in intestinal mucosa. Besides, one lymphatic-intestinal fistula, one lymphatic-abdominal leakage was confirmed. Compared to IOE and histology, the accuracy of CTL was 72.7% in detecting intestinal lymphangiectasia. CONCLUSION: Compared to IOE, CTL demonstrates feasibility in detection of intestinal lymphangiectasia and other abnormalities in whole lymphatic circulation for PIL. Combination of CTL with IOE accommodates guidance for preoperative evaluation and therapeutic management for PIL.

For a century-old problem, edema and its treatment have gone remarkably unnoticed by the biomedical community. Given the prevalence of lymphedema and its debilitating repercussions, there is an acute need for both efficacy-based measures and clinical standards to guide compression garment design and therapeutic application. This review outlines the current state of the art in compression treatment and suggests an integrated biomedical engineering approach going forward. Characterizing the pressure gradient profiles of commercial compression sleeves is necessary to better understand the role of compression treatment in the mitigation of swelling. Integration of pressure sensor technologies with advanced materials design and manufacture provides a critical path not only to elucidate the mechanisms of but also to improve on current compression-based therapies and associated therapeutic devices.

PURPOSE OF REVIEW: Lymphangioleiomyomatosis (LAM) is a rare systemic disease that occurs almost exclusively in women. In the last few years, our understanding of disease pathobiology has improved substantially; in addition, a guideline document has recently been developed that provides recommendations for the diagnosis and clinical management of patients with LAM. Yet, significant gaps in knowledge remain. RECENT FINDINGS: Groundbreaking insights into the cellular biochemistry of LAM have led to the reclassification of the disease as a low-grade, destructive, metastasizing neoplasm. In addition, recent data confirm the potential of next-generation sequencing to detect low-prevalence mutations in tuberous sclerosis (TSC) genes in sporadic LAM. A randomized, double-blind, multicentre trial has confirmed the efficacy of sirolimus in stabilizing lung function, improving functional performance and quality of life, and reducing lymphatic manifestations in patients with LAM. Accordingly, recent guidelines issued by the American Thoracic Society and the Japanese Respiratory Society recommend sirolimus treatment for patients with LAM and reduced lung function. Uncertainty remains, however, with regard to patient selection, and timing of initiation, duration and dosing of treatment. SUMMARY: Significant advances have been made in the diagnosis and clinical management of patients with LAM. However, additional studies are needed to assess long-term safety and efficacy of sirolimus therapy, and to identify predictors of disease behaviour and response to treatment.

PURPOSE: While the normal cornea has limited innervation by the lymphatic system, chronic immune-inflammatory disorders such as dry eye (DE) can induce lymphangiogenesis in the ocular surface. Using a conditional knock-down murine model, Lyve-1(Cre);VEGFR2(flox) mice, this study investigated the role of lymphangiogenesis in the pathophysiology of DE. METHODS: DE was induced in both wild type (WT) B6 and Lyve-1(Cre);VEGFR2(flox) mice. Tissue immunostaining and volumetric gross measurements were used to assess changes in the ocular surface, skin, and lymph nodes (LNs). The expression of lymphangiogenic factors (TNF-alpha, IL-6/-8/-12/-17, VEGF-C/-D, IFN-gamma, VEGFR-2/-3, Lyve-1, and podoplanin) and the frequency of immune cells (CD4, CD11b, and CD207) on the ocular surface and lacrimal glands were quantified by real-time polymerase chain reaction and flow cytometry. RESULTS: Compared to WT mice, there were fewer lymphatic vessels and a reduction in lymphangiogenic markers in the ocular surface and skin of Lyve-1(Cre);VEGFR2(flox) mice. After DE induction, mRNA levels of TNF-alpha, IL-8, and IFN-gamma were significantly reduced in Lyve-1(Cre);VEGFR2(flox) mice compared to WT mice (p < .01). Surprisingly, the LNs from Lyve-1(Cre); VEGFR2(flox) mice with DE were significantly smaller and populated by fewer dendritic cells and effector T cells than those from WT mice (p < .001). Furthermore, immunostaining showed corneal nerves in the DE-induced Lyve-1(Cre);VEGFR2(flox) mice were notably intact like in the naive condition. CONCLUSIONS: Inhibition of lymphangiogenesis in the cornea effectively attenuates not only the inflammatory response including trafficking of immune cells but also preserves corneal nerves under desiccating stress. Corneal lymphangiogenesis might be a contributing factor in deterioration on the ocular surface homeostasis.

BACKGROUND: Lymphatic filariasis (LF) and podoconiosis are neglected tropical diseases (NTDs) that pose a significant physical, social and economic burden to endemic communities. Patients affected by the clinical conditions of LF (lymphoedema and hydrocoele) and podoconiosis (lymphoedema) need access to morbidity management and disability prevention (MMDP) services. Clear estimates of the number and location of these patients are essential to the efficient and equitable implementation of MMDP services for both diseases. METHODOLOGY/PRINCIPLE FINDINGS: A community-based cross-sectional study was conducted in Ethiopia using the Health Extension Worker (HEW) network to identify all cases of lymphoedema and hydrocoele in 20 woredas (districts) co-endemic for LF and podoconiosis. A total of 612 trained HEWs and 40 supervisors from 20 districts identified 26,123 cases of clinical morbidity. Of these, 24,908 (95.3%) reported cases had leg lymphoedema only, 751 (2.9%) had hydrocoele, 387 (1.5%) had both leg lymphoedema and hydrocoele, and 77 (0.3%) cases had breast lymphoedema. Of those reporting leg lymphoedema, 89.3% reported bilateral lymphoedema. Older age groups were more likely to have a severe stage of disease, have bilateral lymphoedema and to have experienced an acute attack in the last six months. CONCLUSIONS/SIGNIFICANCE: This study represents the first community-wide, integrated clinical case mapping of both LF and podoconiosis in Ethiopia. It highlights the high number of cases, particularly of leg lymphoedema that could be attributed to either of these diseases. This key clinical information will assist and guide the allocation of resources to where they are needed most.

OBJECTIVE: Phlebolymphedema (chronic venous insufficiency-related lymphedema) is a common and costly condition. Nevertheless, there is a dearth of evidence comparing phlebolymphedema therapeutic interventions. This study sought to examine the medical resource utilization and phlebolymphedema-related cost associated with Flexitouch (FLX; Tactile Medical, Minneapolis, Minn) advanced pneumatic compression devices (APCDs) relative to conservative therapy (CONS) alone, simple pneumatic compression devices (SPCDs), and other APCDs in a representative U.S. population of phlebolymphedema patients. METHODS: This was a longitudinal matched case-control analysis of deidentified private insurance claims. The study used administrative claims data from Blue Health Intelligence for the complete years 2012 through 2016. Patients were continuously enrolled for at least 18 months, diagnosed with phlebolymphedema, and received at least one claim for CONS either alone or in addition to pneumatic compression (SPCDs or APCDs). The main outcomes included direct phlebolymphedema- and sequelae-related medical resource utilization and costs. RESULTS: After case matching, the study included 86 patients on CONS (87 on FLX), 34 on SPCDs (23 on FLX), and 69 on other APCDs (67 on FLX). Compared with CONS, FLX was associated with 69% lower per patient per year total phlebolymphedema- and sequelae-related costs net of any pneumatic compression device-related costs ($3839 vs $12,253; P = .001). This was driven by 59% fewer mean annual hospitalizations (0.13 vs 0.32; P < .001) corresponding to 82% lower inpatient costs and 55% lower outpatient hospital costs. FLX was also associated with 52% lower outpatient physical therapy and occupational therapy costs and 56% lower other outpatient-related costs. Compared with SPCDs, FLX was associated with 85% lower total costs ($1153 vs $7449; P = .008) driven by 93% lower inpatient costs ($297 vs $4215; P = .002), 84% lower outpatient hospital costs ($368 vs $2347; P = .020), and 85% lower other outpatient-related costs ($353 vs $2313; P = .023). Compared with APCDs, FLX was associated with 53% lower total costs ($3973 vs $8436; P = .032) because of lower outpatient costs and lower rates of cellulitis (22.4% vs 44.9% of patients; P = .02). CONCLUSIONS: This analysis indicates significant benefits attributable to FLX compared with alternative compression therapies that can help reduce the notable economic burden of phlebolymphedema.

Inflammatory bowel disease (IBD) is a chronic disease with gastrointestinal dysfunction as well as comorbidities such as inflammation-induced bone loss and impaired immune response. Current treatments for IBD all have negative, potentially severe side effects. We aimed to test whether exogenous treatment with irisin, a novel immunomodulatory adipomyokine, could ameliorate IBD-induced lymphatic and bone alterations. Irisin treatment improved both gut and bone outcomes by mitigating inflammation and restoring structure. In the gut, IBD caused colonic lymphatic hyperproliferation into the mucosal and submucosal compartments. This proliferation in the rodent model is akin to what is observed in IBD patient case studies. In bone, IBD increased osteoclast surface and decreased bone formation. Both gut and osteocytes in bone exhibited elevated levels of TNF-alpha and receptor activator of NF-kappaB ligand (RANKL) protein expression. Exogenous irisin treatment restored normal colonic lymphatic architecture and increased bone formation rate concurrent with decreased osteoclast surfaces. After irisin treatment, gut and osteocyte TNF-alpha and RANKL protein expression levels were no different from vehicle controls. Our data indicate that the systemic immunologic changes that occur in IBD are initiated by damage in the gut and likely linked through the lymphatic system. Additionally, irisin is a potential novel intervention mitigating both local inflammatory changes in the gut and distant changes in bone.-Narayanan, S. A., Metzger, C. E., Bloomfield, S. A., Zawieja, D. C. Inflammation-induced lymphatic architecture and bone turnover changes are ameliorated by irisin treatment in chronic inflammatory bowel disease.

Background: Prox1 is a transcription factor necessary for lymphangiogenesis and lymphatic function. The aim of the study was to assess the correlation between the expression of Prox1 and postoperative recurrence in Crohn's Disease (CD). Methods: Forty CD patients who underwent ileocolonic resection were included. Expression levels of Prox1 and D2-40 were detected using immunohistochemistry. Expression levels of Prox1, VEGFR3, and VEGFC protein were also detected in fresh CD specimens using western blotting and Q-PCR. Endoscopic recurrence was used as the endpoint. Patients comprised two groups: endoscopic recurrence (Group R+) and no endoscopic recurrence (Group R-). Results: Prox1 protein expression was significantly higher in CD than in normal tissues (P < 0.05), as detected using both immunohistochemistry and western blotting. Analysis of interrelationships revealed significant correlation between Prox1 expression and lymphatic vessel density (P < 0.001, r = 0.823). There was also significant correlation between Prox1 expression and the visceral fat area (VFA) (P = 0.002, r = -0.469). The Group R- patients had significantly higher Prox1 expression than the Group R+ patients (21.08 +/-1.61 vs. 15.64 +/-1.17, P = 0.011). Also, the lymphatic vessel density value was lower in Group R+ than in Group R- patients (6.02 +/-0.39 vs. 8.13 +/-0.59, P = 0.004). Moreover, there was a significant difference in the VFA between Group R- and Group R+ patients (64.43 +/-7.76 vs. 90.44 +/-6.11, P = 0.016). In addition to Prox1, VEGFC/VEGFR3 was found to increase, which was further confirmed using Q-PCR. Conclusions: Prox1 expression could be useful as a protective factor against recurrence in CD patients. The therapeutic role of Prox1 may lead to improved treatments.

The mucosa of uterine tube forms multiple and branched longitudinal mucosal folds and takes part in many reproduction events, such as oocyte pick-up, gamete transport, sperm capacitation, fertilization, and early embryonic development. In the habilitation thesis of German physician Paul Kroemer (1904) was the first to describe the lymphatic lacunae inside the tubal folds (by injection of Indian ink), which the author named the oLymphbahnen” (olymphatic channels”). Despite the fact that this first description has existed for 110 years, there is no mention of these lacunae in most of the current literature. In this article we present a rediscovery of completely overlooked morphological structures of uterine tubes - the lymphatic lacunae in their mucosal folds. The specimens from the uterine tubes were taken from 72 women (mean age 46.25 years) who underwent transabdominal or laparoscopic salpingectomy. The tissue samples from anatomically different parts of the uterine tubes were used for hematoxylin and eosin staining and for immunohistochemistry. Primary antibodies were used to label and detect podoplanin D2-40, a selective marker of lymphatic endothelia, CD34 antigen, and von Willebrand factor (Factor VIII). In the histological slides of the uterine tubes, there were noticeable slits or gaps within the loose connective tissue of the lamina propria of the mucosal folds. They were lined with one layer of squamous endothelial cells. These oempty spaces” were most prominent in the fimbriae, but were still well recognizable in mucosal folds of the ampulla. They always run through the central part of the fold. As a results of immunohistochemistry, we confirmed that in the centre of every mucosal fold, as well as in the fimbriae of the uterine tubes, dilated lymphatic spaces were situated and were lined with a simple layer of lymphatic endothelial cells (positive for podoplanin and CD34, and negative for Factor VIII). As there is no mention on them in the current Terminologia Histologica, we proposed the term olymphatic lacunae of tubal mucosal folds and fimbriae” in English and olacunae lymphaticae plicae mucosae et fimbriae” in Latin. According to our hypothesis, these lymphatic lacunae may be responsible for the thickening of the fimbriae during the oocyte pick-up and the maintenance of the tubal fluid.

BACKGROUND: Vascularized lymph node transfer is a promising surgical treatment for lymphedema. This study investigates the effect of ischemia on the lymphatic drainage efficiency of vascularized lymph node flaps and the critical ischemia time of lymph nodes. METHODS: Twenty-four lymph nodes containing groin flaps in twelve Sprague-Dawley rats were dissected. Clamping of the vascular pedicle was performed for 0, 1, 3, 5, 6, 7 hours, then each allowed to re-perfuse via the vascular pedicle for one hour. Perfusion and ischemic changes were assessed using indocyanine green lymphography, laser Doppler flowmetry, and histological studies with associated LYVE-1, CD68, DAPI, TUNEL and GSH assay stains. RESULTS: The mean latency period of the groin lymph node flaps was 247+/-67, 83+/-15, 72+/-42, 30+/-18, and 245+/-85 seconds in the 0-, 1-, 3-, 5- and 6-hour groups, respectively. Perfusion detected by laser Doppler was 85.2+/-14.5, 87.2+/-36.7, 129.8+/-33.7, 140.4+/-148.5, 156.1+/-91.4 and 41.2+/-34.8 perfusion units at ischemia times of 0, 1, 3, 5, 6, and 7 hours, respectively. Cell damage measured by glutathione was 46.8+/-10.2, 67.7+/-14.2, 62.8+/-15.4, 126.6+/-5.9, 259.0+/-70.3, and 109.1+/-27.5 at ischemia times of 0, 1, 3, 5, 6, and 7 hours, respectively. Histologically, as ischemia time increased, hemorrhage and congestion became more severe. CONCLUSIONS: The critical ischemia time of vascularized lymph nodes is five hours in the rodent animal model, verified by ICG lymphatic fluid uptake, laser Doppler perfusion, and histologic assessments. Interestingly, lymphatic drainage and perfusion of vascularized lymph nodes were improved with an increased ischemia time before the critical five hours was reached.

Emberger Syndrome (ES) is a rare genetic disorder characterized by lymphedema and myelodysplasia. It is also associated with hearing loss. The genetic mutations associated with ES are not part of the comprehensive 80 gene next generation sequencing (NGS) panel. As a result, the otolaryngologist should maintain an index of suspicion for ES in any child with SNHL who presents repeatedly with recurrent infections, lymphedema and/or cutaneous warts. This paper describes the clinical evolution and management of two children who were followed up for hearing loss and eventually were diagnosed with ES.

AIMS: We aimed to determine whether cancer-associated fibroblasts (CAFs) are associated with microvessel density (MVD) and lymphatic vessel density (LVD) in lung squamous cell carcinoma, as well as their clinical significance in predicting survival. METHODS: 122 patients were enrolled in the study. Samples were obtained on resection at the Department of Thoracic Surgery of the Qingdao Municipal Hospital between January 2011 and December 2014. Immunohistochemistry was used to determine vessel and lymphatic vessel density, and CAF abundance (fibroblast activation protein alpha (FAP-alpha) positivity). Statistical analyses were performed on 85 patients to test for correlation of CAF density and other clinicopathological variables with 3-year overall survival (OS) and disease-free survival (DFS). RESULTS: High stromal CAF abundance significantly correlated with increased MVD and LVD in lung squamous cell carcinoma (p < 0.05). chi(2) test revealed a significant association of CAF density with lymph node metastasis. Cox proportional hazards model showed that both higher CAF density and lymph node metastasis negatively correlate with survival. CAF density or lymph node status can be used as an independent prognostic factor to predict 3-year OS and DFS. CONCLUSIONS: CAF density, identified by FAP-alpha staining pattern, should be considered as a novel biomarker for disease prognosis in patients with lung squamous cell carcinoma.

BACKGROUND: Breast cancer-related lymphedema (BCRL) is a chronic progressive disease that results from breast cancer treatment and nodal surgery. NCCN guidelines support baseline measurements with prospective assessment for early diagnosis and treatment. We sought to determine if baseline measurement with bioimpedance spectroscopy (BIS) and serial postoperative evaluations provide early detection amenable to conservative interventions that reduce BCRL. METHODS: Breast cancer patients with unilateral disease high-risk for BCRL from a single institution were evaluated from November 2014 to December 2017. High risk was defined as axillary lymph node dissection with radiation and/or taxane chemotherapy. Patients received preoperative baseline BIS measurements followed by postoperative measurements with at least two follow-ups. Patients with BIS results that were 2 standard deviations above baseline (10 + points) started home conservative interventions for 4–6 weeks. Postintervention measurements were taken to assess improvement. RESULT: A total of 146 patients high-risk for BCRL were included. Forty-nine patients (34%) developed early BCRL and started self-directed treatment. Forty patients (82%) had elevated BIS measurements return to normal baseline range. Nine (6%) patients had persistent BCRL requiring referral for advanced therapy. Patients with persistent BCRL had significant nodal burden on surgical pathology; eight (89%) had N2/N3 disease. Six (76%) with BCRL refractory to conservative measures died of their breast cancer. CONCLUSION: Our results demonstrated that early conservative intervention for breast cancer patients high risk for BCRL who were prospectively monitored by utilizing BIS significantly lowers rates of BCRL. These findings support early prospective screening and intervention for BCRL. Early detection with patient-directed interventions improves patient outcomes and decreases the risk of persistent BCRL.

A puppy was diagnosed with lymphangiosarcoma associated with lymphedema based on lymphography and histopathology. The lesions resolved after toceranib therapy, and the dog remains in remission 1 year later. This is the first report of a successful outcome following oral toceranib as first-line therapy for lymphangiosarcoma in a dog.

Local and systemic metastasis is the main reason for the poor survival rate of patients with ovarian cancer (OC). MicroRNAs (miRNAs/miRs) are short non-coding RNAs that serve critical roles in the initiation and progression of OC. The present study demonstrated that expression of miR-19b was significantly increased in OC tissues and cell lines. Analysis of clinicopathological features revealed that the increased expression of miR-19b was associated with advanced International Federation of Gynecology and Obstetrics stage and lymphatic metastasis of OC patients. Loss-of-function experiments demonstrated that the silencing of miR-19b reduced the migration and invasion of OVCAR-3 cells; contrarily, the overexpression of miR-19b facilitated the migration and invasion of CAOV-3 cells. Furthermore, miR-19b regulated the expression of phosphatase and tensin homolog (PTEN) and the activity of the PTEN/RAC serine/threonine-protein kinase pathway in vitro. Notably, the results of dual-luciferase reporter assays indicated that PTEN was a direct downstream target of miR-19b in OC. Taken together, the results of the current study demonstrated that miR-19b serves an oncogenic role in the progression of OC, and could potentially act as a biomarker and therapeutic target for OC patients.

Sentinel lymph node metastasis is a prognostic indicator for systemic tumor spread in many types of cancers, and tumor lymphangiogenesis correlates with reduced survival. Consequently, lymphatic vessels have been suggested to promote tumor progression in multiple ways. Tumor lymphangiogenesis occurs both in primary tumors and at distant (pre-) metastatic sites, and facilitates lymphatic invasion and tumor cell dissemination. Lymphatic vessels have also emerged as regulators of tumor immunity, transporting tumor antigens to lymph nodes and directly interacting with immune cells. Furthermore, lymphatic vessels might provide a 'lymphovascular' niche contributing to the maintenance of stem-like tumor cells that are tightly related to tumor recurrence. Thus, targeting tumor lymphangiogenesis or specific lymphatic-associated functions might represent a promising approach to inhibit tumor progression.

Lymph node (LN) transplantation is a recognized method for reconstruction of the lymphatic system and is used in the clinical setting to treat lymphedema. However, it is unclear whether transplanted LNs contribute to immune surveillance. In our study, we investigated whether a single transplanted non-vascularized LN, defined as a tumor-draining transplanted lymph node (TDTLN), could exert an immune-mediated antitumor effect. LN and lung metastases and primary tumor enlargement were evaluated in mice that were inoculated with B16-F10-luc2 melanoma cells in a hind limb footpad without (group 1) and with (group 2) popliteal lymph node (PLN) resection and in mice that underwent LN transplantation after PLN resection (group 3). The function of a TDTLN (group 3) and a tumor-draining popliteal lymph node (TDPLN; group 1) was evaluated in the context of cancer. LN and lung metastases were significantly aggravated by PLN resection but were significantly decreased by LN transplantation. Immunohistochemistry showed that the TDTLNs retained T-cells and B-cells and fluorescence-activated cell sorting analysis confirmed expansion of lymphocytes in these nodes; however, the degree of expansion in TDTLNs was different from that in TDPLNs. Expression of cytokines associated with immunostimulation was confirmed in the TDTLNs as well as in the TDPLNs. One of the differences in the immune-mediated antitumor effect of the TDPLNs and TDTLNs was ascribed to a difference in the site of lymphocyte homing to peripheral LNs through high endothelial venules. Non-vascularized LN transplantation had an immune-mediated antitumor effect.

Lymphatic metastasis is facilitated by lymphangiogenic growth factor VEGFC that is secreted by some primary tumors. We previously identified tumor necrosis factor superfamily 15 (TNFSF15), a blood vascular endothelium-derived cytokine, in lymphatic endothelial cells, as a key molecular modulator during lymphangiogenesis. However, the effect of TNFSF15 on tumor lymphatic metastasis and the underlying molecular mechanisms remain unclear. We report here that TNFSF15, which is known to inhibit primary tumor growth via suppressing angiogenesis, can promote lymphatic metastasis through facilitating lymphangiogenesis in tumor. Mice bearing tumors induced by A549 cells stably overexpressing TNFSF15 exhibited a significant increase in densities of lymphatic vessels and a marked enhancement of A549 tumor cells in newly formed lymphatic vessels in the primary tumors as well as in lymph nodes. Treatment of A549 cells with TNFSF15 results in up-regulation of VEGFC expression, which can be inhibited by siRNA gene silencing of death domain-containing receptor-3 (DR3), a cell surface receptor for TNFSF15. Additionally, TNFSF15/DR3 signaling pathways in A549 cells include activation of NF-kappaB during tumor lymphangiogenesis. Our data indicate that TNFSF15, a cytokine mainly produced by blood endothelial cells, facilitates tumor lymphangiogenesis by up-regulating VEGFC expression in A549 cells, contributing to lymphatic metastasis in tumor-bearing mice. This finding also suggests that TNFSF15 may be of potential as an indicator for prognosis evaluation. This article is protected by copyright. All rights reserved.

The tumor microenvironment is one of the key factors contributing to the efficiency of drug delivery to a tumor. It has been reported that lymphangiogenesis is induced in certain tumors. Because the lymphatic system functions as a drainage one, it is possible that tumor lymphatic vessels alter not only the tumor microenvironment, but also the distribution of drug nanocarriers accumulated in the tumor tissue. Herein, we aimed to elucidate the involvement of the tumor lymphatic system in the translocation of intratumoral liposomes to regional lymph nodes by using vascular endothelial growth factor (VEGF)-C-overexpressing B16F10 tumor-bearing mice (B16/VEGF-C). When the amount of polyethylene glycol (PEG)-modified liposomes in lymph nodes (cervical, brachial, axillary, and inguinal lymph nodes) was measured after the radiolabeled liposomes had been intratumorally injected into B16/VEGF-C-bearing mice or wild-type B16-bearing mice, the accumulation of liposomes in the axillary and inguinal lymph nodes was significantly higher on the tumor-implanted side of B16/VEGF-C-bearing mice than on that of the B16-bearing ones. On the other hand, the accumulation of liposomes in these lymph nodes on the control side (no implantation) of either type of tumor-bearing mice was very low; and no difference could be observed between the 2 sides. Furthermore, the intratumoral distribution of liposomes was observed to be located near the lymphatic vessels. These results indicate that the tumor lymphatic system contributed to the extrusion of a portion of PEG-modified liposomes from the tumor tissue, suggesting that tumor lymphangiogenesis would be one of the key factors to determine the intratumoral distribution of liposomes and their subsequent fate.

Neuroblastoma is the most common extra-cranial solid pediatric cancer and causes approximately 15% of all childhood deaths from cancer. Although lymphatic vasculature is a prerequisite for the maintenance of tissue fluid balance and immunity in the body, little is known about the relationship between lymphatic vascularization and prognosis in neuroblastoma. We used our previously-published custom-designed tool to close open-outline vessels and measure the density, size and shape of all lymphatic vessels and microvascular segments in 332 primary neuroblastoma contained in tissue microarrays. The results were correlated with clinical and biological features of known prognostic value and with risk of progression to establish histological lymphatic vascular patterns associated with unfavorable histology. A high proportion of irregular intermediate lymphatic capillaries and irregular small collector vessels were present in tumors from patients with metastatic stage, undifferentiating neuroblasts and/or classified in the high risk. In addition, a higher lymphatic microvascularization density was found to be predictive of overall survival. Our findings show the crucial role of lymphatic vascularization in metastatic development and maintenance of tumor tissue homeostasis. These patterns may therefore help to indicate more accurate pre-treatment risk stratification and could provide candidate targets for novel therapies.

BACKGROUND: Several studies and a meta-analysis showed that fibrin sealant patches reduced lymphatic drainage after various lymphadenectomy procedures. Our goal was to investigate the impact of these patches on drainage after axillary dissection for breast cancer. METHODS: In a phase III superiority trial, we randomized patients undergoing breast-conserving surgery at 14 Swiss sites to receive versus not receive three large TachoSil((R)) patches in the dissected axilla. Axillary drains were inserted in all patients. Patients and investigators assessing outcomes were blinded to group assignment. The primary endpoint was total volume of drainage. RESULTS: Between March 2015 and December 2016, 142 patients were randomized (72 with TachoSil((R)) and 70 without). Mean total volume of drainage in the control group was 703 ml [95% confidence interval (CI) 512-895 ml]. Application of TachoSil((R)) did not significantly reduce the total volume of axillary drainage [mean difference (MD) -110 ml, 95% CI -316 to 94, p = 0.30]. A total of eight secondary endpoints related to drainage, morbidity, and quality of life were not improved by use of TachoSil((R)). The mean total cost per patient did not differ significantly between the groups [34,253 Swiss Francs (95% CI 32,625-35,880) with TachoSil((R)) and 33,365 Swiss Francs (95% CI 31,771-34,961) without, p = 0.584]. In the TachoSil((R)) group, length of stay was longer (MD 1 day, 95% CI 0.3-1.7, p = 0.009), and improvement of pain was faster, although the latter difference was not significant [2 days (95% CI 1-4) vs. 5.5 days (95% CI 2-11); p = 0.2]. CONCLUSIONS: TachoSil((R)) reduced drainage after axillary dissection for breast cancer neither significantly nor relevantly.

Somatic variants have been well described in tumorigenesis; however, they are only recently appreciated in other human disorders, such as mosaic overgrowth syndromes. Although overgrowth is a manifestation in many genetic syndromes, not all overgrowth syndromes are inherited. Mosaic somatic variants have been lately described in several overgrowth disorders, such as Proteus syndrome, CLOVES (congenital, lipomatous, overgrowth, vascular malformations, epidermal nevi, and spinal/skeletal anomalies and/or scoliosis) syndrome, and megalencephalyepolymicrogyria-polydactyly-hydrocephalus syndrome. These syndromes are caused by somatic variants in the genes associated with the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway, resulting in a spectrum of overgrowth syndromes with overlapping features that could be difficult to distinguish based on phenotypic presentations alone. In addition, Sanger sequencing is ineffective for the detection of a causal variant because of the mosaic nature of these variants, whereas targeted next-generation sequencing technology offers a deeper sequencing coverage and allows the detection of low-level mosaicism. Recent studies have shown that the causal variants are only present in the affected tissues in most cases, and can be enriched by in vitro tissue culture. In this review, we describe several mosaic somatic overgrowth syndromes caused by variants in genes of the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway, their phenotypic and molecular spectrum, and the clinical utility of next-generation sequencing technology in the diagnosis of these disorders.

Rapidly involuting congenital hemangioma is a subtype of congenital hemangioma. Ulceration and bleeding are rarely reported in rapidly involuting congenital hemangioma, with only four cases reported in the literature to our knowledge. We describe a case of a newborn girl who presented with rapidly involuting congenital hemangioma complicated by ulceration and severe bleeding and discuss treatment.

Recent studies have discovered a group of overgrowth syndromes, such as congenital lipomatous overgrowth with vascular, epidermal, and skeletal anomalies (CLOVES) syndrome, Proteus syndrome, and megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, are caused by somatic activating variants in genes involved in the phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway. Because of the low-abundance nature of these variants, Sanger sequencing often yields negative results. We have developed and validated a next-generation sequencing (NGS) panel that targets all known variants associated with these syndromes. Fifty cases, including two prenatal cases, were tested using the panel. A pathogenic variant in the PIK3CA, PIK3R2, or AKT1 gene was identified in 28 of the 50 cases with the variant allele frequencies ranging from 1.0% to 49.2%. These variants were only present in the affected tissues in most of the cases, demonstrating a causal role in the development of these diseases. In vitro cell culture showed significant enrichment of the cells harboring variant alleles, suggesting that these variants render growth advantages to mutant cells. Phenotype-genotype correlation analysis showed PIK3CA mutation hotspots at residues E542, E545, and H1047 are often associated with CLOVES syndrome, whereas PIK3CA G914R is preferentially related to MCAP. We thus demonstrate that NGS technology is highly sensitive for detecting low-level mosaicism and can facilitate clinical diagnosis of mosaic overgrowth syndromes in both prenatal and postnatal settings.

Generalized lymphatic anomaly is a rare, complex, lymphatic anomaly generally involving soft tissues, spleen, and bones. It can lead to focal skeletal fragility and pathologic effusions. A recent prospective trial of sirolimus for complicated vascular anomalies showed partial response in seven patients with generalized lymphatic anomaly treated with sirolimus with a target trough level of 10-15 ng/mL for 1 year (Adams et al). We describe successful treatment of generalized lymphatic anomaly with a lower-dose, long-term course of sirolimus.

BACKGROUND: Propranolol is the mainstay of treatment for infantile haemangioma. Despite its good safety profile, it is not risk-free. Guidelines for propranolol initiation and monitoring have been suggested, but protocols vary among practitioners. OBJECTIVE: This study sought to assess the prevalence of adverse events and clinically significant fluctuations in haemodynamic parameters in children with infantile haemangioma during initiation of treatment with propranolol in a day-hospitalization setting. METHODS: Children with infantile haemangioma treated with propranolol in a day-hospitalization department of a tertiary paediatric medical centre in 2008–2014 were identified retrospectively. The pretreatment evaluation included clinical examination by a paediatric dermatologist and electrocardiography, echocardiography and clinical examination by a paediatric cardiologist. The propranolol dosage was escalated from 0.5 mg/kg/day to 2 mg/kg/day, divided into three doses/day, over 3 days. Heart rate, blood pressure and blood glucose level were measured before treatment onset and 60 min after the first two doses each day. The third dose was given at home. RESULTS: The cohort included 220 children aged 1 month to 5 years. No severe treatment-related adverse events were documented; 27 patients had minor side-effects. There was a significant decrease in heart rate each day after the first two doses (P < 0.001), and in systolic blood pressure, on day 2 (1 mg/kg/day) after the first dose (P = 0.01). Blood glucose level remained stable. The haemodynamic changes were clinically asymptomatic and did not require intervention. CONCLUSIONS: Propranolol treatment (2 mg/kg/day in three doses) for infantile haemangioma is well tolerated and safe and may be administered and monitored in an ambulatory setting.

This case report describes a novel presentation of littoral cell angioma (LCA) and lymphatic malformations involving the omentum and mesentery. To our knowledge, these 2 entities have not been reported in the same patient. A 1-month term infant male presented with chylous ascites. During his workup, imaging detected splenic nodules. Biopsies revealed that the nodules were LCA and the chylous ascites was secondary to microscopic mesenteric and omental lymphatic malformations. Evaluation for a secondary malignancy, an underlying immunologic defect, and genetic causes were unrevealing. The presence of LCA and lymphatic malformations in the same patient suggests a genetic link between these 2 rare vascular disorders and may help elucidate the etiopathogenesis of these 2 poorly understood anomalies.

BACKGROUND: Klippel-Trenaunay syndrome (KTS) is characterized by the triad of capillary malformation (CM), venous malformation (VM) +/- lymphatic malformation, and limb overgrowth. Patients with KTS have lower scores in general and mental health, physical function, and quality of life than the general population. OBJECTIVE: To determine the prevalence of pain and psychiatric comorbidity in patients with KTS. METHODS: A retrospective review of 410 patients with KTS evaluated between 1976 and 2012 was conducted to identify the presence of pain, psychiatric comorbidities, and psychosocial stressors. RESULTS: Pain was reported by 260 patients (63.4%) and was associated with any KTS complication (p < 0.0001) and VMs of the lower extremities (p = 0.0008) and feet (p = 0.0007). Ninety-five patients had a diagnosed psychiatric condition (23.2%), most commonly depression (15.1%) and anxiety (5.1%). Pain (p = 0.0016), superficial thrombosis (p = 0.0269), deep embolic/thrombotic events (p = 0.0005), gastrointestinal complications (p = 0.0085), genitourinary complications (p = 0.0163), and CM of the hands (p = 0.0040) were associated with having a psychiatric diagnosis. LIMITATIONS: Retrospective study that relied on physician detection and reporting of variables. CONCLUSIONS: Pain and psychiatric conditions, particularly depression and anxiety, are common in patients with KTS. Awareness of the psychosocial impact of KTS and appropriate screening are important.

PURPOSE: There is paucity of data on patient-perceived outcomes of bleomycin sclerotherapy for low-flow vascular malformations. In this study, the long-term outcomes of bleomycin sclerotherapy were investigated in terms of quality of life (QoL) and patient-perceived changes in health. MATERIALS AND METHODS: A cohort of Dutch patients with vascular malformations treated with bleomycin sclerotherapy (June 2010-November 2015) completed a questionnaire evaluating disease symptoms, QoL (Short Form 36), patient-perceived change in health status (Global Rating of Change scales) and treatment satisfaction. QoL was assessed for the patient's status before and after treatment and was analyzed relative to an age and sex-matched Dutch reference population. Predictive factors associated with QoL and patient-perceived improvement in overall health status were assessed using multivariable linear and logistic regression analyses, respectively. RESULTS: Seventy-seven patients, with a median follow-up of 22 months, were enrolled. About half of the respondents (49.3%) indicated that they perceived (any form of) improvement in their overall health status. Most often improved were the specific health aspects 'pain' (54.5%) and 'overall severity of symptoms' (57.1%). No factors were significantly predictive for patient-perceived improvement in health with respect to the vascular malformation. Impairment in work- or study-related activities prior to sclerotherapy was found to negatively impact physical QoL at follow-up (p = 0.03). CONCLUSION: Approximately half of patients with low-flow vascular malformations indicate an improvement in overall health status following bleomycin sclerotherapy, particularly concerning pain and severity of symptoms. However, most patients only perceived little to moderate improvement to their health and desire further treatment.

BACKGROUND: Few studies have reported the clinical features, complications and predictors of Kasabach-Merritt phenomenon (KMP) associated with Kaposiform haemangioendothelioma (KHE). OBJECTIVES: To determine the clinical characteristics present at diagnosis and to identify features that may aid clinicians in managing KHE. METHODS: We conducted a cohort study of 146 patients diagnosed with KHE. RESULTS: KHE precursors or lesions were present at birth in 52.1% of patients. In 91.8% of patients, lesions developed within the first year of life. The median age at diagnosis of KHE was 2.3 months (interquartile range 1.0-6.0). The extremities were the dominant location, representing 50.7% of all KHEs. Among KHEs in the cohort, 63.0% were mixed lesions (cutaneous lesions with deep infiltration). Approximately 70% of patients showed KMP. A KHE diagnosis was delayed by >/ = 1 month in 65.7% of patients with KMP. Patients with KMP were more likely to have major complications than patients without KMP (P = 0.023). Young age (< 6 months), trunk location, large lesion size (> 5.0 cm) and mixed lesion type were associated with KMP in a univariate analysis. In the multivariate analysis, only age [odds ratio (OR) 11.9, 95% confidence interval (CI) 4.07-34.8; P < 0.001], large lesion size (OR 5.08, 95% CI 2.24-11.5; P < 0.001) and mixed lesion type (OR 2.96, 95% CI 1.23-7.13; P = 0.016) were associated with KMP. CONCLUSIONS: Most KHEs appeared before 12 months of age. KHEs are associated with various major complications, which can occur in combination and develop early in the disease process. Young age, large lesion size and mixed lesion type are important predictors of KMP.

Vascular tumors in infants present a diagnostic and treatment dilemma for both clinicians and pathologists. Infantile hemangioma, the most common vascular tumor in infants, can be confused for other less common vascular tumors in infants. Correct and timely diagnosis is important, as some vascular tumors can be associated with life-threatening coagulopathy. We present the cases of 5 vascular tumors that have clinical and histologic overlap: infantile hemangioma, pyogenic granuloma, noninvoluting congenital hemangioma, tufted angioma, and kaposiform hemangioendothelioma. Typical clinical and histopathologic features of each lesion are summarized. We review the utility and characteristic immunohistochemistry including CD31, CD34, GLUT-1, D2-40, LYVE-1, Prox-1, and WT-1. Collaboration between the clinician and the dermatopathologist correlating the clinical history and histopathologic features can lead to the correct diagnosis, whereas the utility of immunohistochemistry remains in question.

Importance: Patients with vascular malformations (VAMs) and vascular overgrowth syndromes have lower health-related quality of life (HRQoL) attributable to social stigmatization, poor mental health, severity, and pain. However, the factors that contribute to this decreased HRQoL are not clear. Objective: To perform a systematic review and meta-analysis of studies that used validated HRQoL instruments to compare the HRQoL of persons with VAMs with the US general population. Data Sources: A comprehensive search was performed in MEDLINE, Embase, PsycINFO, CINAHL, and Scopus from 1946 to March 31, 2017, with the consultation of an experienced librarian. Study Selection: All VAM studies with validated HRQoL instruments published in the English language were included. Case reports, review articles, non-English-language publications, and studies about the development of new HRQoL instruments were not included. Data Extraction and Synthesis: Two reviewers assessed studies' eligibility and the risk of bias and performed data extraction. The meta-analysis was performed using the random-effects model. Comparisons of means were performed using the unpaired, 2-sample t test. Main Outcomes and Measures: The outcome was HRQoL. Results: Eleven studies met the inclusion criteria for a total of 692 patients with VAMs. Six studies (320 patients) were included in the meta-analysis, whereas 5 studies were included in the qualitative analysis (372 patients). Those with VAMs had lower 36-Item Short-Form Health Survey scores in bodily pain (mean difference, -11.87; 95% CI, -21.45 to -2.29; I2 = 92%; P = .02) and mental health (mean difference, -6.04; 95% CI, -11.55 to -0.52; I2 = 83%; P = .03) compared with the US general population. Conclusions and Relevance: Patients with VAMs had increased pain and psychosocial distress compared with the US general population. Pain and psychological morbidity are associated with poorer HRQoL and may serve as indicators for quality of life.

Sirolimus is an effective therapy for children with kaposiform hemangioendothelioma with or without the Kasabach-Merritt phenomenon. We report the case of a child with kaposiform hemangioendothelioma and the Kasabach-Merritt phenomenon who developed Pneumocystis carinii pneumonia (PCP) while on sirolimus and a prednisolone taper, after lack of adequate response to prednisolone, propranolol, and vincristine. He had a prompt positive clinical and laboratory response to sirolimus, but 4 weeks after starting it, at the age of 4 months, he developed PCP. This led to respiratory failure, which required extracorporeal membrane oxygenation. Sirolimus was temporarily discontinued, and he was successfully treated for PCP with sulfamethoxazole-trimethoprim and methylprednisolone. He was restarted on sirolimus 3 weeks after discharge and given sulfamethoxazole-trimethoprim prophylaxis. At the age of 22 months, while still on sirolimus, the lesion continued to improve with test results revealing stable hemoglobin and platelet counts. PCP is a rare but life-threatening side effect of sirolimus therapy, especially in the setting of concurrent steroid treatment. Pneumocystis prophylaxis should be considered for patients receiving sirolimus.

We describe the case of a 33-week preterm infant who developed nonimmune hydrops fetalis secondary to a kaposiform hemangioendothelioma (KHE). The tumor was successfully treated with vincristine, prednisone, ticlopidine, and aspirin. KHE can be an unusual cause of hydrops fetalis; in such cases, diagnosis can be challenging since generalized edema can obscure KHE.

Infantile choriocarcinoma (ICC) is a rare, highly malignant form of gestational trophoblastic neoplasia. Rapid diagnosis and initiation of treatment are paramount in reaching a successful outcome. Patients with these tumors typically present with a triad of anemia, hepatomegaly, and precocious puberty. Cutaneous manifestations of ICC are extraordinarily rare with few documented cases. Here, we describe a male neonate who presented to our Dermatology clinic with a rapidly growing, markedly vascular glabellar mass associated with abnormal laboratory values suggestive of Kasabach-Merritt phenomenon. The initial clinical impression of infantile hemangioma led to an initial treatment with propranolol. However, the mass continued to enlarge and a biopsy was obtained. Histology revealed a high-grade, poorly differentiated carcinoma. A robust immunohistochemical battery demonstrated tumor reactivity with Glut-1, GATA3, Glypican-3, CAM5.2, and beta-hCG establishing the diagnosis of metastatic choriocarcinoma. The diagnosis was further supported by the elevated serum beta-hCG. In addition to the glabellar mass, imaging demonstrated tumor foci in the liver and lung. Clinical investigation of the mother revealed no evidence of disease.

Various mixed associations between arteriovenous malformations, cavernous malformations, developmental venous anomalies, and capillary telangiectasias have been described, and a common pathophysiologic event has been suggested to be present, although it is yet to be elucidated. We depict herein the imaging features of a patient who presented with a spontaneous cerebellar hemorrhage, in whom radiologic studies demonstrated a pontine telangiectasia, a brainstem/cerebellar developmental venous anomaly, and a cerebellar proliferative angiopathy. This unique, not previously reported combination of lesions shows that the spectrum of mixed vascular malformations continues to expand. A pathophysiologic mechanism related to the angiogenesis seen in these malformations is also hypothesized.

BACKGROUND: The use of sirolimus for patients with multidrug-resistant Kasabach-Merritt phenomenon (KMP) has been reported in recent years. We present the experience of a single center in treating vincristine-resistant KMP using sirolimus alone. METHODS: Children with vincristine-resistant KMP who were treated with oral sirolimus alone were eligible for inclusion in the study. We evaluated responses according to graded response criteria and acute toxicities according to the National Cancer Institute Common Toxicity Criteria. RESULTS: Between March 2012 and October 2014, eight patients underwent sirolimus treatment. The response rate of hematologic parameters was 100% (8/8). Three tumors shrank enough to allow excision. The tumors were resected after hematologic parameters normalized. Of the five patients with unresectable vascular lesions, three had complete response, and two had partial response of their tumors at the completion of long-term (39.7 +/- 24.4 wks) sirolimus treatment. Grade 3 or 4 adverse events were not documented during treatment or follow-up. No recurrence or progression of the disease was observed during follow-up. CONCLUSION: In this small case series, we found sirolimus to be highly effective, with minimal side effects, for vincristine-resistant KMP. A larger study to compare sirolimus and vincristine for KMP is warranted.

PTEN is a tumor suppressor gene inactivated in over 30% of human cancers. It encodes a lipid phosphatase that serves as a gatekeeper of the phosphoinositide 3-kinase signaling pathway. Germline mutation frequently occurs in this gene in patients diagnosed with PTEN Hamartoma Tumor Syndrome (PHTS). PHTS individuals are characterized by macrocephaly, benign growth of multiple tissues and increased tumor risk. In addition, autistic phenotypes are found in 10–20% of individuals carrying the germline PTEN mutation with macrocephaly. In this report, 13 suspected PHTS patients were screened for mutation in the PTEN gene. A missense variant (c. 302T > C) substituting the isoleucine at codon 101 to a threonine, a single nucleotide insertion (c. 327-328insC) causing a frame shift mutation and termination at codon 109, and a nonsense variant (c. 1003C > T) truncated the protein at codon 335 were identified. The I101T mutation significantly reduced PTEN protein expression levels by 2.5- to 4.0-fold. Mechanistically, I101T reduced the protein half-life of PTEN possibly due to enhanced polyubiquitination at Lysine 13. However, the I101T mutant retained almost 30% of the lipid phosphatase activity of the wild-type protein. Finally, the I101T mutant has reduced phosphorylation at a PTEN auto-dephosphorylation site at Threonine 366 and a lowered ratio of nuclear to cytosolic protein level. These partial losses of multiple PTEN biochemical functions may contribute to the tissue overgrowth and autistic features of this PHTS patient. Autism Res 2018. (c) 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc. LAY SUMMARY: The genetics of autism spectrum disorders is highly complex with individual risk influenced by both genetic and environmental factors. Mutation in the human PTEN gene confers a high risk of developing autistic behavior. This report revealed that PTEN mutations occurred in 23% of a selected group of Hong Kong patients harboring autistic features with gross overgrowth symptoms. Detailed characterization of a PTEN mutation revealed reduced protein stability as one of the underlying mechanisms responsible for reduced PTEN activity.

RASA1-related disorders are vascular malformation syndromes characterized by hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM), arteriovenous fistulas (AVF), or Parkes Weber syndrome. The number of cases reported is relatively small; and while the main clinical features are CMs and AVMs/AVFs, the broader phenotypic spectrum caused by variants in the RASA1 gene is still being defined. Here, we report the clinical and molecular findings in 69 unrelated cases with a RASA1 variant identified at ARUP Laboratories. Sanger sequencing and multiplex ligation-dependent probe amplification were primarily used to evaluate RASA1. Several atypical cases were evaluated using next-generation sequencing (NGS) and array-comparative genomic hybridization (aCGH). Sixty individuals had a deleterious RASA1 variant of which 29 were novel. Nine individuals had a variant of uncertain significance. Five large RASA1 deletions were detected, giving an overall deletion/duplication rate of 8.3% (5/60) among positive cases. Most (75.4%) individuals with a RASA1 variant had CMs, and 44.9% had an AVM/AVF. Clinical findings in several cases expand the RASA1 phenotype. Our data suggest that screening for large RASA1 deletions and duplications in this disorder is important and suggest that NGS multi-gene panel testing is beneficial for the molecular diagnosis of cases with complex vascular phenotypes.

Kaposiform hemangioendothelioma (KHE) is a rare infiltrative vascular tumor that is potentially life-threatening when presenting with Kasabach-Merritt phenomenon (KMP). KMP is clinically characterized as severe thrombocytopenia and hypofibrinogenemia and therefore is associated with a high mortality rate. There is no standard of cure for KHE currently. Potential medications, including corticosteroids, propranolol, and chemotherapy drugs such as sirolimus, are often used for alleviating KHE symptoms. Although some case reports of sirolimus treatment have shown promising results with recovered coagulant parameters, the off-target effects may cause severe problems. Here we describe 2 cases of infant patients with KHE and KMP who were scheduled to receive sirolimus on a long-term basis. However, both patients developed paroxysmal cough and tachypnea shortly after the onset of sirolimus treatment and succumbed to infection thereafter. This report reveals a potential risk of infection in sirolimus-treated infant patients. The fatal complication highlights the importance of antibiotic prophylaxis and serum sirolimus level monitoring to ensure the safe use of sirolimus in the treatment of infant patients with KHE.