Cytometric analysis and clinical features in a Moroccan cohort with severe combined immunodeficiency

Abstract

Severe combined immunodeficiency (SCID) is a form of primary immunodeficiency disease (PID). It is characterized by a serious abnormality of the cellular and sometimes humoral system due to a deficiency in development of T cells, B cells and/or NK cells. The early diagnosis of SCID improves the prognosis. Typically, the initial consideration of SCID is made based on low lymphocyte counts. Notwithstanding, the heterogeneity of lymphocyte count presentation makes the diagnosis of SCID a significant challenge. The objective of this cross-sectional retrospective study was to analyze the lymphocyte subpopulation counts along with clinical manifestations within a Moroccan cohort diagnosed as SCID compared to children diagnosed with non-PID diseases. Thirty-five SCID confirmed patients were selected in the period between 2008 and 2018 and compared with non-PID patients. Results of peripheral blood T, B, and NK lymphocyte subpopulation counts were measured by flow cytometry for each SCID subtype. As expected, T cell count was less than 300 cells/ $\mu$ L in most patients with SCID (85.5%). Unexpectedly, significantly higher T cell counts were detected in some patients with a confirmed clinical diagnosis and family history of SCID. 5.7% of our SCID Moroccan cohort had T cell numbers in the range between 300 and 500 cells/ $\mu$ L. 8.7% of our SCID Moroccan cohort had T cell numbers higher than 500 cells/ $\mu$ L. Of the SCID subtypes, the proportion of SCID with B cell deficiencies was highly represented in our cohort. 71.4% of Moroccan SCID patients (25 out of 35 patients) were of T-B-subtype. Furthermore, 40% of the patients (14 out of 35 patients) had a T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ profile and 31.4% had a T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ profile (11 out of 35 patients). The most common clinical manifestations observed in our SCID cohort were pneumonia, failure to thrive, candidiasis, diarrhea, bronchitis and urinary tract infections. Our results not only highlight the relatively frequent presence of atypical SCID in the Moroccan population with unexpectedly high T cell numbers, but also describes the incidence pattern of common SCID subtypes in Morocco. Physicians in Morocco may find this local region-specific difference in SCID important for making improved early diagnosis of this disease.

Keywords

Severe combined immunodeficiency diagnosis primary immunodeficiency lymphocytes subpopulation counts flow cytometry Morocco

1. Introduction

Severe combined immunodeficiency (SCID) is a genotypically and phenotypically heterogenous set of inherited primary immunodeficiencies (PID). SCID is considered a life-threatening pediatric emergency [16]. SCID kids are normal during childbirth and start suffering from severe infections in the first month of their life [6]. Transplantation of HLA-identical or T-cell-depleted haploidentical marrow from related donors is a life-saving treatment in patients with any type of SCID. SCID results in early death unless urgently treated by allogeneic hematopoietic stem cell transplantation, highlighting the critical importance of early diagnosis [7, 16]. Respiratory infections, failure to thrive, chronic diarrhea, persistent oral candidiasis, pneumonia, and sepsis are the most common presentation in SCID patients [6, 26].

SCID immunodeficiencies can be classified based on presence or absence of B and NK cells in the peripheral blood into T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ or T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ and T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ or T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ . The different subtypes of SCID result from discrete mutations in genes essential for T cell differentiation, which are variably associated with abnormal development of B and/or NK cells [24, 33]. Mutations in ADA (adenosine deaminase) or AK (2) (adenylate kinase) are most frequently associated with T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ SCID and are autosomal recessive [24, 33]. Mutations such as in RAG1 and RAG2 that affect V(D)J recombination, critical for functional T cell receptors (TCRs), give rise to T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ SCID [24, 33]. Mutations in Artemis/DCLRE1C and DNA-PKcs (PRKDC) also result in T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ SCID [24, 33]. NHEJ1 and LIG4 deficiencies also give rise to T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ SCID [24, 33]. Mutations affecting the common $\gamma$ -chain of IL-2, 4, 7, 9 and 15 receptors that signals through JAK3 tyrosine kinase cause T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ SCID [24, 33]. This is an X-linked inherited disease [24, 33]. However, JAK3 mutations can also give rise to a similar T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ disease, which is autosomal recessive [24, 33]. IL2RG mutations give rise to T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ SCID. Mutations in IL7R, CORO1A, CD45 (PTPRC), CD3D, CD3E, CD3Z (CD247) and LAT give rise to T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ SCID [24, 33]. Finally, there are Combined Immunodeficiencies (CID) with residual T cells, which are less profound than SCID [24]. Mutations in genes such as DOCK2, ICOS, CD40, CD40LG, CD3G, CD8A, ZAP70, TAP1, TAP2, TAPBP, B2M, CIITA, RFXANK, RFX5, RFXAP, DOCK8, RHOH, STK4, TRAC, p56/LCK, MALTI, CARD11, BCL10, BCL11B, IL21, IL21R, TNFRSF4, IKBKB, MAP3K14, RELB, MSN, and TFRC are associated with CID [24]. Other genetic defects such as mutations in STAT5, FOXN1 or IL2RA can also decrease the number of T cells [24]. Because of this heterogeneity, the immunological and clinical presentations of SCID are diverse, making diagnosis a significant challenge. The knowledge of the characteristics of the regional presentation of SCID, including the range of lymphocyte counts, can help increase the awareness of local physicians and help in more rapid diagnosis. In the framework of its mission in the immunological exploration of PID in Morocco, our group recently published the normal reference values for lymphocytes populations within Moroccan children population [9]. Here we report our immunological findings on Moroccan patients clinically diagnosed as SCID from a group of total 657 patients suspected of PID during the last 10 years. We report that some patients have higher than expected T cell numbers.

We also describe the prevalence of SCID subtypes in Morocco and their clinical characteristics. The prevalence of SCID worldwide is estimated to be 1 in 40,000 to 75,000 live births [16]. Amongst Mediterranean populations, SCID represents 8.2% of PID in Tunisian Population [20], and 5.7% of PID in a Spanish study [18]. As indicated in the first report on the Moroccan registry, 8.74% of PID in the Moroccan population were diagnosed as SCID [4]. The distribution of various subtypes of SCID differs in different countries. In countries with consanguineous marriages, autosomal recessive SCID incidences can be higher [12, 29, 32, 33], although X-linked SCID is the most common worldwide form [33]. The percentage of SCID is significantly higher (21.1%) in the Iranian population [1]. It was also reported that, in Iran, the prevalence of undiagnosed PID was extremely high [3]. El Maataoui et al. reported that in Morocco, the most common subtype of SCID was T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ [10]. We similarly observe more frequent T ${}^{-}$ B ${}^{-}$ SCID and its association with consanguinity, versus less consanguinity associated with T ${}^{-}$ B ${}^{+}$ SCID.

Figure 1.

Representative example of flow cytometry gating strategy and identification of specific lymphocyte subsets. Lymphocytes were selected based on their side-scatter and CD45 positive staining. Subsequently, T lymphocytes were identified as T cells (CD3 ${}^{+}$ ). Non-CD3 ${}^{+}$ lymphocytes were identified as B cells (CD19 ${}^{+}$ ) or NK cells (CD16 ${}^{+}$ CD56 ${}^{+}$ ). Non-PID patients are shown in (b). The four SCID subgroups are shown in c–f.

2. Materials and methods

2.1 Subjects and samples

The study subjects were selected during a 10-year period from 2008 to 2018, from patients admitted to the Immuno-allergology and Respiratory Diseases unit of the Children’s Hospital of Rabat and referred to the Cellular Immunology Laboratory of the National Institute of Hygiene for determination of the lymphocyte subpopulations. Thirty-five patients were confirmed as SCID, while 622 young patients ( $<$ 2 years) who were initially suspected as suffering from PID were later confirmed to be affected by non-SCID diseases. Confirmed diagnoses of SCID were made by pediatricians based on the age $<$ 2 years, low lymphocyte count and clinical profile suggestive of SCID. Patients with SCID are typically defined as with very low level of T cells ( $<$ 300 cells/ $\mu$ L) and/or with strong clinical presentation of SCID (recurrent infections and failure to thrive), as well as supportive SCID familial history. Clinical profile included failure to thrive, repetitive infections, oral thrush, pneumonitis and other clinical features characteristic of SCID. Information on clinical manifestations, familial history of SCID and consanguinity were collected from medical records. Blood samples were obtained by venipuncture.

2.2 Immunophenotyping

Lymphocyte subpopulations were determined from peripheral whole blood by lyse, no-wash flow cytometry protocol [9]. Fluorochrome-labeled monoclonal antibodies were used to identify and estimate the percentage of CD4 ${}^{+}$ T and CD8 ${}^{+}$ T, B and NK lymphocyte subpopulations. The following antibodies were used: PerCP-CD45, FITC-CD3, PE-CD8, PE-CD56, PE-CD16, APC-CD19 and APC-CD4 (all from BD Sciences). Sample acquisition was performed using a FACS Canto II cytometer (BD Sciences) and data analysis was done using FlowJo software (Tree Star, Inc).

Table 1
Demographic data of patients with severe combined immunodeficiency and children with non-PID

	Cohort size	Sex ratio (M/F)	Median age in months (min & max)	Consanguinity	SCID familial history
All SCID group	35	19/16 (1.19)	3 (0.2–24)	39.5%	68.5%
T ${}^{-}$ B ${}^{+}$ SCID subtype	10	4/6 (0.6)	3 (1–24)	33%	50%
T ${}^{-}$ B ${}^{-}$ SCID subtype	25	15/10 (1.5)	4 (0.2–24)	50%	63%
Non-PID group	622	391/231 (1.69)	7 (0.53–24)	24%	9%

Table 2

Lymphocyte sub-population counts within the four SCID sub-types

	Phenotypes
	Non-SCID group			T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ $n=$ 11			T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ $n=$ 14			T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ $n=$ 5			T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ $n=$ 5
VALUES	Median	Min	Max	Median	Min	Max	Median	Min	Max	Median	Min	Max	Median	Min	Max
WBC (median-min-max)	9.86	1.74	18.11	1.88	0.40	5.13	3.13	0.10	6.98	6.41	2.88	1.13	9.20	0.83	1.76
Lymphocytes (median-min-max)	5.9	0.4	22	0.22	0.07	0.58	0.61	0.04	4.06	1.72	0.74	4.10	1.58	0.30	2.48
CD3 ${}^{+}$ (median-min-max)	3.8	0.2	15.8	0.15	0.00	0.43	0.08	0.01	0.28	0.01	0.00	1.27	0.21	0.00	1.51
CD4 ${}^{+}$ (median-min-max)	2.1	0.08	7.4	0.03	0.00	0.29	0.03	0.00	0.17	0.01	0.00	0.88	0.11	0.00	1.17
CD8 ${}^{+}$ (median-min-max)	1.4	0.06	8.4	0.08	0.00	0.38	0.01	0.00	0.14	0.01	0.00	0.30	0.07	0.00	0.57
CD19 ${}^{+}$ (median-min-max)	1.06	0.09	11.4	0.02	0.00	0.17	0.03	0.00	0.24	1.27	0.54	3.77	0.71	0.34	1.28
CD56 ${}^{+}$ 16 ${}^{+}$ (median-min-max)	0.48	0.17	4.9	0.02	0.00	0.06	0.32	0.16	2.43	0.04	0.00	0.06	0.22	0.16	0.73

Median, minimum (min) and maximum (max) values are represented as x1000 cells/ $\mu$ l.

2.3 Gating strategy

Data were analyzed in FlowJo software (BD Biosciences). Cells were initially gated for lymphocytes (CD45 versus FSC-A). CD3 ${}^{+}$ surface expression was then determined. CD3 ${}^{-}$ cells were examined for CD19, CD16 and CD56 expression. The numbers of following lymphocyte subpopulations were determined: lymphocytes (CD45 ${}^{+}$ ), T lymphocytes (CD3 ${}^{+}$ ), B lymphocytes (CD19 ${}^{+}$ ), NK cells (CD3 ${}^{-}$ , CD16 ${}^{+}$ and/or CD56 ${}^{+}$ ). Representative example of gating strategy and identification of specific lymphocytic subsets in non-PID, T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ , T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ , T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ and T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ are shown in Fig. 1. The percentages of each gated lymphocyte subpopulation are directly given by the analysis software. The subpopulation absolute sizes were determined by multiplying the acquired cells count by the volume calculated using a known concentration of True Count ${}^{\@setsize{\scriptsize}{8pt}{\viipt}{\@viipt}\textregistered}$ beads. Deficiencies in T, B or NK lymphocytes subpopulation were estimated using the minimal cutoff of normal values corresponding to 1-year-old children (T cell: 3.2–7.9 cells/ $\mu$ L, B cells: 0.46–3.63 cells/ $\mu$ L and NK cells: 0.05–1.64 cells/ $\mu$ L) or to 2 years old children (T cell: 2.9–10.00 cells $\mu$ L, B cells: 0.95–3.72 cells/ $\mu$ L, NK cells: 0.17–1.44 cells $\mu$ L) [9]. The hematological and serological assessment of the subjects also included complete blood count (CBC) and the levels of serum immunoglobulins (IgA, IgM, and IgG). Patients with HIV-positive serology, as well as those with DiGeorge syndrome, were excluded.

2.4 Statistical analysis

Cell counts were expressed as medians (min-max). Statistical analysis was performed using SPSS 20.0. The non-parametric Kruskal-Wallis test was used to determine differences in predominance, biological and clinical features across the study subjects’ groups. $p<$ 0.05 values were considered statistically significant.

2.5 Ethics

Permissions were obtained from the datasets owner institutions for this retrospective study to use de-identified information from their databases.

3. Results

3.1 Characteristics of the study groups

Collected demographic information from different SCID groups and non-SCID control group is presented in Table 1. The sex ratio in our SCID group (M/F) was lower compared to non-SCID children (1.19 versus 1.69, respectively; $p<$ 0.05). Consanguinity was present in 39.5% of SCID patient’s parents, while it was 24% within non-SCID children’s parents. The percentage of familial history of PID in the SCID group was also higher in comparison to the non-SCID group (68.5% versus 9%, respectively; $p<$ 0.05). We observed that the median age at the time of the first suspicion of SCID was significantly lower in children with confirmed SCID compared to the non-SCID group (90 days versus 210 days, respectively; $p<$ 0.05). Furthermore, even among the SCID group, this age was considerably lower in the 24 children with a familial history of SCID, in comparison to those without a family history (75 days versus 165 days, respectively; $p<$ 0.05) (data not shown).

3.2 Laboratory findings

Results of lymphocyte phenotyping are summarized in Table 2. As was expected, in our study lymphopenia ( $<$ 1800 lymphocytes/ $\mu$ L) was observed in 77% of SCID patients with the median being 560 cells/ $\mu$ L. Lymphopenia, defined as $<$ 1000 to 1500 cells/ $\mu$ L, is a hallmark of SCID [13]. However, Gossage and Buckley had previously demonstrated that normal infants have much higher lymphocyte numbers than adults (lower limit of the 95% confidence interval is 2000 to 4500 cells/ $\mu$ L) [13]. Therefore, they suggest that any count lower than 2000 cells/ $\mu$ L could be considered as lymphopenia within kids. Regardless, a marked blood lymphopenia ( $<$ 1000 cells/ $\mu$ L) was noted in the vast majority of our patients. The exception were three patients who had higher lymphocyte levels. Their lymphocyte counts were 2,700 cells/ $\mu$ L, 2,500 cells/ $\mu$ L and 2,300 cells $\mu$ L, respectively. Lymphocyte subpopulation counts were significantly lower within patients of SCID group when compared to the non-PID patients. Only 30% of non-PID patients had lymphocyte numbers under normal range. Nevertheless, six non-PID patients (0.96%) showed values lower than the average value (186 cells/ $\mu$ L) of a subset of 24 SCID patients (68.6%). The measurement of immunoglobulins was also low in most patients, with the exception of five patients. Kids younger than 6 months of age are known to retain maternal immunoglobulins [35]. These patients, who were all less than 6 months of age, most likely still retained maternal immunoglobulins. Among the SCID subtypes, lymphocyte counts were lower within T ${}^{-}$ B ${}^{-}$ subtype compared to the T ${}^{-}$ B ${}^{+}$ subtype (median of 370 cells/ $\mu$ L versus 1650 cells/ $\mu$ L, respectivel; $p<$ 0.05).

Figure 2.

Lymphocyte subpopulation counts within SCID subgroups. Distribution of independent data for T cells (a), B cells (b) and NK cells (c) counts in the four SCID subgroups are graphically represented with the cut-offs as well as the median in non-PID patients (indicated by dotted lines). Gray area represents the range where values measured within SCID and non-PID patients overlap.

The remaining 11 SCID patients had extremely low number of T cells (5 cells/ $\mu$ L). As expected, in our study, 30 SCID patients (85.7%) had an absolute count of T cells of $<$ 300 cells/ $\mu$ L. The partitioning of SCID patients into subtypes demonstrated that the T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ and the T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subtypes are more highly represented in comparison with the other subtypes (T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ and the T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ ). The distribution of T, B and NK cells counts within the non-PID and the four SCID subtypes are shown in Fig. 2. Within the patients with T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subtype, 52% of patients showed a complete absence of T cells (T cell count $=$ 0) (Fig. 2). Similarly, within the patients with T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ subtype, 57% had T cell count of zero. Both T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ and T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subtype of SCID patients had similar percentage of patients with an absence of B cells. The percentage of patients lacking B cells was 37.5% for T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ and 35.3% for T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ . Patients with T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ more frequently showed an absence of NK cells in comparison to T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ subtype (25% vs 14% respectively, $p<$ 0.005). Remarkably, two subjects from the T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ subtype (5.7%) had T cell counts in the range between 300 to 500 cells/ $\mu$ (Fig. 2). These two patients were clinically diagnosed as SCID taking into account other clinical criteria. In fact, these two patients manifested repetitive respiratory infection, failure to thrive, meningitis and urinary tract infections since their first months of life. One of these patients died and the T cell count in the other dropped to less than 300 cells/ $\mu$ L when re-tested 3 months later. This later patient had positive famlial history of SCID and the family was consanguineous. These findings are consistent with the proposal of Roifman et al. suggesting that patients with typical SCID could be better identified by a threshold of $<$ 500 circulating CD3 ${}^{+}$ T cells since T cells from such patients had markedly decreased in vitro responses to phytohaemagglutinin (PHA) [28]. Moreover, two patients from the T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ subtype (5.7%) and one patient from the T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ subtype (2.85%) had T cell counts $>$ 500 cells/ $\mu$ (Fig. 2). One of the patients was of T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$ subtype. This patient suffered from respiratory infection, diarrhea and urinary tract infection. The other two patients were of T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ subtype. Both manifested respiratory infection and diarrhea. Although the T cell values for these 3 patients are atypical for SCID, and more similar to CID [28], all 3 patients across both subtypes had positive family history of SCID. When re-tested after 6 months, the T cell counts for all 3 patients dropped to less than 300 cells/ $\mu$ L. The percent incidence of the SCID subtypes in Morocco (this study and [10]) is compared with percent incidence of SCID in Brazil [19], Greece [21], India [2], Iran [11] and Italy [8] in Table 3.

Table 3

Comparison of incidence (%) of SCID subtypes in Morocco and other countries

Country	Total number of patients	Incidence of SCID subtypes $n$ (%)				Sex ratio (M/F)
		T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$	T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$	T ${}^{-}$ B ${}^{+}$ NK ${}^{-}$	T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$
Morocco (this study)	35	11 (31.4%)	14 (40%)	5 (14.3%)	5 (14.3%)	19/16 (1.19)
Morocco (El Maataoui et al.) ${}^{3}$	30	2 (8%)	14 (56%)	3 (12%)	6 (24%)	17/13 (1.31)
Brazil (Mazzucchelli et al.) ${}^{5}$	70	17 (24.3%)	23 (33%)	8 (11.4%)	15 (21.4%)	49/21 (2.33)
Greece (Michos et al.) ${}^{6}$	30	2 (6.7%)	12 (40%)	6 (20%)	3 (10%)	19/11 (1.73)
India (Aluri et al.) ${}^{1}$	57	10 (17.5%)	12 (21%)	14 (25%)	2 (3.5%)	40/17 (2.35)
Iran (Fazlollahi et al.) ${}^{4}$	63	15 (23.8%)	22 (34.9%)	9 (14.3%)	10 (15.9%)	43/20 (2.15)
Italy (Cirillo et al.) ${}^{2}$	111	13 (12%)	17 (15%)	18 (16%)	19 (17%)	63/48 (1.31)

Notes: ${}^{1}$ J. Aluri, M. Desai, M. Gupta, A. Dalvi, A. Terance, S.D. Rosenzweig, J.L. Stoddard, J.E. Niemela, V. Tamankar, S. Mhatre, U. Bargir, M. Kulkarni, N. Shah, A. Aggarwal, H.P. Lashkari, V. Krishna, G. Govindaraj, M. Kalra and M. Madkaikar, Clinical, Immunological, and Molecular Findings in 57 Patients With Severe Combined Immunodeficiency (SCID) From India, Front Immunol 10 (2019), 23. ${}^{2}$ E. Cirillo, C. Cancrini, C. Azzari, S. Martino, B. Martire, A. Pession, A. Tommasini, S. Naviglio, A. Finocchi, R. Consolini, P. Pierani, I. D’Alba, M.C. Putti, A. Marzollo, G. Giardino, R. Prencipe, F. Esposito, F. Grasso, A. Scarselli, G. Di Matteo, E. Attardi, S. Ricci, D. Montin, F. Specchia, F. Barzaghi, M.P. Cicalese, G. Quaremba, V. Lougaris, S. Giliani, F. Locatelli, P. Rossi, A. Aiuti, R. Badolato, A. Plebani and C. Pignata, Clinical, Immunological, and Molecular Features of Typical and Atypical Severe Combined Immunodeficiency: Report of the Italian Primary Immunodeficiency Network, Front Immunol 10 (2019), 1908. ${}^{3}$ A. El Maataoui and Z. Ouzzif, [Haemoglobin C/OArab: About a family], Pathol Biol (Paris) 60 (2012), 320–321. ${}^{4}$ M.R. Fazlollahi, Z. Pourpak, A.A. Hamidieh, M. Movahedi, M. Houshmand, M. Badalzadeh, M. Nourizadeh, M. Mahloujirad, S. Arshi, M. Nabavi, M. Gharagozlou, A. Khayatzadeh, A. Dabbaghzade, L. Atarod, F. Zandieh, M. Sadeghi Shabestary, M. Mesdaghi, I. Mohammadzadeh, S.A. Mahdaviani, M.H. Eslamian, F. Pesaran, E. Bahraminia, F. Abolnezhadian, Z. Arij and M. Moin, Clinical, Laboratory, and Molecular Findings for 63 Patients With Severe Combined Immunodeficiency: A Decade s Experience, J Investig Allergol Clin Immunol 27 (2017), 299–304. ${}^{5}$ J.T. Mazzucchelli, C. Bonfim, G.G. Castro, A.A. Condino-Neto, N.M. Costa, L. Cunha, E.O. Dantas, V.M. Dantas, M.I. de Moraes-Pinto, J.F. Fernandes, H.C. Goes, E. Goudouris, A.S. Grumach, L.M. Guirau, G. Kuntze, M.C. Mallozzi, F.P. Monteiro, L.S. Moraes, V. Nudelman, J.A. Pinto, M.C. Rizzo, A.C. Porto-Neto, P. Roxo-Junior, M. Ruiz, V.E. Rullo, A. Seber, O.A. Takano, F.S. Tavares, E. Toledo, M.M. Vilela, and B.T. Costa-Carvalho, Severe combined immunodeficiency in Brazil: management, prognosis, and BCG-associated complications, J Investig Allergol Clin Immunol 24 (2014), 184–191. ${}^{6}$ A. Michos, M. Tzanoudaki, A. Villa, S. Giliani, G. Chrousos and M. Kanariou, Severe combined immunodeficiency in Greek children over a 20-year period: rarity of gammac-chain deficiency (X-linked) type, J Clin Immunol 31 (2011), 778–783.

Figure 3.

Clinical manifestations in non-PID and SCID patients. Graphical representation of frequency of different clinical manifestations associated with SCID in SCID and non-PID patient groups. Mann-Whitney test, n.s. $=$ non-significant, ${}^{*}p<$ 0.05, ${}^{**}p<$ 0.01, ${}^{***}p<$ 0.001 and ${}^{****}p<$ 0.0001.

3.3 Clinical findings

The distribution of the clinical manifestations within the study patient groups is represented in Fig. 3. In general, respiratory infections, failure to thrive and diarrhea were observed to be the most frequently present clinical manifestation within the SCID group, while the non-PID group most commonly presented with respiratory infections and diarrhea. Meningitis was observed more frequently in SCID patients in comparison with non-PIDs. Urinary tract infections, oral thrush, CMV infection and disseminated BCG infection after vaccination was only observed in the SCID group and not in non-PID group. By contrast, sepsis was more prevalent in non-PID group.

Figure 4.

Distribution of clinical manifestations within four subgroups of SCID patients. Graphical representation of frequency of different clinical manifestations associated with SCID in the four subgroups of SCID patients.

Distribution of clinical manifestations within the four subgroups of SCID patients is represented in the Fig. 4. Respiratory infections were observed across all the SCID groups, except T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ . While T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ , T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ and T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subgroups presented with failure to thrive, a higher percentage of patients from T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subtype had this presentation (34%; $p<$ 0.05), compared to other subtypes. Additionally, within the SCID subgroups, The T ${}^{-}$ B ${}^{+}$ NK ${}^{+}$ subtype showed a higher percentage of patients suffering from urinary tract infections (50%; $p<$ 0.05), compared to other subtypes. A higher percentage of patients from T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ subtype had diarrhea (40%; $p<$ 0.05) compared to other subtypes. Additionally, a comparison of the clinical manifestations in our cohort with that of studies from China [36], Egypt [25], France [31], India [2], Iran [11] and Italy [8] is presented in Table 4.

Table 4

Comparison of presentation (%) of clinical features of SCID in Morocco and other countries

Clinical manifestations	This study	China, 2013 ${}^{6}$	Egypt, 2009 ${}^{4}$	France, 1993 ${}^{5}$	India, 2019 ${}^{1}$	Iran, 2017 ${}^{3}$	Italy, 2019 ${}^{2}$
Lung/respiratory infections	36%	86.36%	100%	58%	66%	77.80%	67%
Persistent diarrhea	22%	77.27%	89.74%	61%	35%	23.80%	24%
Failure to thrive	22%	38.64%	94.74%	NR	60%	20.6%	17%
Meningitis	14%	15.91%	10.53%	4.40%	NR	NR	3%
Candidiasis	8%	45.45%	94.74%	34%	21%	46%	17%
CMV infections	8%	4.55%	NR	NR	3.50%	NR	16%
Disseminated infection following BCG	8%	41.18%	21.05%	35.71%	12%	34.90%	4.50%

NR, not reported. Notes: ${}^{1}$ J. Aluri, M. Desai, M. Gupta, A. Dalvi, A. Terance, S.D. Rosenzweig, J.L. Stoddard, J.E. Niemela, V. Tamankar, S. Mhatre, U. Bargir, M. Kulkarni, N. Shah, A. Aggarwal, H.P. Lashkari, V. Krishna, G. Govindaraj, M. Kalra and M. Madkaikar, Clinical, Immunological, and Molecular Findings in 57 Patients With Severe Combined Immunodeficiency (SCID) From India, Front Immunol 10 (2019), 23. ${}^{2}$ E. Cirillo, C. Cancrini, C. Azzari, S. Martino, B. Martire, A. Pession, A. Tommasini, S. Naviglio, A. Finocchi, R. Consolini, P. Pierani, I. D’Alba, M.C. Putti, A. Marzollo, G. Giardino, R. Prencipe, F. Esposito, F. Grasso, A. Scarselli, G. Di Matteo, E. Attardi, S. Ricci, D. Montin, F. Specchia, F. Barzaghi, M.P. Cicalese, G. Quaremba, V. Lougaris, S. Giliani, F. Locatelli, P. Rossi, A. Aiuti, R. Badolato, A. Plebani and C. Pignata, Clinical, Immunological, and Molecular Features of Typical and Atypical Severe Combined Immunodeficiency: Report of the Italian Primary Immunodeficiency Network, Front Immunol 10 (2019), 1908. ${}^{3}$ M.R. Fazlollahi, Z. Pourpak, A.A. Hamidieh, M. Movahedi, M. Houshmand, M. Badalzadeh, M. Nourizadeh, M. Mahloujirad, S. Arshi, M. Nabavi, M. Gharagozlou, A. Khayatzadeh, A. Dabbaghzade, L. Atarod, F. Zandieh, M. Sadeghi Shabestary, M. Mesdaghi, I. Mohammadzadeh, S.A. Mahdaviani, M.H. Eslamian, F. Pesaran, E. Bahraminia, F. Abolnezhadian, Z. Arij and M. Moin, Clinical, Laboratory, and Molecular Findings for 63 Patients With Severe Combined Immunodeficiency: A Decade s Experience, J Investig Allergol Clin Immunol 27 (2017), 299–304. ${}^{4}$ S.M. Reda, H.M. Afifi and M.M. Amine, Primary immunodeficiency diseases in Egyptian children: a single-center study, J Clin Immunol 29 (2009), 343–351. ${}^{5}$ J.L. Stephan, V. Vlekova, F. Le Deist, S. Blanche, J. Donadieu, G. De Saint-Basile, A. Durandy, C. Griscelli and A. Fischer, Severe combined immunodeficiency: a retrospective single-center study of clinical presentation and outcome in 117 patients, J Pediatr 123 (1993), 564–572. ${}^{6}$ C.M. Yao, X.H. Han, Y.D. Zhang, H. Zhang, Y.Y. Jin, R.M. Cao, X. Wang, Q.H. Liu, W. Zhao and T.X. Chen, Clinical characteristics and genetic profiles of 44 patients with severe combined immunodeficiency (SCID): report from Shanghai, China (2004–2011), J Clin Immunol 33 (2013), 526–539.

4. Discussion

The most intriguing finding in our study is that some SCID patients have unexpectedly high lymphocyte and T cell numbers. Diagnostic criteria of SCID mentions that T cell count should be lower than the cut off of 300 cells/ $\mu$ L [18]. The majority of our cases (85.7%) did match the criteria of $<$ 300 T cells/ $\mu$ L. Nevertheless, two SCID patients (5.7%) of T ${}^{-}$ B ${}^{-}$ NK ${}^{-}$ subtype had T cell counts between 300–500 cells/ $\mu$ L. Surprisingly, we also found that the T cell counts of three patients (8.7%) were $>$ 500 cells/ $\mu$ L. Leaky expression of the mutated genes or mutations in genes that function after the development of T cells can explain this surprisingly high number of T cells. Although our patients presented with the classical symptoms of SCID, patients identified with SCID or PID often undergo subsequent genetic testing for confirmation. Unfortunately, neither molecular nor T cell functional exploration [34] was possible for the patients in our cohort. We rarely detected non-PID patients with low lymphocyte counts. These could be transient lymphopenia caused by infections that induce immune lymphocyte activation and binding to endothelium [14]. Alternatively, it could be caused by glucocorticoids that induce apoptosis of lymphocytes [30]. Collectively, our studies indicate that future diagnosis of SCID in Morocco can be improved by not simply depending on $<$ 300 T cells/ $\mu$ L or even $<$ 500 T cells/ $\mu$ L. Instead, immunophenotyping should also include quantitation of naïve and activation markers. A recent paper from the EuroFlow consortium recommends using CD62L ${}^{+}$ CD45RO ${}^{-}$ HLA-DR ${}^{-}$ CD31 ${}^{+}$ for recent thymic emigrants, CD62L ${}^{+}$ CD45RO ${}^{-}$ HLA-DR ${}^{-}$ for naïve CD8 ${}^{+}$ and CD4 ${}^{+}$ T cells while eliminating activated HLA-DR ${}^{+}$ cells as well as TCR $\gamma\delta^{+}$ cells, when assaying for functional T cell deficiencies [15]. Ex vivo assays such as PHA activation of T cells should also be performed along with immunophenotyping.

Consanguineous marriages in populations increase the prevalence of autosomal recessive SCID [12, 29, 32, 33]. In our study, positive consanguinity was found in 34% and information was not available for 14% of patients. Albeit significantly less than the 80% identified in an Iranian study [37], consanguinity in our cohort is still relatively high. The most common SCID subtype observed in our studies was T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ , which is autosomal recessive. This finding is identical to previous reports from Mediterranean countries such as by Michos et al. [21] from Greece and by El Maataoui et al. [10] from Morocco. Sex ratio in our cohort was similar to the one found by El Maataoui et al. [10] but was lower compared to those described in other studies [17, 18]. In summary, our cohort is characterized by high consanguinity and prevalence of autosomal recessive SCIDs, and not X-linked SCID that displays a more significant male bias.

The percentage of patients in our study with a positive history of immunodeficiency in the family was 68.5%. This number is near to the 50% observed in an Iranian study [1]. In our study, the patients with SCID familial history were diagnosed earlier in comparison to the other SCID patients. A similar result was found in the study by Stephan et al. [31]. This is probably because families with history of SCID are more aware of this disease state through previous experiences. The majority of SCID infants in Morocco are diagnosed in a specialized pediatric medical center, often in a different city, after the family travels extensive distances to seek medical intervention. The understanding of SCID is generally poor without a family history and the symptoms are confused with repeated bouts of common infections. Albeit the diagnosis was earlier than SCID patients with no family history, it still took 75 days from time of birth. Brown et al. recently reported that detection of SCID at birth because of positive family history can improve outcome by over 90% [5]. Universal newborn screening could radically transform the outcome of SCID in Morocco, but in its absence, at the least Moroccan patients with positive family history should be tested at birth. Family history-based recommendation for testing at birth is likely to greatly increase the outcome in the interim, while we await universal newborn screening.

The clinical findings in the Moroccan cohort were mostly similar with other studies. For example, respiratory infection was the most frequent symptom across all the SCID groups, except in the T ${}^{-}$ B ${}^{-}$ NK ${}^{+}$ subtype, in our study. The exception was probably due to the sample size of the study. Previously, lung and upper airway infections were reported as the most common clinical finding in studies from France [31], Italy [8], Iran [11], and India [2]. Meningitis appears to be more common in the Moroccan cohort. Early hematopoietic stem cell transplant (HSCT) is crucial for improving the outcome in SCID. An age over 3.5 months and active infection at the time of HSCT drastically reduces the survival rate [23]. Given the preponderance of viral and fungal infections in SCID patients, it is imperative to contain infections while the patients await HSCT. For example, following the Australasian Society of Clinical Immunology and Allergy (ASCIA)-Transplantation and Primary Immunodeficiency (TAPID) consensus guideline for the use of co-trimoxazole and fluconazole for prophylaxis against Pneumocystis and fungal infections, respectively as well as acyclovir and palivizumab for prophylaxis against herpes simplex virus (HSV) and respiratory syncytial virus (RSV) infections may help improve outcome [27]. CMV infections were seen in 8% of Moroccan SCID patients. Since mothers who are breast feeding or who wish to breastfeed are not routinely checked for CMV in Morocco, breastfeeding should be stopped if SCID is suspected. Another recommendation would be to screen for SCID before Bacillus Calmette-Guérin (BCG) vacciation. BCG, which contains live attenuated Mycobacterium bovis, is contraindicated in patients with SCID or with other immunodeficiencies as disseminated infections can occur following vaccination in these patients [17, 19, 22]. This was seen in 8% of our patients. Compliance with this contraindication is, however, difficult since BCG is given at birth in tuberculosis endemic countries such as Morocco.

5. Conclusion

Family history, consanguinity of patient’s parents, clinical profile and an abnormality in lymphocytes subpopulation counts should be considered together for the diagnosis of SCID in Morocco. Physicians must take into consideration the above mentioned signs even when the criteria of T lymphopenia less than 300 cells/ $\mu$ L is absent since 14.3% of SCID cases in Morocco did not present with lymphopenia $<$ 300 cells/ $\mu$ L. Inclusion of additional markers for immunophenotyping such as CD62L ${}^{+}$ CD45RO ${}^{-}$ HLA-DR ${}^{-}$ CD31 ${}^{+}$ for recent thymic emigrants, CD62L ${}^{+}$ CD45RO ${}^{-}$ HLA-DR ${}^{-}$ for naïve CD8 ${}^{+}$ and CD4 ${}^{+}$ T cells and eliminating activated HLA-DR ${}^{+}$ cells as well as TCR $\gamma\delta^{+}$ cells, along with ex vivo functional T cell assays is recommended to improve the diagnosis of SCID. Screening of SCID at birth, at least in families with clinical history of SCID, together with prophylactic treatment with antifungals, delaying BCG vaccination and avoidance of breast feeding may help improve SCID outcome in Morocco.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Authors contributions

FS was responsible for the conception and design of the study. AEA, SEF, HT, KS and HB performed the acquisition and analysis of biological data. AEA and NEH were in charge of the collection of clinical features. NEH analyzed the clinical data. EAE, FS, NEH, and YB wrote and revised the manuscript. All authors read and approved the final manuscript.

Footnotes

Acknowledgments

The authors thank the personnel of the Immunology, Allergic and Respiratory Diseases Unit, Children’s Hospital of Rabat for their participation in the recruitment of study subjects and sample collections. We also thank Lindsey D. Hughes for help in preparation of this manuscript, including critical reading. We thank Carla V. Rothlin and Sourav Ghosh for helpful discussions and critical reading of the manuscript.

Conflict of interest

The authors declare that there is no conflict of interest regarding the publication of this paper.

References

Aghamohammadi

Mohammadinejad

Abolhassani

Mirminachi

Movahedi

Gharagozlou

Parvaneh

Zeiaee

Mirsaeed-Ghazi

Chavoushzadeh

Mahdaviani

Mansouri

Yousefzadegan

Sharifi

Zandieh

Hedayat

Nadjafi

Sherkat

Shakerian

Sadeghi-Shabestari

Hosseini

R.F.

Jabbari-Azad

Ahanchian

Behmanesh

Zandkarimi

Shirkani

Cheraghi

Fayezi

Mohammadzadeh

Amin

Aleyasin

Moghtaderi

Ghaffari

Arshi

Javahertrash

Nabavi

Bemanian

M.H.

Shafiei

Kalantari

Ahmadiafshar

Khazaei

H.A.

Atarod

and Rezaei

, Primary immunodeficiency disorders in Iran: Update and new insights from the third report of the national registry, J Clin Immunol 34 (2014), 478–490.

Aluri

Desai

Gupta

Dalvi

Terance

Rosenzweig

S.D.

Stoddard

J.L.

Niemela

J.E.

Tamankar

Mhatre

Bargir

Kulkarni

Shah

Aggarwal

Lashkari

H.P.

Krishna

Govindaraj

Kalra

and Madkaikar

, Clinical, immunological, and molecular findings in 57 patients with severe combined immunodeficiency (SCID) from india, Front Immunol 10 (2019), 23.

Bahrami

Sayyahfar

Soltani

Khodadost

Moazzami

and Rezaei

, Evaluation of the frequency and diagnostic delay of primary immunodeficiency disorders among suspected patients based on the 10 warning sign criteria: A cross-sectional study in Iran, Allergol Immunopathol (Madr) (2020).

Bousfiha

A.A.

Jeddane

El Hafidi

Benajiba

Rada

El Bakkouri

Kili

Benmiloud

Benhsaien

Faiz

Maataoui

Aadam

Aglaguel

Baba

L.A.

Jouhadi

Abilkassem

Bouskraoui

Hida

Najib

Alj

H.S.

Ailal

and I. Moroccan Society for Primary, First report on the Moroccan registry of primary immunodeficiencies: 15 years of experience (1998–2012), J Clin Immunol 34 (2014), 459–468.

Brown

Xu-Bayford

Allwood

Slatter

Cant

Davies

E.G.

Veys

Gennery

A.R.

and Gaspar

H.B.

, Neonatal diagnosis of severe combined immunodeficiency leads to significantly improved survival outcome: The case for newborn screening, Blood 117 (2011), 3243–3246.

Buckley

R.H.

, Molecular defects in human severe combined immunodeficiency and approaches to immune reconstitution, Annu Rev Immunol 22 (2004), 625–655.

Buckley

R.H.

, Transplantation of hematopoietic stem cells in human severe combined immunodeficiency: Longterm outcomes, Immunol Res 49 (2011), 25–43.

Cirillo

Cancrini

Azzari

Martino

Martire

Pession

Tommasini

Naviglio

Finocchi

Consolini

Pierani

D’Alba

Putti

M.C.

Marzollo

Giardino

Prencipe

Esposito

Grasso

Scarselli

Di Matteo

Attardi

Ricci

Montin

Specchia

Barzaghi

Cicalese

M.P.

Quaremba

Lougaris

Giliani

Locatelli

Rossi

Aiuti

Badolato

Plebani

and Pignata

, Clinical, immunological, and molecular features of typical and atypical severe combined immunodeficiency: Report of the italian primary immunodeficiency network, Front Immunol 10 (2019), 1908.

El Allam

El Fakihi

Tahoune

Sahmoudi

Bousserhane

Bakri

El Hafidi

and Seghrouchni

, Age-stratified pediatric reference values of lymphocytes in the Moroccan population, Hum Antibodies (2020).

10.

El-Maataoui

Ailal

Naamane

Benhsaien

Jeddane

Farouqi

Benslimane

Jilali

Oudghiri

and Bousfiha

, Profil immunophénotypique des déficits immunitaires combinés sévères au maroc, Immuno-analyse & Biologie Spécialisée 26 (2011), 161–164.

11.

Fazlollahi

M.R.

Pourpak

Hamidieh

A.A.

Movahedi

Houshmand

Badalzadeh

Nourizadeh

Mahloujirad

Arshi

Nabavi

Gharagozlou

Khayatzadeh

Dabbaghzade

Atarod

Zandieh

Sadeghi Shabestary

Mesdaghi

Mohammadzadeh

Mahdaviani

S.A.

Eslamian

M.H.

Pesaran

Bahraminia

Abolnezhadian

Arij

and Moin

, Clinical, laboratory, and molecular findings for 63 patients with severe combined immunodeficiency: a decade s experience, J Investig Allergol Clin Immunol 27 (2017), 299–304.

12.

Golan

Dalal

Garty

B.Z.

Schlesinger

Levy

Handzel

Wolach

Rottem

Goldberg

Tamir

Koren

Levy

Katz

Passwell

and Etzioni

, The incidence of primary immunodeficiency syndromes in Israel, Isr Med Assoc J 4 (2002), 868–871.

13.

Gossage

D.L.

and Buckley

R.H.

, Prevalence of lymphocytopenia in severe combined immunodeficiency, N Engl J Med 323 (1990), 1422–1423.

14.

Herbinger

K.H.

Hanus

Beissner

Berens-Riha

Kroidl

von Sonnenburg

Loscher

Hoelscher

Nothdurft

H.D.

and Schunk

, Lymphocytosis and lymphopenia induced by imported infectious diseases: A controlled cross-sectional study of 17,229 diseased german travelers returning from the tropics and subtropics, Am J Trop Med Hyg 94 (2016), 1385–1391.

15.

Kalina

Bakardjieva

Blom

Perez-Andres

Barendregt

Kanderova

Bonroy

Philippe

Blanco

Pico-Knijnenburg

Paping

Wolska-Kusnierz

Pac

Tkazcyk

Haerynck

Akar

H.H.

Formankova

Freiberger

Svaton

Sediva

Arriba-Mendez

Orfao

van Dongen

J.J.M.

and van der Burg

, Euro flow standardized approach to diagnostic immunopheneotyping of severe PID in newborns and young children, Front Immunol 11 (2020), 371.

16.

Kumrah

Vignesh

Patra

Singh

Anjani

Saini

Sharma

Kaur

and Rawat

, Genetics of severe combined immunodeficiency, Genes Dis 7 (2020), 52–61.

17.

Marciano

B.E.

Huang

C.Y.

Joshi

Rezaei

Carvalho

B.C.

Allwood

Ikinciogullari

Reda

S.M.

Gennery

Thon

Espinosa-Rosales

Al-Herz

Porras

Shcherbina

Szaflarska

Kilic

Franco

J.L.

Gomez Raccio

A.C.

Roxo

, Jr. Esteves

Galal

Grumach

A.S.

Al-Tamemi

Yildiran

Orellana

J.C.

Yamada

Morio

Liberatore

Ohtsuka

Lau

Y.L.

Nishikomori

Torres-Lozano

Mazzucchelli

J.T.

Vilela

M.M.

Tavares

F.S.

Cunha

Pinto

J.A.

Espinosa-Padilla

S.E.

Hernandez-Nieto

Elfeky

R.A.

Ariga

Toshio

Dogu

Cipe

Formankova

Nunez-Nunez

M.E.

Bezrodnik

Marques

J.G.

Pereira

M.I.

Listello

Slatter

M.A.

Nademi

Kowalczyk

Fleisher

T.A.

Davies

Neven

and Rosenzweig

S.D.

, BCG vaccination in patients with severe combined immunodeficiency: Complications, risks, and vaccination policies, J Allergy Clin Immunol 133 (2014), 1134–1141.

18.

Matamoros Flori

Mila Llambi

Espanol Boren

Raga Borja

and Fontan Casariego

, Primary immunodeficiency syndrome in Spain: First report of the national registry in children and adults, J Clin Immunol 17 (1997), 333–339.

19.

Mazzucchelli

J.T.

Bonfim

Castro

G.G.

Condino-Neto

A.A.

Costa

N.M.

Cunha

Dantas

E.O.

Dantas

V.M.

de Moraes-Pinto

M.I.

Fernandes

J.F.

Goes

H.C.

Goudouris

Grumach

A.S.

Guirau

L.M.

Kuntze

Mallozzi

M.C.

Monteiro

F.P.

Moraes

L.S.

Nudelman

Pinto

J.A.

Rizzo

M.C.

Porto-Neto

A.C.

Roxo-Junior

Ruiz

Rullo

V.E.

Seber

Takano

O.A.

Tavares

F.S.

Toledo

Vilela

M.M.

and Costa-Carvalho

B.T.

, Severe combined immunodeficiency in Brazil: Management, prognosis, and BCG-associated complications, J Investig Allergol Clin Immunol 24 (2014), 184–191.

20.

Mellouli

Mustapha

I.B.

Khaled

M.B.

Besbes

Ouederni

Mekki

Ali

M.B.

Largueche

Hachicha

Sfar

Gueddiche

Barsaoui

Sammoud

Boussetta

Becher

S.B.

Meherzi

Guandoura

Boughammoura

Harbi

Amri

Bayoudh

Jaballah

N.B.

Tebib

Bouaziz

Mahfoudh

Aloulou

Mansour

L.B.

Chabchoub

Boussoffara

Chemli

Bouguila

Hassayoun

Hammami

Habboul

Hamzaoui

Ammar

Barbouche

M.R.

and Bejaoui

, Report of the tunisian registry of primary immunodeficiencies: 25-years of experience (1988–2012), J Clin Immunol 35 (2015), 745–753.

21.

Michos

Tzanoudaki

Villa

Giliani

Chrousos

and Kanariou

, Severe combined immunodeficiency in Greek children over a 20-year period: Rarity of gammac-chain deficiency (X-linked) type, J Clin Immunol 31 (2011), 778–783.

22.

Norouzi

Aghamohammadi

Mamishi

Rosenzweig

S.D.

and Rezaei

, Bacillus calmette-guerin (BCG) complications associated with primary immunodeficiency diseases, J Infect 64 (2012), 543–554.

23.

Pai

S.Y.

Logan

B.R.

Griffith

L.M.

Buckley

R.H.

Parrott

R.E.

Dvorak

C.C.

Kapoor

Hanson

I.C.

Filipovich

A.H.

Jyonouchi

Sullivan

K.E.

Small

T.N.

Burroughs

Skoda-Smith

Haight

A.E.

Grizzle

Pulsipher

M.A.

Chan

K.W.

Fuleihan

R.L.

Haddad

Loechelt

Aquino

V.M.

Gillio

Davis

Knutsen

Smith

A.R.

Moore

T.B.

Schroeder

M.L.

Goldman

F.D.

Connelly

J.A.

Porteus

M.H.

Xiang

Shearer

W.T.

Fleisher

T.A.

Kohn

D.B.

Puck

J.M.

Notarangelo

L.D.

Cowan

M.J.

and O’Reilly

R.J.

, Transplantation outcomes for severe combined immunodeficiency, 2000–2009, N Engl J Med 371 (2014), 434–446.

24.

Picard

Bobby Gaspar

Al-Herz

Bousfiha

Casanova

J.L.

Chatila

Crow

Y.J.

Cunningham-Rundles

Etzioni

Franco

J.L.

Holland

S.M.

Klein

Morio

Ochs

H.D.

Oksenhendler

Puck

Tang

M.L.K.

Tangye

S.G.

Torgerson

T.R.

and Sullivan

K.E.

, International union of immunological societies: 2017 primary immunodeficiency diseases committee report on inborn errors of immunity, J Clin Immunol 38 (2018), 96–128.

25.

Reda

S.M.

Afifi

H.M.

and Amine

M.M.

, Primary immunodeficiency diseases in Egyptian children: A single-center study, J Clin Immunol 29 (2009), 343–351.

26.

Reust

C.E.

, Evaluation of primary immunodeficiency disease in children, Am Fam Physician 87 (2013), 773–778.

27.

Richards

Gennery

A.R.

Davies

E.G.

Wong

Shaw

P.J.

Peake

Fraser

Gray

Brothers

Sinclair

Prestidge

Preece

Quinn

Ramachandran

Loh

McLean-Tooke

Mitchell

Cole

, I. Australasian Society of Clinical Allergy

and Immunodeficiency

, Diagnosis and management of severe combined immunodeficiency in Australia and New Zealand, J Paediatr Child Health 56 (2020), 1508–1513.

28.

Roifman

C.M.

Somech

Kavadas

Pires

Nahum

Dalal

and Grunebaum

, Defining combined immunodeficiency, J Allergy Clin Immunol 130 (2012), 177–183.

29.

Saleem

A.F.

Ali Khawaja

R.D.

Shaikh

A.S.

Ali

S.A.

, and Mehdi Zaidi

A.K.

, Severe combined immune deficiency syndrome, J Coll Physicians Surg Pak 23 (2013), 570–573.

30.

Smith

L.K.

and Cidlowski

J.A.

, Glucocorticoid-induced apoptosis of healthy and malignant lymphocytes, Prog Brain Res 182 (2010), 1–30.

31.

Stephan

J.L.

Vlekova

Le Deist

Blanche

Donadieu

De Saint-Basile

Durandy

Griscelli

and Fischer

, Severe combined immunodeficiency: A retrospective single-center study of clinical presentation and outcome in 117 patients, J Pediatr 123 (1993), 564–572.

32.

Suliamann

Al-Ghonaium

and Harfi

, High incidence of severe combined immune deficiency in the eastern province of saudi arabia, Pediatric Asthma, Allergy & Immunology 19 (2006), 14–18.

33.

Tasher

and Dalal

, The genetic basis of severe combined immunodeficiency and its variants, Appl Clin Genet 5 (2012), 67–80.

34.

van der Spek

Groenwold

R.H.

van der Burg

and van Montfrans

J.M.

, TREC based newborn screening for severe combined immunodeficiency disease: A systematic review, J Clin Immunol 35 (2015), 416–430.

35.

Winkelstein

J.A.

Marino

M.C.

Lederman

H.M.

Jones

S.M.

Sullivan

Burks

A.W.

Conley

M.E.

Cunningham-Rundles

and Ochs

H.D.

, X-linked agammaglobulinemia: Report on a United States registry of 201 patients, Medicine (Baltimore) 85 (2006), 193–202.

36.

Yao

C.M.

Han

X.H.

Zhang

Y.D.

Zhang

Jin

Y.Y.

Cao

R.M.

Wang

Liu

Q.H.

Zhao

and Chen

T.X.

, Clinical characteristics and genetic profiles of 44 patients with severe combined immunodeficiency (SCID): Report from Shanghai, China (2004–2011), J Clin Immunol 33 (2013), 526–539.

37.

Yeganeh

Heidarzade

Pourpak

Parvaneh

Rezaei

Gharagozlou

Movahedi

Shabestari

M.S.

Mamishi

Aghamohammadi

and Moin

, Severe combined immunodeficiency: A cohort of 40 patients, Pediatr Allergy Immunol 19 (2008), 303–306.

Cytometric analysis and clinical features in a Moroccan cohort with severe combined immunodeficiency

Abstract

Keywords

1. Introduction

2.1 Subjects and samples

2.2 Immunophenotyping

Table 1 Demographic data of patients with severe combined immunodeficiency and children with non-PID

2.4 Statistical analysis

2.5 Ethics

3. Results

3.1 Characteristics of the study groups

3.2 Laboratory findings

5. Conclusion

Funding

Authors contributions

Footnotes

Acknowledgments

Conflict of interest

References

Table 1
Demographic data of patients with severe combined immunodeficiency and children with non-PID