Abstract
A 61-year old female with dengue haemorrhagic fever developed anaemia and rising transaminase levels on the 6th day of illness. She was found to have haemolysis with a negative direct antiglobulin test (DAT), and no red cell fragmentation. She recovered with supportive care. Haemolysis with associated Haemolytic uraemic syndrome (HUS), Disseminated intravascular coagulation (DIC) and cold Auto-immune haemolytic anaemia (AIHA) is reported previously; DAT negative haemolytic anaemia associated with dengue fever has not. This case suggests a need for further studies on other immune mechanisms that can lead to haemolysis with dengue fever.
Case report
A 61-year old, previously healthy, Sri Lankan female was admitted to hospital on her second day of illness with dengue fever diagnosed by positive NS1 antigen. Her admission haemoglobin was 126 g/l and her platelet count was 150 × 109/l. The Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) were 0.95μkat/l and 0.81μkat/l respectively.
On the fourth day of illness, she entered a critical phase. The platelet count dropped to 82 × 109/l, her haemoglobin remained at 111 g/l, her packed cell volume (PCV) 34% and the AST and ALT levels had increased to 7.8 μkat/l and 7.12 μkat/l respectively. Her haemodynamic parameters remained stable throughout this critical phase.
On the sixth day of illness, she became icteric and pale, although she remained afebrile and felt clinically better. Her haemoglobin had fallen to 97 g/l with a fall in platelet count to 12 × 109/l. Her transaminase levels worsened the next day, with AST of 33.8 μkat/l and ALT of 24.6 μkat/l, with bilirubin rising to 74umol/l, with higher indirect fraction of 44umol/l. Haemolytic anemia was suspected; a blood film was leucoerythroblastic with polychromasia and nucleated red cells without autoagglutination, fragmentation or toxic granules in the neutrophils. The reticulocyte count was 8% and LDH (Lactate Dehydrogenase) was 71.9 μkat/l. The coagulation profile and renal function remained normal. DAT was negative for IgG and IgM antibodies. Further investigations for other possible aetiology of haemolysis were negative, including mycoplasma antibodies, EBV antibodies, retroviral screening, ANA and malaria parasite screening. An abdominal ultrasound scan showed no evidence of splenomegaly or gall stones. Past history of haemolysis or family history thereof was denied. No drugs could be implicated.
Our patient fully recovered on the 12th day of illness with a platelet count of 152 × 109/l. and haemoglobin 102 g/l. She remained asymptomatic at follow up with a stable haemoglobin. A glucose-6-phosphate dehydrogenase assay three months later was normal (Table 1).
Investigation findings.
Discussion
This case highlights an unusual occurrence of haemolysis with dengue fever.
Haemolysis in setting of dengue can lead to a suspicion of bleeding with dengue hepatitis, which is a common occurrence in dengue haemorrhagic fever. Both conditions are associated with pallor, icterus, rising transaminase levels and dropping haemoglobin; however patients with bleeding and severe hepatitis tend to be clinically ill.
Haemolysis in dengue may occur for multiple reasons, such as: DIC, 1 Thrombotic – thrombocytopenic purpura and HUS (TTP-HUS) spectrum disorders, 2 drug induced haemolysis, inherited haemolytic anemia. 3 Rarely dengue fever may precipitate cold AIHA with positive DAT. 4
Although further immunological work up was not performed to ascertain the exact mechanism of haemolysis in our case, which is a major limitation in this case, we consider our patient to have had an immunological aetiology. It is well known that viral infections may cause immune haemolytic anaemias by various mechanisms. 5 Our case highlights the need for further studies on other potential mechanisms of haemolysis induced by dengue.
Footnotes
Acknowledgements
We thank the patient on whom the case report was based on and the ward staff.
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship and/or publication of this article.
