Objective: To describe the epidemiology, clinical features, laboratory findings, outcome and the difficulties in diagnosis and management of children with Hemo-phagocytic Lymphohistiocytosis (HLH) in a tertiary children's hospital in India.
Study design: Retrospective analysis of case records of all the children with a diagnosis of HLH from December 2006 to December 2008.
Setting: Tertiary care children's teaching hospital in Chennai, India.
Results: 43 children had a diagnosis of hemo-phagocytosis, of who only 33 (19 male, mean age 46 months, range 50 days-14 years) met the inclusion criteria based on the HLH 2004 protocol of the Histiocyte Society. The predominant presenting features included prolonged fever and hepatosplenomegaly. CNS symptoms were present in 36%. Anemia (Hb <9 gm/dL), and thrombocytopenia (platelets <1,00,000/mm3) were present in 97% and 72%, respectively. Among the biochemical markers, hyperferritinemia was present in 97%, and hypofibrinogenemia and high LDH in 92%. Bone marrow examination showed hemophagocytosis in 84%. Infectious agents were identified in 42% children, with viruses accounting for 2/3 of them (5 Dengue virus, 3 EBV, 1 CMV, 1 TB and 5 bacterial agents). The mean duration between the onset of symptoms and the diagnosis was 16 days. Corticosteroids were the most commonly used immunomodulatory agents (67%), followed by IVI g (64%). Cyclosporine was used in 33% and Etoposide in 15%. Improvement of laboratory parameters was noticed within 5-7 days of starting treatment. Overall survival rate was 76%.
Conclusion: HLH should be considered in the differential diagnosis of children with prolonged fever, hepatosplenomegaly and cytopenia. Prompt recognition and appropriate therapy may result in good outcome, particularly in Infection associated HLH.