Etiology, Treatment and Outcome of Children Diagnosed with Secondary Hemophagocytic Lymphohistiocytosis in A Tertiary Hospital

Background: Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome that is associated with a variety of underlying conditions leading to the same characteristic hyperinflammatory phenotype. Objectives: To describe the clinical profile of patients diagnosed with HLH admitted between January 1, 2010 to September 30, 2019 in a tertiary care hospital. Methods: Retrospective descriptive study of pediatric patients diagnosed with HLH in a tertiary care hospital. Results: Eleven subjects were included in the study. Age distribution showed a bimodal pattern: < 5 years old (5, 46%) and 10-15 years old (4, 36%). Male to female ratio is 4.5:1. All patients presented with fever (100%) followed by hepatomegaly (5, 45%) and splenomegaly (4, 36%) on physical examination. All eleven subjects fulfilled the following criteria for HLH such as fever, splenomegaly, and hyperferritinemia. Six out of eleven showed hypofibrinogemia (55%) and hypertriglyceridemia (55%). Among the eleven with two cell cytopenia, five presented with anemia (46%), six with neutropenia (55%), while all of them had thrombocytopenia (100%). Other laboratory findings noted were elevated ALT (5, 46%), CRP (4, 36%), AST (3, 27%), alkaline phosphatase (3, 27%), and hyponatremia (3, 27%). EBV and dengue (3, 27%) were the most common etiologies. Pneumonia (3, 27%) was the most common complication, followed by sepsis (2, 18%). All but one patient were responsive to either dexamethasone (7, 64%) and or IVIG (5, 45%) and chemotherapy (1, 9%). The antibiotic most commonly used was piperacillin tazobactam (3, 27%). The median hospital stay was 17 days. There was one mortality (9%). Conclusion: HLH should be considered in children presenting with prolonged fever, hepatomegaly, and or splenomegaly, with hyperferritinemia, thrombocytopenia, anemia and neutropenia.