Pediatric Hemophagocytic Lymphohistiocytosis - A Single Center Study

Abstract

Objective: To describe the epidemiological features, outcomes and prognostic factors in diagnosis of pediatric hemophagocytic lymphohistiocytosis (HLH).

Methods: 118 children fulfilling the inclusion criteria for HLH were identified from review of hospital records for period January, 2010 to December, 2019.

Result: Median age at diagnosis was 4 years (range13 days-15 years). Presenting features were fever (100%), hepatosplenomegaly (91%), neurological symptoms (23%), bicytopenia (76%), transaminitis (67.3%), increased soluble interleukin-2 receptor) (sIL-2R) (78%) and hemophagocytosis on bone marrow (75%). Median follow-up duration was 13.5 months (3 days to 102 months). Primary HLH was identified in 27 (23%) patients. Etiology of secondary HLH was infections in 53 (45%), rheumatologic illnesses in 21 (18%) and malignancies in 8 (6%) children. Treatment modalities were steroid only (25%), anti-infectious agent (58%), multi-agent chemotherapy (43%) and HSCT (40%); mortality among above treatment groups were 25%, 58%, 43% and 40%, respectively. 15 patients (13%) had relapsed/refractory HLH who were treated with salvage chemotherapy and hematopoietic stem cell transplantation (HSCT). The overall mortality rate was 39%; mortality within 30 days seen in 23%. Estimated overall survival (OS) and event free survival (EFS) at 3 years were 62% and 61%, respectively.

Conclusion: Pediatric HLH is an aggressive disease with high mortality. Hyponatremia, hyperbilirubinemia, coagulopathy and increased sIL2 receptor level at diagnosis predicts poor outcome.