BACKGROUND:Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by extreme immune activation, resulting in pathologic inflammation that may be life-threatening. Early recognition is crucial since survival largely depends on early initiation of treatment which utilizes a combination of chemotherapy, immunotherapy and in some cases even bone marrow transplantation.

OBJECTIVES:This study aims to describe the clinical characteristics, treatment received and outcome of patients diagnosed with HLH at the Philippine Children’s Medical Center from 2004 to 2017.

MATERIALS AND METHODS:A retrospective analysis of records of children 0-18 years of age diagnosed with HLH from January 2004 to December 2017 was done.

RESULTS:A total of 39 patients were included in the study which gave an incidence of 1.22 per 3000 patients admitted under 18 years of age. There were 29 males (74.4%) and 10 females (25.6%) with a male to female ratio of 2.9:1 Mean age was 6.12 ± 3.89 years. The average time from initial presentation to diagnosis was 6 weeks and 2 days. The most commonly seen clinical and laboratory features observed in these patients were fever (100%), splenomegaly (71.8%), anemia (87.17%), thrombocytopenia (79.48%) and hypertriglyceridemia (69.23%). Only 5 patients were confirmed to be familial HLH with 3 having XLP gene mutation, and one each having syntaxin and perforin gene mutations. Majority of patients received a combination of treatment based on the HLH 2004 regimen while almost one third only received antibiotics. Only 23% of patients survived during the study period and all but one of these patients received drug combinations based on the HLH 2004 protocol.

CONCLUSIONS AND RECOMMENDATIONS:HLH is a rare but important condition that must be recognized early and treated appropriately to optimize survival. The mortality rate of 39 patients seen in this institution is high. There is a need to better utilize the diagnostic criteria of the disease and to employ a more uniform treatment strategy. Increasing awareness among health care personnel can also improve case finding, characterization and treatment.