ABSTRACT
PURPOSE: Hemophagocytic lymphohistiocytosis (HLH) is an important differential diagnosis in infants and children who present with prolonged fever, hepatosplenomegaly, marked hypertriglyceridemia and cytopenia. HLH is currently curable with immunomodulatory therapy, chemotherapy and stem cell transplantation. We evaluated the clinical characteristics and treatment outcomes in patients with HLH. METHODS: We reviewed retrospectively the medical records of 22 children with HLH from January 1996 to June 2003 at Catholic University St. Mary's Hospital. RESULTS: Among the 22 patients, 11 patients were male and the others were female. The median age of onset was 5.5 (0.6~14.4) years including 6 cases presenting before 2 years of age. Family history of suspicious HLH was observed in 3 patients and Epstein Barr virus (EBV) was demonstrated in 10 patients. The most frequent manifestation was fever and the median duration of fever at diagnosis was 18 (6~46) days. Common laboratory findings were neutropenia, anemia, thrombocytopenia, hypertriglyceridemia, hypofibrinogenemia and abnormal liver function tests. Bone marrow examinations showed significant hemophagocytic lymphohistiocytosis in all of these patients. No treatment was needed in 3 patients and 6 patients were treated with high dose immunoglobulin and antiviral agents, 9 cases with chemotherapy and 4 patients were transplanted with sibling bone marrow or unrelated cord blood. The causes of death were refusal to treatment in 1 patient, disease progression in 6 and pulmonary hemorrhage in 1. CONCLUSION: If the disease is familial or relapsing, progressive or persistent even without family history, hematopoietic stem cell transplantation from the best available donor is strongly recommended. In less severe secondary HLH cases, either no treatment or a short duration of therapy might suffice, but future studies are necessary to define these subsets, possibly with additional genetic markers.