Changes in Cytokine Profile during Initial Treatment of Pediatric Hemophagocytic Lymphohistiocytosis Associated with Epstein-Barr Virus

Hemophagocytic lymphohistiocytosis (HLH) associated with Epstein-Barr virus (EBV) infection can be self-limiting, severe/aggressive, or fatal. We report a case of EBV-HLH with persistent fever, severe pancytopenia, hypertriglyceridemia, and hypofibrinogenemia in a 4-year-old boy. Levels of plasma cytokines and chemokines were measured with a Bio-Plex system at 1, 2, 3, 4, 5, and 8 days after hospital admission. Administration of steroid and high-dose intravenous immunoglobulin (1 g/kg) did not alleviate fever or reduce cytokine production; however, after administration of etoposide (an antineoplastic agent), fever decreased immediately, the patient's general condition improved, and levels of IL-6, IL-10, IL-8, MCP-1, IFN-γ, and TNF-α declined after etoposide administration. In particular, IFN-γ production sharply declined, from 1,104.1 pg/mL to 101.5 pg/mL, and IL-6 level decreased from 229.8 pg/mL to 11.0 pg/mL, on the day after initial etoposide administration. There was no later recurrence of symptoms during treatment with dexamethasone, etoposide, and cyclosporine A. This case suggests that early etoposide administration is critical for treatment success and indicates that etoposide promptly inhibits cytokine production.