Requirement for etoposide in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis

Purpose: We sought to identify the clinical variables most critical to succ essful treatment of Epstein-Barr virus (EBV)-associated hemophagocytic lymp hohistiocytosis (HLH). Patients and Methods: Among the factors tested were age at diagnosis (< 2 y ears or < 2 years), time from diagnosis to initiation of treatment with or without etoposide-containing regimens, timing of cyclosporin A (CSA) admini stration during induction therapy, and the presence or absence of etoposide . Results: By Kaplan-Meier analysis, the overall survival rate for the entire cohort of 47 patients, most of whom had moderately severe to severe diseas e, was 78.3% +/- 6.7% (SE) at 4 years. The probability of longterm survival was significantly higher when etoposide treatment was begun less than 4 we eks from diagnosis (90.2% +/- 6.9% v 56.5% +/- 12.6% for patients receiving this agent later or not at all; P < .01, log-rank test). Multivariate anal ysis with the Cox proportional hazards model demonstrated the independent p rognostic significance of a short interval from EBV-HLH diagnosis to etopos ide administration (relative risk of death for patients lacking this featur e, 14.1; 95% confidence interval, 1.16 to 166.7; P = .04). None of the comp eting variables analyzed had significant predictive strength in the Cox mod el. However, concomitant use of CSA with etoposide in a subset of patients appears to have prevented serious complications from neutropenia during the first year of treatment. Conclusion: We conclude that early administration of etoposide, preferably with CSA, is the treatment of choice for patients with EBV-HLH. (C) 2001 by American Society of Clinical Oncology.