Successful use of rituximab for refractory hemophagocytic lymphohistiocytosis in a melanoma patient treated with targeted therapy.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by aberrant immune hyperactivation of T CD8 lymphocytes and macrophages driven by cytokine dysfunction. We report a 64-year-old man, with advanced BRAF-mutant melanoma treated by combined targeted therapies who had a recalcitrant and cortico-dependent Epstein-Barr virus (EBV)-induced HLH. One rituximab cycle led to a rapid and prolonged HLH remission which allowed to switch the targeted therapy for immunotherapy rituximab thus makes it possible to limit the use of corticosteroids, which limits the effectiveness of immunotherapy. The patient finally died of a cerebral tumoral progression 2 years later. Despite secondary hypogammaglobulinemia, we did not observe any severe infections during this period. This case suggests that rituximab can be a valuable option for EBV-induced HLH to avoid the T-suppressive effects of high-dose of corticosteroids in immunotherapy-treated patients.