Clinical features and treatment strategies of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.

Epstein-Barr virus (EBV) is the major triggering factor producing hemophagocytic syndrome or hemophagocytic lymphohistiocytosis (HLH). In this review, diagnostic problems, clinical and histopathological features, and treatment strategies of EBV-HLH have been described. In patients with EBV-HLH, the EBV-infected T cells or natural killer (NK) cells are mostly mono- or oligo-clonally proliferating, where hypercytokinemia plays a major role and causes hemophagocytosis, cellular damage and dysfunction of various organs. Although the majority of EBV-HLH cases develop in apparently immunocompetent children and adolescents, it also occurs in association with infectious mononucleosis, chronic active EBV infection, familial HLH, X-linked lymphoproliferative disease, lymphoproliferative disease like peripheral T-cell lymphoma and NK cell leukemia. In terms of treatment, special therapeutic measures are required to control the cytokine storm generated by EBV and to suppress proliferating EBV-genome-containing cells, because the clinical courses are often fulminant and result in a poor outcome.