Volume 6, Number 6—December 2000 Hemophagocytic Syndromes and
Infection Hemophagocytic lymphohistiocytosis (HLH) is an unusual
syndrome characterized by fever, splenomegaly, jaundice, and the
pathologic finding of hemophagocytosis (phagocytosis by
macrophages of erythrocytes, leukocytes, platelets, and their
precursors) in bone marrow and other tissues. HLH may be
diagnosed in association with malignant, genetic, or autoimmune
diseases but is also prominently linked with Epstein-Barr (EBV)
virus infection. Hyperproduction of cytokines, including
interferon-γ and tumor necrosis factor-α, by EBV-infected T
lymphocytes may play a role in the pathogenesis of HLH. EBV-
associated HLH may mimic T-cell lymphoma and is treated with
cytotoxic chemotherapy, while hemophagocytic syndromes
associated with nonviral pathogens often respond to treatment of
the underlying infection. The term hemophagocytosis describes
the pathologic finding of activated macrophages, engulfing
erythrocytes, leukocytes, platelets, and their pre