Hemophagocytic lymphohistiocytosis

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by inappropriately activated lymphocytesand natural killer cells that produce high concentrations of cytokines. It is evidenced that "hypercytokinemia"and subsequently uncontrolled activation of histiocytes/ macrophages and T-lymphocytes underline the progressiveorgan dysfunction which leads to death in affected patients. The predominant clinical findings of HLH are persistentfever, cytopenias, hepato-splenomegaly and hemophagocytosis. Diagnosing HLH is extremely challenging and HLH isusually fatal if untreated. The Histiocyte Society treatment study (HLH-2004) outlines diagnostic criteria and treatmentprotocol, based on chemo-immunotherapy, as well as treatment of underlying conditions and supportive care. Subsequenthematopoietic stem cell transplantation is recommended for patients with familial disease or molecular diagnosis,and patients with severe and persistent, or reactivated disease.

Key words: Hemophagocytic lymphohistiocytosis, Histiocyte, HLH-2004