Hemophagocytic Lymphohistiocytosis in Adults.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal syndrome of pathologic immune dysregulation characterized by clinical signs and symptoms of extreme inflammation. HLH can occur as a genetic or sporadic disorder and, though seen as an inherited condition affecting primarily a pediatric population, can occur at any age and can be encountered in association with a variety of underlying diseases. Clinically the syndrome, whether genetic or acquired, is characterized by fever, hepatosplenomegaly, cytopenias, and activated macrophages in hematopoietic organs. Therapy centers on suppression of this hyperinflammatory state with cytotoxic, immunosuppressive therapy and treatment of any existing HLH triggers.