INFECTION-ASSOCIATED AND MALIGNANCY-ASSOCIATED HEMOPHAGOCYTIC SYNDROMES - SECONDARY HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenet ically different diseases in which a T-cell induced, uncontrolled acti vation of phagocytosing macrophages may lead to fever, organomegaly, a nd pancytopenia. The underlying immunologic disturbance can either be genetically transmitted, Like in FHL, or acquired, as in IAHS or MAHS. Triggering infections can be found in all these diseases and do not a llow a reliable differentiation. An international treatment protocol h as been developed for FHL. IAHS and MAHS also have a high fatality rat e, justifying immunomodulatory treatment if the disease is progressive .