Advances in the management of hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a prototype of the hemophagocytic syndrome and occurs most often in children. Progress in cytokine research has now made it possible to show that HLH occurs as a consequence of uncontrolled, dysregulated cellular immune reactivity caused by a number of different underlying diseases. Three major risk groups of HLH can be identified: (1) familial HLH (FHL), (2) Epstein-Barr virus-associated HLH (EBV-HLH), and (3) life-threatening infection-associated or underlying disease-unknown HLH in infancy.

Treatment strategies for Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH).

In Epstein-Barr virus (EBV) infection, the virus immortalizes B lymphocytes and cytotoxic T lymphocytes (CTLs) are directed toward both latent and lytic viral antigens expressed on EBV-infected B-cells. Various EBV-associated diseases occur as a result of this disruption of immune surveillance. In the majority of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) cases, the major cell types containing EBV DNA are not B-cells, but clonally proliferating T-cells or NK-cells.