Virus-associated hemophagocytic syndrome. Diagnosis and treatment

Virus-associated haemophagocytic syndrome (VAHS) is a rare disease characterized by fever, splenomegaly, cytopenia and histiocytic proliferation with haemophagocytosis in the reticuloendothelial system. The clinical course of VAHS can be dramatic and the prognosis is often poor. The pathogenesis of VAHS is not well understood. Many believe that viral infection provokes an abnormal immune response in predisposed individuals leading to hyperactivation of Th1 helper cells, macrophage proliferation and secretion of large amounts of cytokines. The resultant hypercytokinaemia may be responsible for the clinical and biochemical manifestations of VAHS. In this article the clinical features, presumed pathogenesis, diagnostic criteria and treatment of VAHS are discussed.