Hemophagocytic lymphohistiocytosis: mechanisms of development, clinical manifestations, and treatments

Hemophagocytic lymphohistiocytosis (HLH), also known as cytokine storm, hemophagocytic lymphohistiocytosis, and macrophage activation syndrome, is a life-threatening disorder caused by a congenital or acquired defect in the cytolytic activity of cytotoxic T-lymphocytes (CD8+) and natural killers, as well as hyperproduction of interleukins-1, -6, -18, and interferon-γ. HLH develops in children with systemic juvenile idiopathic arthritis (sJIA), often resulting in multiple organ failure, and is characterized by a high risk of death. This article discusses the mechanisms underlying the development of primary and secondary HLH and sJIA, as well as clinical and laboratory manifestations of HLH. It summarizes the information on diagnostic criteria and analyzes therapeutic approaches used for HLH. Key words: hemophagocytic lymphohistiocytosis, systemic juvenile idiopathic arthritis, biologicals, rheumatology, children