Treatment of hemophagocytic lymphohistiocytosis in adults.

Treatment of hemophagocytic lymphohistiocytosis (HLH) has been developed primarily in pediatric centers, where familial HLH (FHL) is the leading cause of HLH in newborns and toddlers. The Histiocyte Society Study Group for HLH developed the HLH-94 and HLH-2004 treatment protocols, and these are frequently also used by centers treating HLH in adults (aHLH). These protocols contain etoposide, dexamethasone, and cyclosporine A; these agents all have strong activity against proliferation of cytotoxic T/NK-cells and macrophages, as well as inhibitory activity against the cytokine storm that induces, and maintains HLH. In children with predominantly hereditary disease, the HLH-94 protocol can be regarded as a "one size fits all" algorithm. HLH in adults is a much more heterogeneous syndrome requiring a more individualized approach depending on the underlying trigger, disease severity and course, as well as genetic background. Additionally, treatment in adults usually needs to be modified in the face of the preceding disease history and comorbidities. Interdisciplinary patient care with rheumatologists, gastroenterologists, neurologists, pediatricians, the transplant team, and pathologists is a prerequisite to successful treatment. The preferred approach should reflect a disease- and risk-adapted treatment that includes rigorous supportive care with continuous reassessment of sequential therapeutic measures. It should be recognized that the algorithm of HLH treatment in adults is based more on expert opinion than on extensive scientific evidence.