Hemophagocytic lymphohistiocytosis and macrophage activation syndrome: A multidisciplinary challenge

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.