Macrophage activation syndrome associated with adult-onset Still's disease: a multicenter retrospective analysis.

MAS occurrence is the major cause of death in AOSD patients. Notable liver dysfunction, as well as splenomegaly, low number of platelets or neutrophils, high levels of serum ferritin, and reduced level of fibrinogen are risk factors for poor outcome. Key Points • This is a multicenter retrospective study of AOSD-associated MAS with large number of cases.