Clinical and laboratory features, treatment, and outcomes of macrophage activation syndrome in 80 children: a multi-center study in China.

About half of MAS occurred when the underlying autoimmune diseases (SJIA, KD, and CTD) were first diagnosed. Hypotension could be an important manifestation before MAS diagnosis. Decreased albumin and increased AST, LDH, ferritin, and ratio of ferritin/ESR could predict the onset or full blown of MAS in patient with SJIA.