Understanding of cytokines and targeted therapy in macrophage activation syndrome.

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of systemic autoinflammatory/autoimmune diseases, generally systemic juvenile idiopathic arthritis and adult-onset Still's disease. It is characterized by an excessive proliferation of macrophages and T lymphocytes. Recent research revealed that cytokine storm with elevated pro-inflammatory cytokines, including IFN-γ, IL-18, and IL-6, may be central to the pathogenesis of MAS. Though the mainstream of MAS treatment remains corticosteroids and cyclosporine, targeted therapies with anti-cytokine biologics are reported to be promising for controlling systemic inflammation in MAS.