Systemic lupus erythematosus

**Definition:** Systemic lupus erythematosus (SLE) is a clinically multisystem disease, which is autoimmune in origin and is characterised by the presence of autoantibodies directed against nuclear antigens. Manifestations include rash, arthritis and fatigue, nephritis, neurological problems, anaemia and thrombocytopenia at the more severe end of the spectrum.

**Long definition:** Systemic lupus erythematosus is a multisystemic autoimmune disease resulting from immune system–mediated tissue damage. Manifestations can involve the skin, joints, kidney, central nervous system, cardiovascular system, serosal membranes, and the hematologic and immune systems. The disease is highly heterogeneous, with individual patients manifesting variable combinations of clinical features. The molecular triggers of the disease are unknown, but the pathogenesis is understood to involve the production of autoantibodies exhibiting multiple specificities, with reactivity to nucleic acid–binding proteins being a common feature. Immune complexes, together with immune system cells and soluble mediators, generate inflammation and tissue damage.