Systemic lupus erythematosus (pron-ens??st?m?k ?lu?p?s ??r???i?m??to?s?sSystemic lupus erythematosus pronunciation.ogg, often abbreviated to SLE or lupus, is a chronic autoimmune (Autoimmunity) connective tissue disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body?s cells and tissue, resulting in inflammation and tissue damage.

SLE most often harms the heart, joints, skin, lungs, blood vessels, liver, kidneys, and nervous system (Nervous system#Vertebrates). The course of the disease is unpredictable, with periods of illness (called flares) alternating with remission (remission (medicine))s. The disease occurs nine times more often in women than in men, especially between the ages of 15 and 50, and is more common in those of non-European descent.

SLE is treatable through addressing its symptoms (Symptomatic treatment), mainly with cyclophosphamides, corticosteroids and immunosuppressants (immunosuppression); there is currently no cure. SLE can be fatal, although with recent medical advances, fatalities are becoming increasingly rare. Survival for people with SLE in the United States, Canada, and Europe is approximately 95% at five years (five-year survival rate), 90% at 10 years, and 78% at 20 years.