SLE

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by loss of immune tolerance and the production of autoantibodies that form immune complexes, causing inflammation and tissue damage in multiple organ systems.

SLE primarily affects women of childbearing age and varies in prevalence by ethnicity, being more common in people of African, Hispanic, and Asian descent. Onset is usually in adolescence to middle age.

The disease arises from an interaction of genetic susceptibility, environmental triggers such as ultraviolet light and infections, and hormonal factors. B cell hyperactivity leads to autoantibody production (including ANA, anti-dsDNA, and anti-Smith), with immune complexes injuring skin, joints, kidneys, and other tissues.

Clinical features are heterogeneous. Common manifestations include arthralgia or non-erosive arthritis, a malar rash, photosensitivity, oral ulcers, serositis, kidney involvement (lupus nephritis), neurological or neuropsychiatric symptoms, and hematologic abnormalities. Disease activity often waxes and wanes.

Diagnosis relies on established criteria (e.g., SLICC or EULAR/ACR). ANA is sensitive but not specific; anti-dsDNA and anti-Smith antibodies support the diagnosis. Low complement levels and abnormal urinalysis or kidney biopsy may indicate organ involvement.

Treatment is tailored to organ involvement and disease activity. Hydroxychloroquine is commonly used; NSAIDs manage pain; corticosteroids control flares, with steroid-sparing immunosuppressants such as mycophenolate mofetil or azathioprine for severe disease. Belimumab is available for select patients.

Prognosis varies widely. With modern therapy, survival improves, but long-term risks include lupus nephritis, cardiovascular disease, infection, and drug toxicity. Regular monitoring and multidisciplinary care are essential.