Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a diverse autoimmune rheumatic disease principally affecting women during childbearing years. The female-to-male ratio is around 9:1. Although virtually all patients have skin and joint disease between 30 and 50% will also develop renal, lung, heart and central nervous system involvement. SLE has a prevalence of approximately 40 to 200 per 100,000, occurring most commonly in Afro-Caribbean population. Its diversity of clinical features is, apparently, matched by the wide range of associated autoantibodies. Of the most commonly found are those to dsDNA, ssDNA, nucleosomes, C1q, Ro and RNP. Autoantibodies to dsDNA and nucleosomes are useful diagnostically and probably contribute to the pathogenesis of the disease. Its pathogenesis is a complex combination of hormonal, genetic and trigger factors (infection, ultra-violet radiation). The prognosis has improved in the past 50 years from 50% 4-year survival to around 85% 10-year survival. This improvement has been brought about in part by optimizing the use of plaquenil, corticosteroids and immunosuppressives (azathioprine, cyclophosphamide and more recently mycophenolate). With an increased knowledge of the factors involved in pathogenesis some exciting new modes of treatment (e.g. B cell depletion anti-B cell stimulating factors) are entering clinical trials with the hope of improving mortality and morbidity.