Lupus nephropathy and vasculitis

Multi-system autoimmune diseases, including systemic lupus erythematosus (SLE) and vasculitis, are inflammatory conditions of unknown cause. Renal involvement can occur in a variety of forms and usually represents a severe disease manifestation. SLE is frequently complicated by renal involvement (lupus nephritis). The main renal manifestation of vasculitis is pauci-immune, necrotizing, crescentic glomerulonephritis. This is potentially reversible but, if left untreated, results in end-stage renal failure and death within days to weeks. Vasculitis is the most common cause of the syndrome of rapidly progressive glomerulonephritis (RPGN), but this can also be seen in SLE and anti-glomerular basement membrane disease. Other less frequent examples of renal involvement in multi-system autoimmune disease include vascular lesions in scleroderma, and interstitial nephritis or glomerular lesions in Sjögren's syndrome or rheumatoid arthritis. Lupus nephritis and renal vasculitis are the most frequent causes of renal failure in multi-system autoimmunity and are discussed in this contribution.