Renal tubular dysfunction in rheumatic diseases.

Evidence of renal tubular dysfunction as defined by abnormal urinary levels of alpha 1 and beta 2 microglobulin with or without microalbuminuria was found in 47 (16.5%) of 285 patients with a variety of rheumatic diseases, compared with a prevalence of less than 1% in 500 healthy adults. Previous work from this unit has shown a prevalence of tubular dysfunction of 24% in patients with severe rheumatic disease admitted to hospital, probably associated with severe rheumatoid arthritis. Although our study confirms a high prevalence of renal tubular dysfunction, we have shown that it is related to age and intercurrent illness, particularly urinary tract infection, rather than to rheumatic disease or drug therapy, although it is possible drug therapy could add to a compound insult on ageing or damaged kidney.