[Kidney function problems in rheumatoid arthritis].

Rheumatoid arthritis is a systemic, disabling disease with significant excess mortality which is partly caused by renal disease, infection and renal insufficiency being the main contributors. The bulk of renal problems in reumatoid arthritis are related to complications such as vasculitis and amyloidosis, and complications to the medical treatment of the disease, the main offenders being gold salts, penicillamine and cyclosporine. Also, there is increasing evidence that reumatoid arthritis per se can cause subclinical renal dysfunction with microalbuminuria as well as clinical disease, caused by immune-complex mediated glomerulonephritis and interstitial tubular fibrosis. In reumatoid arthritis serum creatinine can overestimate renal function by as much as 30% and it is suggested that more sensitive methods such as measuring urinary albumin excretion and glomerular filtration rate should be used for monitoring renal function.