Renal biochemistry in rheumatic disease.

In patients with osteo-arthritis, renal disease will almost invariably be the consequence of unrelated coincidental renal pathology. In polyarthritic rheumatoid arthritis and ankylosing spondylitis, renal disease can arise as part of the pathology of a systemic disease, or more likely its treatment. As a rule amyloidosis is the most important complication in terms of progressive irreversible loss of renal function. By contrast, SLE, polyarteritis and Sjögren's disease carry a much higher risk of renal involvement. The regular evaluation of renal function in such patients can enable the kidney damage to be assessed at an early stage and allow treatment to be instituted early.