Renal tubular dysfunction as a complication of gold therapy in patients with rheumatoid arthritis

Forty-five patients with uncomplicated rheumatoid arthritis and 45 control individuals were subjected to immunochemical investigation of the urinary excretion of renal tubular basement membrane antigen (TBM), renal tubular epithelial antigen (RTE), and beta-2-microglobulin. Tubular proteinuria occurred significantly more frequently in patients treated with gold salts than in those not treated (P less than 0.05). Large amounts of RTE and TBM were detected only in the urine of patients who received gold salt therapy. However, the amounts of these proteins in urine did no correlate with the total dose of gold. These results indicate that renal tubular damage frequently occurs in patients with rheumatoid arthritis who are treated with gold salts; the tests outlined are useful in detecting renal tubular disorders developing during gold salt therapy and have certain advantages over routine urinalysis.