Proteinuria in rheumatoid arthritis--drug-induced or amyloid?

Over a 5-year period 325 patients with rheumatoid arthritis received treatment with gold (162) or D-penicillamine (163). Thirty-eight (11.7%) developed proteinuria, which persisted in 10 patients; renal biopsies in these 10 patients revealed 6 cases of amyloid disease. These 6 cases illustrate the importance of investigation of rheumatoid patients developing proteinuria even when they are receiving potentially nephrotoxic drugs.