Membranous glomerulonephritis in patients with rheumatoid arthritis.

We investigated the cause of membranous glomerulonephritis (MGN) in 24 patients with rheumatoid arthritis (RA). The class or stage of RA was diagnosed using the criteria of the American Rheumatism Association, and MGN was diagnosed using renal biopsy. Renal biopsy and laboratory findings, including serologic analysis, were evaluated. Eighteen patients had previously received one of the following antirheumatic agents: bucillamine (n = 13), D-penicillamine (n = 3), or gold (n = 2). The renal lesions of all 24 patients resembled lesions seen with idiopathic MGN on examination by light microscopy, electron microscopy, and immunofluorescence. We concluded that patients with RA are predisposed to develop MGN, whether or not they receive antirheumatic agents.