[Clinicopathological study of nephropathy in patients with rheumatoid arthritis]

We carried out a retrospective study to investigate the clinical and pathological findings in 31 patients with rheumatoid arthritis (RA). In clinical findings, 17 patients showed nephrotic syndrome, five had isolated proteinuria, two had proteinuria and hematuria and seven had renal failure. In pathological findings, there were 16 patients with membranous nephropathy (MN), two with proliferative glomerulonephritis (DPGN), two with minor glomerular abnormality (MGA), six with amyloidosis, 2 with tubulointerstitial nephritis, and three patients had accompanying lupus nephritis. Eleven of 16 with MGN had been treated with gold, bucillamine or D-penicillamine, so they were diagnosed as drug induced MGN. In the other five patients, we could not decide which drugs induced the nephropathy. The 2 cases of MGA were associated with nephrotic syndrome and acute renal failure, which were caused by non-steroidal antiinflammatory drugs. There were two cases of non-Ig A DPGN, which was regarded as the native nephropathy in RA. The three cases with lupus nephritis were diagnosed as systemic lupus erythematosus by the criteria of the American Rheumatism Association (ARA). In conclusion, the nephropathy in patients with RA was varied and renal biopsy was a useful examination.