[Kidney involvement in patients with rheumatoid arthritis].
Renal pathology was revealed in 284 out of 498 patients with rheumatoid arthritis (RA) subjected to the 15 years' prospective controlled follow-up and given individualized pharmacotherapy. Biopsy specimens of the kidney were examined in 90 cases. Of these, in 14 patients, they were examined repeatedly. On morphology the following alterations were detected in renal tissue: minimum morphological alterations (18 cases), glomerulonephritis (32 cases), amyloidosis (53 cases), interstitial nephritis (4 cases), and arteriosclerotic nephrosclerosis (1 case). In patients with nephropathy, no pathology nas revealed on morphology (5 cases). Chronic pyelonephritis was diagnosed in 137, nephroptosis in 47, nephrolithiasis in 17, papillary necrosis in 3, and drug nephropathy in 33 patients. Many patients had concomitant renal pathology. Repeated morphological examinations of renal tissue point to dynamic morphological alterations occurring during treatment and disease. Chlorbutin was found to exert a beneficial effect not only on the manifestations of arthritis but also on renal tissue. It could be seen in patients with a primary morphological diagnosis of mesangioproliferative nephritis and minimum morphological alterations in renal tissue. In some cases the clinical and morphological data did not agree, which provides evidence in favour of making renal biopsy in RA patients with a purpose of early diagnosis and specification of renal pathology, choice of the treatment policy.