[Kidney involvement in rheumatoid arthritis].

Two cases of rheumatoid arthritis with renal lesions are presented. In one of the patients a mesangial IgM nephropathy and in the other patient a mesangiocapillary glomerulonephritis were proved clinically and by biopsy. In the first patient proteinuria was found only while in the second patient the proteinuria was combined with nephrotic syndrome and arterial hypertension. The various renal lesions in rheumatoid arthritis and their causes are discussed.