[Rapidly progressive glomerulonephritis associated with myeloperoxidase specific-antineutrophil cytoplasmic antibody in patients with rheumatoid arthritis : report of three cases].

The reports on the patients with rheumatoid arthritis (RA) complicated with the myeloperoxidase specific-antineutrophil cytoplasmic antibody (MPO-ANCA) associated glomerulonephritis, whose clinical feature is rapidly progressive glomerulonephritis (RPGN), have been rare. We here report three cases of RPGN with MPO-ANCA in RA patients. Case 1. A 44-year-old woman with RA for 25 years was admitted because of RPGN. The level of MPO-ANCA was markedly high (293 EU) and the histological examination of the kidney showed diffuse crescentic glomerulonephritis. In spite of the intensive immunosuppressive therapy, her renal function did not recover and she underwent hemodialysis (HD). Case 2. A 58-year-old man with RA for 5 years was admitted due to RPGN (MPO-ANCA ; 147 EU, Ccr ; 16 ml/min) with the nephrotic syndrome and fever. The treatment with the immunosuppressive agents and the plasma exchange was partially effective to stop the rapid progression of the disease, but a few months later, his renal function worsened (Ccr 7 ml/min). A recent histological examination of the kidney failed to establish the CrGN because of endstage kidney. Case 3. A 56-year-old woman with RA for the past 10 years was admitted because of RPGN (MPO-ANCA ; 652EU). Intensive therapy could not be performed because of an active duodenal ulcer and markedly impaired renal function (Ccr ; 6 ml/min), and soon she underwent HD. Renal biopsy was not done. These three cases suggest that RPGN can occur in part of RA patients with MPO-ANCA.