Rapidly progressive glomerulonephritis with D-penicillamine.

We present 3 cases of anti-myeloperoxidase, anti-neutrophil cytoplasmic antibody (MPO-ANCA)-positive rapidly progressive glomerulonephritis developed during the treatment with D-penicillamine (D-PC) for rheumatoid arthritis. Rheumatoid arthritis was diagnosed in these patients, and D-PC was administered to them at doses of 100, 200, and 300 mg per day for 32, 42, and 39 months, respectively. They developed proteinuria, hematuria, renal insufficiency, and anemia, and D-PC was stopped. On admission, MPO-ANCA was strongly positive in their sera. Renal biopsy showed glomerulonephritis with cellular crescents. Immunofluorescence examination revealed deposits of granular IgG, IgM, IgA, C1q, and C3 in the mesangium. The 3 patients were treated with steroid pulse therapy along with administration of anticoagulants, and cyclophosphamide was also used in 2 patients. Their renal function improved gradually and MPO-ANCA disappeared after immunosuppressive treatment.