Propylthiouracil-associated antineutrophil cytoplasmic autoantibody-positive vasculitis: retrospective study of 19 cases.

Abstract

OBJECTIVE: To investigate the features, followup data, and outcomes of patients with propylthiouracil (PTU)-associated antineutrophil cytoplasmic autoantibody (ANCA)-positive vasculitis. METHODS: Nineteen patients with PTU-associated ANCA-positive vasculitis diagnosed in our hospital from 2000 to 2006 were analyzed retrospectively. RESULTS: Our data showed a female predominance among the patients. Eleven patients had involvement of more than one organ. Renal involvement was the most common manifestation. Fourteen patients underwent renal biopsy. Four patients had focal proliferative glomerulonephritis with crescent formation. Two had necrotizing glomerulonephritis with crescent formation. Two patients had minor glomerular abnormalities, 2 had IgA nephropathy, one had membranous nephropathy, one had focal proliferative glomerulonephritis, one had granulomatous interstitial nephritis, and the remaining one had focal segmental glomerular sclerosis. Immune complex glomerulonephritis was found in 3 patients. On indirect immunofluorescence, 17 patients were perinuclear-pattern ANCA-positive, one was positive for atypical ANCA, and one was positive for cytoplasmic-pattern-ANCA. By ELISA, 4 patients were positive for both myeloperoxidase (MPO)-ANCA and proteinase-3 (PR3)-ANCA, one was positive for PR3-ANCA only, and the others were positive for MPO-ANCA only. For the treatment of vasculitis, 5 patients received prednisone alone, 10 received prednisone and cyclophosphamide, and the remaining 4 did not receive prednisone or cyclophosphamide. During followup, 15 patients achieved remission, 3 patients died, and one patient depended on dialysis. In general, MPO-ANCA concentration did not correlate with disease progression, and a delayed decrease of MPO-ANCA concentration was found in most patients who achieved remission. CONCLUSION: Most patients with PTU-associated ANCA-positive vasculitis had good outcomes; however, severe cases existed. We suggest early recognition and adequate treatment are necessary to improve outcome.