Clinical and pathological features of renal involvement in propylthiouracil-associated ANCA-positive vasculitis.

Background: The kidney is one of the organs affected in patients with propylthiouracil (PTU)-associated antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. We present a series of Chinese patients with renal involvement in PTU-associated ANCA-positive vasculitis and describe their clinical and pathological characteristics.
Methods: Clinical and pathological data from patients with PTU-associated ANCA-positive vasculitis with renal involvement, diagnosed in Peking University First Hospital, were collected and analyzed retrospectively.
Results: Nineteen patients with PTU-associated ANCA-positive vasculitis were treated at Peking University First Hospital between December 1999 and December 2005, and 15 of them had renal involvement. Of the 15 patients, 13 were female and 2 were male, with an average age of 26.3 +/- 11.8 years. All 15 patients were perinuclear ANCA positive with specificities to myeloperoxidase (15 of 15), cathepsin G (9 of 15), human leukocyte elastase (8 of 15), lactoferrin (7 of 15), azurocidin (5 of 15), and proteinase 3 (4 of 15). Duration of PTU administration was 43.0 +/- 31.2 months. All 15 patients had clinical markers of renal involvement, including hematuria (100%), proteinuria (100%), and renal function abnormality (47%). All 15 patients underwent percutaneous renal biopsy. Ten patients had necrotizing crescentic glomerulonephritis, and 7 of these 10 patients had immune complex deposition. Three patients had minimal involvement, 2 patients had immunoglobulin A nephropathy, and 2 patients had membranous nephropathy. PTU treatment was discontinued in all 15 patients. All except 2 patients with minimal renal involvement received immunosuppressive treatment. Eleven of 15 patients achieved complete clinical remission.
Conclusion: Renal involvement in our case series of patients with PTU-associated ANCA-positive vasculitis was heterogeneous, and nearly half our patients had renal immune complex deposition.