A Case of ANCA-positive RPGN after Propylthiouracil Treatment

Anti neutrophil cytoplasmic antibody (ANCA)-positive vasculitis and crescentic glomerulonephritis has been rarely reported in patients suffering from Graves' disease and treated with Propylthiouracil. We experienced a case of ANCA-positive crescentic glomerulonephritis presenting good prognosis after discontinuing Propylthiouracil. A 40-year-old female visited due to the proteinuria and hematuria in urinalysis. She had been medi- cated Propylthiouracil for 3 years. Blood pressure was 100/60 mmHg. BUN and serum creatinine were 24.7 mg/dL, and 1.9 mg/dL, respectively. Urinalysis revealed protein 1481 mg/day, many RBC's/HPF (dysmorphic 80%), Serological ANCA was positive, anti-myeloperoxidase (MPO) antibody 1,922 AAU/ mL (normal <150 AAU/mL). The histologic finding showed crescentic glomerulonephritis on light mic- roscopy, but no immuno deposit on immunofluorescence and light microscopy. So we diagnosed ANCA positive pauci-immune glomerulonephritis. Propylthiouracil was discontinued and steroid, cyclophospha- mide was medicated within about 1 month, but stopped due to cytopenia. Patient's creatinine level was maintained 1.3 mg/dL and showed stable progress for about over 18 months. We report this case that showed good prognosis after discontinuation of Propylthiouracil.