Antineutrophil cytoplasmic autoantibody-associated rapidly progressive glomerulonephritis in a patient with primary biliary cirrhosis.

A 72-year-old woman with primary biliary cirrhosis (PBC) and antineutrophil cytoplasmic autoantibody (ANCA)-associated rapidly progressive glomerulonephritis is described. She had a 6-year history of PBC diagnosed histologically, with a positive test finding for antimitochondrial antibodies and elevated biliary enzyme activity. The myeloperoxidase-ANCA test result was negative. The patient was treated with ursodeoxycholic acid (600 mg/day) and had been stable for 6 years. She was admitted to our hospital because of general fatigue, exertional dyspnea, and peripheral edema. Her serum level of creatinine was increased (4.4 mg/dL), and her hemoglobin concentration was reduced (8.0 g/dL). The patient was diagnosed as having rapidly progressive glomerulonephritis. Test results for serum antinuclear antibody and myeloperoxidase-ANCA were positive. The diagnosis by renal biopsy was necrotizing crescentic glomerulonephritis. Prednisolone followed by methylprednisolone pulse therapy and cyclophosphamide were administered. The patient underwent plasma exchange twice weekly for 4 weeks. After 4 weeks, her serum creatinine level fell to 1.8 mg/dL, and she recovered renal function without hemodialysis. After 24 weeks, her renal function (serum creatinine level, 1.6 mg/dL) was stable.