MPO-ANCA-Positive Anti-glomerular Basement Membrane Antibody Disease Successfully Treated by Plasma Exchange and Immunosuppressive Therapy

Abstract

Anti-glomerular basement membrane (GBM) antibody disease is clinically manifested as rapidly progressive glomerulonephritis (RPGN) with crescentic changes. The renal prognosis is poor. We report here the case of a 61-year-old woman with myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive anti-GBM antibody disease. This patient was referred to our hospital because of RPGN. Anti-GBM antibody was positive with a titer of 38 EU. The MPO-ANCA titer was 65 EU. Chest imaging examination revealed pulmonary multiple nodules. ANCA-associated vasculitis was suspected. Renal pathology revealed cellular crescents in 13 out of 17 glomeruli. Immunofluorescence with anti-IgG antibody, anti-C3 antibody, and anti-fibrin antibody showed linear staining along the glomerular capillary walls. Based on these findings, the patient was diagnosed with anti-GBM antibody disease. Hemodialysis was started because of uremic syndrome with elevated serum creatinine (6.84 mg/dL). In addition, treatment with plasma exchange using 3.6 L (90 mL/kg) of fresh frozen plasma combined with an oral dose of 40 mg of prednisolone was initiated. Within 3 weeks, both types of autoantibodies became undetectable. Subsequently, this patient achieved dialysis independence and remission of glomerulonephritis. No adverse effects were observed. In patients with MPO-ANCA-positive anti-GBM antibody disease, intensive therapy predominantly with plasma exchange might be operative, even though renal function is less likely to recover.