A case of myeloperoxidase/proteinase3 anti-neutrophil cytoplasmic antibody double positive rapidly progressive glomerulonephritis with diffuse alveolar hemorrhage successfully treated by quick induction of plasma exchange

Abstract

A 70-year-old Japanese woman visited her home doctor with a complaint of sustained cough and was diagnosed as having interstitial pneumonia. Seven months later, she was admitted to a regional hospital with complaints of general malaise and appetite loss. Because of the acute deterioration of her renal function (serum creatinine 4.2mg/dL), she was referred to our hospital. On admission, her myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA)≥300U/mL and proteinase3(PR3)-ANCA 9.7U/mL suggested ANCA-positive rapidly progressive glomerulonephritis. After admission, methylprednisolone pulse therapy was administered from day 3. On day 4, she was placed on a ventilator because of respiratory failure with hemoptysis. From day 5, plasma exchange was initiated. On day 18, she was released from the respirator. On days 26 and 57, cyclophosphamide was administered. On day 85, her MPO-ANCA level decreased and her renal function recovered, and she was finally discharged. We describe a case of severe ANCA-associated vasculitis in which the high-grade pulmonary-renal syndrome was successfully treated by quick induction of plasma exchange.