[A case of MPO-ANCA-related vasculitis with chronic alveolar hemorrhage].

It has been reported that alveolar hemorrhage caused by ANCA-associated vasculitis occurs in the seriously acute stage. However, we report a rare case of chronic alveolar hemorrhage in a 26-year-old woman who had been on maintenance hemodialysis because of rapidly progressive glomerulonephritis (RPGN) since the age of 17. On a regular checkup at her clinic, chest radiographs revealed diffuse micronodular opacities in both lung fields when she was 22 years of age, and anemia was identified at 24. Before the patient was referred to our hospital, the shadows on the radiographs remained almost unchanged, whereas the anemia, for reasons unknown, slowly deteriorated. She was referred to our hospital because of micronodular opacities detected on a chest radiogram in an annual health check at the age of 26. She was asymptomatic, but her laboratory data showed a normochromic anemia (hemoglobin 6.3 g/dl), and the serum level of MPO-ANCA was 195 EU. Bronchoalveolar lavage at bronchoscopy macroscopically revealed bloody fluids containing hemosiderin-laden macrophages. Histological examination of the biopsy specimen by video-assisted thoracoscopic lung biopsy revealed pauci-immune pulmonary capillaritis and alveolar hemorrhage. She was diagnosed as having MPO-ANCA-related vasculitis, especially microscopic polyangiitis preceding RPGN, and the clinical course suggesting alveolar hemorrhage was progressing slowly. The diagnosis was therefore "chronic alveolar hemorrhage". We emphasize that it is necessary to consider alveolar hemorrhage when a patient who has been on maintenance hemodialysis for RPGN has a combination of anemia and diffuse micronodular opacities, even if the condition is not accompanied with any respiratory symptoms.