title: [A case of crescentic glomerulonephritis associated with anti-myeloperoxidase antibody presenting as alveolar hemorrhage].
abstract: A 77-year-old man was admitted because of hemoptysis. Chest roentgenograms initially showed progressive infiltrative shadows, which improved spontaneously in 3 months. Transbronchial lung biopsy specimens obtained during the first admission revealed alveolar hemorrhage with neither granuloma nor vasculitis. Alveolar hemorrhage associated with renal dysfunction recurred 9 months later. Serum creatinine level was elevated to 3.5 mg/dl. No other organ than lungs or kidneys was involved. Renal biopsy was performed to confirm the pathological diagnosis of crescentic glomerulonephritis. Anti-basement-membrane antibody was negative, whereas anti-neutrophil-cytoplasmic antibody was positive for perinuclear pattern (P-ANCA) by indirect immunofluorescent (IF) method. He was diagnosed as having idiopathic crescentic glomerulonephritis complicated with alveolar hemorrhage, and the presence of anti-myeloperoxidase (MPO) antibody in serum was anticipated. Anti-MPO antibody level in his serum evaluated by ELISA was markedly elevated. Although myeloperoxidase has been considered as a common antigen to P-ANCA and anti-MPO antibody, the determination of P-ANCA has been clinically unreliable because of equivocal results. In contrast, the presence of anti-MPO antibody is highly specific for idiopathic crescentic glomerulonephritis complicated with alveolar hemorrhage or its incomplete variant case. Also, it is a better index of disease activity. Therefore, there is a possibility that those patients diagnosed as having idiopathic pulmonary hemosiderosis or pulmonary-renal syndrome may be categorized into the one disease, anti-MPO antibody-associated disease, and the measurement of anti-MPO antibody may lead to prompt treatment prior to the histological diagnosis.
authors.affiliation: First Department of Internal Medicine, Tokyo Medical and Dental University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Umino
authors.forename: S
authors.initials: S
authors.lastname: Ohdama
authors.forename: M
authors.initials: M
authors.lastname: Sawada
authors.forename: S
authors.initials: S
authors.lastname: Takano
authors.forename: S
authors.initials: S
authors.lastname: Miyake
authors.forename: S
authors.initials: S
authors.lastname: Tachibana
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshizawa
authors.forename: N
authors.initials: N
authors.lastname: Aoki
authors.forename: O
authors.initials: O
authors.lastname: Matsubara
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies / Q000032:analysis*; D005921:Glomerulonephritis / Q000150:complications / Q000276:immunology*; D006470:Hemorrhage / Q000209:etiology*; D006801:Humans; D008171:Lung Diseases / Q000209:etiology*; D008297:Male; D009195:Peroxidase / Q000276:immunology*; D011650:Pulmonary Alveoli
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D001323:Autoantibodies; D009195:Peroxidase