title: Myeloperoxidase Anti-Neutrophil Cytoplasmic Antibody-Positive Interstitial Pneumonia Associated with Granulomatosis with Polyangiitis Diagnosed by Surgical Lung Biopsy.
abstract: Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis that often involves the lung. However, interstitial pneumonia (IP) is rarely seen in GPA patients. We herein report 3 cases of IP associated with GPA diagnosed by surgical lung biopsy. High-resolution CT showed uniform subpleural reticular opacity with traction bronchiectasis. Biopsies from all 3 patients revealed neutrophilic capillaritis, microabscesses with giant cells, and coexisting histological findings of usual IP pattern or fibrosing nonspecific IP pattern. All 3 patients had elevated levels of serum myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), but not proteinase 3-ANCA. We diagnosed GPA and treated with corticosteroid and cyclophosphamide. Follow-up CT showed improvement of the lesions in all patients. Surgical lung biopsy specimens which revealed GPA enabled us to conduct the most suitable therapy. This report indicates the importance of surgical lung biopsy for differentiating idiopathic IPs from GPA-associated IP and suggests a relationship between MPO-ANCA and IP in GPA.
authors.affiliation: Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Chino
authors.forename: Eri
authors.initials: E
authors.lastname: Hagiwara
authors.forename: Hideya
authors.initials: H
authors.lastname: Kitamura
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Baba
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamakawa
authors.forename: Tamiko
authors.initials: T
authors.lastname: Takemura
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogura
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D001706:Biopsy; D003520:Cyclophosphamide / Q000627:therapeutic use; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D017563:Lung Diseases, Interstitial / Q000188:drug therapy / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology*; D014057:Tomography, X-Ray Computed
chemical_list: D000305:Adrenal Cortex Hormones; D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents; D003520:Cyclophosphamide; D009195:Peroxidase