title: Prevalence and Responsiveness to Treatment of Lung Abnormalities on Chest Computed Tomography in Patients With Microscopic Polyangiitis: A Multicenter, Longitudinal, Retrospective Study of One Hundred Fifty Consecutive Hospital-Based Japanese Patients.
abstract: OBJECTIVE
  To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.
  
  
  METHODS
  We retrospectively identified 167 consecutive hospital-based patients with MPA in 3 hospitals in Japan. We longitudinally collected clinical information for 150 of these patients, for whom CT images obtained before treatment were available. We then determined the presence of 22 imaging components of lung abnormalities in these patients.
  
  
  RESULTS
  The vast majority of patients (97%) had at least 1 lung abnormality on chest CT images, including interstitial lung lesions (66%), airway lesions (66%), pleural lesions (53%), and emphysematous lesions (37%). In multivariate analyses, ground-glass opacity was associated with the Birmingham Vasculitis Activity Score, whereas 3 of 4 airway lesions were associated with myeloperoxidase-antineutrophil cytoplasmic antibodies. Latent class analysis identified a distinct group of patients with airway-predominant lung lesions. Airway lesions such as bronchiolitis and bronchovascular bundle thickening were among the components that showed improvement within 3 months of the initial treatment. An idiopathic pulmonary fibrosis pattern was the only chest CT variable that was independently associated with shorter survival.
  
  
  CONCLUSIONS
  Abnormalities in a wide range of anatomic areas, including the whole airway, can be identified in the lungs of patients with MPA before treatment. The prevalence, clustering patterns, and responsiveness to treatment of individual lung abnormalities provide groundwork for informing future studies to understand the pathophysiology of MPA.
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Mieko
authors.initials: M
authors.lastname: Yamagata
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsushima
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Iesato
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Abe
authors.affiliation: Chiba University, Chica City and Asahi General Hospital, Asahi, Chiba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.affiliation: Asahi General Hospital, Asahi City, Chiba, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kashiwakuma
authors.affiliation: Asahi General Hospital, Asahi City, Chiba, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Kagami
authors.affiliation: Asahi General Hospital, Asahi City, Chiba, Japan.
authors.forename: Itsuo
authors.initials: I
authors.lastname: Iwamoto
authors.affiliation: National Hospital Organization Shimoshizu Hospital, Yotsukaido, Chiba, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Nakagomi
authors.affiliation: National Hospital Organization Shimoshizu Hospital, Yotsukaido, Chiba, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Sugiyama
authors.affiliation: Komoro Kosei General Hospital, Komoro, Nagano, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Maruyama
authors.affiliation: Chiba University, Chiba, Japan and Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Furuta
authors.affiliation: Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK.
authors.forename: David
authors.initials: D
authors.lastname: Jayne
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Uno
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Tatsumi
authors.affiliation: Chiba University, Chiba, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakajima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000402:Airway Obstruction / Q000150:complications / Q000000981:diagnostic imaging; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008137:Longitudinal Studies; D008171:Lung Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D055953:Microscopic Polyangiitis / Q000150:complications* / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015999:Multivariate Analysis; D009195:Peroxidase / Q000276:immunology; D010995:Pleural Diseases / Q000150:complications / Q000000981:diagnostic imaging; D011656:Pulmonary Emphysema / Q000150:complications / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents; D009195:Peroxidase