title: Clinical Implication of Proteinase-3-antineutrophil Cytoplasmic Antibody in Patients with Idiopathic Interstitial Pneumonias.
abstract: OBJECTIVE
  The clinical significance of proteinase-3-antineutrophil cytoplasmic antibody (PR3-ANCA) positivity is not well established in idiopathic interstitial pneumonia (IIP) patients. We aimed to determine the clinical features of PR3-ANCA-positive IIP patients.
  
  
  METHODS
  We retrospectively reviewed 377 consecutive IIP patients; of these, 360 patients had PR3-ANCA and myeloperoxidase-antineutrophil cytoplasmic antibody test results available. The clinical features of PR3-ANCA-positive IIP patients and control ANCA-negative idiopathic pulmonary fibrosis patients (ANCA-negative IPF) were compared.
  
  
  RESULTS
  Sixteen patients (4.4 %) were PR3-ANCA-positive IIP and 94 (26 %) were ANCA-negative IPF. The median age at diagnosis (72 vs. 70 years, P = 0.17) and proportion of males (75 vs. 89 %, P = 0.12) in PR3-ANCA-positive IIP and ANCA-negative IPF patients, respectively, were not significantly different. Radiologically, the HRCT patterns of PR3-ANCA-positive IIP patients varied (UIP, n = 3, 18.8 %; possible UIP, n = 3, 18.8 %; NSIP, n = 5, 31.3 %; unclassifiable CT pattern, n = 5, 31.3 %) more than those of ANCA-negative IPF patients (UIP, n = 69, 73.4 %; possible UIP, n = 25, 26.6 %; P < 0.001). No PR3-ANCA-positive IIP patients developed ANCA-associated vasculitis. The 5-year survival rate was 50 % in PR3-ANCA-positive IIP patients and 52 % in ANCA-negative IPF patients with no significant difference (P = 0.96 by log-rank test).
  
  
  CONCLUSIONS
  The HRCT patterns of PR3-ANCA-positive IIP patients varied more than those of the IPF patients, but the clinical features of high IIP-onset age and male predominance were similar between the groups. Furthermore, PR3-ANCA-positive IIP patients had a poor prognosis similar to that of IPF patients.
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan. hozumi@hama-med.ac.jp.|Department of Emergency and Disaster Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan. hozumi@hama-med.ac.jp.
authors.forename: Hironao
authors.initials: H
authors.lastname: Hozumi
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Enomoto
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Oyama
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kono
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Inui
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama Higashiku, Hamamatsu, 431-3192, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000097:blood* / Q000175:diagnosis / Q000276:immunology / Q000401:mortality; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D053146:Myeloblastin / Q000276:immunology*; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D053146:Myeloblastin
keywords: ANCA; ILD; Interstitial lung disease; Interstitial pneumonia; PR3-ANCA; Proteinase-3-antineutrophil cytoplasmic antibody