title: Heterogeneity of incidence and outcome of acute exacerbation in idiopathic interstitial pneumonia.
abstract: Acute exacerbations (AEs) of idiopathic pulmonary fibrosis (IPF) and other idiopathic interstitial pneumonia (IIP) have a poor prognosis. This study aims to clarify the incidence and prognosis of AE in IPF and the other IIP.
  
  
  
  A total of 229 patients were enrolled, of whom 92 had IPF and 137 had 'IIP other than IPF' based on the American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Association (ATS/ERS/JRS/ALAT) 2011 IPF Guidelines. IIP other than IPF included 11 patients with a surgical lung biopsy (SLB) and the remainder without such a biopsy. IIP other than IPF was further classified into IIP with a 'possible usual interstitial pneumonia (UIP)' pattern on HRCT (n = 75) and IIP with 'inconsistent with UIP' pattern (n = 62) based on published guidelines. Predictors of AE and the prognosis after AE were examined in these groups.
  
  
  
  The 1-year incidence of AE in IPF, IIP with possible UIP HRCT patterns and IIP with inconsistent with UIP HRCT patterns was 16.5%, 8.9% and 4.0%, respectively. AE occurred significantly more frequently in IPF than in IIP with possible UIP and inconsistent with UIP HRCT patterns after adjustment for BMI, modified Medical Research Council score and %forced vital capacity. Prognosis of AE-IIP with possible UIP HRCT pattern was significantly worse than that of AE-IPF.
  
  
  
  Although AE occurred significantly less frequently in IIP with possible UIP and inconsistent with UIP HRCT patterns than in IPF, the prognosis of AE-IIP with possible UIP HRCT patterns might be worse than that of AE-IPF.
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Arai
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.|Department of Internal Medicine, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kagawa
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.|Department of Internal Medicine, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Department of Internal Medicine, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Sugawara
authors.affiliation: Division of Clinical Trial, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Chikatoshi
authors.initials: C
authors.lastname: Sugimoto
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.|Department of Internal Medicine, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Tachibana
authors.affiliation: Department of Pathology, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.|Department of Pathology, National Hospital Organization Minami Wakayama Medical Center, Tanabe, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kitaichi
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.|Department of Radiology, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Akira
authors.affiliation: Department of Internal Medicine, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Hayashi
authors.affiliation: Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan. giichi@kch.hosp.go.jp.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000368:Aged; D001706:Biopsy / Q000379:methods; D005260:Female; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D054990:Idiopathic Pulmonary Fibrosis / Q000473:pathology; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008168:Lung / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies; D000067251:Symptom Flare Up; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: acute exacerbation; high-resolution computed tomography; idiopathic interstitial pneumonia; idiopathic pulmonary fibrosis; usual interstitial pneumonia