title: Acute exacerbation of interstitial pneumonia associated with collagen vascular diseases.
abstract: BACKGROUND
  Acute exacerbation (AE) is currently established as a distinct condition with acute deterioration of respiratory status in idiopathic pulmonary fibrosis (IPF). Recently, several studies have reported that AE also occurred in interstitial pneumonias other than IPF, such as collagen vascular disease-associated interstitial pneumonia (CVD-IP). However, the incidence of AE in CVD-IP and its clinical characteristics remain to be fully determined. This study was conducted to elucidate cumulative incidence of AE in CVD-IP and its clinical features.
  
  
  METHODS
  We reviewed 83 biopsy-proven CVD-IP patients, estimated cumulative incidence of AE, and examined its clinical characteristics.
  
  
  RESULTS
  Among 83 CVD-IP patients, six patients with a mean age of 65.7 years developed AE (overall incidence, 7.2%; 1-year incidence, 1.25%). Underlying CVDs included rheumatoid arthritis (RA) (n=5; overall incidence, 20.0%) and primary Sjögren syndrome (n=1; overall incidence, 5.9%). Patients with AE showed acute respiratory deterioration with severe hypoxemia (mean PaO(2)/FiO(2) ratio, 131). Radiologically, ground-glass opacity was superimposed on the underlying reticular abnormalities. Preexisting histological patterns included three usual interstitial pneumonia (UIP) and two non-specific interstitial pneumonia (NSIP). Five (83.3%) of six patients died of respiratory failure despite intensive therapy. Univariate Cox's proportional hazards analysis showed that age and RA diagnosis were significantly associated with AE. Multivariate Cox's proportional hazards analysis indicated that age was an independent significant factor predicting AE.
  
  
  CONCLUSIONS
  These data suggest that AE can occur in CVD-IP, and this condition is closely similar to that of IPF with poor prognosis. AE is most common in RA, and associated with higher ages.
authors.affiliation: 2nd Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192, Japan. suda@hama-med.ac.jp
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kaida
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Enomoto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Shiro
authors.initials: S
authors.lastname: Imokawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Hashizume
authors.forename: Tateaki
authors.initials: T
authors.lastname: Naito
authors.forename: Dai
authors.initials: D
authors.lastname: Hashimoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takehara
authors.forename: Naoki
authors.initials: N
authors.lastname: Inui
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Colby
authors.forename: Kingo
authors.initials: K
authors.lastname: Chida
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001706:Biopsy; D018893:Bronchoalveolar Lavage; D003240:Connective Tissue Diseases / Q000150:complications*; D003520:Cyclophosphamide / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015994:Incidence; D008168:Lung / Q000473:pathology; D017563:Lung Diseases, Interstitial / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use; D008875:Middle Aged; D016016:Proportional Hazards Models; D012131:Respiratory Insufficiency / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014652:Vascular Diseases / Q000150:complications*
chemical_list: D000893:Anti-Inflammatory Agents; D007166:Immunosuppressive Agents; D003520:Cyclophosphamide; D008775:Methylprednisolone