title: Prognostic factors in interstitial lung disease associated with primary Sjögren's syndrome: a retrospective analysis of 33 pathologically-proven cases.
abstract: BACKGROUND
  Interstitial lung disease associated with primary Sjögren's syndrome (pSS-ILD) shows several patterns such as nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP). Although UIP is a well-recognized prognostic determinant in idiopathic interstitial pneumonias, whether this is also the case in pSS-ILD is unclear. The objectives of this study were to evaluate the prognostic effect of UIP, and to identify the prognostic factors in pSS-ILD.
  
  
  METHODS
  A retrospective review of medical records identified 33 consecutive patients with pathologically-proven pSS-ILD. Each patient was classified into each ILD pattern by multidisciplinary analysis. Baseline clinical-radiologic-pathologic characteristics and survival rates were compared between the ILD patterns. Finally, the prognostic factors in pSS-ILD were assessed by univariate and subsequent multivariate analyses using Cox's proportional hazards regression model.
  
  
  RESULTS
  pSS-ILD patients were diagnosed with NSIP (n = 22) or UIP (n = 11). The median follow-up period was 110 months, and five-year survival rate was 87.3% in the total patient population. The prognosis of the UIP patients was not significantly different from that of the NSIP patients (NSIP to UIP, hazard ratio [HR]: 0.77, 95% confidence interval [CI]: 0.18-3.36, P = 0.73). Multivariate analysis identified PaCO2 (HR: 1.68 per 1 Torr increase, 95% CI: 1.24-2.28, P < 0.01), extent of reticular abnormality on high-resolution CT (HR: 4.17 per 1-grade increment, 95% CI: 1.18-14.73, P = 0.03), and severity of fibroblastic foci (HR: 9.26 per 1-grade increment, 95% CI: 1.74-49.35, P < 0.01) as prognostic factors in pSS-ILD.
  
  
  CONCLUSIONS
  UIP in pSS-ILD was not related to poorer prognosis than NSIP. Assessment of detailed clinical-radiologic-pathologic findings is more important than distinguishing UIP to evaluate prognosis in this disease.
authors.affiliation: Department of Respiratory Medicine, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Enomoto
authors.forename: Tamiko
authors.initials: T
authors.lastname: Takemura
authors.forename: Eri
authors.initials: E
authors.lastname: Hagiwara
authors.forename: Tae
authors.initials: T
authors.lastname: Iwasawa
authors.forename: Yuh
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Noriyo
authors.initials: N
authors.lastname: Yanagawa
authors.forename: Fumikazu
authors.initials: F
authors.lastname: Sakai
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Baba
authors.forename: Shouhei
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogura
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000706:statistics & numerical data; D011379:Prognosis; D016016:Proportional Hazards Models; D011859:Radiography; D012189:Retrospective Studies; D012859:Sjogren's Syndrome / Q000150:complications / Q000175:diagnosis* / Q000628:therapy
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