Prognostic factors in interstitial lung disease associated with primary Sjögren's syndrome: a retrospective analysis of 33 pathologically-proven cases

PLoS One. 2013 Sep 9;8(9):e73774. doi: 10.1371/journal.pone.0073774. eCollection 2013.


Introduction: 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.

MeSH terms

  • Aged
  • Female
  • Follow-Up Studies
  • Humans
  • Idiopathic Interstitial Pneumonias / complications
  • Idiopathic Interstitial Pneumonias / diagnosis*
  • Idiopathic Interstitial Pneumonias / therapy
  • Kaplan-Meier Estimate
  • Lung / diagnostic imaging
  • Lung / pathology*
  • Lung Diseases, Interstitial / complications
  • Lung Diseases, Interstitial / diagnosis*
  • Lung Diseases, Interstitial / therapy
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care / methods
  • Outcome Assessment, Health Care / statistics & numerical data
  • Prognosis
  • Proportional Hazards Models
  • Radiography
  • Retrospective Studies
  • Sjogren's Syndrome / complications
  • Sjogren's Syndrome / diagnosis*
  • Sjogren's Syndrome / therapy

Grants and funding

The authors have no funding or support to report.