Interstitial Lung Disease and Pulmonary Damage in Primary Sjögren's Syndrome: A Systematic Review and Meta-Analysis

Abstract

Background: Pulmonary lung involvement is the most common extra-glandular manifestation in patients with primary Sjögren's syndrome (pSS), leading to a worsening of the patient's prognosis. To date, different studies have assessed the prevalence of pulmonary involvement and interstitial lung disease (ILD) in pSS patients with different results.

Methods: We performed a systematic literature review and meta-analysis on ILD pooled prevalence in pSS according to the PRISMA and MOOSE guidelines. Furthermore, we explored the pooled prevalence of the two main presentations of pSS-ILD, nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP).

Results: We analysed the pSS-ILD prevalence in 30 studies including 8255 pSS patients. The pSS-ILD pooled prevalence was 23% (95% CI: 16-30). For NSIP, we found a pooled prevalence of 52% (CI 41-64), and for UIP we found a pooled prevalence of 44% (CI: 32-55). Regarding the meta-regression analysis, male gender, DLco value, country, and HRCT seem to contribute to the ILD presence.

Conclusions: At least 20% of pSS patients have a comorbid ILD, usually NSIP. Male gender and alteration in DLco value may be considered the most important independent factors supporting an active search of lung complications during the clinical history of pSS patients.

Keywords: HRCT; NSIP; Sjogren’s syndrome; UIP; interstitial lung disease; meta-analysis; pulmonary involvement.

Figure 1

PRISMA 2009 flow diagram [8].

Figure 2

Forest plots depicting the pooled prevalence estimate for ILD in Sjogren patients with subgroup analyses for HRCT. Diamonds indicate the overall summary estimates, and width of the diamonds represents the 95% confidence interval (CI); boxes indicate the weight of individual studies in the pooled results [17,18,19,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46].

Figure 3

Forest plots depicting the pooled prevalence estimate for NSIP and UIP in ILD patients. (a) Forest plots depicting the pooled prevalence estimate for NSIP in ILD patients. Diamonds indicate the overall summary estimates, and width of the diamonds represents the 95% confidence interval (CI); boxes indicate the weight of individual studies in the pooled results. (b) Forest plots depicting the pooled prevalence estimate for UIP in ILD patients. Diamonds indicate the overall summary estimates, and width of the diamonds represents the 95% confidence interval (CI); boxes indicate the weight of individual studies in the pooled results [17,18,19,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46].

Figure 4

Contour-enhanced funnel plot. The funnel is centred at 0. Various levels of statistical significance of the points, representative of the studies, are indicated in the plot.