Risk factors for primary Sjogren syndrome-associated interstitial lung disease

Background: Primary Sjogren syndrome (pSS) is a chronic inflammatory autoimmune disease that is characterized by lymphocytic infiltration of the exocrine glands and extraglandular organ systems. Interstitial lung disease (ILD) is common in pSS patients and is one of the independent risk factors for a poor prognosis. The previously reported characteristics and potential risks contributing to pSS-associated ILD have been controversial. Methods: A cohort of 201 newly diagnosed pSS patients were studied over a period of 3 years. Data were from clinical charts. The pSS patients were classified into two groups, namely pSS-ILD or pSS without ILD, according to the lung evaluation. Results: In total, the prevalence of pSS-associated ILD was 78.6%. The pSS patients associated ILD were more likely to be male, older and smokers in comparison to the pSS patients without ILD. There were no significant differences in multiorgan involvement between the two groups. Nonspecific interstitial pneumonia (NSIP) was the most common radiological pattern (45.5%). pSS with ILD was associated with increasing age [odds ratio (OR) = 1.073], smoking (OR = 8.544) and antinuclear antibody (ANA) positive (OR = 3.286). Over a median follow-up period of 24 months (range, 18-30 months), no patients died, experienced acute exacerbation of ILD, or had newly diagnosed pSS-ILD. Conclusions: pSS associated ILD were more commonly in males, older patients and smokers. Aging, cigarette smoking, and ANA positivity may be potential risk factors contributing to ILD in pSS patients.