Interstitial lung disease and associated factors in patients with Sjögren's syndrome

Interstitial lung disease (ILD) is a common pulmonary manifestation of Sjögren's syndrome (SjS) and associated with an increased risk of death. Early detection and treatment of ILDs and knowing the risk factors are very important for prognosis in rheumatic diseases.

This study was performed to determine ILD and associated factors in patients with SjS.

Four hundred three SjS patients were evaluated in this cross-sectional cohort study. Clinical, laboratory, serological, and imaging features were compared of patients with and without pulmonary involvement. Logistic regression analyses were used to identify risk factors for lung involvement and to identify independent risk factors.

Thirty-five (8.7%) of SjS patients had ILD and 368 (91.3%) had no ILD. The presence of Raynaud's phenomenon was significantly more common in ILD. The geriatric age group over the age of 65 years (OR 8198; 95% CI 3788-17,742; p < 0.001), Raynaud's phenomenon (OR 17,852; 95% CI 6155-51,779; p < 0.001), and smoking (OR 3598; 95% CI 1495-8657; p = 0.003) were risk factors to be associated for ILD in the multivariable analysis. The most common abnormality was non-specific interstitial pneumonia in 20 patients (57.1%) and usual interstitial pneumonia in 15 (42.9%) patients.

The distribution of male patients compared to female patients was higher in patients with lung involvement than in patients without lung involvement. This may be related to older age, higher smoking rate, and longer nicotine consumption in men. Age, smoking, and severity of lung involvement are more important than inflammation status and autoantibodies for prognosis.