The respiratory manifestations in patients with primary Sjögren's syndrome: is interstitial lung disease related to disease activity?

BACKGROUND

Sjögren's syndrome is a systemic, autoimmune disease and can affect many organs and systems. In this study, we aimed to evaluate the respiratory manifestations, and the association between interstitial lung disease (ILD) and disease activity in primary SS (pSS) patients.

METHODS

The study design was retrospective cross-sectional, and 151 patients followed up with a diagnosis of pSS between 2004 and 2019 were included in the study. Demographic and clinical data, laboratory results, chest radiographs and thorax computed tomography (CT) results were obtained from patient files and hospital imaging system. Thorax CT was requested from all patients with respiratory complaints and abnormalities in physical examination and pulmonary function test. Disease activity was calculated with EULAR pSS disease activity index (ESSDAI) and clinical European League Against Rheumatism SS Disease Activity Index (clin-ESSDAI).

RESULTS

In our study, 97% of pSS patients were female, and the mean age was 55.9 ± 12 years, disease onset age was 45.5 ± 12.1 years, disease duration was 10.7 (1-38) years. According to CT findings of 120 patients, 35% had nodules, and 13.3% had ILD (62.5% nonspecific interstitial pneumonia, 25% lymphocytic interstitial pneumonia, 12.5% usual interstitial pneumonia). Bronchiectasis, emphysema, sequelae fibrotic changes, and pleural thickening was found in 3.3%, 5.8%, 15.8%, and 1.7% of patients, respectively. It was observed that there was a significant relationship between the presence of ILD and persistent cough, mediastinal LAP, low DLCO, high ESSDAI and clin-ESSDAI scores reflecting disease activity.

DISCUSSION: The most common pulmonary manifestation in our patients was ILD. ILD was observed more frequently in patients with moderate and severe disease activity. Some of the ILD patients were diagnosed while they were asymptomatic. Even if they are asymptomatic, it is important to follow up the patients with physical examination, spirometry, DLCO and thorax CT.