The clinical, functional and imaging landscape of lung involvement in Sjögren Disease: a potential link between...

Interstitial lung disease (ILD) and small airways disease (SAD) are prominent pulmonary manifestations of Sjögren disease (SjD) but their association and real prevalence are still elusive. Our purpose was to explore the clinical landscape and potential associations of pulmonary disease in SjD.

Eighty three consecutive SjD patients with respiratory symptoms and/or abnormal pulmonary function tests (PFTs) were prospectively recruited. Participants underwent high resolution computed tomography (HRCT) of the lungs, evaluation for small airways function with: i. forced expiratory flow after an expiration of 25% to 75% of forced vital capacity (FEF_25-75) measured by spirometry, and ii) resistance difference between 5Hz and 20Hz (R5-R20) measured by oscillometry, and responded to specific questionnaires for dyspnea and cough. Clinical, laboratory and histopathologic data were also collected and analyzed.

Twenty six (31.3%) patients had ILD findings on HRCT. SjD-ILD patients had more severe respiratory symptoms assessed by specific questionnaires and higher disease activity measured by ESSDAI (12 vs. 2, p < 0.0001), and presented more frequently lymphoma history (33% vs. 10%, p = 0.020), and higher focus score (4.25 vs. 1.50, p = 0.005) compared to non-ILD-SjD patients. The prevalence of SAD based on FEF_25-75, and R5-R20 was 34% and 65% respectively. SjD-ILD patients had lower FEF_25-75 (mean: 64.0 vs 90.8%, p = 0.002), higher R5-R20 (median: 0.149 vs. 0.085 kPa/L/s, p = 0.0006) and presented more frequently SAD defined by R5-R20 (92% vs. 53%, p = 0.0004) compared to non-ILD SjD patients.

ILD and SAD occur frequently among SjD patients and are clinically associated, implying a potential pathophysiologic link between them.