Lymphocytic focus score is positively related to airway and interstitial lung diseases in primary Sjögren's syndrome.

Objective: Although high-resolution computed tomography (HRCT) is useful for the characterization of minute morphological changes in the lungs, no study has investigated risk factors for lung involvement detected by HRCT in patients with Sjögren's syndrome with or without respiratory symptoms. The aim of the current study was to investigate risk factors for lung involvement in patients with primary Sjögren's syndrome detected by HRCT, with a particular focus on airway and interstitial lung diseases.

Methods: We performed a retrospective cohort study of patients with primary Sjögren's syndrome and investigated risk factors for lung involvement detected by HRCT. A total of 101 patients with primary Sjögren's syndrome with initial HRCT examinations were enrolled.

Results: Higher age, dry mouth, and higher labial gland biopsy focus scores (≥4) were risk factors for airway diseases (odds ratio [OR] 1.064 confidence interval [CI] 1.026-1.102, OR 8.795 CI 2.317-33.378 and OR 3.261 CI 1.100-9.675, respectively) in the multivariable analysis. Higher age, male sex, and higher labial gland biopsy focus scores (≥4) were risk factors for interstitial lung diseases (OR 1.078 CI 1.032-1.127, OR 12.178 CI 1.121-132.307 and OR 3.954 CI 1.423-10.987, respectively) in the multivariable analysis. The presence of anti-T-lymphotropic virus type 1 antibodies was significantly more common in patients with airway diseases.

Conclusions: This study showed significant associations of labial gland biopsy focus scores and dry mouth with pulmonary manifestations in patients with primary Sjögren's syndrome. Focus scores as well as dry mouth may reflect lymphoproliferative activity in the lungs in patients with primary Sjögren's syndrome.