Patients with pSS seen in the Division of Rheumatology, the second affiliated hospital of Zhejiang University, School of Medicine (SAHZU) during January 2016 to July 2018, were retrospectively reviewed. Characteristics were analyzed.

Patients with pSS were retrospectively reviewed, and pSS-ILD and pSS non-ILD were identified. Clinical data, laboratory parameters, pulmonary high-resolution CT (HRCT), and pulmonary function tests (PFTs) were collected. pSS-ILD patients were further categorized into subgroups according to HRCT patterns or PFTs.

Inclusion Criteria:

• All patients with pSS fulfilled the 2002 revised version of the European criteria proposed by the American-European Consensus Group
• Patient with pSS evaluated with pulmonary HRCT and/or PFTs were included in the pSS-ILD group

Exclusion Criteria:

• patients with hepatitis C infection, past head and neck radiation treatment, sarcoidosis, acquired immunodeficiency syndrome, pre-existing lymphoma, graft-versushost disease, and use of anticholinergic drugs, IgG4-related disease
• Patients with other connective tissue diseases (CTD) or other pulmonary diseases were further excluded, including those with pulmonary arterial hypertension, pulmonary infections, tuberculosis, chronic bronchitis, emphysema, asthma, chronic obstructive pulmonary disease, malignancies, pulmonary lesions related with environmental, occupational or medication exposures, or history of smoking

Eighty-five patients with pSS-ILD were identified, and 85 patients with pSS non-ILD were used for comparison. The average age at disease onset and median disease duration in patients with pSS-ILD were greater when compared with pSS non-ILD patients. There was no difference regarding presenting symptoms at disease onset between pSS-ILD and pSS non-ILD patients.