Pulmonary involvement in primary Sjögren's syndrome: contribution of the different means in the systematic investigation.

The prevalence of pulmonary involvement in primary Sjögren´s syndrome (pSS) varies depending on investigation methods. Our study aimed to identify the contribution of the different means of investigation in the systematic screening for pulmonary involvement in pSS. This is a retrospective and descriptive study including medical records of pSS patients, who validated the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for pSS and who had undergone pulmonary assessment. We enrolled 30 patients: twenty-nine females (97%) and one male (3%). The mean age was 55±17.4. In nine patients (30%), pulmonary disease revealed the diagnosis. Dyspnoea and cough were respectively reported by 43% (N=13) and 30% (N=9) of patients. The six-minute walk test showed desaturation in four cases (14%) and the percent predicted distance was less than 70% in three cases (11%). Pulmonary function tests (PFTs) showed restrictive patterns (N=7, 26%), obstructive patterns (N=2, 7%), combined patterns (N=1, 4%), and isolated small airway disease (N=1, 4%). The prevalence of pulmonary involvement based on high-resolution computed tomography (HRCT) was 31% (N=9/29). The most frequent interstitial lung disease (ILD) was observed in five scans (56%) and usual interstitial pneumonia was the most frequently seen in three cases (60%). Bronchiolitis was observed in four cases (25%) out of 16 abnormal scans. The six-minute walk test results correlated with PFT results (P<0.05). Pulmonary involvement was noted in 50% of cases (N=15). It was clinically silent in one-third of cases (N=5). In conclusion, pulmonary involvement in Sjögren´s syndrome can be asymptomatic in 33% of cases. The six-minute walk test has a strong correlation with the results of PFT, it should be considered as an assessment tool that reflects the functional state of the patient.