To study the longitudinal development of pulmonary function in patients with primary SS (pSS) and its association with respiratory symptoms, pulmonary radiographic findings and clinical features of pSS.
Forty-one pSS patients, previously evaluated by pulmonary function tests (PFTs), were included in the study. The patients were studied at baseline and follow-up by PFT and at follow-up also by high-resolution CT scan of the lungs, the St George's Respiratory Questionnaire and by inflammatory and serological tests. The PFT results were compared with previously studied population-based controls, standardizing results with regard to gender, age, height, weight and tobacco consumption.
The mean follow-up time was 11 years. The pSS patients displayed signs of both obstructive and restrictive lung disease at baseline and at follow-up, and deteriorated in forced expiratory volume in 1 s (FEV(1)), ratio of FEV(1) to vital capacity and in diffusing capacity for carbon monoxide during follow-up. Chronic obstructive pulmonary disease (COPD) was diagnosed in 37% of the pSS patients at follow-up. In pSS patients, respiratory symptoms and radiographic abnormalities were common, although with a poor association with PFT variables.
The pSS patients showed signs of both obstructive and restrictive pulmonary disease and COPD commonly developed during follow-up. Respiratory symptoms and radiographic abnormalities were common but poorly associated with PFT in pSS patients.