Abstract
To investigate the characteristics of elderly-onset primary Sjögren syndrome (pSS) using chest high-resolution computed tomography and pulmonary function tests (PFTs). The data of 102 patients with pSS with interstitial lung disease were retrospectively analyzed. The chest high-resolution computed tomography, PFTs, and clinical and laboratory data were evaluated based on the age of onset: elderly-onset pSS (EopSS) (≥65 years) versus adult-onset pSS (AopSS) (<65 years). Among the 102 patients with pSS-interstitial lung disease, there were 34 of EopSS and 68 of AopSS. EopSS patients presented a significantly higher incidence of usual interstitial pneumonia (EopSS [38.2%] vs AopSS [11.8%], P = .005) and a significantly lower incidence of nonspecific interstitial pneumonia (EopSS [8.8%] vs AopSS [25%], P = .042). Unlike the AopSS group, the significant decreases in the vital capacity (VC) (the percentage of the predicted value of each parameter [%pred]) and the forced VC (%pred), PFTs showed that VC (%pred) and forced VC (%pred) were >80% in the EopSS group. Forced expiratory volume in 1 second significantly decreased and residual volume significantly increased in the EopSS group (P = .001). The percentage of small airway disease was significantly higher in the EopSS group (P = .021). Diffusing capacity of the lung for carbon monoxide/alveolar volume (%pred) was <80% in both groups with a lower percentage in the AopSS group. Usual interstitial pneumonia is more common in the EopSS group. Although there is no significant difference in ventilation dysfunction between the EopSS and AopSS groups, small airway disease is more common in the EopSS group, while restrictive ventilatory dysfunction is more common in the AopSS group. Therefore, the EopSS group has its own characteristics and it is worth studying and noting.