シェーグレン症候群の呼吸機能と肺画像所見 : 横断的および縦断的検討

Abstract

In order to assess the pulmonary manifestations of Sjögren's syndrome (SS), pulmonary function and radiological findings were evaluated in 82 patients with primary SS (pSS), 14 patients with secondary SS and rheumatoid arthritis (SS+RA), and 26 patients with rheumatoid arthritis without SS (RA). The most common functional abnormalities were small-airway disturbances in all 3 groups : 54.9% in pSS, 28.6% in SS +RA, and 15.4% in RA. Restrictive and obstructive ventilatory disturbances appeared less frequently in all groups. The incidence of restrictive ventilatory disturbance was 6.1% in pSS, 7.1% in SS+RA, and 3.8% in RA, and that of obstructive ventilatory disturbance was 6.1% in pSS, 14.3% in SS+RA, and 15.4% in RA. The lung diffusion factor for carbon monoxide (DLco) was decreased in pSS (49%), in SS+RA (43%), and in RA (42%). The incidence of small-airway disturbances was signifiantly higher in SS than that in RA (p< 0.01). The incidence of radiographic changes in each group was as follows ; interstitial changes, 14.6% in pSS, 14.3% in SS+RA, and 42.3% in RA ; bronchiolitic changes, 11.0% in pSS, 14.3% in SS+RA, and 15.4% in RA ; pleurisy, 8.5% in pSS, 21.4% in SS+RA, and 15.4% in RA; and lymphnode lesions, 2.4% in pSS, 7.1% in SS+RA, and 3.8% in RA. The incidence of interstitial changes was significantly higher in RA than those in SS or SS+RA (p<0.01). Moreover, a 3-year longitudinal evaluation of pulmonary involvement was performed in 24 patients with pSS. %DLco decreased in 4 patients, and total lung capacity (TLC) and functional residual capacity (FRC) decreased in 2 patients during follow-up. In conclusion, small-airway disturbances were the most common functional abnormal- ities in pSS. Remarkable reductions in %DLco, TLC and FRC during follow-up suggest the progression in interstitial lesions in the course of pSS.