Analysis of incidence of primary Sj gren syndrome associated with interstitial lung disease and its risk factors

  Objective  To analyze the incidence of primary Sj gren syndrome (pSS) associated with interstitial lung disease (ILD) and its risk factors.

  Methods  A total of 278 patients with pSS were retrospectively enrolled and divided into pSS-ILD group (n=83) and pSS group (n=195) according to the results of lung high-resolution CT examination. The incidence of pSS-ILD was analyzed, and the baseline data, clinical symptoms and laboratory indicators of the two groups were compared. The risk factors of pSS-ILD were analyze.

  Results  Among 278 patients with pSS, 83 cases (29.86%) developed pSS-ILD. The age of the pSS-ILD group was significantly higher, and the proportion of smoking history, incidence of cough, expectoration, chest tightness and asthma were significantly higher than those of the pSS group (P < 0.05). The levels of white blood cell (WBC), neutrophil, complement C3, complement C4, antinuclear antibody titer and anti-SSA antibody positive rate in pSS-ILD group were significantly higher than those in the pSS group (P < 0.05). The multivariate age(OR=0.814, 95%CI, 0.620 to 1.147, P < 0.001), smoking history(OR=0.712, 95%CI, 0.557 to 0.960, P=0.013) and antinuclear antibody titer(OR=0.764, 95%CI, 0.528 to 0.995, P=0.021) were independent influencing factors for ILD in pSS patients (P < 0.05).

  Conclusion  In this study, the incidence of pSS-ILD is high. Advanced age, smoking and high antinuclear antibody titer suggest that the risk of ILD is significantly increased in pSS patients.