Cytokine expression in patients with interstitial lung disease in primary Sjogren's syndrome and its clinical significance.

To explore the cytokine expression level of interstitial lung disease in primary Sjogren's syndrome (ILD-pSS) patients and its clinical significance. 50 pSS patients in our hospital from Jan 2017 to Dec 2019 were selected as pSS group and separated into pSS-ILD (15 cases) and pSS-non-ILD (35 cases) based on whether patients had ILD or not. Then 20 healthy people who underwent physical examination at the same time were matched as a control group. The levels of IL-6, IL-8, IL-10 and TNF-α between the pSS-ILD group and the pSS-non-ILD group were compared. The efficacy of ILD in pSS patients based on the analysis of the IL-6, IL-8, IL-10, and TNF-α levels with ROC curves was evaluated. The IL-6, IL-8, and TNF-α levels of patients in the pSS group were significantly higher than those in the control group. The IL-10 expression level in the pSS group was significantly lower than that in the control group (P<0.05). The IL-6, IL-8 and TNF-α expression levels of patients in the pSS-ILD group were higher than these in the pSS-non-ILD group. The IL-10 expression level in the pSS-ILD group was significantly lower than that in the pSS-non-ILD (P<0.05). The result of the ROC curve showed that the AUC of IL-6, IL-8, IL-10, and TNF-α were 0.667, 0.712, 0.894 and 0.733 respectively. Among them, the AUC of IL-10 was the largest (0.894, the sensitivity was 87.54%, the specificity was 78.63%, and cut off value was 5.162 pg/ml. The serum IL-6, IL-8, IL-10 and the cytokine TNF-α are closely related to the ILD in pSS patients. They may participate in the occurrence and development of the pSS-ILD in patients.