Abstract: Objective To detect the levels of T helper 17 (Th17) and regulatory T (Treg) cells in peripheral blood of Sjogren's syndrome (SS) patients combined with primary biliary cirrhosis (PBC), to analyze their clinical characteristics, and to investigate the effects of Th17/Treg cells on these patients. Methods A total of 22 patients with SS complicated with PBC aged (54.1 ± 9.6) years, including 7 males and 15 females, and 48 SS patients aged (56.7 ± 10.2) years, including 10 males and 38 females, in our hospital from March 2012 to February 2018 were enrolled. And 68 healthy volunteers were enrolled, including 16 males and 52 females, with an average age of (55.2 ± 4.5) years. The measurement data of normal distribution are expressed by mean ± standard deviation, the measurement data of non-normal distribution are expressed by median (percentage 25, percentage 75)], and the comparison between the groups is conducted by t test or Kruskal-Wallis H test. Counting data are expressed as percentages, and comparisons between the groups are made by chi-square test. Results There were 20 cases (90.9%) in the observation group (SS combined with PBC) with the main clinical manifestations of jaundice, skin pruritus, ascites, gastrointestinal hemorrhage, dry mouth, esophageal varices, fever and dry eyes, higher than 37 cases (77.1%) in the control group (SS). However, the number of patients with weight loss in the control group (46, 95.8%) was significantly higher than that in the observation group (17, 77.3%). The alanine aminotransferase, aspartate transaminase, alkaline phosphatase, γ -glutaminase and total bilirubin in the observation group were higher than those in the control group and the healthy group (P<0.05). The percentage of Th17 cells in the observation group was 16.6% (10.1%, 22.5%), significantly higher than that in the control group [9.4% (7.0%, 13.0%), P<0.05] and the healthy group [4.9% (4.3%, 9.8%%, P<0.05]. The ratio of Th17/Treg cells in observation group [0.52 (0.42, 0.62)] was significantly higher than that in control group [0.25 (0.14, 0.37), P<0.05] and healthy group [0.22 (0.13, 0.26), P<0.05]. Conclusion The levels of Th17/Treg cells and their ratios in peripheral blood of SS patients with PBC are obviously out of balance, suggesting that Th17 cells are very likely to be involved in the pathogenesis process. In addition, Th17/Treg ratio has certain correlation with some liver function indexes, and further hierarchical analysis can be carried out stratified by the severity of the disease in future studies.

Key words: Sjogren's syndrome, Primary biliary cirrhosis, Regulatory cell, T helper cell 17