Clinical parameter and Th17 related to lymphocytes infiltrating degree of labial salivary gland in primary Sjögren’s syndrome

The aim of this study is to investigate the correlation between clinical parameter, Th17, and degree of lymphocytes infiltrating in labial salivary gland in primary Sjögren’s syndrome (pSS). Minor labial gland biopsies from a cohort of 103 patients fulfilling the American-European consensus classification criteria for pSS were examined and grouped into G1 to G3 according to infiltration degree of lymphocytes in labial salivary glands and formation of germinal center. IL-17 level and Th17 proportion of peripheral blood samples in 54 patients with pSS were analyzed simultaneously. Among the 103 labial salivary glands samples, there were 10.5 % of G1, 68.4 % of G2, and 21.1 % of G3, respectively. Some clinical parameters were markedly associated with the degree of inflammatory cells infiltration in labial glands, including white blood cell counts, lymphocytes, liver enzymes, and pulmonary function diffusion rates. The average optical density of IL-17 correlated with the severity of lymphocytic infiltration in the labial glands, while the proportion of Th17 cells in the peripheral blood mononuclear cells showed no significant relationship to the degree of lymphocytic infiltration in the labial glands from the SS patients. IL-17A mRNA levels in peripheral blood mononuclear cells from pSS patients before immunosuppressant treatment were significantly higher than that in patients after immunosuppressant treatment. The degree of inflammatory cells infiltration in labial glands was related to some clinical manifestations in pSS. IL-17 may play a role in the pathogenesis of lymphocytic infiltration in the labial glands. Immunosuppressive treatment might affect Th17 cells.