Background: Sjögren syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltration of the salivary and lacrimal glands. The CXCL10–CXCR3 axis is considered central in promoting inflammation and damaging the gland, while oral microbial dysbiosis may amplify immune activation. Materials and Methods: This is a cross-sectional case–control study in which 37 patients who met the 2016 ACR–EULAR criteria and 17 age- and sex-matched healthy controls were recruited at the College of Dentistry, University of Baghdad. Oral sample was cultured on selective media to characterize oral bacteria, serum IL-35 and IL-39 levels were quantified by ELISA, and labial salivary gland biopsies from patients underwent histopathology and CXCL10/CXCR3 immunohistochemistry Results: Patients showed a pronounced systemic imbalance in cytokines, with reduced IL-35 and increased IL-39, significantly different from controls, and a highly decreased IL-35/IL-39 ratio (all P <0.001). The receiver operating characteristic curve analysis revealed high sensitivity, specificity, and overall efficiency for IL-35 (AUC=0.933), IL-39 (AUC=0.956), and the ratio (AUC=0.983). Immunohistochemistry of the labial salivary glands revealed generalized overexpression of CXCL10 and CXCR3 (all P <0.001) in patients. Oral microbiologic evaluation revealed increased Lactobacillus (Rogosa) and significant selective growth of Gram-positive cocci, Gram-negative bacilli ( P =0.003). No correlation with disease activity, ESR was evident. Conclusions: This research has revealed that patients with pSS have a noticeable shift in the immune response, characterized by decreased IL-35, increased IL-39, and increased CXCL10–CXCR3, simultaneously with changes in the oral microbiota. Future research with a more precise research design, a larger population, and the use of modern microbiota analysis is required.
Ali et al. (Fri,) studied this question.