Alterations in CD8⁺CD45RA⁺CCR7^- T cells as a potential biomarker for primary Sjögren's syndrome

In this study, we found that the CD8⁺CD45RA⁺CCR7^- T cell subpopulation was increased in the peripheral blood of patients with primary Sjögren's syndrome (pSS) compared with healthy donors. Moreover, both CD8⁺TIM-3⁺ T cells and CD8⁺CD45RA⁺CCR7^- T cells were positively correlated with serum anti-SSA antibody concentrations in patients. In animal experiments, prolonged administration of β-glucan (whole glucan particle [WGP]) effectively reduced the onset and progression of pSS. Compared with the control group, the WGP-treated group showed a significant reduction in the proportions of CD4⁺PD-1⁺ T cells, CD4⁺TIM-3⁺ T cells, CD8⁺PD-1⁺ T cells, CD8⁺TIM-3⁺ T cells, and CD8⁺CD45RA⁺CCR7^- T cells in the spleens and peripheral blood of non-obese diabetic mice. Notably, β-glucan exhibited therapeutic efficacy comparable to that of hydroxychloroquine sulfate, a conventional treatment for pSS. These findings suggest that the CD8⁺CD45RA⁺CCR7^- T cell subpopulation may represent a promising new therapeutic target for the disease.