The frequency of CD4+ and CD8+ circulating T stem cell memory in type 1 diabetes.

Introduction: The frequencies and functions of T stem cell memory (TSCM) subsets vary in autoimmune diseases. We evaluated the frequencies of CD4+ and CD8+ TSCM subsets as well as their PD‐1 expression levels in patients with T1D. Methods: Blood samples were collected from new case (NC) (n = 15), and long‐term (LT) (n = 15) groups and healthy controls (n = 15). Five subsets of T cells including TCM(CD4+/CD8+ CCR7+ CD45RO+ CD95+), TCMhi (CD4+/CD8+ CCR7+ CD45ROhi CD95+), TEM(CD4+/CD8+ CCR7− CD45RO+ CD95+), TSCM(CD4+/CD8+ CCR7+ CD45RO− CD95+), and T naive (CD4+/CD8+ CCR7+ CD45RO− CD95−) were detected by flow‐cytometry. Results: The frequency of CD4+ TSCM was higher in NC patients than LT patients and controls (p <.0001 and p =.0086, respectively). A higher percentage of the CD8+ T naive cells was shown in NC patients as compared with LT and healthy individuals (p =.0003 and p =.0002, respectively). An increased level of PD‐1 expression was observed on the CD4+TCM and TCMhi cells in LT patients as compared with healthy controls (p =.0037 and p =.0145, respectively). Also, the higher PD‐1 expression was observed on the CD8+ TCM and TCMhi in NC and LT patients as compared with controls (p =.0068 and p <.0001; p =.0012 and p =.0012, respectively). Conclusion: Considering TSCMs' capacities to generate all memory and effector T cells, our results may suggest a potential association between the increased frequencies of TSCMs and T1D progression. [ABSTRACT FROM AUTHOR]