AIM:To investigate alterations in the expression levels of inflammatory cytokines and subsets of CD8⁺ T cells in the peripheral blood of patients with diabetic retinopathy(DR).

METHODS:Retrospective study. A total of 40 patients with type 2 diabetes admitted to Xi'an People's Hospital(Xi'an Fourth Hospital)from April to July 2022 were recruited for this study and categorized into two groups: 20 cases in the simple type 2 diabetes mellitus(DM)group, and 20 cases in the DR group. Additionally, 20 healthy individuals undergoing routine physical examinations served as the control group. The expression levels of cytokines, including interleukin(IL)-6, IL-8, and IL-10 in peripheral blood were quantified using ELISA. Flow cytometry was employed to analyze the expression of programmed cell death-1(PD-1), T cell immunoglobulin domain and mucin domain protein-3(TIM-3), CD28, and CD57 on CD8⁺ T cells.

RESULTS:The peripheral blood expression of IL-6, IL-8, and IL-10 inflammatory cytokines were significantly elevated in DR patients as detected by ELISA(all P<0.001); flow cytometry analysis showed that the expression of PD-1, TIM-3, and CD57 were elevated in peripheral blood CD8⁺ T cells of DR patients(all P<0.001), and the expression of CD28 was decreased(all P<0.001).

CONCLUSION:In DR patients, CD8⁺ T cells may undergo depletion and senescence as a result of elevated pro-inflammatory cytokines, including IL-6, IL-8, and IL-10.