Abstract: Objective To investigate the role of CD8+CD25+Foxp3+Treg（CD8+Treg）cells in the pathogenesis of type 2 diabetes (T2DM). Methods 90 patients with T2DM were selected and divided into NMAU group containing 45 T2DM patients (MAL<30 mg/24 h) and MAU group containing 45 patients with microalbuminuria (MAL 30~300 mg/24 h), based on urinary microalbumin (MAL). Additionally, 45 healthy patients were selected as control group (HC). The concentration of mAlb were measured by Specific protein analyzer; the proportion of CD8+Tregs were measured by flow cytometry; and the concentration of serum interleukin (IL)-8, 1β, 6, and tumor necrosis factor (TNF)-α were measured by Luminex200. Results Compared with the HC group [4.43 (3.26-5.75) %], the proportion of CD8+Tregs in the NMAU group [4.06 (3.15-5.43) %] and the MAU group [3.52 (2.30-4.87) %] were decreased, and lower in MAU group (P<0.05). The serum levels of TNF-α, IL-8, IL-6 and IL-1β in the MAU group and the NMAU group were higher than that of HC group (P<0.05). The percentage of CD8+Treg cells showed a negative correlation with TNF-α (r=-0.4448 P<0.01), IL-8 (r=-0.3412 P<0.05), IL-6 (r=-0.3653 P<0.05) and IL-1β (r=-0.3192 P<0.05) respectively; Logistic regression analysis showed that CD8+Tregs may have a protective effect on T2DM. Conclusion By regulating the proportion of peripheral blood CD8+ Tregs in patients with T2DM, it is possible to slow down the progression of diabetes.

Key words: Type 2 diabetes, CD8+Treg, Microalbuminuria