Relationship between peripheral blood Th17 cells and Th17-related cytokines and postoperative cognitive dysfunction in elderly patients undergoing general anesthesia

Abstract

Objective To evaluate the relationship between perioperative peripheral blood Type 17 helper (Th17) cells and Th17-related cytokines and postoperative cognitive dysfunction (POCD) in elderly patients undergoing general anesthesia. Methods Ninety-six patients of both sexes, aged 65-86 yr, of American Society of Anesthesiologists physical statusⅡor Ⅲ, scheduled for elective hip replacement under general anesthesia, were selected.At 3 days before operation and 1, 2, 3 and 7 days after operation, Montreal Cognitive Assessment (MoCA) was used to evaluate the cognitive function, and fasting venous blood samples were taken for determination of the percentage of Th17 cells and serum interleukin-17 (IL-17) and IL-22 concentrations. The patients were divided into POCD group and non-POCD group according to whether the patients developed POCD at day 7 after operation or not. Pearson linear correlation of the percentage of Th17 cells and serum IL-17 and IL-22 concentrations with MoCA scores was analyzed. Results Twenty-six patients developed POCD (27.1%). The percentage of peripheral blood Th17 cells and serum IL-17 and IL-22 concentrations were significantly higher at each time point after operation than before operation in POCD group and at 1 and 2 days after operation than before operation in non-POCD group (P<0.05). The percentage of peripheral blood Th17 cells and serum IL-17 and IL-22 concentrations were significantly higher at each time point after operation in POCD group than in non-POCD group (P<0.05). The percentage of peripheral blood Th17 cells was negatively correlated with MoCA scores (r=-0.867, P<0.01) and serum IL-17 and IL-22 concentrations were negatively correlated with MoCA scores (r=-0.662 and -0.638, P<0.01) in group POCD. Conclusion The development of POCD is related to the increase in the percentage of peripheral blood Th17 cells and concentrations of Th17-related cytokines IL-17 and IL-22 in elderly patients undergoing general anesthesia. Key words: Th17 cells; Anesthesia, general; Aged; Cognition disorders