Abstract: Objective To investigate the correlation between miR-21 and peripheral blood lymphocyte subsets in elderly dialysis patients. Methods Twenty-eight elderly maintenance hemodialysis patients were enrolled as the observation group from the Department of Geriatrics of Beijing Friendship Hospital from January 2020 to January 2021. Forty-seven elderly healthy check-up people were included in the control group. The percentage of T lymphocyte subsets and the expression levels of miR-21, miR-23a, miR-150, miR-100; miR-128 and miR-211 were examined in control group and observation group. The percentage of CD4⁺ and Treg cells and the expression levels of miR-21 were detected before and after dialysis. Results The levels of systolic blood pressure, urea nitrogen, neutrophile percentage and interleukin-6 in patients with the observation group were significantly higher than that of the control group (P＜0.001). The levels of estimated glomerular filtration rate, hemoglobin, glutamic-pyruvate transaminase, albumin were significantly lower in the observation group(P＜0.001), and the percentages of CD4⁺ and Treg cells were significantly increased(P＜0.001). The relative expression of miR-21-5p was increased in the observation group(P＜0.05). Pearson correlation analysis showed that the relative expression of miR-21 was positively correlated with the ratio of Treg cells in the observation group before and after dialysis (P＜0.05). Conclusions There are micro-inflammation in elderly patients undergoing dialysis and the expression level of miR-21 in serum is positively correlated with the ratio of Treg cells before and after dialysis.

Key words: elderly, hemodialysis, T lymphocyte, micro-inflammation, miR-21