Changes in senescence-and function-related parameters of CD8⁺T cells after direct-acting antiviral treatment in patients with hepatitis C virus infection

Objective To investigate the changes in the senescence-and function-related parameters of CD8+T cells after direct-acting antiviral( DAA) treatment and their clinical significance in patients with hepatitis C virus( HCV) infection. Methods A total of 26 patients with HCV infection who attended the Second Affiliated Hospital of Air Force Medical University from January 2017 to December 2018 were enrolled,and all patients were given sofosbuvir and daclatasvir tablets. A total of 22 patients who were cured and 20 healthy controls were enrolled. Flow cytometry was used to measure the expression of silent information regulator 1( SIRT1),CD57,programmed death-1( PD-1),and Tim-3 on CD8+T cells; RT-PCR was used to measure the expression of p21 and p53; Luminex liquid suspension chip was used to observe senescence-associated secretory phenotype in peripheral blood. A one-way analysis of variance was used for comparison of continuous data between multiple groups,and the least significant difference t-test was used for further comparison between two groups. Results There were significant differences in the expression of SIRT1,PD-1,and Tim-3 between the three groups( F = 6. 712,4. 202,and 4. 575,all P < 0. 05). Compared with the healthy control group,the HCV group had significant increases in the expression of SIRT1,PD-1,and Tim-3 on CD8+T cells( all P < 0. 05),and the HCV cured group had a significant increase in the expression of Tim-3( P< 0. 05),with no significant changes in SIRT1 and PD-1( both P > 0. 05). There were significant differences in the expression of p53 and p21 between the three groups( F = 11. 144 and 6. 594,both P < 0. 05). Compared with the healthy control group,the HCV cured group and the HCV group had significant reductions in the expression of p53( both P < 0. 001) and p21( both P < 0. 05),and there were no significant differences between the HCV group and the HCV cured group( both P > 0. 05). There were significant differences in interleukin-6 ( IL-6) and tumor necrosis factor α( TNFα) between the three groups( F = 3. 920 and 6. 337,both P < 0. 05),and compared with the healthy control group,the HCV group had significant increases in the levels of IL-6 and TNFα in peripheral blood( both P < 0. 05). There were no significant changes in IL-6 and TNFα in the HCV cured group( both P > 0. 05),and compared with the HCV group,the HCV cured group had a significant reduction in the level of TNFα( P = 0. 007). Conclusion Senescence of CD8+T cells is observed in patients with HCV infection and is alleviated after DAA treatment,with partial recovery of the function of CD8+T cells.