[Study on the correlation between viral load and activation and exhaustion levels of CD8+T cells in HIV/AIDS patients].

Objective: To investigate and analyze the correlation between the expression levels of CD38, HLA-DR and programmed cell death-1 (PD-1) on peripheral blood CD8⁺T cells and HIV-1 RNA viral load, immune activation and exhaustion in patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Methods: A total of 81 HIV/AIDS patients (64 without antiretroviral therapy and 17 with therapy) and 40 healthy donors in the same period were enrolled as the control group. Flow cytometry was used to analyze the CD4⁺T lymphocyte count and the expression levels of activation markers CD38 and HLA-DR and apoptosis marker PD-1 on CD8⁺T cells. HIV-1 RNA in the plasma of HIV-1 infected patients was quantitatively detected by real-time fluorescence quantitative polymerase chain reaction. Variance analysis was used to compare the expression levels of CD38, HLA-DR and PD-1 on CD8⁺T cells between HIV/AIDS patients and healthy controls. Spearman correlation analysis was used to analyze the correlation between different T lymphocyte counts and HIV RNA viral load, and the correlation between HIV RNA viral load and peripheral blood CD8⁺T cell CD38, HLA-DR and PD-1. Results: Among the 81 HIV/AIDS patients, 69 (85.19%) were males and 12 (14.81%) were females, with an age M (Q₁, Q₃) of 58 (36.5, 65.0) years. There were 60 HIV/AIDS patients over 55 years old (74.07%) and 21 HIV/AIDS patients between 18 and 55 years old (25.93%). The results of variance analysis showed that compared with the healthy control group, the expression levels of CD38, HLA-DR and PD-1 on CD8⁺T cells in HIV/AIDS patients increased, and the differences were statistically significant (all P<0.05). In addition, the expression of CD38, HLA-DR and PD-1 increased significantly in patients with CD4⁺T cell count less than 350 cells/μl, and the differences were statistically significant (all P<0.05). Spearman correlation analysis showed that CD4⁺and CD4⁺/CD8⁺were negatively correlated with viral load in HIV/AIDS patients (r=-0.407 and -0.378, respectively, both P<0.05), and CD8⁺was positively correlated with viral load (r=0.356, P<0.05). When the HIV RNA level was≤10⁵ CPs/ml, there was no correlation between the HIV RNA level and the expression levels of CD38, HLA-DR and PD-1 on CD8⁺T cells (all P>0.05). However, when the level of HIV RNA was>10⁵ CPs/ml, the level of HIV RNA was positively correlated with the expression levels of CD38, HLA-DR and PD-1 on CD8⁺T cells (r=0.412, 0.387, 0.395, respectively, all P<0.05). Conclusions: The activation levels of CD38 and HLA-DR and the expression of PD-1 on CD8⁺T cells in the peripheral blood of HIV/AIDS patients are increased. When the viral load is high, the HIV RNA viral load is positively correlated with the activation and exhaustion levels of CD8⁺T cells.