Changes of PD-1/PD-L1 in peripheral blood in AIDS patients receiving highly active antiretroviral treatment for 24 weeks

Objective To discuss the changes in expression of programmed death-1(PD-1) and programmed cell death 1 ligand l(PD-L1) in AIDS patients receiving highly active antiretroviral treatment(HAART) for 24 weeks. Methods According to the CD4+T cell counts, 45 AIDS patients receiving HAART were divided into three groups(1-100 cells／l, 101-200 cells／l and 201-350 cells／l ), Peripheral blood samples were taken before HAART and at 24 weeks after HAART, PD-1/PD-L1 expressions on CD4+ T cells were assessed by flow cytometry, Plasma HIV RNA loads were determined by real-time fluorescent quantitative polymerase chain reaction(PCR). The data were analyzed with t test and Pearson correlation analysis. Results The PD-1 and PD-L1 expression levels on CD4+T cells in AIDS patients were(1.160.26)% and(0.630.140)% respectively before HAART, which were significantly higher those of healthy controls(t=6.31 and 4.27, all P0.01). The PD-1 and PD-L1 expressions levels were(0.760.14)% and(0.520.06)% 24 wwks later. The PD-l expression level declined significantly compared with that before HAART(t=3.77,P=0.000). The PD-L1 expression level declined too compared with that before HAART, but no statistically significance was found(t=1.78,P=0.056).The PD-1 expression level in patients with CD4+T cell count of 201-350 showed a remarkable decline than two other groups(38.54% vs. 25.66% and 23.77%) 24 weeks later, The decline rate of PD-L1 expression levels was greater than those of two groups(18.97% vs. 15.87% and 12.31%). The level of PD-1 expression was significantly negatively correlated with CD4+T cell count before HAART and 24 weeks later (r=-0.434 and-0.317;P0.01 or 0.05), and was significantly positively correlated with viral load before HAART and 24 weeks later(r=0.499 and 0.319, P0.01 or 0.05). The PD-L1 expression level was significantly negatively correlated with the CD4+T cell count before HAART and 24 weeks later(r=-0.454 and-0.314, P=0.002 and 0.012), and was significantly positively correlated with viral load before HAART and 24 weeks later(r=0.513 and 0.428, all P=0.000 and 0.004). Conclusion The expression levels of PD/PD-L1 were up-regulated in AIDS patients and associated with HIV disease progress