[PD-1 is associated with CD8(+)T lymphocyte dysfunction in patients with acute and chronic liver failure]

Objective: To explore whether peripheral blood CD8(+)T lymphocyte dysfunction is correlated with the programmed death receptor-1 (PD-1) expression in patients with acute-on-chronic liver failure (HBV-ACLF). Methods: Peripheral blood mononuclear cells (PBMC) were collected from patients with HBV-ACLF and healthy controls. CD8(+)T lymphocytes number and PD-1 expression condition in CD8(+)T lymphocytes were detected by flow cytometry. CD8(+)T lymphocytes isolated from peripheral blood of HBV-ACLF patients were further cultured in vitro. One group was added with PD-L1-IgG fusion protein (ACLF+PD-1 group), and the other group was added with IgG fusion protein (ACLF group). Proliferation ability (ki67), cell viability (CD69), and secretion ability of effector cytokines (IL-2, IFN-γ, TNF-α) were analyzed. Results: 30 cases with HBV-ACLF and healthy controls were enrolled. CD8(+)T lymphocytes absolute number was significantly lower in the peripheral blood of patients with ACLF group (333.88 ± 147.74)/μl than healthy controls (872.50 ± 206.64)/μl (P < 0.001). PD-1 expression in peripheral blood CD8(+)T lymphocytes were significantly increased in ACLF group (13.33% ± 2.52%), (P = 0.027) than healthy controls (7.02% ± 2.12%). In in vitro culture, compared with healthy controls, the peripheral blood CD8(+)T lymphocytes cell viability (CD69), proliferation ability (ki67) (all P ​​< 0.001), and the level of cytokine production (IL-2, IFN-γ, TNF-α) (all P < 0.05) were equally weakened in patients with ACLF group. Compared with ACLF group, CD8(+)T cell viability (CD69), proliferation ability (KI67) (all P < 0.05), and the level of cytokine production were weakened in ACLF+PD-1 group (all P < 0.05). Conclusion: HBV-ACLF patients have CD8(+)T lymphocyte dysfunction. Therefore, PD-1 may have correlation in the regulation of CD8(+)T lymphocyte dysfunction in ACLF patients.