OBJECTIVETo analyze PD-1 expression in CD8 + T cell of Peripheral blood with HBV-associated acute-on-chronic liver failure and effect on CD8+ T cell.

METHODSWe selected 60 patients with HBV-ACLF and collected their peripheral blood. We analyzed the expressions of PD-1, CD95, perforin, granzyme A, granzyme B, CD107a on CD8+ T lymphocytes and the expression of PD-L1 on monocytes peripheral blood by using flow cytometry. 15 liver cirrhosis patients( LC) and 15 healthy individuals( HC) are control groups.

RESULTPD-1 expression was (1) The PD-1 expression in HBV-ACLF patients was significantly elevated compared with those in HC and lower in improved group than that in invalid group and death group (P < 0.05) and increased from prophase, metaphase to advanced stage (P < 0.05). Moreover, (2) PD-L1 expression on monocytes was positively correlated with disease progression. (P < 0.05). (3) Both PD-1 and CD95 expressions were higher in dead group than those in improved and non-improved groups. Perforin, granzymes and CD107a expressions on CD8+ T cells significantly increased in dead group compared with those in improved and non-improved groups (P < 0.05). However, PD-1 expressions on these cells were lower, compared with normal persons.

CONCLUSIONSThe expression of PD-1 and PD-L1 in HBV-ACLF patients was positively correlated with disease progression. The elevated PD-1 expression promoted apoptosis of CD8+ T cells. For HBV-ACLF patients, the PD-1 expression on effector CD8+ T cells was lower than those in other CD8+ T cells, which maybe accounted for the failure to controlling immune injury in liver.