摘要Background:Post-cardiac arrest syndrome involves systemic inflammation,which causes subsequent neurological impairments.We investigated the influence of targeted temperature management(TTM)therapy in patients with out-of-hospital cardiac arrest(OHCA)after retum of spontaneous circulation(ROSC)by observing the changes in circulating CD14+ monocytes and the expression of human leuko-cyte antigen D-related(HLA-DR)and programmed cell death ligand 1(PD-L1)in CD14+ monocytes.Methods:Adult patients admitted to the emergency department of Beijing Chao-Yang Hospital after OHCA between January 2017 and March 2018 were included in this study.Thirty control subjects,10 patients with OHCA,and 37 patients with OHCA who received 72 hours of TTM therapy were enrolled.Peripheral blood samples of patients in the OHCA and TTM groups were collected on Days 1 and 3(D1 and D3)after ROSC and evaluated for HLA-DR and PD-L1 expression on CD14+ monocytes using flow cytometry.Results:Compared with control subjects,the percentage of circulating CD14+ monocytes,HLA-DR+/CD14+monocyte ratios,and mean fluorescence intensity were significantly decreased in patients with OHCA.After ROSC,HLA-DR expression in CD14+monocytes in the TTM group was lower than that in patients with OHCA.However,there were no significant differences in the percentage of PD-L1+/CD14+ monocytes or the mean fluorescence intensity between patients with OHCA and healthy volunteers.Conclusion:After ROSC,circulating CD14+ monocytes and HLA-DR+/CD14+ monocyte ratios decreased significantly in patients with OHCA.Human leukocyte antigen D-related expression in CD14+ monocytes was lower in patients treated with TTM.