余 晓

血流感染可引起炎症激活、免疫抑制及器官功能损伤，患者转归不仅受病原体负荷影响，也与宿主免疫状态密切相关。程序性死亡受体1（PD-1）及其配体PD-L1主要参与适应性免疫抑制；Toll样受体9（TLR9）可识别病原体来源DNA及损伤相关DNA，并通过髓样分化因子88（MyD88）/核因子κB（NF-κB）介导先天炎症反应。两条信号轴作用层面不同，却可能共同参与感染过程中炎症与免疫抑制并存的免疫失衡。本文围绕其免疫学作用、潜在联系、外周血单个核细胞（PBMCs）检测基础及临床研究价值展开综述，并讨论其作为候选免疫标志物的证据边界。

血流感染；外周血单个核细胞；PD-1；PD-L1；TLR9；NF-κB

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