Changes Of Dendritic Cells In Patients With Sepsis Under Abnormal Lymphocyte Status

ObjectiveTo investigate the changes of dendritic cells in sepsis patients with abnormal lymphocyte status.Methods1.A prospective observational cohort study was conducted.Critically ill patients admitted to ICU and emergency ICU who met the new diagnostic criteria of sepsis 3.0 were enrolled.Observation indicators on day 1:(1)APACHEⅡ and SOFA scores;(2)Expression rate of CD4+T cells,CD8+T cells,regulatory T cells,mHLA-DR,dendritic cells and their apoptosis in peripheral blood were detected by flow cytometry.(3)Plasma levels of TNF-α,IL-6,IL-10 and IL-12 p70 were evaluated by enzyme linked immunosorbent assay(ELISA).2.Primary cultured dendritic cells with clinically collected serum of sepsis patients,divided into control group,normal lymphocyte group and abnormal lymphocyte group.Supernatant levels of TNF-α,IL-6,IL-10 and IL-12 p70 were evaluated by ELISA.Expression rate of function and apoptosis of dendritic cells were detected by flow cytometry.Results1.APACHE Ⅱ score in abnormal lymphocyte group were significantly higher than those in normal lymphocyte group;blood lactic acid and urea nitrogen were significantly higher in abnormal lymphocyte group than in normal lymphocyte group,while blood lactic acid and urea nitrogen were independent risk factors for predicting death.2.The proportion of CD4+T lymphocytes and regulatory T cells in peripheral blood in abnormal lymphocyte group were significantly higher than those in normal lymphocyte group,while the proportion of CD8+T lymphocytes and mHLA-DR positive expression in abnormal lymphocyte group were lower than those in normal lymphocyte group.The proportion of regulatory T cells was independent risk factors for predicting sepsis death.About the cytokine secretion,serum IL-6 and IL-10 in abnormal lymphocyte group were significantly higher than those in normal lymphocyte group,while IL-12 p70 in abnormal lymphocyte group were significantly lower than those in normal lymphocyte group.TNF-α were no statistical difference in two groups.3.The proportion of dendritic cells in peripheral blood of sepsis patients generally decreased,while those in abnormal lymphocyte group were significantly lower than that of normal lymphocyte group.Although the proportion of early apoptosis and late apoptosis in dendritic cells were no statistical difference in two groups,the apoptosis of dendritic cells in normal lymphocyte group were mainly in the early stage,while that in the abnormal lymphocyte group were mainly in the late stage.4.There was no significant difference between the 28-day mortality and the 90day mortality in two groups.5.In vitro experiments,the positive expression of MHC Ⅱ and CD86 of dendritic cells in abnormal lymphocyte group were lower than those in normal lymphocyte group,while those in abnormal lymphocyte group were significantly higher than those in control group.About the cytokine secretion,TNF-α,IL-6 and IL-12 p70 in abnormal lymphocyte group were significantly lower than those in abnormal lymphocyte group,higher than control group,while IL-10 were significantly higher than those in normal lymphocyte group and control group.There were no statistical difference among each group in the proportion of early apoptosis in dendritic cells,while the proportion of late apoptosis in dendritic cells in the abnormal lymphocyte group were significantly lower than those in normal lymphocyte group and control group.Conclusion1.The lymphocyte subsets-of-sepsis patients with early abnormal lymphocytes were distributed as a decrease in the proportion of CD8+T cells,increased the proportion of CD4+T cells and Treg,decreased the level of HLA-DR expressed by monocytes,increased the secretion of TNF-α,IL-6 and IL-10,and reduced the secretion of IL-12 p70 in plasma.2.Early lymphocyte abnormalities in sepsis patients maybe can promote late apoptosis of dendritic cells,decrease the proportion of dendritic cells in peripheral blood,impair their functions,reduce the expression of its surface molecules and the secretion of TNF-α,IL-6 and IL-12 p70,but increase the secretion of IL-10.