The Changes Of Neutrophil Apoptosis And Its Mechanism In Sepsis

and to observe the relationships between them.Method:45 cases were divided into three groups:septic patients group(N=30); non-septic patients group(N=10);healthy controls(N=5).According to APACHEⅡscores, the septic patients were divided into two sub-groups:APACHEⅡ＜12 group(N=20); APACHEⅡ≥12 group(N=10).After two weeks,the septic patients were then also divided into survival group(N=22) and death group(N=8).Blood samples were collected within 24hs after diagnosis of sepsis.Polymorphonuclear neutrophils were separated from the heparinized blood,and then the apoptosis rate of PMNs was measured by flow cytometric techniques.Serum levels of IL-1β,IL-10,TNF-α,and sFas were measured by enzyme-linked immunosorbent assay(ELISA).The relationship was analysed between the apoptosis rate of PMNs and serum levels of IL-1β,IL-10,TNF-α,sFas,and prognosis.Statistical analysis:All the data was analysed by SPSS 11.5 software,and was expressed and plotted as means±standard deviation;the differences between two patient groups were analysed using independent-samples T test or nonparametric test based on the peculiarity of the data,and between more than two groups were analysed using nonparametric test.Spearman's rank correlation coefficient was caculated to assess the association between PMN apoptosis rate and IL-1β,IL-10,TNF-α,sFas.The criterion for significance was set at p＜0.05.Results:The apoptosis rate of PMNs in APACHEⅡ≥12 group(N=10) was significantly decreased compared to APACHEⅡ＜12 group(N=20)(p＜0.01) The "apoptosis rate in septic patients(N=30) was significantly lowered than non-septic patients group(N=10) (p＜0.01) and healthy control group(N=5)(p＜0.01).Compared to healthy group,the serum levels of pro-inflammatory cytokines(IL-1β,TNF-α) in the septic patients(N=30) (p＜0.01)and non-septic patients(N=10)(p＜0.01)were significantly higher.The difference of apoptosis rate between survival group(N=22) and death group(N=8) had no significance. Apoptosis rate of PMNs was negatively correlated with serum concentration of sFas(p＜0.05),however was irrelevant to IL-1β,IL-10,and TNF-αconcentration.Conclusion:PMN apoptosis rate is decreased in sepsis,and is related to the severity. The increased sFas level in septic patients' serum may take some part in PMN apoptosis. The decreased PMN apoptosis is independent to some single inflammatory mediator such as IL-1β,IL-10,and TNF-α,and PMN apoptosis can't predict septic patients prognosis.