The Role Of The PD-1 Expression Of The T Cells On The Prognosis Of Septic Patients

Objective:To investigate the value of PD-1 expression on the T cells in predicting the prognosis of septic patients.Methods:From September 2017 to May 2019,septic patients were included in 6 Department of Intensive Care Unit(Zhejiang Hospital,Zhejiang People’s Hospital,Second Affiliated Hospital of Zhejiang University of medicine,Zhejiang Tongde Hospital,Hangzhou First People’s Hospital and Zhejiang Traditional Chinese Medicine Hospital).Patients were divided into survivors and non-survivors according to whether they survived at 28 days.Record patient basic data and clinical information,collect blood samples and the PD-1 expression on the T cells and serum IL-2 were measured.Compare the baseline characteristics,inflammatory biomarkers,Lac,biochemical indicators,blood coagulation function and PD-1 expression on T cells between the two groups.Spearman analysis was performed to observe the correlation between the percentage of PD-1+/T cells and the general data of patients.Logistic regression was conducted to analyze independent risk factor related to death within 28 days,and ROC analysis was conducted to observe the predictive value of PD-1 expression on T cells on the prognosis of septic patients.Results:A total of 64 septic patients were enrolled to this study,including 32 survivors and 32 non-survivors.There was no significant difference in baseline characteristics,inflammatory index,lactic acid,biochemical index and coagulation function between the two groups(p>0.05).There was no significant tendency in serum IL-2 concentration in septic patients within 1 week,and there was no statistically significant difference between the survivors and the non-survivors(p>0.05).The PD-1 expression on the T cells in the death group was significantly higher than that in the survival group(p<0.05).Spearman analysis showed that the percentage of PD-1+/CD3+T cells and the percentage of PD-1+/CD4+T cells were positively correlated with PCT(r=0.261,p=0.037;r=0.375,p=0.003),Logistic regression analysis showed that the PD-1 expression on the T cells was an independent risk factor for the death of sepsis patients.ROC analysis showed that the PD-1 expression on the T cells had a good predictive ability for the 28-day mortality of septic patients,among which the PD-1+/T cell percentage on the third day had the highest predictive value[The cut-off value of PD-1+/CD3+T cells was 3.63%(AUC:0.842,sensitivity:96.43%,specificity:59.38%,p<0.0001).The cut-off value of PD-1+/CD4+T cells was 4.65%(AUC 0.847,sensitivity 96.43%,specificity:62.50%,p<0.0001).The cut-off value of PD-1+/CD8+T cells was 3.91%(AUC 0.771,sensitivity 64.29%,specificity 81.25%,p=0.0003)].Conclusion:The PD-1 expression on the T cells in the death group of the septic patients was higher than that in the survival group.The PD-1 expression on the T cells was an independent risk factor for the death of septic patients,and has a prediction value for 28-day mortality of the septic patients.Furthermore,combination of PD-1 expression on the CD3+T cells,CD4+T cells and CD8+T cells could improve the predictive value of prognosis.