B And T Lymphocyte Attenuator Expression On CD4+T Cells And Monocyte Programmed Death Ligand-1 Expression Associate With The Severity And Mortality Of Septic Patients

Objective: B and T lymphocyte attenuator(BTLA) is an inhibitory receptor, whose primary role in CD4+ T cell is thought to inhibit cytokine production. We explore BTLA expression on CD4+ T cells in healthy controls and septic patients, and assess the correlation of BTLA expression on CD4+ T cells in the early stage of sepsis with the severity and mortality of septic patients in the emergency department(ED).Methods: Between May 2014 and February 2015, consecutive patients who fulfilled the systemic inflammatory response syndrome(SIRS) criteria defined by the American College of Chest Physicians/Society of Critical Care Medicine(ACCP/SCCM) were enrolled. Fifty healthy individuals comprised the age-matched control group from volunteers in Physical examination center of Beijing Chao-yang Hospital. According to ACCP/SCCM criteria, patients were classified at the time of enrollment as having sterile SIRS, sepsis, severe sepsis, or septic shock, Subject data, name, age, sex, past medical history and vital signs were recorded immediately at enrollment. Some correlative laboratory examinations were carried out and recorded within 24 hours. Samples of peripheral blood were collected in ethylenediamine tetraaccetic acid(EDTA) anticoagulant tubes. The samples were transported to the laboratory at 4℃ within 1 h. Erythrocytes were lysed and cells were stained by researcher who was blinded to the clinical data. PCT was measured using an immunoassay analyzer at bedside. All enrolled patients were recorded all-cause mortalities at 28-day follow-up. All data were analyzed using SPSS 19.0 software. Non-normally distributed data, were expressed as the median(25th to 75 th percentile). Kruskal–Wallis one-way analysis of variance was applied for multi-group comparisons, and two-group comparisons were performed using the Mann–Whitney U test. To compare the prediction of biomarkers for 28-day mortality, receiver operating characteristic(ROC) curves were constructed and the areas under the ROC curves(AUCs) were determined. Binary logistic regression analysis was applied to determine the independent predictors of 28-day mortality.Results: BTLA/CD4+T was skewed distributed data and were showed in 25-75 significantly reduced in severe sepsis and septic shock than in healthy controls(all P < 0.01), and was obviously reduced in septic shock than in severe sepsis(P < 0.01). The AUC of percentage and MFI of BTLA+/CD4+ T cells for predicting 28-day mortality were 0.693 and 0.653, which was not statistically different compared with the MEDS score(0.743) or PCT(0.726). The percentage of BTLA+/CD4+T cells was lower in non-survivors compared with survivors. Similar results were obtained when expressed as MFI of BTLA on CD4+ T cells. n multivariate analysis, logistic regression model was adjusted for age, gender, WBC, ALC, PCT concentrations, the MEDS score, the percentage of BTLA+/CD4+T cells, and MFI of BTLA on CD4+ T cells to determine the relationship of 28-day mortality in septic patients. Using multivariate logistic regression analysis, the percentage of BTLA+/CD4+T cells(OR = 0.869, 95%CI 0.769 – 0.981, P = 0.023) is associated with the 28-day mortality. percentages. On admission, the level of the percentage of BTLA/CD4+T were 90.3%(85.6%-91.9%)in 50 healthy controls, 91.3%(89.0%-93.2%)in 59 SIRS patients, 88.4%(81.9%-91.3%)in 93 sepsis patients,86.5%(78.6%-90.1%)in 63 severe patients, 79.5%( 63.6%-86.6%) in 63 septic shock patients. The MFI of BTLA/CD4+T in five group(healthy control, SIRS, sepsis, severe sepsis and septic shock) were 7.2(6.0-8.1), 10.2(8.7-13.3), 8.7(7.0-11.0), 7.6(6.2-8.9) and 6.5(4.9-8.7). Interestingly, we observed that the percentage of BTLA+/CD4+T cells wasConclusion: In conclusion, our study shows that the percentage of BTLA+/CD4+ T cells was high in healthy volunteers. Furthermore, lower percentage of BTLA+/CD4+ T cells during the early stage of sepsis is associated with the severity and the mortality of septic patients.Introduction: Septic shock is a major healthcare problem with a high mortality rate, which might be caused by immunosuppression. Programmed cell death receptor-1(PD-1) and programmed cell death receptor ligand-1(PD-L1) which are co-inhibitory receptor molecules participate in sepsis-induced immunosupression. In this study we investigated which PD-1 related molecules can be used to evaluate the risk stratification and prognosis of septic patients. Furthermore, we explored the prognostic significance of a combination of ideal predictors and conventional clinical risk parameters in septic shock patients.Methods: Between June 2014 and September 2015, consecutive patients who fulfilled the systemic inflammatory response syndrome(SIRS) criteria defined by the American College of Chest Physicians/Society of Critical Care Medicine(ACCP/SCCM) were enrolled. Twenty-nine healthy individuals comprised the age-matched control group from volunteers in Physical examination center of Beijing Chao-yang Hospital. According to ACCP/SCCM criteria, patients were classified at the time of enrollment as having sterile sepsis or septic shock, Subject data, name, age, sex, past medical history and vital signs were recorded immediately at enrollment. Some correlative laboratory examinations were carried out and recorded within 24 hours. Samples of peripheral blood were collected in ethylenediamine tetraaccetic acid(EDTA) anticoagulant tubes. The samples were transported to the laboratory at 4℃ within 1 h. Erythrocytes were lysed and cells were stained by researcher who was blinded to the clinical data. PCT was measured using an immunoassay analyzer at bedside. All enrolled patients were recorded all-cause mortalities at 28-day follow-up. All data were analyzed using SPSS 19.0 software. Non-normally distributed data, were expressed as the median(25th to 75 th percentile).Kruskal–Wallis one-way analysis of variance was applied for multi-group comparisons, and two-group comparisons were performed using the Mann–Whitney U test. To compare the prediction of biomarkers for 28-day mortality, receiver operating characteristic(ROC) curves were constructed and the areas under the ROC curves(AUCs) were determined. Binary logistic regression analysis was applied to determine the independent predictors of 28-day mortality.easured on circulating CD4+ T cells, CD8+ T cells and monocytes(PD-L1 only) by flow cytometry.Results: The percentage of PD-L1/CD14, PD-1/CD4+T cells, PD-1/CD8+T cells, PD-L1/CD4+T cells and PD-L1/CD8+T cells in healthy control were 12.9%(10.4%-15.3%), 26.2%(23.2%-29.9%), 22.6%(18.7%-28.2%), 18.2%(12.3%-22.6%) and 22.6%(17.1%-26.2%). The percentage of PD-L1/CD14, PD-1/CD4+T cells, PD-1/CD8+T cells, PD-L1/CD4+T cells and PD-L1/CD8+T cells in sepsis were 29.2%(12.1%-43.9%), 34.1%(28.4%-44.4%), 31.6%(23.9%-46.6%), 21.5%(16.5%-30.5%) and 18.8%(14.9%-37.6%). The percentage of PD-L1/CD14, PD-1/CD4+T cells, PD-1/CD8+T cells, PD-L1/CD4+T cells and PD-L1/CD8+T cells in septic shock were 35.9%(20.4%-54.7%), 38.2%(29.2%-47.7%), 36.5%(27.3%-51.3%), 21.0%(9.3%-30.6%) and 19.5%(10.3%-37.4%). Only monocytes PD-L1 expression was valuable for risk stratification. According to the 28-day mortality, septic shock patients were classified into survivors and non-survivors. The percentage of PD-L1/CD14, PD-1/CD4+T cells, PD-1/CD8+T cells, PD-L1/CD4+T cells and PD-L1/CD8+T cells in survivors were 28.9%(17.9%-43.6%), 35.1%(28.5%-44.8%), 33.0%(24.8%-44.3%), 16.4%(8.6%-28.4%) and 23.2%(10.8%-38.9%). The percentage of PD-L1/CD14, PD-1/CD4+T cells, PD-1/CD8+T cells, PD-L1/CD4+T cells and PD-L1/CD8+T cells in non-survivors were 53.9%(31.8%-72.9%), 42.9%(34.9%-49.0%), 47.1%(30.3%-53.9%), 22.1%(12.0%-34.0%) and 12.9%(9.9%-32.5%). We also found that only monocytes PD-L1 expression was associated with mortality. The AUC of percentage of PD-L1/CD14 cells for predicting 28-day mortality were 0.729, which was statistically different compared with the SAPS II score or SOFA score. The cut-off value of PD-L1/CD14 cells for predicting 28-day mortality was 44.2%. Using multivariate logistic regression analysis, the percentage of PD-L1/CD14 is associated with the 28-day mortality. Area under the receiver operating characteristic curve(AUC) analysis of the combination of monocyte PD-L1 expression and conventional clinical risk parameters indicated a more significant prognostic ability than analysis of each parameter alone.Conclusion: Our study demonstrated that among PD-1 related molecules, only monocytes PD-L1 expression was valuable for the risk stratification of septic patients. Furthermore, measurement of monocytes PD-L1 expression was promising independent prognostic marker for septic shock patients. In summary, there was certain clinical value for PD-L1/CD14 expression in diagnosis of sepsis, risk stratification, assessment of prognosis in septic patients in emergeny department.