Development Of Early Warning Model Of Sepsis And B Lymphocyte Immune Targeted Therapy And Its Mechanism

Objective:Sepsis is an important cause of high incidence rate and mortality in intensive care unit.Early diagnosis and timely treatment are important means to reduce the damage of sepsis.This study intends to build an early warning model of sepsis,early identify the high-risk population of sepsis,then interference targeting the early immune overreaction of sepsis,and study the corresponding change mechanism,in order to provide a new strategy for the early diagnosis and immune targeted treatment of sepsis.Methods:1.The establishment of an early warning mode of sepsis: screening the high-risk factors of sepsis based on the Least Absolute Shrinkage and Selection Operator(LASSO),use the multivariate regression analysis model to clarify the independent risk factors of sepsis,further construct the early warning model,and establish the sepsis early warning scoring system.C-index was used to evaluate the predictive ability of the warning model,and the calibration chart was used to modify the model.By analyzing the nomogram decision curve,the relationship between the net benefit of the model and the threshold probability is determined,the clinical practicability of the model is clarified,and the prediction ability of the model is verified by internal data sampling.2.Target immunotherapy and its mechanism: we have found that the B lymphocyte and T lymphocyte attenuators(BTLA)is closely related to the prognosis of sepsis.Combined with existing studies,we put forward a scientific hypothesis:upregulating the expression level of BTLA could reduce the mortality of sepsis.Then it was verified.Firstly,the In-cell Western method was used to screen drugs that can promote the expression of BTLA from the commercial inhibitor drug library,and an animal model of sepsis was constructed to verify the protective effect of inhibitors on sepsis.Then,cytokines involved in the regulation of early inhibitors were screened by cytokine protein chip and liquid chip,and verified by quantitative real-time PCR in animals and cells.The changes of lymphocytes involved in immune regulation in sepsis patients and animal models were analyzed by flow cytometry.Finally,by analyzing the changes of cytokines and lymphocytes,we speculate the possible mechanism of inhibitor targeted regulation of early hyperimmune response in sepsis.Results:1.Three independent risk factors of prothrombin time > 15 s,antithrombin III activity > 80(%)and D-dimer > 1mg/L were screened by the LASSO and multivariate logistic regression.2The independent risk factors were combined to construct the early warning model of sepsis.According to the nomogram of the model,it was found that the higher the prediction score of the model,the higher the incidence of sepsis.The C-index in the early prediction model is 0.85(95% Cl: 0.81-0.90),and the C-index in the validation data set is 0.85(95% Cl: 0.81-0.90),which has good prediction ability.The calibration chart shows that the prediction performance of the prediction model is excellent.Decision curve analysis showed that the model had strong clinical applicability when the probability threshold of sepsis was between15% and 87%.2.The screening of inhibitor drug library found that the Platelet-derived growth factor receptor(PDGFR)signal pathway inhibitor CP-673451 significantly up-regulated the expression of BTLA,and had a significant protective effect on organ injury and mortality in cecal ligation and puncture model.Cytokine chip detection and verification showed that CP-673451 could inhibit CXCL13,CCL1,CCL2,CCL7,IL-1β And IL-10 release.Flow cytometry analysis also showed that the proportion of B lymphocytes in patients with sepsis and animal models increased,and CP-673451 treatment could reduce the proportion of B lymphocytes in peripheral blood of animal models.Conclusions:Based on the analysis of clinical data,this study screened out three risk factors closely related to the occurrence of sepsis.The risk factors were combined to build an early warning model and scoring system for sepsis.Early treatment with PDGFR signaling pathway inhibitor after early identification of high-risk groups of sepsis,and inhibition of chemokine CXCL13,CCL1,CCL2 and CCL7 release to reduce the chemotaxis of B and T lymphocytes in peripheral blood and important organs,and then reduce the pro-inflammatory factor IL-1β and anti-inflammatory factor IL-10 produced by lymphocytes.Which can inhibit excessive pro-inflammatory and anti-inflammatory activation,reduce early excessive immune inflammatory response,diminished organs damage,and then reduce mortality.