Relation Between Intestinal Barrier Function Markers And Disease Activity In Crohn’s Disease

ObjectiveCrohn’s disease(CD)is a chronic inflammatory disease that affects the gastrointestinal tract and is characterized by recurrent episodes.At present,the pathogenesis of CD has not been clarified,and environmental factors,genetic factors,intestinal microecology and immune factors are believed to be related to the occurrence of the disease.CD is characterized by the destruction of the integrity of the intestinal barrier,the increase of intestinal permeability,the imbalance of intestinal flora homeostasis,and the abnormal mucosal immune system.At present,the disease activity of CD is mainly evaluated by biomarkers,endoscopy and imaging.Endoscopy and imaging are invasive,radioactive,poorly accepted by patients,and limited in clinical application.Therefore,the exploration of convenient and sensitive biological markers to evaluate the disease activity and recurrence of CD is a hot spot in clinical research.infliximab(IFX),a kind of monoclonal antibody against tumor necrosis factor(TNF-α),serves as the main therapeutic agent for CD,which has been used extensively and for the longest time in clinic.The therapeutic effect of CD and the risk of recurrence are closely related to IFX drug valley concentration,so it is very important to monitor IFX drug valley level.Chapter I Our study found that intestinal barrier function markers(D-LA and DAO levels)were closely correlated with disease activity of CD.This study further analyzed whether intestinal barrier function markers were correlated with IFX drug trough levels in peripheral blood of patients with CD,and evaluated whether intestinal barrier function markers could be used to predict IFX drug trough levels.Methods1.Research objectExperiment ① From November 2021 to June 2022,98 patients with CD were hospitalized in a large Grade Ⅲ hospital in Jiangsu Province and met the inclusion criteria,40 healthy physical examination subjects were hospitalized in the physical examination center of the hospital during the same period,and 40 patients with inflammatory colon polyps were hospitalized during the same period.Clinical data of patients were collected and 5ml of fasting venous blood was collected.After centrifugation,plasma was frozen and stored for later use.Experiment ② Thirty-one patients with CD who met the inclusion criteria were screened out.5ml of fasting venous blood before IFX treatment was collected,and plasma was collected by centrifugation for later use.2.Experimental methodsIntestinal mucosal barrier function detection indicators:D-LA level was detected by Dlactic acid(D-LA)colorimetric test box,DAO level was detected by human diamine oxidase(DAO)enzyme-linked immunosorbent assay(ELISA)kit.Infliximab enzyme-linked immunoassay(ELISA)kit was used to detect IFX-TLs.The examination center of a Top three hospital in Jiangsu Province completed the following examinations:the FC level was detected by ELISA,the CRP level was determined by immunoturbidimetry,and the ESR level was determined by Weil method.3.Experimental group① The patients with CD were divided into remission group according to CDAI score:CDAI score<150;Activity group:CDAI score 150-450;Inflammatory polyp control group:patients with pathological evidence of inflammatory colon polyp;Healthy control group:the same period of the hospital physical examination center physical examination subjects.②According to the valley value of IFX drugs,they were divided into low valley concentration group(IFX-TLS<3μg/ml)and standard valley concentration group(IFX-TLS≥3μg/ml).4.Statistical methodsThe difference of the general clinical data among the groups was compared,and the prediction of the intestinal mucosal barrier function markers on the disease activity and endoscopic activity of CD was compared by ROC curve.Logistic regression analysis was used to analyze the influencing factors of IFX drug valley level.ROC curve was used to compare the predictive value of DAO to IFX drug trough level.ResultsChapter One1.Plasma D-LA level and DAO level were significantly increased in CD activity group compared with remission group(t was 7.55 and 4.76,respectively,P<0.001);There were no significant differences in plasma D-LA and DAO levels between the remission group and the inflammatory polyp group and the healthy control group(P>0.05).2.Pearson and Spearman correlation analysis showed that plasma D-LA and DAO levels were positively correlated with disease activity scores in CD patients(P<0.05),and the correlation degree was higher than CRP and ESR levels.3.Pearson and Spearman correlation analysis showed that DAO,D-LA and endoscopic score of Crohn’s disease severity(SES-CD score)were correlated with SES-CD.DAO,D-LA,CRP,ESR and FC were correlated with SES-CD.However,DAO and FC had better correlation(r 0.51 and 0.36,respectively;P<0.0001 for both).4.Spearman correlation analysis showed that plasma D-LA and DAO levels were correlated with FC levels in patients with CD(P<0.05),but there was no significant correlation with CRP,ESR and Hb levels(P>0.05).5.According to ROC curve,D-LA and DAO in plasma of patients had good predictive value for disease activity of CD(P<0.05):When D-LA was 2.46 mmol/L,the sensitivity and specificity for diagnosis of disease activity were 67%and 91.6%,respectively.With a DAO of 25.23ng/ml,the sensitivity and specificity for diagnosing disease activity were 74%and 81.3%,respectively.Chapter Two1.Compared with the standard group,D-LA,DAO and other experimental indexes in the low concentration group were significantly increased,with statistical differences(all P<0.05).2.Spearman correlation analysis showed that IFX-TLs was negatively correlated with DAO,IL-6 and ESR.3.Binary Logistic regression analysis showed that DAO was an independent predictor of IFXTLs<3μg/ml in the low-concentration group of patients with CD.DAO was a risk factor for IFX-TLs<3μg/ml in the low concentration group of CD patients,that is,the higher the DAO level,the higher the possibility of patients detecting IFX-TLs<3μg/ml.4.ROC curve analysis results showed that when DAO>35ng/ml,IFX drug trough level<3μg/ml could be predicted during treatment.The area under the curve of DAO predicting IFX drug valley level was 0.575(P<0.05),and DAO had potential value in predicting IFX drug valley level<3μg/ml.Conclusion1.Intestinal barrier function indexes D-LA and DAO can reflect the degree of disease inflammation and disease activity of CD,which is consistent with FC,and has a good value in predicting disease activity.The combination of D-LA and DAO with other biomarkers may significantly improve the efficiency of disease diagnosis.Monitoring the level of intestinal mucosal barrier markers can assess disease activity and endoscopic manifestations of Crohn’s disease,indirectly reflecting the treatment effect of Crohn’s disease.2.Intestinal barrier function indicators are helpful to evaluate IFX-TLS and therapeutic effect in patients with CD during IFX treatment.