Cohort Study Of Clinical,histopathologic And Radiographic Features Of CD-related ARFS And TFA Intervention Of Intestinal Fibrosis In Crohn’s Disease

Background:Anorectal fibrostenosis(ARFS)is one of the most serious phenotypes of perianal Crohn’s disease(PCD).Many patients have to accept permanent bowel stoma to achieve clinical remission.What’s more,some patients may carry the complication of anorectal malignancy,severely affecting the quality of life and survival.Presently,the clinical studies of ARFS are mainly small-sample reports without systematic designs.Objective:To explore the clinical,histopathologic and rectal MRI features of patients with CD-related ARFS.Methods:We collected clinical,histopathologic and rectal MRI characteristics of ARFS patients at Affiliated Hospital of Nanjing University of Chinese Medicine from Jun 2016 to Apr 2023,which were evaluated by clinicians,pathologists and radiologists.Results:The prevalence of ARFS in this study was 12.5%(100/798).CD patients with perianal lesions developed ARFS in a shorter time without significantly difference(logrank=0.96).The prevalence of rectal malignancies in patients with ARFS was 5%(5/100).Compared with non-ARFS patients,ARFS patients were more likely to be female(49%vs 27.4%,P<0.001).Besides,they tended to have an older age of diagnosis(30.2±9.86 vs 27.4 ± 11.21,P=0.01 7)and a longer duration of CD disease(142 ± 62 vs 100 ± 53,P<0.001).More CD patients with ARFS had a history of intestinal surgery and enterostomy(41%vs 12.5%,P<0.001;16%vs 3.2%,P<0.001).Montreal classification B2/3(94%vs 33.8%,P<0.001)and L2/3(91%vs 77.9%,P<0.001)were more common in ARFS patients.Similarly,Wexner score was significantly increased in ARFS patients(4.24±5.6 vs 0.26±1.3,P<0.001).In addition,more patients with ARFS were treated with glucocorticoids(36%vs 17.3%,P<0.001),azathioprine(42%vs 28.7%,P=0.007)and ulinumab(30%vs 13.5%,P<0.001).ARFS patients were with less severe inflammatory activity,but with poorer nutritional status than non-ARFS patients.In the ARFS group,WBC(5.5±2 vs 7±3,P<0.001),RBC(4.3±0.6 vs 4.5±0.7,P=0.005),NC(3.8±2.1 vs 4.7±2.6,P<0.001),LC(1.1±0.5 vs 1.5±0.6,P<0.001),Hb(116.5±23.2 vs 122.4±20.8,P=0.009),Hct(36±6 vs 37.9±5.7,P=0.001),CRP(17.3±24.5 vs 23.6±30.5,P=0.02)and BMI index(19.76±3.21 vs 20.72±3.44,P=0.009)were significantly lower than those in the non-ARFS group.Compared with non-ARFS patients,there was a significant increase of perianal non-fistula lesions in ARFS patients.The specific manifestations including perianal skin tags(27%vs 13.2%,P<0.001),internal hemorrhoids(12%vs 4.4%,P=0.002),vulvar metastatic CD(6%vs 0.2%,P<0.001),rectovaginal fistula(8%vs 3.1%,P=0.02)and proctitis(27%vs 13.2%,P=0.008)were significantly higher than those in the non-ARFS group.SHAP importance score was used to predict the risk factors of ARFS formation.The results showed that Montreal B(SHAP value=0.0662),Wexner score(SHAP value=0.0469),total perianal lesions(SHAP value=0.0169),CD disease duration(SHAP value=0.0169),perianal lesions(SHAP value=0.0145),LC(SHAP value=0.0143),proctitis(SHAP value=0.0141),WBC(SHAP value=0.0137),CD-related intestinal surgery history(SHAP value=0.0103),the number of perianal operations(SHAP value=0.01),NC(SHAP value=0.0091),perianal skin tags(SHAP value=0.0089),Montreal L(SHAP value=0.0085)and Hct(SHAP value=0.0078)were risk factors,and the effects on ARFS were gradually decreased.What’s more,we found that the use of ulinumab(SHAP value=0.0068)also had an effect on the formation of ARFS with the lowest impact value.Kaplan-Meier analysis found that the cumulative incidence of ARFS was higher in women(P<0.0001).CD patients with Montreal L(P<0.001),gastrointestinal surgery history(P<0.0001)and enterostomy(P<0.0001)had a higher cumulative incidence of ARFS.Besides,CD patients treated with corticosteroids(P<0.0001),azathioprine(P=0.0022),and ulinumab(P=0.0006)also had a higher cumulative incidence of ARFS.Rectal MRI and histopathological analysis were performed in 45 cases with ARFS.Among the rectal MRI parameters,36 cases(80%)were accompanied by mucosal ulceration,35 cases(77.8%)were accompanied by intestinal wall edema,5 cases(11%)were stratified enhancement,6 cases(13%)were homogeneous enhancement,and 12 cases(27%)were mucosal enhancement.The mean intestinal wall thickness was 13mm,the mean T1 ratio was 2.6,the mean ADC was 1.3*10^-3mm2/s,and the Clermont mean score was 64.4.In conclusion,the rectal MRI features of ARFS showed significant thickening of the intestinal wall,as well as,accompanied by mucosal ulcers,intestinal wall edema,and varying degrees of enhancement.The results of pathological score showed that 33 patients(73%)had moderate-severe mucositis,28 patients(62%)had moderate-severe submucositis,37 patients(82%)had moderate-severe interstitial fibrosis,and 22 patients(49%)had moderate-severe fibrous components.The pathological characteristics of ARFS were the coexistence of inflammation and fibrosis,while fibrosis was more obvious.Bowel wall edema was significantly associated with pathologic inflammation scores in rectal MRI(P=0.036).Mucosal ulcers were significantly associated with interstitial fibrostenosis scores(P=0.044).However,maximal intestinal wall thickness,ADC,T1 ratio and Clermont score were not significantly associated with pathological inflammation and fibrosis scores.Conclusions:Clinical data,pathological information and rectal MRI features are reliable predictors of ARFS in Crohn’s disesase.Background: Patients with CD accepted bowel surgeries mainly because of intestinal fibrostenosis.Frustratingly,numerous clinical studies have demonstrated that major therapeutic agents preventing intestinal inflammation couldn’t effectively suppress the progression of intestinal fibrosis.Some related studies have found that TFA could significantly inhibit the release of intestinal inflammatory cytokines and improve survival in TNBS-induced CD models,which could effectively improve intestinal inflammation and fibrosis.However,the mechanism of TFA treating the CD-related intestinal fibrosis is still unknown.Objective: To investigate the key biomakers and to elucidate the mechanism of TFA curing CD-related intestinal fibrosis.Methods: To evaluate changes of intestinal microbiota and metabolites in TNBS-induced CD models with the intervention of TFA,by the technique of LC-MS and 16S rDNA analyses.Results:Based on LC-MS,common differential metabolites including PC(18:1(9Z)/19;1(9Z)),Itaconic acid,PS(17:0/19:1(9Z))and gamma-Glutamylisoleucine were detected as potential biomarkers of TFA intervening in intestinal fibrosis in TNBS-induced CD models.By the enrichment analysis of metabolic pathways,we found that itaconic acid may affect the metabolic process of CD intestinal fibrosis through C5-Branched dibasic acid metabolism.Subsequently,we detected that the expression of itaconic acid and IRG1 was significantly higher in the colon tissues of TNBS-induced mice,and significantly decreased after TFA intervention.It was found that IRG1 was highly expressed in the inflammatory cell models.Based on 16 s rDNA,we concluded that odoribacter,ruminiclostridium,A2,lactococcus,intestinimonas and butyricicoccus may participate in the TFA intervening in TNBS-induced intestinal fibrosis,and may play an active therapeutic or prophylactic role.By the analysis of the relationship between intestinal common differential metabolites and intestinal differential microbiota,we found that changes in intestinal microbiota could affect intestinal metabolism,whereas TFA could improve inflammation and fibrosis of CD intestine through specific enteric microbiota.Conclusions: We preliminatively found that TFA may reduce CD-related intestinal inflammation and fibrosis by affecting itaconic acid and specific intestinal flora,but the relevant mechanism remained further researches.