Non-inflammatory Bowel Disease Research Articles

Fibrostricturing Crohn's Disease Is Marked by an Increase in Active Eosinophils in the Deeper Layers.

Approximately 50% of patients with Crohn's disease (CD) develop intestinal strictures necessitating surgery. The immune cell distribution in these strictures remains uncharacterized. We aimed to identify the immune cells in intestinal strictures of patients with CD. During ileocolonic resections, transmural sections of terminal ileum were sampled from 25 patients with CD and 10 non-inflammatory bowel disease controls. Macroscopically unaffected, fibrostenotic, and inflamed ileum was collected and analyzed for immune cell distribution (flow cytometry) and protein expression. Collagen deposition was assessed through a Masson Trichrome staining. Eosinophil and fibroblast colocalization was assessed through immunohistochemistry. The Masson Trichrome staining confirmed augmented collagen deposition in both the fibrotic and the inflamed regions, though with a significant increased collagen deposition in the fibrotic compared with inflamed tissue. Distinct Th1, Th2, regulatory T cells, dendritic cells, and monocytes were identified in fibrotic and inflamed CD ileum compared with unaffected ileum of patients with CD as non-inflammatory bowel disease controls. Only minor differences were observed between fibrotic and inflamed tissue, with more active eosinophils in fibrotic deeper layers and increased eosinophil cationic protein expression in inflamed deeper layers. Last, no differences in eosinophil and fibroblast colocalization were observed between the different regions. This study characterized immune cell distribution and protein expression in fibrotic and inflamed ileal tissue of patients with CD. Immunologic, proteomic, and histological data suggest inflammation and fibrosis are intertwined, with a large overlap between both tissue types. However strikingly, we did identify an increased presence of active eosinophils only in the fibrotic deeper layers, suggesting their potential role in fibrosis development.

Western diet reduces small intestinal intraepithelial lymphocytes via FXR-Interferon pathway

The prevalence of obesity in the United States has continued to increase over the past several decades. Understanding how diet-induced obesity modulates mucosal immunity is of clinical relevance. We previously showed that consumption of a high fat, high sugar “Western” diet (WD) reduces the density and function of small intestinal Paneth cells, a small intestinal epithelial cell type with innate immune function. We hypothesized that obesity could also result in repressed gut adaptive immunity. Using small intestinal intraepithelial lymphocytes (IEL) as a readout, we found that in non-inflammatory bowel disease (IBD) subjects, high body mass index correlated with reduced IEL density. We recapitulated this in wild type (WT) mice fed with WD. A 4-week WD consumption was able to reduce IEL but not splenic, blood, or bone marrow lymphocytes, and the effect was reversible after another 2 weeks of standard diet (SD) washout. Importantly, WD-associated IEL reduction was not dependent on the presence of gut microbiota, as WD-fed germ-free mice also showed IEL reduction. We further found that WD-mediated Farnesoid X Receptor (FXR) activation in the gut triggered IEL reduction, and this was partially mediated by intestinal phagocytes. Activated FXR signaling stimulated phagocytes to secrete type I IFN, and inhibition of either FXR or type I IFN signaling within the phagocytes prevented WD-mediated IEL loss. Therefore, WD consumption represses both innate and adaptive immunity in the gut. These findings have significant clinical implications in the understanding of how diet modulates mucosal immunity.

Increased CpG methylation at the CDH1 locus in inflamed ileal mucosa of patients with Crohn disease

BackgroundE-cadherin, a major actor of cell adhesion in the intestinal barrier, is encoded by the CDH1 gene associated with susceptibility to Crohn Disease (CD) and colorectal cancer. Since epigenetic mechanisms are suspected to contribute to the multifactorial pathogenesis of CD, we studied CpG methylation at the CDH1 locus. The methylation of the CpG island (CGI) and of the 1st enhancer, two critical regulatory positions, was quantified in surgical specimens of inflamed ileal mucosa and in peripheral blood mononuclear cells (PBMC) of 21 CD patients. Sixteen patients operated on for a non-inflammatory bowel disease, although not normal controls, provided a macroscopically normal ileal mucosa and PBMC for comparison.ResultsIn ileal mucosa, 19/21 (90%) CD patients vs 8/16 control patients (50%) (p < 0.01) had a methylated CDH1 promoter CGI. In PBMC, CD patients with methylated CGI were 11/21 (52%) vs 7/16 controls (44%), respectively. Methylation in the 1st enhancer of CDH1 was also higher in the CD group for each of the studied CpGs and for their average value (45 ± 17% in CD patients vs 36 ± 17% in controls; p < 0.001). Again, methylation was comparable in PBMC. Methylation of CGI and 1st enhancer were not correlated in mucosa or PBMC.ConclusionsMethylation of several CpGs at the CDH1 locus was increased in the inflamed ileal mucosa, not in the PBMC, of CD patients, suggesting the association of CDH1 methylation with ileal inflammation. Longitudinal studies will explore if this increased methylation is a risk marker for colorectal cancer.

WESTERN DIET DEPLETES SMALL INTESTINAL INTRAEPITHELIAL LYMPHOCYTES VIA FXR-INTERFERON PATHWAY

Abstract BACKGROUND The prevalence of obesity has continued to increase over the past several decades. Understanding how diet-induced obesity modulates mucosal immunity is of clinical relevance. We previously showed that consumption of a high fat, high sugar “Western” diet (WD) reduces the density and function of small intestinal Paneth cells, a small intestinal epithelial cell type with innate immune function. We hypothesized that obesity could also result in repressed adaptive immunity. METHODS Small intestine samples from non-inflammatory bowel disease (IBD) subjects who underwent resection were used for CD3 immunohistochemistry (IHC), and the CD3+ intraepithelial lymphocytes (IEL) densities were correlated with the patients’ body mass index (BMI). Mice were fed with either standard diet (SD) or WD for various durations, and IELs were isolated for flow cytometry analysis. RESULTS In non-IBD subjects, high BMI correlated with reduced IEL density. We recapitulated this in wild type (WT) mice fed with WD. A 4-week WD consumption was able to deplete IEL (including major subsets CD4+, CD8+, CD8α+8β-CD4+, and γδCD8+ T cells) but not splenic lymphocytes, and the effect was reversible after another 4 weeks of SD washout. ob/ob mice that spontaneously developed obesity while fed with SD did not show IEL depletion, suggesting that the quality, not the quantity of the diet is key to this phenotype. Importantly, WD-associated IEL depletion was not dependent on the presence of gut microbiota, as WD-fed germ-free mice also showed IEL depletion. We previously showed that a key molecular pathway activated by WD in the ileum is the FXR pathway. Phagocyte-specific Fxr conditional knockout (cKO) mice were protected from WD-mediated IEL depletion, suggesting that FXR activation in the phagocytes is critical in mediating this phenotype. Activated FXR signaling stimulated phagocytes to secrete type I interferon (IFN), and inhibition of type I IFN signaling within the phagocytes (type I IFN monoclonal antibody treatment and Stat1 cKO mice) prevented WD-mediated IEL loss. CONCLUSION WD consumption depletes IEL by a FXR-IFN pathway mediated by gut phagocytes. These findings have significant clinical implications in understanding the pathogenesis of gut inflammatory disorders such as IBD.

DOP38 A rare KRT17+ population emerges from the epithelium in the inflamed intestinal mucosa of patients with Ulcerative Colitis

Abstract Background KRT17 is an epithelial "alarmin" that contributes to the early host innate immune response to insults. We previously found that KRT17 transcription, not detectable in the healthy colon, is up-regulated in the intestinal mucosa of patients with active ulcerative colitis (UC). Here, we aimed to characterize the epithelial cells expressing KRT17 in UC mucosa and explore the contribution of the intestinal environment in promoting the emergence of this cell population. Methods We conducted single-cell RNAseq (scRNA-seq) on the epithelial compartment of intestinal biopsies from a cohort of non-inflammatory bowel disease (IBD) controls and patients with active UC. Analysis was performed using our own-curated pipeline in Seurat1. Spatial protein localization was analysed by immunofluorescence on fixed intestinal samples. To measure the modulation of KRT17 and associated markers, ex vivo air-liquid interface (ALI) epithelial cultures derived from human non-IBD organoids were used. The signatures of UC-derived organoids2 were mapped onto the scRNA-seq dataset. Results ScRNA-seq analysis identified a rare KRT17+ epithelial cell population emerging in active UC characterized by the expression of KRT17 (Fig. 1A) and other alarmins (KRT6A, KRT16, S100A8), metalloproteinases (MMP1, MMP10), and inflammatory markers (SAA1, DUOX2…). KRT17 protein, absent in non-IBD colon, was expressed in the epithelium of the inflamed UC mucosa exhibiting a patchy pattern, and marked epithelial clusters with both columnar and squamous-like morphology (Fig. 1B). The ALI culture closely recapitulated the differentiated intestinal epithelium in homeostasis by showing a columnar aspect, high expression of differentiation markers, and low or undetectable expression of stem/proliferation or KRT17+-cell markers. Exposure of the ALI culture to hypoxic stress (by re-submersion in expansion medium) induced the expression of KRT17+ cell-specific and inflammation markers (Fig. 1C), and the acquisition of a squamous morphology (Fig. 1D). IBD-related IFN-ɣ and IL-22 cytokines could not fully replicate this phenotype (Fig. 1E). Lastly, we observed that genes up-regulated in UC, compared to non-IBD organoids, were predominantly expressed within the KRT17+ population (Fig. 1F). Conclusion Our results suggest that a novel KRT17+ epithelial population may arise from the intestinal cells of inflamed UC mucosa under the influence of specific environmental factors. This population could contribute to the persistence of the disease over time.

Endoscopic features of non-IBD colitis

Background: Studies about the endoscopic aspect of non-inflammatory bowel disease (IBD) colitis are scarce. Aims and Objectives: The aim of this retrospective study was to describe the endoscopic appearance of non-IBD colitis (NIC) in an outpatient cohort. Materials and Methods: All cases of NIC, from 2018 to 2021, with a recent outpatient colonoscopy, were enrolled. Diagnosis was based on clinical, endoscopic, and histological characteristics, and follow-up ≥6 months to recognize misdiagnosed IBD because of mimic causes. Results: 158 patients (63 males, age 54 years±19) performed a colonoscopy with a final diagnosis of NIC associated with drug-exposition (74), food allergies (26), recent/active gastrointestinal infections (20), ischemic colitis (14), segmental colitis associated diverticulosis (SCAD) (10), obstructed defecation syndrome (ODS) (8) and microscopic colitis (6). Frequencies of endoscopic features and colon distribution were: Drug exposition (hyperemia, erosions/ulcers, 88%; right colon, 70%), recent infection (erosions, 60%; left colon/rectum, 88%), food allergies (red spots/erosions, 67%; all the colon), ischemic colitis (ulcers, 86%; right or left colon), SCAD (hyperemia/edema, 75%; always left colon), ODS (hyperemia, erosions, and loss of vascularity, 90%; always rectum), microscopic colitis (edema and hyperemia; all the colon). Conclusion: Drug-exposition is the most frequent cause of out-patient NIC. In an appropriate diagnostic context, red spots, hyperemia, and erosions are associated with drug expositions, recent infections, and food allergies. Ulcers are more frequent with ischemic colitis or drug-exposition.

A blood-based transcriptomic signature stratifies severe Crohn’s disease and defines potentially targetable therapeutic pathways

IntroductionDespite advances in medical therapy, many patients with Crohn’s disease (CD) ultimately require surgery for disease management. Identifying the underlying molecular pathways for subgroup stratification is critical to the improvement of prognostics and therapeutics and to biomarker discovery.MethodsWe purified CD3+ T cells from the paired blood and mucosa samples of 100 CD and 17 non-inflammatory bowel disease (IBD) subjects requiring surgery. Longitudinal samples (n = 49) were collected 4–13 months postoperatively.ResultsTranscriptional profiling at the time of surgery revealed two CD patient subgroups: the CD-PBT subgroup, which was clustered tightly with non-IBD subjects, and the CD-PBmu(cosal) subgroup, which shifted from peripheral toward a mucosal-like expression profile. The CD-PBmu subgroup was characterized by differential gene expression, elevated genetic transcriptional risk score (TRS), and a distinct T-cell subset composition associated with perianal-penetrating/stricturing disease, post-surgical recurrence, and immunoreactivity to multiple microbial antigens. CD-PBmu subtyping was validated in a CD cohort in whom anti-TNF therapy had been unsuccessful. The CD-PBmu subgroup, in contrast to the CD-PBT subgroup, was distinguished by decreased pro-inflammatory cytokine/chemokine and adhesion molecule expression postoperatively. For clinical translation, we identified a CD-PBmu 42-gene classifier associated with a TRS signature, clinical severity markers, and underlying protein kinase signaling pathways to identify therapeutic targets.DiscussionThe CD-PBmu signature holds potential for future investigation to improve accuracy in identifying a subset of patients with severe CD who may benefit from early initiation of therapeutics to defined molecular pathways.

Characteristics of the intestinal microbiota in patients with colorectal cancer

AIM: to study the intestinal microbiota and identify its characteristic features in patients with colorectal cancer.PATIENTS AND METHODS: in this study, the composition of the intestinal microbiota in patients with colorectal cancer was analyzed, while the comparison group consisted of patients with non-inflammatory bowel diseases.RESULTS: previous studies have shown the possible role of enterococci and some types of clostridia in stimulating oncogenic processes and, on the contrary, the vital role of lactobacilli and bifidobacteria in intestinal homeostasis maintaining. The aim of this study was to compare the gut microbiota composition in colorectal cancer patients and non-inflammatory bowel diseases patients gut microbita. The proportion of enterococci was increased in patients with colorectal cancer (12.7% in the study group and 7.6% in the control group) on the contrary the proportion of bifidobacteria and obligate anaerobes was decreased (1.5% in the study group and 4% in the control groups) and (3.3 % of the study group and 9.7% in the control group) respectively. Decrease of the microbiota biodiversity was observed for the patients with colorectal cancer that was calculated by the Shannon diversity Index (4.46 in the study group and 4.8 in the control group), also two-fold increase of Pseudomonas aeruginosa share (2.2% in the study group and 1.1% in the control group) was found for this cohort, Clostridium septicum was isolated only from patients with colorectal cancer.CONCLUSION: this study results suggest the diagnostic significance of the species diversity of the intestinal microbiota.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography, Part II: The Reliable Disclosure of Crohn's Disease and Non-Inflammatory Small Bowel Disorder Plot through MRI Findings.

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but a rigorous methodology for describing and interpreting the pathological findings is mandatory. Strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, strictures, and mesentery fat hypertrophy are all indicators of small bowel damage in inflammatory and non-inflammatory small bowel disease, and they are all commonly and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. Differential MRE appearance allows us to distinguish between Crohn's disease and non-inflammatory small bowel disorder. The purpose of this paper is to present the MRE pathological findings of small bowel disorder.

Differentiation of Active Ulcerative Colitis vs Noninflammatory Bowel Disease Proctitis by Transperineal Superb Microvascular Imaging.

Transabdominal ultrasonography and transperineal ultrasonography (TPUS) appear correspond to colonoscopy (CS) for evaluating ulcerative colitis (UC) activity, but their utility in UC diagnosis remains unclear. This research compared the accuracy of TPUS and CS for assessing rectal activity and differentiating noninflammatory bowel disease proctitis from UC in pediatric cases. The study is a blinded, prospective, and controlled trial. Prospectively, values of fecal calprotectin (FCP) and findings of the TPUS and CS were compared between child cases of UC and non-IBD proctitis. Findings of rectal wall thickening (RWT), rectal wall flow (RWF) on power Doppler, and microvascular signal at wall circumference (MSWC) on monochrome superb microvascular imaging assessed using TPUS were compared with the CS. Thirty patients with Mayo endoscopic subscore (MES) 0 to 1 UC, 57 with MES 2 to 3 UC, and 44 with proctitis were registered. Fecal calprotectin, RWF, and MSWC indicated significant differences among the groups (P < .05). Rectal wall thickening showed no significant difference between MES 0-1 and proctitis (P = .76). Rectal wall thickening and MSWC were independent predictors of endoscopic activity of UC, resulting in a sensitivity and specificity of 100% for RWT ≥4.5 mm and positive MSWC. Fecal calprotectin and RWF were independent predictors for differentiating MES 0 to 1 and proctitis, and FCP and RWT were independent predictors for differentiating MES 2 to 3 and proctitis. Sensitivity and specificity were 77.2% and 80.9%, respectively, for FCP >242.5 μg/g and RWF negative; and they were both 100% for RWT >4.1 mm and MSWC positive. Transperineal ultrasonography with mSMI may enable the evaluation of rectal activity and differentiation of UC from non-IBD proctitis with accuracy comparable to endoscopy.

P2X7 Receptor Regulates Collagen Expression in Human Intestinal Fibroblasts: Relevance in Intestinal Fibrosis.

Intestinal fibrosis is a common complication that affects more than 50% of Crohn´s Disease (CD) patients. There is no pharmacological treatment against this complication, with surgery being the only option. Due to the unknown role of P2X7 in intestinal fibrosis, we aim to analyze the relevance of this receptor in CD complications. Surgical resections from CD and non-Inflammatory Bowel Disease (IBD) patients were obtained. Intestinal fibrosis was induced with two different murine models: heterotopic transplant model and chronic-DSS colitis in wild-type and P2X7-/- mice. Human small intestine fibroblasts (HSIFs) were transfected with an siRNA against P2X7 and treated with TGF-β. A gene and protein expression of P2X7 receptor was significantly increased in CD compared to non-IBD patients. The lack of P2X7 in mice provoked an enhanced collagen deposition and increased expression of several profibrotic markers in both murine models of intestinal fibrosis. Furthermore, P2X7-/- mice exhibited a higher expression of proinflammatory cytokines and a lower expression of M2 macrophage markers. Moreover, the transient silencing of the P2X7 receptor in HSIFs significantly induced the expression of Col1a1 and potentiated the expression of Col4 and Col5a1 after TGF-β treatment. P2X7 regulates collagen expression in human intestinal fibroblasts, while the lack of this receptor aggravates intestinal fibrosis.

Inflammatory Bowel Disease With Chronic Kidney Disease and Acute Kidney Injury

It remains unclear whether inflammatory bowel disease is associated with long-term risk of chronic kidney disease (CKD) and acute kidney injury (AKI) in the general population. A total of 417,302 participants, including 2,940 patients with ulcerative colitis and 1,261 patients with Crohn's disease, without previous CKD and AKI at baseline (2006-2010) from the UK Biobank were included. The study outcomes included incident CKD and AKI, ascertained by self-report data and data linkage with primary care, hospital admissions, and death registry records. Analysis was conducted in 2022. During a median follow-up of 12.5 years, 13,564 and 14,331 participants developed CKD and AKI, respectively. Compared with the hazard ratio for non-inflammatory bowel diseases, the hazard ratios for CKD and AKI related to inflammatory bowel diseases were 1.57 (95% CI=1.37, 1.79) and 1.96 (95% CI=1.74, 2.20) after adjustments for age, sex, and race and were 1.32 (95% CI=1.15, 1.51) and 1.70 (95% CI=1.51, 1.91) after further adjustments for biological, behavioral, and socioeconomic factors in addition to mental health and self-rated health. Similar results were found for patients with Crohn's disease (adjusted hazard ratio=1.38 (95% CI=1.09, 1.75) for CKD and 1.62 [95% CI=1.30, 2.02] for AKI) and those with ulcerative colitis (adjusted hazard ratio=1.29 (95% CI=1.09, 1.51) for CKD and 1.71 [95% CI=1.49, 1.97] for AKI) in the fully adjusted models. Genetic risks of kidney diseases did not significantly affect the association of inflammatory bowel disease with incident CKD and AKI (both p-interactions>0.05). The association between inflammatory bowel disease and the risk of incident CKD (p-interaction=0.010) and AKI (p-interaction<0.001) were stronger in younger participants than in older participants. Inflammatory bowel disease was associated with higher risks for CKD and AKI, independent of genetic risks of kidney diseases.

Surface-enhanced Raman spectroscopy analysis reveals biochemical difference in urine of patients with perianal fistula

Background & aimsPerianal fistulising Crohn's disease (PFCD) is different from the characteristics and outcomes of traditional non-inflammatory bowel disease (IBD) anal fistulas. The presence of perianal disease was a poor prognostic indicator for Crohn's disease (CD) patients and PFCD patients were more likely to bear an increased risk of recurrence. However, the effective and accurate diagnosis methods to early distinguish PFCD from simple perianal fistula were still scarce. The purpose of this study is to develop a non-invasive detecting approach to predict CD in patients with perianal fistulas. MethodsData on patients with anal fistulizing disease were collected from July 2020 to September 2020 in two IBD centers. Urine samples from PFCD and simple perianal fistula patients were investigated by surface-enhanced Raman spectroscopy (SERS). Principal component analysis (PCA)-support vector machine (SVM) was utilized to establish classification models to distinguish PFCD from simple perianal fistula. ResultsAfter a case-matched 1:1 selection by age and gender, 110 patients were included in the study. By analyzing the average SERS spectra of PFCD and simple perianal fistula patients, it revealed that there were significant differences in intensities at 11 Raman peaks. The established PCA-SVM model distinguished PFCD from simple perianal fistula with a sensitivity of 71.43%, specificity 80.00% and accuracy 75.71% in the leave-one-patient-out cross-validation. The accuracy of the model in validation cohort was 77.5%. ConclusionsInvestigation of urine samples by SERS helps clinicians to predict Crohn's disease from perianal fistulas, which make patients achieve benefit from a more individualized treatment strategy.

Risk of anorectal cancer in patients with Crohn's disease and perianal fistula: a nationwide Danish cohort study.

Patients with Crohn's disease (CD) often suffer from perianal fistulizing disease. Their risk of anorectal cancer remains uncertain. We aimed to examine the long-term risk of anorectal cancer in a population-based cohort of CD patients with anorectal fistula. Our study population covered all individuals (n = 7 987 520) aged 15+ years living in Denmark from 1978 to 2018. We identified all patients with CD and anorectal fistula in the Danish National Patient Register (NPR) and 50 matched noninflammatory bowel disease (IBD) individuals from the general population. Using Cox regression analyses, we examined the risk of anorectal cancer in CD fistula patients versus non-IBD individuals. All patients with CD were identified using codes from the International Classification of Diseases and their data extracted from the NPR. The main outcome measure was cases of anorectal cancer. A total of 2786 CD patients with anorectal fistula and 139 300 non-IBD individuals were followed for 1 553 917 person-years. During follow-up, anorectal cancer was observed in 19 CD patients (0.68%) and 340 non-IBD individuals (0.24%), corresponding to a 2.9-fold increased hazard ratio (HR) of anorectal cancer in CD fistula patients (95% CI 1.80-4.53), with a particularly high risk of anal cancer (HR 15.13, 95% CI 6.88-33.31) and a mean time from CD fistula diagnosis to anorectal cancer of 6.7 (SD 6.5) years. The risk was slightly higher in women than men and had no apparent relation to treatment with tumour necrosis factor-α inhibitors. Sensitivity analyses using CD nonfistula patients for comparison revealed similar results. Individual data on smoking and infection with human papilloma virus were not available. Patients with CD and anorectal fistula have a three-fold increased risk of anorectal cancer compared with the general population. The number needed to surveil to detect one case of anorectal cancer in this patient population was 2160 patients per year in patients with long-standing fistula (>6 years).

How to Manage Targeted Immune Suppressants (Biologics and Oral Small-molecule Drugs) Perioperatively for Inflammatory Bowel Disease and non-Inflammatory Bowel Disease surgery

How to Manage Targeted Immune Suppressants (Biologics and Oral Small-molecule Drugs) Perioperatively for Inflammatory Bowel Disease and non-Inflammatory Bowel Disease surgery

Platelet-Rich stroma from Crohn’s disease patients for treatment of perianal fistula shows a higher myeloid cell profile compared to non-IBD controls

BackgroundNew cell-based therapies are under investigation to improve perianal fistulizing Crohn’s disease (pCD) healing. Autologous stromal vascular fraction combined with platelet-rich plasma (referred to as platelet-rich stroma [PRS]) is a new adipose-derived stromal therapy. The effect of Crohn’s disease (CD) on adipose tissue, and adipose-derived therapies, is largely unknown. We characterized the cellular composition of subcutaneous lipoaspirate and PRS of pCD patients and non-Inflammatory Bowel Disease (IBD) controls. MethodsConsecutive pCD patients (≥18 years) and non-IBD controls, who underwent liposuction for the purpose of autologous PRS therapy, were included (October 2020 and March 2021). Mechanically fractionated lipoaspirate and the combined PRS product were analyzed for cell surface marker expression using fluorescence-activated cell sorting analysis. ResultsTwenty-three patients (37.8 [IQR 30.7–45.0] years; 9 [39.1 %] male; 11CD patients) were included. Similar total number of cells were found in CD and non-IBD lipoaspirate (CD 8.23 ± 1.62*105 cells/mL versus non-IBD 12.20 ± 3.39*105). Presence of stromal cells, endothelial like cells, immune cells, T-cells, myeloid cells and M2/M1 macrophage ratio were similar in CD and non-IBD lipoaspirate. In PRS samples, more cells/mL were seen in CD patients (P = 0.030). Myeloid cells were more abundant in CD PRS samples (P = 0.007), and appeared to have a higher regulatory M2/M1 ratio. Interdonor variation was observed between lipoaspirate and PRS samples. ConclusionsThe composition of CD and non-IBD lipoaspirate were found to be similar and interdonor variation was observed. However, PRS from CD patients showed more myeloid cells with a regulatory phenotype. Crohn’s disease does not appear to alter the immunological composition of adipose-derived products.

Mucosal microbiome is predictive of pediatric Crohn's disease across geographic regions in North America.

Background: Patients with Crohn's disease (CD) have an altered intestinal microbiome, which may facilitate novel diagnostic testing. However, accuracy of microbiome classification models across geographic regions may be limited. Therefore, we sought to examine geographic variation in the microbiome of patients with CD from North America and test the performance of a machine learning classification model across geographic regions. Methods: The RISK cohort included 447 pediatric patients with CD and 221 non-inflammatory bowel disease controls from across North America. Terminal ileum, rectal and fecal samples were obtained prior to treatment for microbiome analysis. We divided study sites into 3 geographic regions to examine regional microbiome differences. We trained and tested the performance of a machine learning classification model across these regions. Results: No differences were seen in the mucosal microbiome of patients with CD across regions or in either the fecal or mucosal microbiomes of controls. Machine learning classification algorithms for patients with CD performed well across regions (area under the receiver operating characteristic curve [AUROC] range of 0.85-0.91) with the best results from terminal ileum. Conclusions: This study demonstrated the feasibility of microbiome based diagnostic testing in pediatric patients with CD within North America, independently from regional influences.

Risk Prediction Model for Crohn's Disease Based on Hematological Indicators.

The similarity between Crohn's disease (CD) and non-CD, especially with ulcerative colitis (UC) or intestinal tuberculosis (ITB), makes the diagnostic error rate not low. Therefore, there is an urgent need for an efficient, fast, and simple predictive model that can be applied in clinical practice. The purpose of this study is to establish the risk prediction model for CD based on five routine laboratory tests by logistic-regression algorithm, to construct the early warning model for CD and the corresponding visual nomograph, and to provide an accurate and convenient reference for the risk determination and differential diagnosis of CD, in order to assist clinicians to better manage CD and reduce patient suffering. Using a retrospective analysis, a total of 310 cases were collected from 2020 to 2022 at The Sixth Affiliated Hospital, Sun Yat-sen University, who were diagnosed by comprehensive clinical diagnosis, including 100 patients with CD, 50 patients with ulcerative colitis (UC), 110 patients with non-inflammatory bowel disease (non-IBD) diseases (65 cases of intestinal tuberculosis, radioactive enterocolitis 39, and colonic diverticulitis 6), and 50 healthy individuals (NC) in the non-CD group. Risk prediction models were established by measuring ESR, Hb, WBC, ALb, and CH levels in hematology. The models were evaluated and visualized using logistic-regression algorithm. 1) ESR, WBC, and WBC/CH ratios in the CD group were higher than those in the non-CD group, while ALb, Hb, CH, WBC/ESR ratio, and Hb/WBC ratio were lower than those in the non-CD group, and the differences were statistically significant (all p < 0.05). 2) CD occurrence had a strong correlation with the WBC/CH ratio, with the correlation coefficient exceeding 0.4; CD occurrence was correlated with other indicators. 3) A risk prediction model containing age, gender, ESR, ALb, Hb, CH, WBC, WBC/CH, WBC/ESR, and Hb/WBC characteristics was constructed using a logistic-regression algorithm. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve of the model were 83.0%, 76.2%, 59.0%, 90.5%, and 0.86, respectively. The model based on the corresponding index also had high diagnostic accuracy (AUC = 0.88) for differentiating CD from ITB. Visual nomograph based on the logistic-regression algorithm was also constructed for clinical application reference. In this study, a CD risk prediction model was established and visualized by five conventional hema-tological indices: ESR, Hb, WBC, ALb, and CH, in addition to a high diagnostic accuracy for the differential diagnosis of CD and ITB.

Th17-Derived Cytokines Synergistically Enhance IL-17C Production by the Colonic Epithelium.

Tightly regulated communication between the gastrointestinal epithelium and immune cells in the underlying lamina propria is critical for immune homeostasis and inflammation. IL-17C, produced by epithelial cells after exposure to inflammatory stimuli, facilitates cell-to-cell communication by promoting inflammatory responses in Th17 cells. In this study, we demonstrate that Th17-derived cytokines TNF-α, IL-17A, and IL-22 synergistically enhance IL-17C expression in both human-transformed colonic epithelial cell lines and primary non-inflammatory bowel disease colonic epithelial spheroids. This synergistic expression requires activation of the transcription factor NF-κB downstream of the TNF-α stimulus, evidenced by the reduction of IL-17C expression in the presence of an IκBα inhibitor. IL-17A and IL-22 enhance IL-17C expression through the activation of the transcription factor AP-1 in a p38 MAPK-dependent manner. Colonic spheroids derived from uninvolved epithelial of ulcerative colitis patients stimulated with TNF-α, IL-17A, and IL-22 show muted responses compared with non-inflammatory bowel disease spheroids, and inflamed spheroids yielded more IL-17C expression in the presence of TNF-α, and no response to IL-22 stimulation. Altogether, a role for IL-17C in activating Th17 cells combined with our findings of Th17-derived cytokine-driven synergy in the expression of IL-17C identifies a novel inflammatory amplification loop in the gastrointestinal tract between epithelial cells and Th17 cells.

P32 Therapeutic dilemma due to gut complications with spondyloarthritis

Introduction/BackgroundTumor necrosis factor (TNF) inhibitor therapy is one of the primary modalities of treating spondyloarthritis. However, infections secondary to biologic use is a common complication. Clostridium difficile is a gut colonizer which may become pathogenic in the presence of dysbiosis and antibiotic use. Symptomatic clostridium difficile infection(CDI) due to adalimumab(ADA) use causing lymphocytic colitis(LC) is rarely reported. We present a case of axial plus peripheral spondyloarthritis on adalimumab who developed CDI and presented a therapy related dilemma.Description/MethodWe present a case of a 52-year-old lady who was diagnosed as HLAB27 positive axial spondyloarthritis with bilateral sacroiliitis on MRI bilateral sacroiliac joint in 2016. She failed two non-steroidal antinflammatory drugs (NSAID) with high disease activity scores(BASDAI 8.6, BASFI 6.2, Spinal VAS 9). She was eventually initiated on injection adalimumab in 2017. There was clinical improvement after 6 months of initiating ADA. Repeat MRI spine and SI joint showed resolution of inflammatory changes with adalimumab. Sulfasalazine was added in the treatment protocol due to peripheral arthralgia, however she developed a drug rash to it and it was stopped. In September 2021, she developed recurrent non-bloody watery diarrhoeal episodes. Adalimumab was stopped and she tested positive for Clostridium difficile on three occasions. She received multiple courses of vancomycin, fidoxamycin and metronidazole with partial resolution of diarrhoea. Adalimumab was rechallended in January 2022 since her disease activity was worsening in the absence of NSAID and biologic use. However, it was paused again due to worsening of diarrhoea. Gastroenterology conducted a Colonoscopy and biopsy of colonic polyps which showed increased number of intraepithelial lymphocytes with no thickening of subepithelial collagen plate suggestive of lymphocytic colitis (LC). It was postulated that CDI may have been the trigger for her LC. She has been started on local corticosteroid therapy(budesonide) for her LC. At this junction, we were faced with the decision of restarting adalimumab for her which may have been the original cause of her CDI.Discussion/ResultsWe present this case in view of a dilemma regarding which problem occurred first Did immunosuppression due to adalimumab lead to CDI? Literature is not suggestive of increased risk of CDI with adalimumab, especially in a non-inflammatory bowel disease (IBD) background. Was the lymphocytic colitis triggered by the CDI or was clostridium difficile just incidentally detected on a background of LC? There is a well documented associated of LC with autoimmune conditions and use of NSAIDs along with proton pump inhibitor is another trigger for it. TNF alpha inhibitor is one of the treatment modalities of refractory LC. Would it be appropriate to restart ADA for her since she responded well despite there being a risk of recurrence of a CDI? Finally, what is the role of gut dysbiosis in the role of CDI and LC in this situation. Presently, she is planned to be treated with local steroid therapy for her LC. ADA will be rechallenged once her gut has responded to the steroid course. In the event of her gut worsening on a rechallenge, she will be given a trial of Infliximab.Key learning points/ConclusionThe case highlights the crucial point of thinking of causes of diarrhea apart from well documented conditions of ulcerative colitis/Crohn’s disease in an immunosuppressed spondyloarthritis patient. A detailed stool examination including bacterial and parasitic examination is crucial in recurrent diarrhea. The threshold for colonoscopy should be low when episodes are refractory to treatment. The case-based conference gives us an opportunity to receive feedback regarding further management approaches in this case.