Thalidomide-induced sinus bradycardia in Crohn's disease: case report and literature review

Thalidomide is effective in inducing and maintaining clinical remission, as well as mucosal healing, in patients with refractory Crohn's disease (CD). However, long-term use of thalidomide has raised concern because of the high incidence of adverse events. Cardiovascular events induced by thalidomide have been reported in patients with multiple myeloma, amyotrophic lateral sclerosis, and transfusion-dependent refractory anemia. We report here an extremely rare case of sinus bradycardia induced by thalidomide in an adult patient with CD. This patient's heart rate converted back to a normal sinus rhythm after withdrawal of thalidomide, but recurred after restarting of thalidomide. Cardiac toxicity should be closely monitored when using thalidomide in patients with CD.

Oral exclusive enteral nutrition induces mucosal and transmural healing in patients with Crohn's disease

Background and aims

Mucosal healing is regarded as a clinical endpoint of Crohn’s disease (CD), and transmural healing is correlated to the concept of deep remission. Current therapies to induce mucosal and transmural healing in CD are not satisfactory. Exclusive enteral nutrition (EEN) is underestimated therapy and its value has not been fully evaluated. Our aim was to investigate the efficacy of oral EEN for inducing mucosal and transmural healing in CD patients.

Methods

This was a prospective, single-center, open-label study including diagnosed CD children and adults conducted between January 2015 and December 2016 in the Sixth Affiliated Hospital of Sun Yat-sen University. All patients were treated with oral EEN and underwent paired assessment at baseline and completion using C-reaction protein, erythrocyte sedimentation rate, platelets, hemoglobin, body mass index, CD activity index, simple endoscopic score for CD and bowel sonography. Azathioprine was combined to prevent relapse.

Results

In this prospective observational study, 29 CD patients with an average age of 28.9 years were identified. After oral EEN treatment, 23 patients (79%) achieved complete mucosal healing, and the mean time to reach mucosal healing was 123 days (ranged from 50 to 212 days). Although only five patients (17%) achieved transmural healing, a significant reduction was observed in bowel-wall thickness (9.41 ± 3.06 vs 4.97 ± 1.76 mm, P < 0.001) and a significant improvement was observed in complications (including fistulas, abscess, ascites, stricture) assessed by bowel sonography (all P < 0.05).

Conclusions

Oral EEN therapy is highly effective for inducing mucosal healing in CD patients. Both CD patients at active stage and those at clinical remission show excellent clinical response to oral EEN.

Oversecretion and Overexpression of Nicotinamide Phosphoribosyltransferase/Pre-B Colony-Enhancing Factor/Visfatin in Inflammatory Bowel Disease Reflects the Disease Activity, Severity of Inflammatory Response and Hypoxia

Nicotinamide phosphoribosyltransferase's (Nampt) association with inflammatory bowel disease (IBD) is unclear. The study was aimed at unraveling Nampt's clinical and diagnostic relevance. The serum concentration (Luminex-xMAP® technology) was measured in 113 patients with Crohn's disease (CD), 127 with ulcerative colitis (UC) and 60 non-IBD controls: 40 healthy individuals and 20 with irritable bowel syndrome (IBS). The leukocyte (44 CD/37 UC/19 IBS) and bowel expression (186 samples) was also evaluated (RT-qPCR). All were referred to IBD phenotype, activity, treatment, and inflammatory/nutritional/angiogenic/hypoxia indices. Serum-Nampt and leukocyte-Nampt were positively correlated and were more elevated in active-IBD than in IBS, with leukocyte-Nampt being a fair differential marker. Serum-Nampt in UC positively correlated with its clinical and endoscopic activity as well as with pro-inflammatory cytokines. Serum-Nampt ≤1.54 ng/mL was a good indicator of mucosal healing. The expression of Nampt was up-regulated both in inflamed and quiescent colon and reflected, similarly to leukocyte-Nampt, the clinical activity of IBD. Bowel-Nampt was independently associated with IL1B and hypoxia-inducible factor 1α (HIF1A) expression in inflamed bowel but with FGF2 expression in quiescent bowel. In summary, Nampt's elevation in IBD at local and systemic levels, and protein and mRNA levels, reflects IBD activity and is associated with inflammation, hypoxia (active) and tissue repair (inactive disease).

Prediction of disease activity of Crohn's disease through fecal calprotectin evaluated by balloon-assisted endoscopy

BACKGROUND AND AIM

Fecal calprotectin (FC) is a useful marker for assessing the activity of intestinal inflammation. However, most studies have used ileocolonoscopy to evaluate the association of FC with intestinal inflammation, and it is not clear whether FC is useful for the evaluation of small-bowel Crohn's disease (CD). This study aimed to determine the usefulness of FC for predicting intestinal inflammation evaluated by balloon-assisted endoscopy (BAE), which can visualize the deep small intestine.

METHODS

This was a cross-sectional, observational study involving 69 CD patients, 39 of whom had only small-bowel disease. The extended simplified endoscopic activity score for Crohn's disease (eSES-CD) was calculated based on the findings of BAE. Mucosal healing was defined as an eSES-CD of 0.

RESULTS

In all CD patients, FC levels were correlated with the eSES-CD (r = 0.663, P < 0.001). The cutoff value to predict mucosal healing was 92 mg/kg, with a sensitivity of 94%, specificity of 88%, positive predictive value of 98%, negative predictive value of 64%, and the area under the curve of 0.91. Even in small-bowel CD patients, FC levels were correlated with the eSES-CD (r = 0.607, P < 0.001). The cutoff value was 92 mg/kg, with a sensitivity of 87%, specificity of 88%, positive predictive value of 96%, negative predictive value of 64%, and area under the curve of 0.85.

CONCLUSIONS

Fecal calprotectin showed a significant correlation with the intestinal inflammation evaluated with BAE even in patients with only small intestinal disease. FC is useful for the evaluation of CD including both the small and large intestines.

The sensitivity of fecal calprotectin in predicting deep remission in ulcerative colitis

BACKGROUND

Mucosal healing is proposed as treat-to-target in ulcerative colitis (UC), even though the definition of mucosal healing remains contested as it has been suggested to be assessed by either endoscopy, histology or both. However, all definitions require an endoscopic evaluation of the mucosa. As endoscopies are invasive and uncomfortable to the patient we aimed to calibrate noninvasive predictors of mucosal inflammatory status defined by both endoscopy and histology.

METHODS

UC patients (n = 106) undergoing a sigmoid-/colonoscopy were prospectively included. Feces (fecal calprotectin, FC), blood samples (hemoglobin, C-reactive protein, orosomucoid, erythrocyte sedimentation rate, albumin) and symptom scores (Simple Clinical Colitis Activity Index, SSCAI) were collected and analyzed. The colonic mucosa was assessed by the Mayo endoscopic sub score and biopsies were obtained for a histologic grading by Geboes score. Predictive cutoff values were analyzed by receiver operating characteristics (ROC). A combined endoscopic and histologic assessment defined deep remission (Mayo =0 and Geboes ≤1) and activity (Mayo ≥2 and Geboes >3).

RESULTS

Only FC showed a significant ROC curve (p < .05). We suggest FC (mg/kg) cutoffs for detection of following: Deep remission: FC ≤25; Indeterminate: FC 25-230 - an endoscopy is recommended if a comprehensive status of both endoscopic and histologic assessed activity is needed; Active disease: FC >230. The complete ROC data is presented, enabling extraction of an FC cutoff value's sensitivity and specificity.

CONCLUSIONS

FC predicts endoscopic and histologic assessed deep remission and inflammatory activity of colon mucosa. Neither the markers in blood nor the SCCAI performed significant ROC results.

Infliximab biosimilar CT-P13 therapy is effective in maintaining endoscopic remission in ulcerative colitis - results from multicenter observational cohort

BACKGROUND

CT-P13, the first biosimilar monoclonal antibody to infliximab (IFX), has previously been confirmed to be efficacious in inducing mucosal healing in ulcerative colitis (UC) patients. The aim of this study was to evaluate the efficacy of CT-P13 therapy in maintaining mucosal healing in UC.

METHODS

CT-P13 trough levels, antibody positivity, serum inflammatory markers as CRP level, fecal calprotectin at weeks 14 and 54, concomitant steroid and azathioprine therapy at the time of induction therapy and at weeks 14 and 54, previous use of anti TNF drug and the need of dose intensification as possible predictive factors for mucosal healing at week 54 were evaluated in this prospective study.

RESULTS

61 patients had already completed the 54-week treatment period. Mucosal healing was shown in 65.5 % and 62.1 %, complete mucosal healing was present in 31% and 38 % at week 14 and 54, respectively. The median values of CRP, leukocytes, thrombocytes, and albumin showed significant difference between baseline and week 54. Serum antibody positivity was proved in 6.5 % and 19.7 % of cases at week 14 and 54, respectively.

CONCLUSION

Our study confirmed the long-term efficacy of CT-P13 therapy on mucosal healing in UC.

Validity of Capsule Endoscopy in Monitoring Therapeutic Interventions in Patients with Crohn's Disease

Mucosal healing in Crohn’s disease (CD) can be evaluated by capsule endoscopy (CE). However, only a few studies have utilized CE to demonstrate the therapeutic effect of medical treatment. We sought to evaluate the validity of using CE to monitor the effect of medical treatment in patients with CD. One hundred (n = 100) patients with CD were enrolled. All patients had a gastrointestinal (GI) tract patency check prior to CE. Patients with baseline CE Lewis score (LS) ≤ 135 were included in the non-active CD group and ended the study. In those with LS > 135 (active CD group), additional treatment was administered, regardless of symptoms, as per the treating clinician’s advice. Patients of the active CD group underwent follow-up CE assessment 6 months later. Out of 92 patients with confirmed GI patency who underwent CE, 40 (43.4%) had CE findings of active inflammation. Of 29 patients with LS > 135 who received additional medications and underwent follow-up CE, improvement of the LS was noted in 23 (79.3%) patients. Eleven patients were asymptomatic but received additional medications; 8 (72.7%) had improvement of the LS. This study demonstrated that additional treatment even for patients with CD in clinical remission and active small-bowel inflammation on CE can reduce mucosal damage.

IL-33 promotes recovery from acute colitis by inducing miR-320 to stimulate epithelial restitution and repair

Defective and/or delayed wound healing has been implicated in the pathogenesis of several chronic inflammatory disorders, including inflammatory bowel disease (IBD). The resolution of inflammation is particularly important in mucosal organs, such as the gut, where restoration of epithelial barrier function is critical to reestablish homeostasis with the interfacing microenvironment. Although IL-33 and its receptor ST2/ILRL1 are known to be increased and associated with IBD, studies using animal models of colitis to address the mechanism have yielded ambiguous results, suggesting both pathogenic and protective functions. Unlike those previously published studies, we focused on the functional role of IL-33/ST2 during an extended (2-wk) recovery period after initial challenge in dextran sodium sulfate (DSS)-induced colitic mice. Our results show that during acute, resolving colitis the normal function of endogenous IL-33 is protection, and the lack of either IL-33 or ST2 impedes the overall recovery process, while exogenous IL-33 administration during recovery dramatically accelerates epithelial restitution and repair, with concomitant improvement of colonic inflammation. Mechanistically, we show that IL-33 stimulates the expression of a network of microRNAs (miRs) in the Caco2 colonic intestinal epithelial cell (IEC) line, especially miR-320, which is increased by >16-fold in IECs isolated from IL-33-treated vs. vehicle-treated DSS colitic mice. Finally, IL-33-dependent in vitro proliferation and wound closure of Caco-2 IECs is significantly abrogated after specific inhibition of miR-320A. Together, our data indicate that during acute, resolving colitis, IL-33/ST2 plays a crucial role in gut mucosal healing by inducing epithelial-derived miR-320 that promotes epithelial repair/restitution and the resolution of inflammation.

Indoleamine 2,3-dioxygenase-dependent expansion of T-regulatory cells maintains mucosal healing in ulcerative colitis

BACKGROUND

Dendritic cell (DC)-derived indolamine 2,3-dioxygenase (IDO) degrades tryptophan to kynurenine, which promotes conversion of inflammatory T cells in immunosuppressive regulatory T cells (Tregs). We analyzed the significance of the IDO:Treg axis for inducing and maintaining mucosal healing in ulcerative colitis (UC).

METHODS

Dextran sodium sulphate (DSS)-induced colitis in BALB/c mice (model for mucosal healing) and C57BL/6 mice (model for persistent disease) was used. Serum, fecal samples and colon-infiltrating immune cells of 65 patients with UC with mucosal healing or persistent colitis were analyzed.

RESULTS

Significantly higher serum levels of kynurenine and downregulated inflammatory cytokines were noticed in DSS-treated BALB/c mice compared with C57BL/6 mice. Increased IDO activity and attenuated capacity for antigen presentation and production of inflammatory cytokines, observed in BALB/c DCs, was followed by a significantly lower number of inflammatory T helper 1 (Th1) and Th17 cells and a notably increased number of Tregs in the colons of DSS-treated BALB/c mice. DCs and Tregs were crucially important for the maintenance of mucosal healing since their depletion aggravated colitis. Mucosal healing, followed by an increase in kynurenine and intestinal Tregs, was re-established when BALB/c DCs were transferred into DC-depleted or Treg-depleted DSS-treated BALB/c mice. This phenomenon was completely abrogated by the IDO inhibitor. Significantly higher serum and fecal levels of kynurenine, accompanied by an increased presence of intestinal Tregs, were noticed in patients with UC with mucosal healing and negatively correlated with disease severity, fecal calprotectin, colon-infiltrating interferon γ and interleukin-17-producing cells, serum and fecal levels of inflammatory cytokines.

CONCLUSION

IDO-dependent expansion of endogenous Tregs should be further explored as a new approach for the induction and maintenance of mucosal healing in patients with UC.

Tryptophan Metabolism through the Kynurenine Pathway is Associated with Endoscopic Inflammation in Ulcerative Colitis

BACKGROUND AND AIMS

Mucosal appearance on endoscopy is an important indicator of inflammatory burden and determines prognosis in ulcerative colitis (UC). Inflammation induces tryptophan metabolism along the kynurenine pathway (KP) and yields immunologically relevant metabolites. We sought to examine whether changes in serum tryptophan metabolites and tissue expression of KP enzymes are associated with UC endoscopic and histologic disease severity.

METHODS

Serum and mucosal samples were prospectively obtained at colonoscopy in patients with UC. Mayo disease activity scores, demographics, smoking status, medications, and outcomes were collected. Serum tryptophan metabolites were analyzed using ultra-high performance liquid chromatography (uHPLC), and gas chromatography-mass spectrometry (GC-MS), and enzyme expression was determined by quantitative real-time polymerase chain reaction. Metabolite and enzyme levels were compared by endoscopic subscore, clinical disease activity, time to surgery, and hospitalization.

RESULTS

This study included 99 patients with Mayo endoscopic subscores 0-3. Kynurenic acid/tryptophan ratio (KYNA/T) and expression of indolamine 2,3-dioxygenase 1 (IDO1), tryptophan 2,3-dioxygenase, kynurinase, and kynurenine monooxygenase correlated positively with endoscopic subscore. Adjusting for age of diagnosis, smoking status, disease extent, and medications yielded significant odds of endoscopic inflammation with increasing KYNA/T (OR 1.0015, P = 0.0186) and IDO1 expression (OR 1.0635, P = 0.0215). The highest tertile ratio of KYNA/T had shorter time to surgery (P = 0.009) and hospitalization (P = 0.01) than the lowest.

CONCLUSIONS

Increasing KYNA/T is closely associated with endoscopic inflammation and predictive of disease outcomes in patients with UC. These findings identify this novel metabolic association and further support the role of the KP in regulating mucosal inflammation in UC. 10.1093/ibd/izy103_video1izy103.video15788135676001.

Expert opinion for use of faecal calprotectin in diagnosis and monitoring of inflammatory bowel disease in daily clinical practice

Background

Despite many publications regarding the role of faecal calprotectin (FC) in inflammatory bowel disease (IBD), clear recommendations for its use in clinical practice are currently lacking in the literature.

Aim

The aim of this article is to provide practical guidance for clinicians for the use of FC in the detection and management of patients with IBD.

Methods

All relevant publications were analysed and practical statements were proposed based on a Delphi consensus approach.

Results

Different commercial assays have been developed but international standardisation is lacking. FC can help in the diagnosis process of IBD. In IBD, FC can predict response to therapy, detect subclinical inflammation and help to drive treatment decisions to achieve better endoscopic and clinical outcomes. After Crohn's surgery FC can identify patients with early endoscopic recurrence.

Conclusion

Although major therapeutic changes should not be based on FC alone, FC is a valuable tool to optimise the care for IBD patients.

Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Evolution of treatment targets in IBD has increased the need for objective monitoring of disease activity to guide therapeutic strategy. Although mucosal healing is the current target of therapy in IBD, endoscopy is invasive, expensive and unappealing to patients. GI ultrasound (GIUS) represents a non-invasive modality to assess disease activity in IBD. It is accurate, cost-effective and reproducible. GIUS can be performed at the point of care without specific patient preparation so as to facilitate clinical decision-making. As compared with ileocolonoscopy and other imaging modalities (CT and MRI), GIUS is accurate in diagnosing IBD, detecting complications of disease including fistulae, strictures and abscesses, monitoring disease activity and detecting postoperative disease recurrence. International groups increasingly recognise GIUS as a valuable tool with paradigm-changing application in the management of IBD; however, uptake outside parts of continental Europe has been slow and GIUS is underused in many countries. The aim of this review is to present a pragmatic guide to the positioning of GIUS in IBD clinical practice, providing evidence for use, algorithms for integration into practice, training pathways and a strategic implementation framework.

Monitoring Crohn's disease activity: endoscopy, fecal markers and computed tomography enterography

BACKGROUND

The treatment goal of Crohn's disease (CD) has moved towards achieving mucosal healing, resolution of transmural inflammation, and normalization of biomarkers. The purpose of this study was to evaluate how well computed tomography enterography (CTE) and fecal calprotectin (FC) correlated with endoscopic activity in newly diagnosed patients with CD and after 1 year of therapy.

METHODS

Consecutive patients with newly diagnosed CD were evaluated by endoscopy, CTE, and FC at diagnosis and 12 months after beginning immunosuppression. Endoscopic severity was assessed using the Simplified Endoscopic Score for Crohn's Disease (SES-CD). Biomarkers, clinical indexes, and FC were recorded on the day of ileocolonoscopy at diagnosis and 1 year after diagnosis. We adapted a CTE score for disease activity based on radiological signs of inflammation (i.e. mural thickness, mural hyperenhancement, mesenteric fat proliferation, mesenteric fat densification, comb sign, presence of strictures, fistulas, abscesses, ascites, and lymphadenopathy). Correlations between endoscopy, CTE, and FC were assessed using Spearman's rank correlation.

RESULTS

A total of 29 patients (48% women; median age 30 (24.5-35.5) years) were included in this prospective cohort. CTE findings significantly correlated with endoscopic findings. Endoscopic remission (ER) at 1-year follow up significantly correlated with improvement in mural hyperenhancement (p = 0.004), mesenteric fat densification (p = 0.001), comb sign (p = 0.004), and strictures (p = 0.008) in CTE. None of the CTE findings improved in patients without ER. FC correlated with SES-CD (rs = 0.696, p < 0.001) and with CTE features of inflammation (rs = 0.596, p < 0.001). A cut-off of 100 µg/g predicted ER with 92% sensitivity, 65% specificity, and 83% accuracy (area under curve 0.878, p < 0.001).

CONCLUSIONS

CTE findings and FC levels correlated with endoscopic activity in CD both at diagnosis and at 1-year follow up. These two noninvasive markers of disease activity may be used as an alternative to endoscopy to monitor disease response to therapy.

Limited uptake of ulcerative colitis "treat-to-target" recommendations in real-world practice

BACKGROUND AND AIMS

A "treat-to-target" approach has been proposed for ulcerative colitis (UC), with a target of combined clinical and endoscopic remission. The aim of the study was to evaluate the extent to which proposed targets are achieved in real-world care, along with clinician perceptions and potential challenges.

METHODS

A multicentre, retrospective, cross-sectional review of patients with UC attending outpatient services in South Australia was conducted. Clinical and objective assessment of disease activity (endoscopy, histology, and/or biomarkers) was recorded. A survey evaluated gastroenterologists' perceptions of treat to target in UC. Statistical analysis included logistic regression and Fisher's exact tests.

RESULTS

Of 246 patients with UC, 61% were in clinical remission (normal bowel habit and no rectal bleeding), 35% in clinical and endoscopic remission (Mayo endoscopic sub-score ≤ 1), and 16% in concordant clinical, endoscopic, and histological (Truelove and Richards' Index) remission. Rather than disease-related factors (extent/activity), clinician-related factors dominated outcome. Hospital location and the choice of therapy predicted combined clinical and endoscopic remission (OR 3.6, 95% CI 1.6-8.7, P < 0.001; OR 3.3, 95% CI 1.1-12.5, P = 0.04, respectively). Clinicians used C-reactive protein more often than endoscopy as a biomarker for disease activity (75% vs 47%, P < 0.001). In the survey, 45/61 gastroenterologists responded, with significant disparity between clinician estimates of targets achieved in practice and real-world data (P < 0.001 for clinical and endoscopic remission).

CONCLUSIONS

Most patients with UC do not achieve composite clinical and endoscopic remission in "real-world" practice. Clinician uptake of proposed treat-to-target guidelines is a challenge to their implementation.

Association of sleep quality and mucosal healing in patients with inflammatory bowel disease in clinical remission

Background

The interaction between sleep and the immune system has been increasingly studied over the last decades. The aim of this study was to investigate the association between sleep quality and mucosal healing in patients with inflammatory bowel disease (IBD) currently in clinical remission.

Methods

Ninety patients with IBD in clinical remission were studied: 54 (60%) with Crohn’s disease and 36 (40%) with ulcerative colitis. All completed the Pittsburgh Sleep Quality Index, and mucosal healing was estimated with ileocolonoscopy. A subgroup analysis was also performed in order to investigate these associations in Crohn’s disease and ulcerative colitis separately.

Results

Of the 90 patients, 45.56% had poor sleep quality. Patients without mucosal healing expressed higher absolute values of the Pittsburgh Sleep Quality Index (P<0.001), while absence of mucosal healing and poor sleep quality were statistically associated (P<0.05). Subgroup analysis showed that the same pattern was present in patients with Crohn’s disease: patients without mucosal healing expressed higher absolute values of the Pittsburgh Sleep Quality Index (P<0.001) and the absence of mucosal healing was statistically associated with poor sleep quality (P<0.05). However, these associations were not observed in the subgroup of patients with ulcerative colitis (P>0.05).

Conclusion

In patients with IBD in clinical remission, absence of mucosal healing seems to be associated with poor sleep quality, especially in patients with Crohn’s disease.

Tetraspanin CD9 Limits Mucosal Healing in Experimental Colitis

Tetraspanins are a family of proteins with four transmembrane domains that associate between themselves and cluster with other partner proteins, conforming a distinct class of membrane domains, the tetraspanin-enriched microdomains (TEMs). These TEMs constitute macromolecular signaling platforms that regulate key processes in several cellular settings controlling signaling thresholds and avidity of receptors. In this study, we investigated the role of CD9, a tetraspanin that regulates major biological processes such as cell migration and immunological responses, in two mouse models of colitis that have been used to study the pathogenesis of inflammatory bowel disease (IBD). Previous in vitro studies revealed an important role in the interaction of leukocytes with inflamed endothelium, but in vivo evidence of the involvement of CD9 in inflammatory diseases is scarce. Here, we studied the role of CD9 in the pathogenesis of colitis in vivo. Colitis was induced by administration of dextran sodium sulfate (DSS), a chemical colitogen that causes epithelial disruption and intestinal inflammation. CD9^−/− mice showed less severe colitis than wild-type counterparts upon exposure to DSS (2% solution) and enhanced survival in response to a lethal DSS dose (4%). Decreased neutrophil and macrophage cell infiltration was observed in colonic tissue from CD9^−/− animals, in accordance with their lower serum levels of TNF-α, IL-6, and other proinflammatory cytokines in the colon. The specific role of CD9 in IBD was further dissected by transfer of CD4⁺ CD45RB^hi naive T cells into the Rag1^−/− mouse colitis model. However, no significant differences were observed in these settings between both groups, ruling out a role for CD9 in IBD in the lymphoid compartment. Experiments with bone marrow chimeras revealed that CD9 in the non-hematopoietic compartment is involved in colon injury and limits the proliferation of epithelial cells. Our data indicate that CD9 in non-hematopoietic cells plays an important role in colitis by limiting epithelial cell proliferation. Future strategies to repress CD9 expression may be of therapeutic benefit in the treatment of IBD.

Mucosal Mesenchymal Cells: Secondary Barrier and Peripheral Educator for the Gut Immune System

Stromal connective tissue contains mesenchymal cells, including fibroblasts and myofibroblasts, which line the tissue structure. However, it has been identified that the function of mesenchymal cells is not just structural-they also play critical roles in the creation and regulation of intestinal homeostasis. Thus, mucosal mesenchymal cells instruct intestinal immune cell education (or peripheral immune education) and epithelial cell differentiation thereby shaping the local environment of the mucosal immune system. Malfunction of the mesenchymal cell-mediated instruction system (e.g., fibrosis) leads to pathological conditions such as intestinal stricture.

Role of short-chain fatty acids in colonic inflammation, carcinogenesis, and mucosal protection and healing

Short-chain fatty acids (SCFAs), mainly acetate, propionate, and butyrate, produced by microbial fermentation of undigested food substances are believed to play a beneficial role in human gut health. Short-chain fatty acids influence colonic health through various mechanisms. In vitro and ex vivo studies show that SCFAs have anti-inflammatory and anticarcinogenic effects, play an important role in maintaining metabolic homeostasis in colonocytes, and protect colonocytes from external harm. Animal studies have found substantial positive effects of SCFAs or dietary fiber on colonic disease, but convincing evidence in humans is lacking. Most human intervention trials have been conducted in the context of inflammatory bowel disease. Only a limited number of those trials are of high quality, showing little or no favorable effect of SCFA treatment over placebo. Opportunities for future research include exploring the use of combination therapies with anti-inflammatory drugs, prebiotics, or probiotics; the use of prodrugs in the setting of carcinogenesis; or the direct application of SCFAs to improve mucosal healing after colonic surgery.

The prognostic value of histology in ulcerative colitis in clinical remission with mesalazine

BACKGROUND

The aim of the study was to compare the prognostic value of histological and endoscopic activity in patients with ulcerative colitis (UC).

METHODS

Patients in clinical remission for 1 year under treatment with mesalazine underwent a planned colonoscopy with biopsies. Histological activity was scored using the histological activity index (HAI). Endoscopic activity was scored using the Mayo endoscopic subscore (MES). The clinical course was evaluated measuring relapses needing steroids during a follow up of 3 years.

RESULTS

A total of 52 patients were enrolled into the study and followed up for 3 years. At baseline 29 patients (55.77%) had no endoscopic lesions, and 17 patients (32.69%) showed no histological alteration. At 3 years of follow up, overall, 26 patients (50%) were still in steroid-free remission. Using univariate logistic regression analysis, both histological (HAI ⩾ 1) and endoscopic activity (MES ⩾ 1) were significantly associated with outcome, showing, respectively, a relapse risk (odds ratio [OR]) 16.4 times higher than histological remission (HAI 0) (96% confidence interval [CI]: 3.2-84.3) and 6.3 times higher with respect to endoscopic remission (MES 0) (96% CI: 1.9-21.3). After multivariate logistic regression analysis, histological activity was the only factor significantly associated with outcome (OR 10.2; 95% CI: 1.7-59.4).

CONCLUSIONS

Histological activity has the most powerful prognostic value in predicting the need for steroids in patients with UC in stable clinical remission on mesalazine. It could be considered as a target of therapy in UC.

Integrated Analysis of Biopsies from Inflammatory Bowel Disease Patients Identifies SAA1 as a Link Between Mucosal Microbes with TH17 and TH22 Cells

BACKGROUND

Inflammatory bowel diseases (IBD) are believed to be driven by dysregulated interactions between the host and the gut microbiota. Our goal is to characterize and infer relationships between mucosal T cells, the host tissue environment, and microbial communities in patients with IBD who will serve as basis for mechanistic studies on human IBD.

METHODS

We characterized mucosal CD4 T cells using flow cytometry, along with matching mucosal global gene expression and microbial communities data from 35 pinch biopsy samples from patients with IBD. We analyzed these data sets using an integrated framework to identify predictors of inflammatory states and then reproduced some of the putative relationships formed among these predictors by analyzing data from the pediatric RISK cohort.

RESULTS

We identified 26 predictors from our combined data set that were effective in distinguishing between regions of the intestine undergoing active inflammation and regions that were normal. Network analysis on these 26 predictors revealed SAA1 as the most connected node linking the abundance of the genus Bacteroides with the production of IL17 and IL22 by CD4 T cells. These SAA1-linked microbial and transcriptome interactions were further reproduced with data from the pediatric IBD RISK cohort.

CONCLUSIONS

This study identifies expression of SAA1 as an important link between mucosal T cells, microbial communities, and their tissue environment in patients with IBD. A combination of T cell effector function data, gene expression and microbial profiling can distinguish between intestinal inflammatory states in IBD regardless of disease types.

Endoscopic shielding technique with a newly developed hydrogel to prevent thermal injury in two experimental models

BACKGROUND AND AIM

A newly developed hydrogel, applied through the endoscope as an endoscopic shielding technique (EndoSTech), is aimed to prevent deep thermal injury and to accelerate the healing process of colonic induced ulcers after therapeutic endoscopy.

METHODS

Lesions were performed in rats (n = 24) and pigs (n = 8). Rats were randomized to receive EndoSTech (eight rats each) with: saline (control), hyaluronic acid and product. In pigs, three ulcer sites were produced in each pig: endoscopic mucosal resection (EMR)-ulcer with prior saline injection (A; EMR-saline), EMR-saline plus EndoSTech with product (B; EMR-saline-P), and EMR with prior injection of product plus EndoSTech-P (C; EMR-P-P). At the end of the 14-day study, the same lesions were performed again in healthy mucosa to assess acute injury. Animals were sacrificed after 7 (rats) and 14 (pigs) days. Ulcers were macroscopically and histopathologically evaluated. Thermal injury (necrosis) was assessed with a 1-4 scale.

RESULTS

In rats, treatment with product improved mucosal healing comparing with saline and hyaluronic acid (70% vs 30.3% and 47.2%; P = 0.003), avoiding mortality (0% vs 50% and 25%; P = 0.038), and perforation (0% vs 100% and 33.3%; P = 0.02); respectively. In pigs, submucosal injection of product induced a marked trend towards a less deep thermal injury (C = 2.25-0.46 vs A and B = 2.75-0.46; P = 0.127). Mucosal healing rate was higher with product (B = 90.2-3.9%, C = 91.3-5.5% vs A = 73.1-12.6%; P = 0.002).

CONCLUSIONS

This new hydrogel demonstrates strong healing properties in preclinical models. In addition, submucosal injection of this product is able to avoid high thermal load of the gastrointestinal wall.

Accuracy of Faecal Immunochemical Test to Predict Endoscopic and Histological Healing in Ulcerative Colitis: A Prospective Study Based on Validated Histological Scores

BACKGROUND AND AIMS

Endoscopic and histological healing are associated with improved clinical outcomes in ulcerative colitis [UC]. We aimed to investigate the predictive value of faecal immunochemical test [FIT] for endoscopic and histological healing in UC.

METHODS

We measured quantitative FIT and faecal calprotectin [FC] in 140 consecutive UC patients who underwent colonoscopy. We assessed the diagnostic accuracy of FIT for predicting endoscopic healing using the Mayo endoscopic subscore [MES 0/1] and for histological healing using the Geboes score [< 2.0] and Nancy index [grade ≤ 1]. The predictive abilities of FIT were compared with those of FC.

RESULTS

FIT had an area under the curve [AUC] of 0.77 (95% confidence interval [CI] 0.67-0.86, p < 0.001) for endoscopic healing, an AUC of 0.77 [95% CI 0.67-0.86, p < 0.001] using the Geboes score, and 0.77 [95% CI 0.66-0.85, p < 0.001] using the Nancy Index for histological healing. The AUC of FIT was comparable to that of FC for endoscopic healing [p = 0.773] and histological healing [p = 0.767-0.960], and was comparable to colonoscopy for histological healing [p = 0.384-0.673]. FIT < 50 ng/ml predicted endoscopic healing with a sensitivity, specificity, and positive predictive value [PPV] of 72%, 68%, and 82%, respectively, and for histological healing with a sensitivity, specificity, and PPV of 73-75%, 67%, and 78-80%, respectively. Combining FIT with FC led to a higher specificity [90%] for histological healing. Over 85% of patients with FIT < 50 ng/ml and FC < 50 μg/g achieved histological healing.

CONCLUSIONS

FIT is highly sensitive and accurate to predict endoscopic and histological healing in UC. It represents a promising non-invasive tool for monitoring mucosal healing in UC.

Accuracy of Diffusion-weighted Magnetic Resonance Colonography in Assessing Mucosal Healing and the Treatment Response in Patients with Ulcerative Colitis

BACKGROUND AND AIMS

Using sigmoidoscopy as the gold standard, we assessed the accuracy, and the responsiveness to change, of diffusion-weighted magnetic resonance colonography in ulcerative colitis, using the Nancy score.

METHODS

A total of 29 ulcerative colitis patients, having undergone at least two diffusion-weighted magnetic resonance colonographies, were included. Disease activity was evaluated using the Mayo endoscopic subscore and the Nancy score. We determined the accuracy of the Nancy score in the diagnosis of mucosal healing. We also assessed its responsiveness to change in 17 patients with a Mayo endoscopic subscore of 2 or 3 at treatment initiation.

RESULTS

A total Nancy score < 7 had a sensitivity of 0.75 and a specificity of 0.67 (area under the curve: 0.72; 95% confidence interval: [0.56-0.88]; p = 0.0063) in the diagnosis of mucosal healing. The total Nancy score was sensitive to change in ulcerative colitis [Guyatt's responsiveness index: 1.8; standardised effect size ratio: 1.36]. The Nancy score was reliable [intra-class correlation coefficient: 0.63; p = 0.01]. The mean Mayo endoscopic subscore and the mean Nancy score both fell significantly in patients who achieved mucosal healing (mean ± standard deviation [SD] Mayo endoscopic subscore: 2.4 ± 0.55 at baseline and 0.6 ± 0.55 at reassessment, p = 0.02; mean Nancy score: 18.2 ± 9.1 at baseline and 3 ± 1.6 at reassessment, p = 0.006). No significant changes in Nancy score were observed in active patients at reassessment.

CONCLUSIONS

The Nancy score is a highly responsive, reliable tool for assessing treatment response in patients with ulcerative colitis. The Nancy score accurately detects mucosal healing.

Factors associated with the achievement of mucosal healing in Crohn's disease: the benefit of endoscopic monitoring in treating to target

BACKGROUND

Mucosal healing (MH), the proposed treat to target in Crohn's disease (CD), is associated with improved disease outcomes. There are still scant data on factors associated with achieving MH in clinical practice. We evaluated the probability of achieving MH and identified factors predictive of subsequent MH in patients with CD.

METHODS

This was a retrospective, observational cohort study. A total of 272 patients with CD with serial endoscopy assessment and subsequent therapeutic management were reviewed. The primary outcome was MH. The cumulative incidence of MH and endoscopic improvement was estimated using the Kaplan-Meier method. Factors independently associated with MH were identified using the Cox proportional hazards model.

RESULTS

Of the 272 patients, 126 (46.32%) achieved MH after a median follow-up period of 33 months (interquartile range: 27-38 months). Factors independently associated with MH by multivariate analysis were time between endoscopic procedures within 26 weeks (hazard ratio [HR]: 1.56; 95% confidence interval [CI]: 1.05-3.39), adjustment of medical therapy when MH was not achieved (HR: 2.07; 95% CI: 1.26-2.33), prior enteric fistula (HR: 0.22; 95% CI: 0.06-0.91), perianal disease at CD diagnosis (HR: 0.58; 95% CI: 0.35-0.95), and C-reactive protein normalization within 12 weeks (HR: 3.23; 95% CI: 1.82-5.88). Similar factors have also been identified for endoscopic improvement.

CONCLUSIONS

Performing serial endoscopic procedures at a 26-week interval and subsequent adjustment in medical treatment are helpful in achieving MH. Endoscopic monitoring plays an important role in the treating to target of CD.

Combined Treatment with Hyaluronic Acid and Mesalamine Protects Rats from Inflammatory Bowel Disease Induced by Intracolonic Administration of Trinitrobenzenesulfonic Acid

Drugs such as mesalamine (5-ASA) are currently recommended for the treatment of inflammatory bowel disease (IBD). To reduce the frequency of their administration and improve their therapeutic effect, this study investigated the adhesion efficacy, wound healing promotion, and decrease in inflammation in ulcers in the colonic tissue of rats with colitis after combined treatment with hyaluronic acid (HA) and 5-ASA (IBD98-M). HA-fluoresceinamine (FL) conjugates successfully adhered to the mucosal layer and were conjugated in the vascular tissue. In addition, macroscopic and microscopic observations indicated that colonic injuries reduced significantly after treatment with IBD98-M. Compared with PBS and 5-ASA treatment alone, treatment with IBD98-M more effectively reduced bowel inflammation and promoted colonic mucosal healing in TNBS-induced colitis. IBD98-M treatment also reduced myeloperoxidase activity and the expression levels of cyclooxygenase 2 and tumor necrosis factor-αin the colitis tissue. In conclusion, IBD98-M treatment strongly promoted wound healing in colonic injuries and significantly inhibited MPO activity in the inflamed colon tissue of rats. Combined treatment with HA and 5-ASA can accelerate wound healing and reduce inflammatory reaction in rat colitis.