Inflammation is an independent risk factor for colonic neoplasia in patients with ulcerative colitis: a case-control study

Study on the susceptibility of bovine coronavirus to BALB/c mice

There are no other bovine coronavirus (BCoV) infection models except calves, which makes efficacy evaluation of vaccines and pathogenic mechanism research of BCoV inconvenient owing to their high value and inconvenient operation. This study aimed to establish a mouse model of BCoV infection. BCoV was used to infect 4-week-old male BALB/c mice and the optimal infection conditions were screened, including the following infection routes: gavage, intraperitoneal injection, and tail vein injection at doses of 1 × 108 TCID50, 2 × 108 TCID50 and 4 × 108 TCID50. Using the optimal infection conditions, BALB/c mice were infected with BCoV, and their body weight, blood routine, inflammatory factors, autopsy, virus distribution, and viral load were measured at 1, 3, 5, and 7 days after infection. The results showed that the optimal conditions for infecting BALB/c mice with BCoV HLJ-325 strain were continuous oral gavage for 3 days with a dose of 4 × 108 TCID50. On the 7th day after infection, there was significant extensive consolidation of the lungs and thinning of the colon wall. Significant inflammation was observed in various organs, especially in the colon and alveoli, where a large number of inflammatory cells infiltrate. Both BCoV Ag and nucleic acid are positive in visceral organs. The viral load in the colon and lungs was significantly higher than that in the other organs (p < 0.001). BCoV-infected mice showed a decreasing trend in body weight starting from day 5, and there was a significant difference compared to the control group on days 6 and 7 (p < 0.001). The total number of white blood cells and lymphocytes began to decrease and was significantly lower than that in the control group 24 h after infection (p < 0.001), and gradually returned to the control level. The cytokine TNF-α, IL-1β, and IL-6 showed an increasing trend, significantly higher than the control group on day 5 and 7 (p < 0.001). These results indicate that the BCoV HLJ-325 strain can infect BALB/c mice and cause inflammatory reactions and tissue lesions. The most significant effect was observed on the seventh day after infection with a dose of 4 × 108 TCID50 and three consecutive gavages. This study established, for the first time, a BALB/c mouse model of BCoV infection, providing a technical means for evaluating the immune efficacy of BCoV vaccines and studying their pathogenic mechanisms.

Dysplasia Detected in Patients With Serrated Epithelial Change Is Frequently Associated With an Invisible or Flat Endoscopic Appearance, Nonconventional Dysplastic Features, and Advanced Neoplasia

The significance of serrated epithelial change (SEC), defined as endoscopically invisible hyperplastic polyp (HP)-like mucosal change identified in patients with inflammatory bowel disease (IBD), remains unclear. Although some studies reported an increased risk of synchronous and/or metachronous colorectal neoplasia in patients with SEC, including advanced neoplasia (high-grade dysplasia or colorectal cancer), the development of SEC is not significantly associated with increased colonic inflammation. This contrasts with the reported positive correlation between increased colonic inflammation and the risk of colorectal neoplasia in ulcerative colitis, arguing against the notion that SEC may represent a form of dysplasia. As such, this study aimed to characterize the features of synchronous and metachronous dysplasia detected in patients with SEC to identify factors contributing to the increased risk of colorectal neoplasia, including advanced neoplasia, observed in a subset of these patients. Clinicopathologic features of 46 IBD patients with SEC (n=109) and synchronous and/or metachronous dysplasia (n=153) were analyzed. All dysplastic lesions were subtyped as either conventional or nonconventional dysplasia. As controls, 45 IBD patients with endoscopically visible or polypoid HP (n=75) and synchronous and/or metachronous dysplasia (n=87) were analyzed. The SEC group included 28 (61%) men and 18 (39%) women with a mean age of 58 years and a long history of IBD (mean duration: 23 years). The majority of patients (n=34; 74%) had ulcerative colitis, and 12 (26%) had Crohn's disease. Thirty-nine (85%) patients had a history of pancolitis, and 2 (4%) had concomitant primary sclerosing cholangitis. Twenty-seven (59%) patients had multifocal SEC. SEC was predominantly found in the left colon (n=52; 48%) and rectum (n=34; 31%). Dysplasia in the SEC group was often endoscopically invisible or flat (n=42; 27%) and demonstrated nonconventional dysplastic features (n=49; 32%). Six nonconventional subtypes were identified in the SEC group, including 17 (11%) dysplasia with increased Paneth cell differentiation, 12 (8%) hypermucinous dysplasia, 8 (5%) crypt cell dysplasia, 7 (5%) goblet cell deficient dysplasia, 3 (2%) sessile serrated lesion-like dysplasia, and 2 (1%) traditional serrated adenoma-like dysplasia. Advanced neoplasia was detected in 11 (24%) patients. The SEC group was more likely to have nonconventional dysplasia (32%, P<0.001), invisible/flat dysplasia (27%, P<0.001), and advanced neoplasia (24%, P<0.001) than the control group (7%, 2%, and 0%, respectively). High-risk nonconventional subtypes (ie, hypermucinous, crypt cell, and goblet cell deficient dysplasias) accounted for 18% of all dysplastic lesions in the SEC group, which were not seen in the control group (P<0.001). The SEC group (n=35; 76%) also had a higher rate of concordance between the location of SEC and the area of synchronous/metachronous dysplasia than the control group (n=22; 49%) (P=0.007). In conclusion, dysplasia detected in patients with SEC is often endoscopically invisible/flat (27%), nonconventional (32%, including the high-risk subtypes), and found in the same colonic segment as SEC (76%), which may in part explain why some patients with SEC are associated with an increased risk of colorectal neoplasia, including advanced neoplasia. The finding of SEC may warrant a careful follow-up colonoscopy with increased random biopsy sampling, especially in the segment of colon with SEC.

The Development of Serrated Epithelial Change in Ulcerative Colitis is not Significantly Associated With Increased Histologic Inflammation

Serrated epithelial change (SEC) in inflammatory bowel disease is most often defined as hyperplastic polyp-like mucosal change detected on random biopsies. Although SEC has been reported to be associated with an increased risk of synchronous and/or metachronous colorectal neoplasia, it remains unknown if SEC represents a form of dysplastic lesion despite the lack of morphologic evidence of dysplasia. Since the risk of colorectal neoplasia in ulcerative colitis (UC) is positively correlated with increased histologic inflammation, this study investigated if increased colonic inflammation is an independent risk factor for SEC. A cohort of 28 UC patients with SEC was analyzed and compared with 51 control UC patients without SEC. None of these patients had a history of colorectal neoplasia. For each patient with SEC, all biopsies conducted before and at the time of SEC diagnosis (versus all biopsies for each control patient) were scored by using a 4-point scoring system: no activity (no epithelial infiltration by neutrophils=0); mild activity (cryptitis only=1); moderate activity (cryptitis plus crypt abscess formation in <50% of crypts=2); and severe activity (crypt abscess formation in ≥50% of crypts, erosion, neutrophilic exudate, and/or ulceration=3). Each biopsy was designated a score, and both mean and maximum inflammation scores were calculated from all biopsies taken during each colonoscopy. The inflammation burden score was calculated for each surveillance interval by multiplying the average maximum score between each pair of surveillance episodes by the length of the surveillance interval in years. The average scores of all colonoscopies for each patient were used to assign the patient's overall mean, maximum, and inflammation burden scores. The SEC cohort included 12 (43%) men and 16 (57%) women with a mean age of 47 years at the time of the first SEC diagnosis and a long history of UC (mean: 13 y). The majority of patients (n=21; 75%) had pancolitis, and only 1 (4%) patient had primary sclerosing cholangitis. A total of 37 SEC were identified in the 28 patients, 4 (14%) of whom had multifocal SEC. SEC was predominantly found in the left colon (n=32; 86%). In the multivariate analysis, none of the 3 summative inflammation scores, including overall mean (odds ratio [OR] 1.9, P =0.489), maximum (OR 0.4, P =0.259), and inflammation burden scores (OR 1.2, P =0.223), were significantly associated with the development of SEC. Similarly, no other potential risk factors, including age, gender, ethnicity, and duration and extent of UC, were significantly correlated with the detection of SEC ( P >0.05). In conclusion, the development of SEC in UC is not significantly associated with increased histologic inflammation. Given the reported association of SEC with an increased risk of synchronous and/or metachronous colorectal neoplasia, along with the presence of molecular alterations in some cases (such as TP53 mutations and aneuploidy), SEC may represent an early morphologic indicator of segmental or pan-colonic molecular abnormalities that have not advanced enough to result in colorectal neoplasia, as opposed to being a form of dysplasia.

Increased Active Inflammation in the Colon is Not a Reliable Predictor of an Elevated Risk of Dysplasia in Patients With Primary Sclerosing Cholangitis and Ulcerative Colitis

Although the increased risk of colorectal neoplasia in patients with both primary sclerosing cholangitis (PSC) and ulcerative colitis (UC; termed PSC-UC) is well documented, the mechanism through which concomitant PSC increases the risk of colorectal neoplasia remains unclear. Given that the risk of colorectal neoplasia in UC is positively correlated with increased histologic inflammation, this study sought to investigate whether increased histologic inflammation could be used to stratify the risk of dysplasia development in patients with PSC-UC. Twenty patients with PSC-UC and dysplasia were compared with 30 control patients with PSC-UC who had no history of neoplasia. For each patient, all surveillance biopsies were scored using a 4-point scoring system: (1) no epithelial neutrophils = 0, (2) cryptitis only = 1, (3) cryptitis plus crypt abscess in <50% of crypts = 2, and (4) crypt abscess in ≥50% of crypts, erosion, neutrophilic exudate, and/or ulceration = 3. A score was designated for each biopsy, and both mean and maximum inflammation scores were calculated from all biopsies taken during each colonoscopy. The inflammation burden score was calculated for each surveillance interval by multiplying the average maximum score between each pair of surveillance episodes by the length of the surveillance interval in years. The average scores derived from all colonoscopies for each patient were used to determine the patient's overall mean, maximum, and inflammation burden scores. In both the dysplasia and control groups, the 3 summative inflammation scores were calculated independently for the entire colon, right colon, and left colon. The dysplasia group consisted of 14 (70%) men and 6 (30%) women, with a mean age of 27 years at UC diagnosis and a long history of pancolitis (mean duration: 17 y). A total of 49 dysplastic lesions were detected in the dysplasia group, and 8 (40%) of the 20 patients had multifocal dysplasia. The majority of dysplastic lesions belonged to nonconventional subtypes (n = 28; 57%) and were located in the right colon (n = 37; 76%). Irrespective of the colon segment, there was no significant difference in the 3 summative inflammation scores between the dysplasia and control groups (P > 0.05). However, in each group, the 3 summative inflammation scores were significantly higher in the right colon than in the left colon (P< 0.05). In conclusion, patients with PSC-UC exhibit increased histologic inflammation in the right colon compared with the left colon, regardless of the presence of dysplasia. Although this may provide an explanation for the predominance of right-sided colorectal neoplasia in patients with PSC-UC, increased histologic inflammation does not reliably predict an elevated risk of dysplasia in patients with PSC-UC. These findings reinforce the current recommendation for annual endoscopic surveillance for all patients with PSC-UC, irrespective of the extent and severity of inflammation.

Heavy arch: from inflammatory bowel diseases to metabolic disorders

BACKGROUND

Metabolic disorders and inflammatory bowel diseases (IBD) have captured the globe during Westernisation of lifestyle and related dietary habits over the last decades. Both disease entities are characterised by complex and heterogeneous clinical spectra linked to distinct symptoms and organ systems which, on a first glimpse, do not have many commonalities in clinical practice. However, experimental studies indicate a common backbone of inflammatory mechanisms in metabolic diseases and gut inflammation, and emerging clinical evidence suggests an intricate interplay between metabolic disorders and IBD.

OBJECTIVE

We depict parallels of IBD and metabolic diseases, easily overlooked in clinical routine.

DESIGN

We provide an overview of the recent literature and discuss implications of metabolic morbidity in patients with IBD for researchers, clinicians and healthcare providers.

CONCLUSION

The Western lifestyle and diet and related gut microbial perturbation serve as a fuel for metabolic inflammation in and beyond the gut. Metabolic disorders and the metabolic syndrome increasingly affect patients with IBD, with an expected negative impact for both disease entities and risk for complications. This concept implies that tackling the obesity pandemic exerts beneficial effects beyond metabolic health.

Treatment endpoints in ulcerative colitis: Does one size fit all?

A treat-to-target strategy in inflammatory bowel disease (IBD) involves treatment intensification in order to achieve a pre-determined endpoint. Such uniform and tight disease control has been demonstrated to improve clinical outcomes compared to treatment driven by a clinician's subjective assessment of symptoms. However, choice of treatment endpoints remains a challenge in management of IBD via a treat-to-target strategy. The treatment endpoints for ulcerative colitis (UC), recommended by the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) consensus have changed somewhat over time. The latest STRIDE-II consensus advises immediate (clinical response), intermediate (clinical remission and biochemical normalisation) and long-term treatment (endoscopic healing, absence of disability and normalisation of health-related quality of life, as well as normal growth in children) endpoints in UC. However, achieving deeper levels of remission, such as histologic normalisation or healing of the gut barrier function, may further improve outcomes among UC patients. Generally, all medical therapy should seek to improve short- and long-term mortality and morbidity. Hence treatment endpoints should be chosen based on their ability to predict for improvement in short- and long-term mortality and morbidity. Potential benefits of treatment intensification need to be weighed against the potential harms within an individual patient. In addition, changing therapy that has achieved partial response may lead to worse outcomes, with failure to recapture response on treatment reversion. Patients may also place different emphasis on certain potential benefits and harms of various treatments than clinicians, or may have strong opinions re certain therapies. Potential benefits and harms of therapies, incremental benefits of achieving deeper levels of remission, as well as uncertainties of the same, need to be discussed with individual patients, and a treatment endpoint agreed upon with the clinician. Future research should focus on quantifying the incremental benefits and risks of achieving deeper levels of remission, such that clinicians and patients can make an informed decision about appropriate treatment end-point on an individual basis.

Comprehensive overview of novel chemical drugs for ulcerative colitis: focusing on phase 3 and beyond

INTRODUCTION

Despite the growing number of highly efficacious biologics and chemical drugs for ulcerative colitis (UC), steroid-free disease control is still difficult to achieve in subgroups of patients due to refractoriness, adverse events, primary or secondary failure. New treatments are therefore still required in order to optimize clinical management of patients with UC.

AREAS COVERED

The efficacy and safety of both currently available and newly developed small molecules have been summarized. The PubMed database and clinicaltrials.gov were considered in order to search for phase 2b and 3 trials on new chemical drugs for UC. The study drugs reviewed included Janus kinases (JAK) and sphingosine-1-phosphate receptor (S1Pr) inhibitors, α4 integrin antagonist, and micro-RNA-124 upregulators.

EXPERT OPINION

Rapidity of onset, low immunogenicity, and safety are the main characteristics of small molecules currently available or under evaluation for treatment patients with UC. Among the currently available chemical drugs, the selective JAK and the S1Pr inhibitors are characterized by a good safety profile combined with the ability to induce clinical remission in UC. A relatively low frequency of endoscopic improvement and healing currently appears associated with their use, being higher in UC patients treated with S1Pr inhibitor Etrasimod. Overall, additional new safe and effective drugs are still required in order to optimize disease control in a larger majority of UC patients.

Amygdalin Alleviates DSS-Induced Colitis by Restricting Cell Death and Inflammatory Response, Maintaining the Intestinal Barrier, and Modulating Intestinal Flora

Inflammatory bowel disease (IBD) refers to a cluster of intractable gastrointestinal disorders with an undetermined etiology and a lack of effective therapeutic agents. Amygdalin (Amy) is a glycoside extracted from the seeds of apricot and other Rosaceae plants and it exhibits a wide range of pharmacological properties. Here, the effects and mechanisms of Amy on colitis were examined via 16S rRNA sequencing, ELISA, transmission electron microscopy, Western blot, and immunofluorescence. The results showed that Amy administration remarkably attenuated the signs of colitis (reduced body weight, increased disease activity index, and shortened colon length) and histopathological damage in dextran sodium sulfate (DSS)-challenged mice. Further studies revealed that Amy administration significantly diminished DSS-triggered gut barrier dysfunction by lowering pro-inflammatory mediator levels, inhibiting oxidative stress, and reducing intestinal epithelial apoptosis and ferroptosis. Notably, Amy administration remarkably lowered DSS-triggered TLR4 expression and the phosphorylation of proteins related to the NF-κB and MAPK pathways. Furthermore, Amy administration modulated the balance of intestinal flora, including a selective rise in the abundance of S24-7 and a decline in the abundance of Allobaculum, Oscillospira, Bacteroides, Sutterella, and Shigella. In conclusion, Amy can alleviate colitis, which provides data to support the utility of Amy in combating IBD.

Histologic Predictors of Clinical Outcomes and Healthcare Utilization in Patients With Ileal Pouch-Anal Anastomosis

BACKGROUND

The prognostic significance of histology in ileal pouch-anal anastomosis (IPAA) remains unclear. The aim of this study was to evaluate if histologic variables are predictive of IPAA clinical outcomes and healthcare utilization.

METHODS

This was a retrospective cohort study of patients with IPAA undergoing surveillance pouchoscopy at a tertiary care institution. Pouch body biopsies were reviewed by gastrointestinal pathologists, who were blinded to clinical outcomes, for histologic features of acute or chronic inflammation. Charts were reviewed for clinical outcomes including development of acute pouchitis, chronic pouchitis, biologic or small molecule initiation, hospitalizations, and surgery. Predictors of outcomes were analyzed using univariable and multivariable logistic and Cox regression.

RESULTS

A total of 167 patients undergoing surveillance pouchoscopy were included. Polymorphonuclear leukocytes (odds ratio [OR], 1.67), ulceration and erosion (OR, 2.44), chronic inflammation (OR, 1.97), and crypt distortion (OR, 1.89) were associated with future biologic or small molecule initiation for chronic pouchitis. Loss of goblet cells was associated with development of chronic pouchitis (OR, 4.65). Pyloric gland metaplasia was associated with hospitalizations (OR, 5.24). No histologic variables were predictive of development of acute pouchitis or surgery. In an exploratory subgroup analysis of new IPAA (<1 year), loss of goblet cells was associated with acute pouchitis (OR, 14.86) and chronic pouchitis (OR, 12.56). Pyloric gland metaplasia was again associated with hospitalizations (OR, 13.99).

CONCLUSIONS

Histologic findings may be predictive of IPAA outcomes. Pathologists should incorporate key histologic variables into pouchoscopy pathology reports. Clinicians may need to more closely monitor IPAA patients with significant histologic findings.

Different levels of healing in inflammatory bowel diseases: mucosal, histological, transmural, barrier and complete healing

Mucosal healing on endoscopy has emerged as a key prognostic parameter in the management of patients with IBD (Crohn's disease, ulcerative colitis/UC) and can predict sustained clinical remission and resection-free survival. The structural basis for this type of mucosal healing is a progressive resolution of intestinal inflammation with associated healing of ulcers and improved epithelial barrier function. However, in some cases with mucosal healing on endoscopy, evidence of histological activity in mucosal biopsies has been observed. Subsequently, in UC, a second, deeper type of mucosal healing, denoted histological healing, was defined which requires the absence of active inflammation in mucosal biopsies. Both levels of mucosal healing should be considered as initial events in the resolution of gut inflammation in IBD rather than as indicators of complete transmural healing. In this review, the effects of anti-inflammatory, biological or immunosuppressive agents as well as small molecules on mucosal healing in clinical studies are highlighted. In addition, we focus on the implications of mucosal healing for clinical management of patients with IBD. Moreover, emerging techniques for the analysis of mucosal healing as well as potentially deeper levels of mucosal healing such as transmural healing and functional barrier healing of the mucosa are discussed. Although none of these new levels of healing indicate a definitive cure of the diseases, they make an important contribution to the assessment of patients' prognosis. The ultimate level of healing in IBD would be a resolution of all aspects of intestinal and extraintestinal inflammation (complete healing).

Update on Endoscopic Dysplasia Surveillance in Inflammatory Bowel Disease

As medical management of inflammatory bowel disease makes great advances, most patients with inflammatory bowel disease will have long life expectancies without need for total colectomy. With prolonged disease duration, however, there is increased risk of dysplasia leading to colorectal cancer. Multiple consensus and guideline documents have been published over the last decade with recommendations to optimize early detection and management of dysplastic lesions. Endoscopic technology has improved tremendously, even over the past few years. Previously invisible dysplasia has become visible in most cases with advanced imaging technologies that now allow for much clearer and more detailed mucosal inspection. New tools to facilitate endoscopic resection of visible lesions have also enabled patients to avoid colectomy, with resulting need to continue colon surveillance. There are limited or conflicting data leading to inconsistent recommendations regarding the need for random biopsies, the preferred endoscopic imaging technique, and surveillance intervals after resection of dysplasia. Similarly, there remains significant variability in the application of guidelines into daily practice and availability of and training with advanced imaging technologies. Here, we present a narrative review of which patients are at highest risk for dysplasia, the current guidelines on surveillance colonoscopy, factors affecting optimal mucosal visualization, enhanced imaging techniques, standardized reporting terminologies for surveillance colonoscopy, endoscopic management of dysplasia, indications for colectomy, and briefly on future potential technologies to assist in dysplasia detection.

Inflammation in the proximal colon is a risk factor for the development of colorectal neoplasia in inflammatory bowel disease patients with primary sclerosing cholangitis

Background

Patients with primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) have an increased risk of developing colorectal neoplasia (CRN) in the proximal colon.

Objectives

To evaluate whether duration and severity of inflammation are linked to the development of CRN in this population.

Design

Retrospective, case-control chart review of patients with PSC and IBD at a tertiary care center.

Methods

Disease activity was scored per colonic segment at each colonoscopy prior to the first instance of observed CRN using a modified Mayo endoscopic sub-score and histologic assessment. Patients in the CRN-positive group were compared to controls that did not.

Results

In all, 72 PSC-IBD patients with no history of CRN were identified, 13 of whom developed CRN after at least one colonoscopy at our institution. Patients in the CRN-positive group had significantly more endoscopic (p < 0.01) and histologic (p < 0.01) inflammation in the right compared to the control group prior to the development of dysplasia. There was significantly greater endoscopic inflammation in the segment of the colon with a dysplastic lesion than other segments of the colon (p = 0.018). Patients with moderate/severe lifetime endoscopic (p = 0.02) or histologic inflammation (p = 0.04) score had a lower probability of remaining free of dysplasia during follow-up. Nearly half of the patients with dysplasia had invisible lesions found on random biopsy.

Conclusions

Endoscopic and histologic inflammation in the proximal colon are risk factors for CRN in patients with PSC-IBD. PSC-IBD patients frequently have subclinical inflammation, and these findings support the practice of regular assessment of disease activity and random biopsy of inflamed and uninflamed areas in patients with PSC with the goal of reducing inflammation to prevent the development of CRN.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD

Cancer is a major cause of morbidity and mortality among people with inflammatory bowel disease (IBD). Intestinal cancers may arise as a complication of IBD itself, while extra-intestinal cancers may arise due to some of the immunosuppressive therapies used to treat IBD. Colorectal cancer (CRC) and small bowel cancer risks remain elevated among persons with IBD as compared to age-and sex-matched members of the general population, and the lifetime risk of these cancers is strongly correlated to cumulative intestinal inflammatory burden. However, the cumulative risk of cancer, even among those with IBD is still low. Some studies suggest that IBD-CRC incidence has declined over the years, possibly owing to improved treatment standards and improved detection and management of early neoplastic lesions. Across studies of extra-intestinal cancers, there are generally higher incidences of melanoma, hepatobiliary cancer, and lung cancer and no higher incidences of breast cancer or prostate cancer, with equivocal risk of cervical cancer, among persons with IBD. While the relative risks of some extra-intestinal cancers are increased with treatment, the absolute risks of these cancers remain low and the decision to forego treatment in light of these risks should be carefully weighed against the increased risks of intestinal cancers and other disease-related complications with undertreated inflammatory disease. Quality improvement efforts should focus on optimized surveillance of cancers for which surveillance strategies exist (colorectal cancer, hepatobiliary cancer, cervical cancers, and skin cancers) and the development of cost-effective surveillance strategies for less common cancers associated with IBD.

Identification of Lipocalin 2 as a Potential Ferroptosis-related Gene in Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic nonspecific inflammatory disease generally limited to the mucosa and submucosa of the colon. Recent studies suggest that ferroptosis is a novel programmed cell death that may be involved in the process of UC. However, the mechanism of ferroptosis in UC remains to be further investigated.

METHODS

The genes associated with UC and ferroptosis were screened by bioinformatics methods, and a random forest model was constructed to identify the core genes of UC and validated with external data sets. Establishment of dextran sodium sulfate (DSS) induced UC in an animal model in vivo. Interferon (IFN)-γ primed immortalized bone marrow-derived macrophages cells stimulated with Lipopolysaccharides (LPS) inflammation model and LPS-stimulated Caco-2 cells colitis model in vitro were constructed. The potential link between Lipocalin-2 (LCN2) and UC ferroptosis was explored by flow cytometry, Fe2+ assay, Western Blot, gene knockdown, hematoxylin and eosin staining, and immunohistochemistry staining.

RESULTS

Analysis of differentially expressed genes (DEGs) showed that LCN2 was highly expressed in UC. The protein-protein interaction (PPI) networks showed that ferroptosis-associated DEGs were highly correlated with the immune gene LCN2. The most important gene in the random forest model, LCN2, was identified as a core gene in UC. In the LPS/IFN-γ-induced inflammation model, LCN2 expression was elevated, lipid peroxidation, Fe2+, ACSL4 and COX-2 levels increased, whereas GPX4 and FTH1 expression decreased. Similarly, in the DSS-induced UC mouse model, Occludin, ZO-1, Claudin-1, and GPX4 expression were significantly decreased, but ACSL4 and LCN2 expression were elevated. In addition, the use of Ferrostatin-1 (Fer-1) can significantly reverse its trend. More importantly, silencing of LCN2 suppressed ferroptosis events in both the LPS/IFN-γ-induced inflammation model and the LPS-stimulated colitis model.

CONCLUSION

In conclusion, our study demonstrates that LCN2 is a key factor in the regulation of ferroptosis in UC and provides additional evidence for the important role of ferroptosis in UC.

Inflammation and Digestive Cancer

Chronic inflammation is linked to carcinogenesis, particularly in the digestive organs, i.e., the stomach, colon, and liver. The mechanism of this effect has, however, only partly been focused on. In this review, we focus on different forms of chronic hepatitis, chronic inflammatory bowel disease, and chronic gastritis, conditions predisposing individuals to the development of malignancy. Chronic inflammation may cause malignancy because (1) the cause of the chronic inflammation is itself genotoxic, (2) substances released from the inflammatory cells may be genotoxic, (3) the cell death induced by the inflammation induces a compensatory increase in proliferation with an inherent risk of mutation, (4) changes in cell composition due to inflammation may modify function, resulting in hormonal disturbances affecting cellular proliferation. The present review focuses on chronic gastritis (Helicobacter pylori or autoimmune type) since all four mechanisms may be relevant to this condition. Genotoxicity due to the hepatitis B virus is an important factor in hepatocellular cancer and viral infection can similarly be central in the etiology and malignancy of inflammatory bowel diseases. Helicobacter pylori (H. pylori) is the dominating cause of chronic gastritis and has not been shown to be genotoxic, so its carcinogenic effect is most probably due to the induction of atrophic oxyntic gastritis leading to hypergastrinemia.

Optimizing individualized management of patients with ulcerative colitis: Identification of risk factors predicting ulcerative colitis-associated neoplasia

The risk of developing colorectal neoplasia in patients with ulcerative colitis (UC) is increased. The purpose of this study is to analyze the risk factors of UC-associated neoplasia (UCAN) in UC patients and establish a clinical prediction model. 828 UC patients were included in this retrospective study. 602 patients were in discovery cohort and 226 patients were in validation cohort (internal validation cohort/external validation cohort: 120/106). Clinical and endoscopic data were collected. The discovery cohort was divided into UC group and UCAN group for univariate and multivariate binary logistic analyses. The UCAN clinical prediction model was established and verified. In the univariate analysis, 7 risk factors were related to UCAN. Multivariate logistic regression analysis showed that age at diagnosis of UC (OR: 1.018, 95% CI: 1.003-1.033), Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score (OR: 1.823, 95% CI: 1.562-2.128), and size of polyps (size1: OR: 6.297, 95% CI: 3.669-10.809; size2: OR: 12.014, 95% CI: 6.327-22.814) were independent risk factors of UCAN. A mathematical equation was established. The area under the ROC curve (AUC) of this model was calculated to be 0.845 (95%CI: 0.809-0.881). The sensitivity was 0.884 and the specificity was 0.688. The AUC of internal validation cohort was 0.901 (95%CI: 0.815, 0.988), sensitivity was 75.0% and specificity was 92.6%. The AUC of external validation cohort was 0.842 (95%CI: 0.709, 0.976), sensitivity was 62.5% and specificity was 93.9%. This prediction model is simple, practical, and effective for predicting the risk of UCAN, which is beneficial to the individualized management of patients with UC.

A Current State of Proteomics in Adult and Pediatric Inflammatory Bowel Diseases: A Systematic Search and Review

Inflammatory bowel diseases (IBD) are systemic immune-mediated conditions with predilection for the gastrointestinal tract and include Crohn's disease and ulcerative colitis. Despite the advances in the fields of basic and applied research, the etiopathogenesis remains largely unknown. As a result, only one third of the patients achieve endoscopic remission. A substantial portion of the patients also develop severe clinical complications or neoplasia. The need for novel biomarkers that can enhance diagnostic accuracy, more precisely reflect disease activity, and predict a complicated disease course, thus, remains high. Genomic and transcriptomic studies contributed substantially to our understanding of the immunopathological pathways involved in disease initiation and progression. However, eventual genomic alterations do not necessarily translate into the final clinical picture. Proteomics may represent a missing link between the genome, transcriptome, and phenotypical presentation of the disease. Based on the analysis of a large spectrum of proteins in tissues, it seems to be a promising method for the identification of new biomarkers. This systematic search and review summarize the current state of proteomics in human IBD. It comments on the utility of proteomics in research, describes the basic proteomic techniques, and provides an up-to-date overview of available studies in both adult and pediatric IBD.

Assessment of the Degree of Variation of Histologic Inflammation in Ulcerative Colitis

INTRODUCTION

Treatment of ulcerative colitis (UC) now includes mucosal healing. Adoption of histologic end points is hindered by a lack of evidence guiding optimal sampling, interpretation, and reproducibility of results.

METHODS

We analyzed biopsy fragments from colonoscopies in 92 patients with UC. Fragments were scored using 6-point histologic inflammatory activity (HIA) scale. Variability was determined using ordinal representations of HIA scores. The most frequently observed score and percentage of biopsy fragments with that score were determined for each biopsy, each segment, and across all 3 segments for each colonoscopy. Mean percentages and 95% confidence intervals (CIs) were calculated.

RESULTS

We reviewed 1802 biopsy fragments. The mean percentages of intrasegment biopsy fragments with the same HIA score were 85.5% (95% CI, 80.9% to 92.9%), 79.6% (95% CI, 76.0% to 87.3%), and 82.7% (95% CI, 79.1% to 90.0%) for the rectum, left colon, and right colon, respectively. The mean percentage of intersegment biopsy fragments with the same HIA score was 70.2% (95% CI, 65.7% to 82.5%). The mean percentages of intrabiopsy fragments with the same HIA score were 83.3% (95% CI, 77.6% to 93.5%), 83.6% (95% CI, 80.1% to 89.7%), and 90.2% (95% CI, 87.6% to 94.7%) for the rectum, left colon, and right colon, respectively. All 3 analyses revealed increased variation when a greater degree of histologic inflammation was present in the biopsies (mean HIA score ≥2).

CONCLUSIONS

We found minimal variability between degree of inflammation among biopsy fragments within and among different colorectal segments in UC, suggesting that even a single biopsy would adequately reflect the inflammation of the entire colorectum. These findings have significant implications for the use of histology as a clinical target and trial end point in UC.

Increased Risk of Non-conventional and Invisible Dysplasias in Patients with Primary Sclerosing Cholangitis and Inflammatory Bowel Disease

BACKGROUND AND AIMS

Patients with primary sclerosing cholangitis and inflammatory bowel disease [termed PSC-IBD] have a higher risk of developing colorectal neoplasia than those with IBD alone. The mechanism by which concomitant PSC increases the risk of colorectal neoplasia remains unknown. Seven distinct non-conventional dysplastic subtypes have been recently described in IBD, including crypt cell dysplasia, hypermucinous dysplasia, goblet cell-deficient dysplasia, dysplasia with increased Paneth cell differentiation [DPD], sessile serrated lesion [SSL]-like dysplasia, traditional serrated adenoma [TSA]-like dysplasia, and serrated dysplasia, not otherwise specified [NOS]. Despite the lack of high-grade morphological features, crypt cell, hypermucinous, and goblet cell-deficient dysplasias often show molecular features characteristic of advanced neoplasia [i.e. aneuploidy and KRAS mutations] and are more frequently associated with advanced neoplasia than conventional dysplasia on follow-up. We aimed to characterise clinicopathological features of dysplasia found in PSC-IBD patients.

METHODS

A cohort of 173 PSC-IBD patients were analysed. All dysplastic lesions were subtyped as either conventional or non-conventional dysplasia. The clinicopathological features of PSC-IBD patients with neoplasia were also compared with those of non-PSC IBD patients with neoplasia.

RESULTS

There were 109 [63%] men and 64 [37%] women, with a mean age of 26 years at IBD diagnosis and a long history of IBD [mean duration: 14 years]. Ulcerative colitis was the most common IBD subtype [80%], and the majority of patients [92%] had a history of pancolitis. A total of 153 dysplastic lesions were detected in 54 [31%] patients, 35 [65%] of whom had multifocal dysplasia. One additional patient presented with colorectal cancer [CRC] without a history of dysplasia. Dysplasia was often non-conventional [n = 93; 61%], endoscopically/grossly invisible [n = 101; 66%], and right/proximal-sided [n = 90; 59%]. All seven non-conventional subtypes were identified, including 46 [30%] crypt cell dysplasia, 23 [15%] hypermucinous dysplasia, 12 [8%] goblet cell-deficient dysplasia, seven [5%] DPD, three [2%] TSA-like dysplasia, one [1%] SSL-like dysplasia, and one [1%] serrated dysplasia NOS. Follow-up information was available for 86 lesions, of which 32 [37%] were associated with subsequent detection of advanced neoplasia [high-grade dysplasia or CRC] within a mean follow-up time of 55 months. PSC-IBD patients with neoplasia were more likely to have pancolitis [98%, p = 0.039] and a longer IBD duration [mean: 17 years, p = 0.021] than those without neoplasia [89% and 12 years, respectively]. When compared with a cohort of non-PSC IBD patients with neoplasia, the PSC-IBD group with neoplasia was more often associated with non-conventional [61%, p <0.001], invisible [66%, p <0.001], and right/proximal-sided [59%, p = 0.045] dysplasias [vs 25%, 21%, and 47%, respectively, for the non-PSC IBD group]. The rate of advanced neoplasia was nearly 2-fold higher in the PSC-IBD group [37%] compared with the non-PSC IBD group [22%] [p = 0.035].

CONCLUSIONS

Nearly a third of PSC-IBD patients developed dysplasia, which is often associated with non-conventional dysplastic features, invisible endoscopic/gross appearance, right/proximal-sided colon, multifocality, and advanced neoplasia on follow-up. These findings underscore the importance of recognising these non-conventional subtypes by practising pathologists and the need for careful and frequent endoscopic surveillance, with random biopsies, in PSC-IBD patients.

Chemoprevention of Colitis-Associated Dysplasia or Cancer in Inflammatory Bowel Disease

The association between inflammatory bowel disease and colorectal cancer is well known. Although the overall incidence of inflammatory bowel disease has declined recently, patients with this disease still have a 1.7-fold increased risk of colorectal cancer. The risk factors for developing colorectal cancer include extensive colitis, young age at diagnosis, disease duration, primary sclerosing cholangitis, chronic colonic mucosal inflammation, dysplasia lesion, and post-inflammatory polyps. In patients with inflammatory bowel disease, control of chronic inflammation and surveillance colonoscopies are important for the prevention of colorectal cancer. The 2017 guidelines from the European Crohn's and Colitis Organisation suggest that colonoscopies to screen for colorectal cancer should be performed when inflammatory bowel disease symptoms have lasted for 8 years. Current evidence supports the use of chemoprevention therapy with mesalamine to reduce the risk of colorectal cancer in patients with ulcerative colitis. Other compounds, including thiopurine, folic acid, statin, and tumor necrosis factor-α inhibitor, are controversial. Large surveillance cohort studies with longer follow-up duration are needed to evaluate the impact of drugs on colorectal cancer risks.

Inflammatory Bowel Disease Risk Variants Are Associated with an Increased Risk of Skin Cancer

BACKGROUND

Inflammatory bowel disease is associated with an increased risk of skin cancer. The aims of this study were to determine whether IBD susceptibility variants are also associated with skin cancer susceptibility and if such risk is augmented by use of immune-suppressive therapy.

METHODS

The discovery cohort included participants in the UK Biobank. The validation cohort included participants in the Michigan Genomics Initiative. The primary outcome of interest was skin cancer, subgrouped into nonmelanoma skin cancers (NMSC) and melanoma skin cancers (MSC). Multivariable logistic regression with matched controls (3 controls:1 case) was performed to identify genomic predictors of skin malignancy in the discovery cohort. Variants with P < .05 were tested for replication in the validation cohort. Validated Single nucleotide polymorphisms were then evaluated for effect modification by immune-suppressive medications.

RESULTS

The discovery cohort included 10,247 cases of NMSC and 1883 cases of MSC. The validation cohort included 7334 cases of NMSC and 3304 cases of MSC. Twenty-nine variants were associated with risk of NMSC in the discovery cohort, of which 5 replicated in the validation cohort (increased risk, rs7773324-A [DUSP22; IRF4], rs2476601-G [PTPN22], rs1847472-C [BACH2], rs72810983-A [CPEB4]; decreased risk, rs6088765-G [PROCR; MMP24]). Twelve variants were associated with risk of MSC in the discovery cohort, of which 4 were replicated in the validation cohort (increased risk, rs61839660-T [IL2RA]; decreased risk, rs17391694-C [GIPC2; MGC27382], rs6088765-G [PROCR; MMP24], and rs1728785-C [ZFP90]). No effect modification was observed.

CONCLUSIONS

The results of this study highlight shared genetic susceptibility across IBD and skin cancer, with increased risk of NMSC in those who carry risk variants in IRF4, PTPN22, CPEB4, and BACH2 and increased risk of MSC in those who carry a risk variant in IL2RA.

Endo-histologic Normalization Is Achievable with Tofacitinib and Is Associated with Improved Clinical Outcomes

BACKGROUND

Recent real-world effectiveness studies investigating tofacitinib have been encouraging. Questions remain regarding the long-term effectiveness and safety of tofacitinib, effect on endoscopic remission rates, histologic changes, and alterations in fecal calprotectin levels.

METHODS

This retrospective study includes consecutive patients with inflammatory bowel disease (IBD) who initiated tofacitinib therapy. We reviewed electronic medical records for demographic and clinical data, as well as all adverse events and hospitalizations. All patients receiving tofacitinib were included in the safety analysis and only patients with ulcerative colitis (UC) were included in the effectiveness analysis.

RESULTS

119 patients with IBD (97 UC, 12 CD, and 10 pouchitis) seen at our center between 2014 and 2020 were included in this study. Median follow-up was 32 weeks (interquartile range (IQR) 3-252). Clinical response and remission were observed in 70% and 21%, 59% and 33%, and 49%, and 37% at weeks 8, 24, and 52, respectively. Endo-histologic healing was achieved by 11%, 25%, and 37.5% of patients at weeks 8, 24, and 52, respectively. Histologic normalization occurred as early as 24 weeks in this cohort and was achieved by 26% of patients in endoscopic remission. Overall, there were 27 (25%) adverse events with 6 (5%) resulting in treatment discontinuation. There were 11 (10%) infections, none required treatment discontinuation. Ten (10.3%) patients underwent colectomy during the follow-up period. There were no cardiovascular adverse events in the cohort during follow-up.

CONCLUSION

This study demonstrates the effectiveness and long-term safety of tofacitinib in patients with UC. Importantly, we show that the endpoint of endo-histologic healing is achievable with tofacitinib and can occur as early as week 8 of therapy.

Histopathological assessment of the microscopic activity in inflammatory bowel diseases: What are we looking for?

Advances in diagnostics of inflammatory bowel diseases (IBD) and improved treatment strategies allowed the establishment of new therapeutic endpoints. Currently, it is desirable not only to cease clinical symptoms, but mainly to achieve endoscopic remission, a macroscopic normalization of the bowel mucosa. However, up to one-third of IBD patients in remission exhibit persisting microscopic activity of the disease. The evidence suggests a better predictive value of histology for the development of clinical complications such as clinical relapse, surgical intervention, need for therapy escalation, or development of colorectal cancer. The proper assessment of microscopic inflammatory activity thus became an important part of the overall histopathological evaluation of colonic biopsies and many histopathological scoring indices have been established. Nonetheless, a majority of them have not been validated and no scoring index became a part of the routine bioptic practice. This review summarizes a predictive value of microscopic disease activity assessment for the subsequent clinical course of IBD, describes the most commonly used scoring indices for Crohn's disease and ulcerative colitis, and comments on current limitations and unresolved issues.

Colorectal Cancer in Inflammatory Bowel Diseases: Epidemiology and Prevention: A Review

Simple Summary

Colorectal cancer (CRC) is one of the most serious potential complications of inflammatory bowel diseases (IBDs). The aging of patients affected by IBDs makes this issue a challenge that will increasingly be faced by clinicians in clinical practice, especially in light of the poorer prognosis for CRC in this group of people when compared with the general population. In this review, we summarize the current epidemiology, risk factors and various prevention strategies proposed for CRC in patients with IBDs.

Abstract

Colorectal cancer (CRC) is currently the third most frequent form of malignancy and the second in terms of mortality. Inflammatory bowel diseases (IBDs) are recognized risk factors for this type of cancer. Despite a worldwide increase in the incidence of CRC, the risk of CRC-related death in IBD patients has declined over time, probably because of successful surveillance strategies, the use of more effective drugs in the management of remission and improved indications to colectomy. This notwithstanding, CRC 5-year survival in patients with IBD is poorer than in the general population. This review provides a summary of the epidemiological features, risk factors and various prevention strategies proposed for CRC in IBD patients. Moreover, there is a special focus on reporting and highlighting the various prevention strategies proposed by the most important international scientific societies, both in terms of chemoprevention and endoscopic surveillance. Indeed, in conducting the analysis, we have given attention to the current primary, secondary and tertiary prevention guidelines, attempting to emphasize unresolved research and clinical problems related to this topic in order to improve diagnostic strategies and management.

Increased Histologic Inflammation is an Independent Risk Factor for Non-Conventional Dysplasia in Ulcerative Colitis

AIMS

Several types of non-conventional dysplasia have been described in inflammatory bowel disease. Hypermucinous, goblet cell deficient, and crypt cell dysplasias are considered high-risk subtypes, as they often have molecular features of advanced neoplasia (e.g., aneuploidy) and are more frequently associated with advanced neoplasia than conventional dysplasia. This study investigated if increased colonic inflammation is a risk factor for non-conventional dysplasia.

METHODS AND RESULTS

A cohort of 125 patients with ulcerative colitis (UC)-associated dysplasia were analyzed and compared with 50 control UC patients without a history of neoplasia. For each patient, all biopsies prior to the initial detection of dysplasia were scored using a 4-point inflammatory activity score. Both mean and maximum scores from all biopsies taken during each colonoscopy were derived. Inflammation burden was calculated by multiplying average maximum score between each pair of surveillance episodes by length of surveillance interval in years. The average scores of all colonoscopies were used to calculate overall mean, maximum, and inflammation burden scores. In multivariate analyses, higher maximum (odds ratio [OR] 3.4) and inflammation burden (OR 4.2) scores were significantly associated with the detection of dysplasia (p < 0.05). Similarly, higher mean and maximum scores increased the odds of non-conventional dysplasia by 2.7 and 4.9, respectively (p < 0.05). There was a stronger association between these two scores and high-risk subtypes (ORs 4.0 and 7.5, respectively, p < 0.05).

CONCLUSIONS

The risk of non-conventional dysplasia is significantly associated with increased inflammation, which may contribute to its higher rates of aneuploidy and malignancy.

Biological roles of toll-like receptors and gut microbiota in colorectal cancer

Colorectal cancer (CRC) is one of the most considerably common malignancies of the alimentary system, with high mortality and incidence rates.  The present study suggested that the occurrence of CRC is closely related to bacteria, as the large intestine is a gathering place for human micro-organisms. However, the nosogenesis of bacteria leading to tumorigenesis is still obscure. Recently, many studies have reported that toll-like receptors and their related molecular pathways are involved in the process of gut micro-organisms generating CRC. Gut micro-organisms can promote or inhibit the development of CRC via binding to special toll-like receptors. In this paper, the authors review the relationship among toll-like receptors, gut micro-organisms and CRC in order to provide a reference for future tumor immunotherapy and targeted therapy.

Histopathology of Colectomy Specimens Predicts Endoscopic Pouch Phenotype in Patients with Ulcerative Colitis

BACKGROUND

The endoscopic appearance in patients with "pouchitis" after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) can be quite heterogenous. Patients with an endoscopic phenotype resembling Crohn's disease (CD) are at high risk of pouch loss.

AIMS

We aimed to assess how the histopathology of colectomy specimens predicts endoscopic pouch phenotypes in UC.

METHODS

We retrospectively assessed pouchoscopies from patients with UC who underwent IPAA and classified pouch findings into 7 main phenotypes: (1) normal, (2) afferent limb involvement, (3) inlet involvement, (4) diffuse, (5) focal inflammation of the pouch body, (6) cuffitis, and (7) pouch with fistulas noted ≥ 6 months from ileostomy takedown. We assessed the clinical and pathological data including deep, focal inflammation, granulomas, and terminal ileal involvement in the colectomy specimens. Logistic regression analysis was performed to identify contributing factors to each phenotype.

RESULTS

This study included 1,203 pouchoscopies from 382 patients with UC. On multivariable analysis, deep inflammation was significantly associated with pouch fistulas (Odds ratio 3.27; 95% confidence interval 1.65-6.47; P = 0.0007). Of the 75 patients with deep inflammation, only two patients (2.7%) were diagnosed with CD based on pathology review. Terminal ileal involvement significantly increased the risk of afferent limb involvement (Odds ratio 2.96; 95% confidence interval 1.04-8.47; P = 0.04). There were no significant associations between other microscopic features and phenotypes.

CONCLUSIONS

We identify histologic features of colectomy specimens in UC that predict subsequent pouch phenotypes. Particularly, deep inflammation in the resected colon was significantly associated with pouch fistulas, a pouch phenotype with poor prognosis.

Role of a mixed probiotic product, VSL#3, in the prevention and treatment of colorectal cancer

Colorectal cancer (CRC) is a multifactorial disease. The incidence of this type of cancer in younger patients has increased in recent years, and more strategies are needed to prevent and delay the progression of CRC. Probiotics play an adjunctive role in the prevention and treatment of CRC and can not only prevent the onset and delay the progression of disease but also reduce the side effects after the application of anti-cancer drugs. The anti-cancer effect of individual probiotics has been extensively studied, and the exact curative effect of various probiotics has been found, but the anti-cancer effect of mixed probiotics is still not well summarized. In this review, we discuss the positive effects of mixed probiotics on CRC and the related mechanisms of action, especially VSL#3 (VSL Pharmaceuticals, Inc., Gaithersburg, MD, USA), thus providing new ideas for the treatment of CRC. Moreover, we suggest the need to search for more therapeutic possibilities, especially via the research and application of synbiotics and postbiotics.

Intestinal Cancer and Dysplasia in Crohn's Disease

Crohn's disease is associated with an increased risk of adenocarcinoma of the involved portions of the small bowel and colorectum and has similar risk factors to those described in ulcerative colitis, most significantly, extent of bowel involvement, PSC, and duration of unresected disease. Prevention strategies include risk stratification and secondary prevention with colonoscopic screening and surveillance to identify dysplasia or early-stage cancers, with surgery when needed. There is emerging information to suggest that control of inflammation may provide primary prevention of neoplasia, but further studies are required to test this strategy.

Oral Conventional Synthetic Disease-Modifying Antirheumatic Drugs with Antineoplastic Potential: a Review

There is an increasing trend of malignancy worldwide. Disease-modifying antirheumatic drugs (DMARDs) are the cornerstones for the treatment of immune-mediated inflammatory diseases (IMIDs), but risk of malignancy is a major concern for patients receiving DMARDs. In addition, many IMIDs already carry higher background risks of neoplasms. Recently, the black box warning of malignancies has been added for Janus kinase inhibitors. Also, the use of biologic DMARDs in patients with established malignancies is usually discouraged owing to exclusion of such patients in pivotal studies and, hence, lack of evidence. In contrast, some conventional synthetic DMARDs (csDMARDs) have been reported to show antineoplastic properties and can be beneficial for patients with cancer. Among the csDMARDs, chloroquine and hydroxychloroquine have been the most extensively studied, and methotrexate is an established chemotherapeutic agent. Even cyclosporine A, a well-known drug associated with cancer risk, can potentiate the effect of some chemotherapeutic agents. We review the possible mechanisms behind and clinical evidence of the antineoplastic activities of csDMARDs, including chloroquine and hydroxychloroquine, cyclosporine, leflunomide, mycophenolate mofetil, mycophenolic acid, methotrexate, sulfasalazine, and thiopurines. This knowledge may guide physicians in the choice of csDMARDs for patients with concurrent IMIDs and malignancies.

Cigarette Smoke Increases Risk for Colorectal Neoplasia in Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease are at increased risk of colorectal neoplasia (CRN) due to mucosal inflammation. As current surveillance guidelines form a burden on patients and healthcare costs, stratification of high-risk patients is crucial. Cigarette smoke reduces inflammation in ulcerative colitis (UC) but not Crohn's disease (CD) and forms a known risk factor for CRN in the general population. Due to this divergent association, the effect of smoking on CRN in IBD is unclear and subject of this study.

METHODS

In this retrospective cohort study, 1,386 IBD patients with previous biopsies analyzed and reported in the PALGA register were screened for development of CRN. Clinical factors and cigarette smoke were evaluated. Patients were stratified for guideline-based risk of CRN. Cox-regression modeling was used to estimate the effect of cigarette smoke and its additive effect within the current risk stratification for prediction of CRN.

RESULTS

153 (11.5%) patients developed CRN. Previously described risk factors, i.e. first-degree family member with CRN in CD (p-value=.001), presence of post-inflammatory polyps in UC (p-value=.005), were replicated. Former smoking increased risk of CRN in UC (HR 1.73; 1.05-2.85), whereas passive smoke exposure yielded no effect. For CD, active smoking (2.20; 1.02-4.76) and passive smoke exposure (1.87; 1.09-3.20) significantly increased CRN risk. Addition of smoke exposure to the current risk-stratification model significantly improved model fit for CD.

CONCLUSIONS

This study is the first to describe the important role of cigarette smoke in CRN development in IBD patients. Adding this risk factor improves the current risk stratification for CRN surveillance strategies.

What Does Disease Progression Look Like in Ulcerative Colitis, and How Might It Be Prevented?

Ulcerative colitis (UC) has been characterized by inflammation limited to the mucosa. Although sustained and durable remission has been associated with mucosal healing, the recurrent phenomenon of persistent clinical disease activity despite mucosal healing has been observed in clinical practice and across pivotal trials. Over time, UC appears to confer an increased risk of progression, defined as changes of disease phenotype; adverse transmural effects on the bowel wall; increased risk of neoplasia development; worsening colorectal function; and increased risk of colectomy, hospitalizations, and other extraintestinal comorbidities. Although the treatment paradigm for Crohn's disease has shifted toward early aggressive intervention to prevent disease progression and irreversible bowel damage, such urgency in efforts to halt disease progression in UC have been largely overlooked. This review summarizes the multiple facets of UC contributing to a modified perception of the disease as a progressive one. We propose further study of the natural history and priorities for further treatment goals that include these considerations.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

Colorectal cancer screening and surveillance in patients with inflammatory bowel disease in 2021

The detection of dysplasia in patients with inflammatory bowel disease (IBD) continues to be important given the increased risk of colorectal cancer in this population. Therefore, in 2017, we performed a review and update of the recommendations for the management and follow-up of patients with IBD based on the clinical practice guidelines of various scientific societies. The present manuscript focuses on new aspects of the detection, follow-up, and management of dysplasia according to the latest studies and recommendations. While chromoendoscopy with targeted biopsy continues to be the technique of choice for the screening and detection of dysplasia in IBD, the associated difficulties mean that it is now being compared with other techniques (virtual chromoendoscopy), which yield similar results with less technical difficulties. Furthermore, the emergence of new endoscopy techniques that are still being researched but seem promising (e.g., confocal laser endomicroscopy and full-spectrum endoscopy), together with the development of devices that improve endoscopic visualization (e.g., Endocuff Vision), lead us to believe that these approaches can revolutionize the screening and follow-up of dysplasia in patients with IBD. Nevertheless, further studies are warranted to define the optimal follow-up strategy in this patient population.

Incident Colorectal Cancer in Inflammatory Bowel Disease

Colorectal cancer (CRC) risk is increased in Inflammatory Bowel Disease (IBD) and surveillance needs to be tailored according to individual risk. The open issues include the role of the characteristics of IBD and CRC in determining the long-term outcome. These issues were assessed in our multicenter study, including a cohort of 56 IBD patients with incident CRC. The clinical and histopathological features of IBD patients and of CRC were recorded. Incident CRC in IBD occurred at a young age (≤40 years) in 25% of patients (median age 55.5 (22-76)). Mucinous signet-ring carcinoma was detected in 6 out of the 56 (10.7%) patients, including 4 with Ulcerative Colitis (UC) and 2 with Crohn's disease (CD). CRC was more frequently diagnosed by colonoscopy in UC (85.4% vs. 50%; p = 0.01) and by imaging in Crohn's Disease CD (5.8% vs. 31.8%; p = 0.02). At onset, CRC-related symptoms occurred in 29 (51.9%) IBD patients. The time interval from the diagnosis of IBD to CRC was shorter in UC and CD patients with >40 years (p = 0.002; p = 0.01). CRC-related death occurred in 10 (29.4%) UC and in 6 (27.2%) CD patients (p = 0.89), with a short time interval from CRC to death (UC vs. CD: 6.5 (1-68) vs. 14.5 (8-40); p = 0.85; IBD: 12 months (1-68)). CRC occurring at a young age, a short time interval from the diagnosis of IBD to CRC-related death in the elderly, CRC-symptoms often mimicking IBD relapse and the observed high mortality rate may support the need of closer surveillance intervals in subgroups of patients.

Risk of malignancy in patients with inflammatory bowel disease: a population-based cohort study from China

Carcinogenesis is one of major complications for patients with inflammatory bowel disease (IBD) and causes poor prognosis. We aimed to describe cancer incidence in Chinese IBD cohort compared with general population-based cancer registration data and further explore associated risk factors for cancer occurrence in IBD patients. IBD inpatients from January 1998 to January 2018 were included in this study. Patients were followed up from date of IBD diagnosis until either the date of first cancer diagnosis or January 2019. Standardized incidence ratios (SIRs) of overall cancer and site-specific cancers were calculated. A total of 869 UC and 516 CD patients were finally included with median follow-up time of 7 and 5 years respectively. 53 cases developed malignancies. After standardization by age and gender, standardized incidence ratio (SIR) of total cancer occurrence in IBD patients was 1.77 (95%CI, 1.33-2.32). As for UC, digestive cancers (SIR 3.75; 95%CI, 2.29-5.80), thyroid cancer (SIR 10.34; 95%CI, 4.72-19.64) and hematological malignancies (SIR 6.25; 95%CI, 1.68-16.00) had the highest incidence, which were prominent in young and middle-aged patients. Use of steroids, immunosuppressants or infliximab did not present higher risk of malignancies in UC patients. There were no significant difference in cancer risk between CD patients and general population. In conclusion, the increased risks of multiple cancers are particularly prominent in Chinese UC patients and these findings can provide more targeted guidance for cancer monitoring in Chinese IBD patients.

5-Aminosalicylic Acid Chemoprevention in Inflammatory Bowel Diseases: Is It Necessary in the Age of Biologics and Small Molecules?

BACKGROUND

Due to the increased incidence of colorectal cancer in inflammatory bowel diseases (IBDs), the value of chemoprevention for this patient group has been repeatedly debated in the past decade. This review describes available evidence and the current recommendations for chemoprevention in national and international guidelines IBD guidelines.

SUMMARY

5-Aminosalicylic acid (5-ASA) compounds are the preferred therapeutic option for mild to moderate ulcerative colitis (UC). Aside from the known anti-inflammatory effects, their chemopreventive abilities have been described in vitro and in vivo. Pooling the increasing number of retrospective and population-based clinical studies over the last 15 years, 7 consecutive meta-analyses revealed partially conflicting results for the chemopreventive efficacy of 5-ASA, and thus, not all IBD guidelines currently recommend chemoprevention with mesalamine compounds. Accumulating evidence for decreasing the colorectal cancer (CRC) risk in support of thiopurines more recently shows a protective effect. This effect seems solely mediated by control of intestinal inflammation since, for this drug class, another mechanistic interference in IBD-associated CRC pathogenesis is not known. The results regarding chemopreventive efficacy for ursodeoxycholic acid or folic acid are equivocal, and the use of these medications to prevent CRC is not firmly established. Like UC, the risk of CRC is also significantly increased in patients with Crohn's disease (CD), especially Crohn's colitis. However, no published studies exclusively assess the effects of surveillance on the early detection of cancer or CRC chemoprevention in CD patients. In meta-analyses, which predominantly included UC patients, 5-ASA or thiopurines were not beneficial in small CD subgroups. The level of evidence for anti-TNFα agents, anti-integrin (e.g., vedolizumab), or anti-IL-12/IL-23 agents (e.g., ustekinumab) and Janus kinase inhibitors is currently too low or nonexistent to use them solely for chemoprevention in UC or CD patients.

KEY MESSAGE

Intestinal inflammation is one of the main risk factors for developing CRC in IBD, and all drugs that induce and maintain mucosal healing most likely also decrease the IBD-associated CRC risk. Thus, a therapeutic strategy of adding a 5-ASA therapy to a successfully mucosal healing-inducing therapy, for example, with a biologic or a small molecule merely to prevent CRC appears to be obsolete.

Measuring Histologic Activity in Inflammatory Bowel Disease: Why and How

Histology is used to confirm the diagnosis of inflammatory bowel disease, exclude superimposed infections, and to evaluate for dysplasia. Histology has rarely been used to measure disease activity and guide therapy despite evidence that histologic measurements have value in predicting important clinical outcomes. More recently, there have been numerous studies supporting a role for histologic disease activity measurements in predicting a variety of outcomes including relapse, hospitalizations, steroid use, and dysplasia. The histologic assessment was superior to endoscopic measurements in many of these studies. This review will summarize the recent literature regarding histologic disease activity measurements in ulcerative colitis and Crohn disease. A detailed description of histologic scoring systems will also be provided to provide pathologists with the necessary tools to accurately measure disease activity.

Microbiome-Mediated Immune Signaling in Inflammatory Bowel Disease and Colorectal Cancer: Support From Meta-omics Data

Chronic intestinal inflammation and microbial dysbiosis are hallmarks of colorectal cancer (CRC) and inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis. However, the mechanistic relationship between gut dysbiosis and disease has not yet been fully characterized. Although the “trigger” of intestinal inflammation remains unknown, a wealth of evidence supports the role of the gut microbiome as a mutualistic pseudo-organ that significantly influences intestinal homeostasis and is capable of regulating host immunity. In recent years, culture-independent methods for assessing microbial communities as a whole (termed meta-omics) have grown beyond taxonomic identification and genome characterization (metagenomics) into new fields of research that collectively expand our knowledge of microbiomes. Metatranscriptomics, metaproteomics, and metabolomics are meta-omics techniques that aim to describe and quantify the functional activity of the gut microbiome. Uncovering microbial metabolic contributions in the context of IBD and CRC using these approaches provides insight into how the metabolic microenvironment of the GI tract shapes microbial community structure and how the microbiome, in turn, influences the surrounding ecosystem. Immunological studies in germ-free and wild-type mice have described several host-microbiome interactions that may play a role in autoinflammation. Chronic colitis is a precursor to CRC, and changes in the gut microbiome may be an important link triggering the neoplastic process in chronic colitis. In this review, we describe several microbiome-mediated mechanisms of host immune signaling, such as short-chain fatty acid (SCFA) and bile acid metabolism, inflammasome activation, and cytokine regulation in the context of IBD and CRC, and discuss the supporting role for these mechanisms by meta-omics data.

Histological inflammatory activity can predict endoscopic relapse in patients with ulcerative colitis who have achieved mucosal healing

BACKGROUND AIMS

Current therapeutic goals in ulcerative colitis (UC) include clinical and endoscopic remission, named mucosal healing (MH). Despite MH, a proportion of patients suffer a clinical relapse, which has been related to histological inflammation. We aimed to identify which histopathological features or histopathological index cut-off was associated with endoscopic relapse (ER) in UC patients with MH.

METHODS

Retrospective analysis of UC patients who underwent surveillance colonoscopy showing complete MH (endoscopic Mayo subscore=0) with random biopsies, and at least one more endoscopy along the follow-up. After a consensus meeting, expert pathologist performed histological assessment according to Simplified Geboes Score (SGS), Nancy Index (NI) and Robarts Histopathological Index (RHI). Other histopathological features were also evaluated. Patients were followed until ER or last endoscopy performed showing persistence of MH.

RESULTS

A total of 95 patients (150 colonoscopies) were included. After mean follow-up of 31.2 months (SD 21.7), 33 patients (34.7%) suffered ER. Neutrophils in lamina propria (OR 2.6; P = 0.037), within the epithelium (OR 2.6; P = 0.03), SGS ≥3.1 (OR 2.6; P = 0.037), NI ≥2 (OR 2.6; P = 0.03) and RHI ≥5 (OR 2.6; P = 0.037) were associated with ER in univariate analysis. In multivariate analysis, eosinophils in the lamina propria (HR 2.5; P = 0.01) and clinical remission<12 months (HR 3.2; P = 0.002) were associated with ER.

CONCLUSIONS

Histopathological findings in UC patients who have achieved endoscopic MH may predict ER. Standardized histopathology reports according to the presence of neutrophils, eosinophils or to defined cut-off of validated histopathologic indexes may represent a useful tool to predict ER and should be considered at therapeutic and surveillance decision process.

A Systematic Review and Meta-Analysis on the Association between Inflammatory Bowel Disease Family History and Colorectal Cancer

Background

Colorectal cancer (CRC) and inflammatory bowel disease (IBD) are closely interrelated. However, the effect of having a family history of one disease on the risk of another remains undetermined.

Aim

The purpose of this meta-analysis was to estimate the prevalence of a family history of CRC among patients with IBD, as well as the prevalence of a family history of IBD among patients with CRC.

Methods

PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched to identify studies reporting the prevalence of family history of IBD among patients with CRC, in addition to the prevalence of family history of CRC among IBD patients. Criteria for study inclusion consisted of the following: (1) studies that evaluated either IBD or CRC and dysplasia, (2) included all age groups, and (3) evaluated the family history effects for IBD or CRC. The total number of IBD patients and IBD patients with a family history of CRC and the total number of CRC patients and CRC patients with a family history of IBD were reviewed. The pooled prevalence of diseases was also estimated according to degree of relatives and geographical area. Random-effects models were used for estimating pooled prevalence.

Results

A total of 27 studies were included with 26,576 IBD and 9,181 CRC or dysplasia patients. Eligible studies included 13 case-control, 10 cohort, and 4 cross-sectional types. The pooled prevalence of a family history of CRC among patients with IBD was 6% (95% CI: 4-9%). The pooled prevalence for first- and second-degree relatives (11%, 95% CI: 0-37%) was more than that for the other relative subgroups of relatedness degree. The prevalence in the American regions (8% (95% CI: 5-13%)) was higher than that in the others. The pooled prevalence for a family history of IBD among CRC or dysplasia patients was 11% (95% CI: 6-16%). The pooled prevalence for first-degree relatives (13% (95% CI: 3-28%) was higher than that for the other relative subgroups of relatedness degree; it was also greater in American countries (15%, 95% CI: 8-23%).

Conclusion

This study emphasizes the relationship between a family history of IBD and CRC development. Additionally, there was notable prevalence for a family history of CRC among IBD patients. American countries and first-degree relatives were identified to have a higher prevalence for both disease processes.

Validation of the 'Inflammatory Bowel Disease-Distribution, Chronicity, Activity [IBD-DCA] Score' for Ulcerative Colitis and Crohn´s Disease

BACKGROUND AND AIMS

Histological scoring plays a key role in the assessment of disease activity in ulcerative colitis [UC] and is also important in Crohn´s disease [CD]. Currently, there is no common scoring available for UC and CD. We aimed to validate the Inflammatory Bowel Disease [IBD]-Distribution [D], Chronicity [C], Activity [A] score [IBD-DCA score] for histological disease activity assessment in IBD.

METHODS

Inter- and intra-rater reliability were assessed by 16 observers on biopsy specimens from 59 patients with UC and 25 patients with CD. Construct validity and responsiveness to treatment were retrospectively evaluated in a second cohort of 30 patients.

RESULTS

Inter-rater reliability was moderate to good for the UC cohort (intraclass correlation coefficients [ICCs] = 0.645, 0.623, 0.767 for D, C, and A, respectively) and at best moderate for the CD cohort [ICC = 0.690, 0.303, 0.733 for D, C, and A, respectively]. Intra-rater agreement ranged from good to excellent in both cohorts. Correlation with the Nancy Histological Index [NHI] was moderate and strong with the Simplified Geboes Score [SGS] and a Visual Analogue Scale [VAS], respectively. Large effect sizes were obtained for all three parameters. External responsiveness analysis revealed correlated changes between IBD-DCA score and NHI, SGS and VAS.

CONCLUSIONS

The IBD-DCA score is a simple histological activity score for UC and CD, agreed and validated by a large group of IBD specialists. It provides reliable information on treatment response. Therefore, it has potential value for use in routine diagnostics as well as clinical studies.

Twenty-five years of biologicals in IBD: What´s all the hype about?

Twenty-five years ago the field was revolutionized by the introduction of infliximab as the first hybrid anti-TNF-antibody. Subsequently, other humanized anti-TNFs were developed and marketed, followed by antibodies to new targets including integrins (vedolizumab) and interleukin 12/23 (ustekinumab). All these so-called biologicals were shown in registrational trials to induce remission superior to placebo but consistently were effective in only a minority of patients. Even though in most trials only the responders were selected to continue on the respective medication for maintenance, many experienced a secondary loss of response and only a minority of usually <25% of the initial cohort achieved long-term (1 year) remission. In 'real life studies', the outcome was somewhat better, probably due to proper selection of patients and open, mostly retrospective study designs. A clear benefit of biologicals is apparent in otherwise treatment refractory patients, in extraintestinal manifestations and in Crohn´s disease (CD) with fistulizing complications. Biologicals achieve mucosal healing (MH) more often than corticosteroids or thiopurines, and MH is associated with improved prognosis. However, this does not justify escalating treatment until MH is reached since controlled trials proving this point of 'treat to target' are lacking both in ulcerative colitis and CD. Surgical rates have decreased with increasing use of biologicals, but disease progression has not been proven to improve. With the exception of opportunistic infections, serious adverse events are rare. In conclusion, biologicals have changed the scene considerably and expanded our armamentarium, but there is also a marketing hype fostering expectations without evidence.

Validated Indices for Histopathologic Activity Predict Development of Colorectal Neoplasia in Ulcerative Colitis

BACKGROUND AND AIMS

To correlate histologic activity in surveillance colonoscopies with the development of colorectal neoplasia in ulcerative colitis [UC].

METHODS

Colorectal biopsies during surveillance [N = 764] from 52 UC patients with colorectal neoplasia were compared to 122 patients without neoplasia enrolled in a prospective natural history registry. All biopsies were scored using validated histologic scoring systems (Geboes score, Nancy histopathologic index [NHI], and Robarts histopathologic index [RHI]). Clinical, endoscopic, and histologic data were correlated with the development of colorectal neoplasia.

RESULTS

In multivariable analysis, mean RHI (hazard ratio [HR] 1.07 for each 1-unit increase in RHI, 95% confidence interval [CI] 1.03-1.12, p = 0.002) and mean NHI [HR 1.89 for each 1-unit increase in NHI, 95% CI 1.34-2.67, p = 0.002] for the entire surveillance period were significantly associated with colorectal neoplasia development. Shorter surveillance interval and increasing age were associated with increased risk of neoplasia development whereas mean Mayo endoscopic score was not significant. To generate a clinically useful measure of neoplasia risk, mean histologic activity in the preceding 5 years before the study endpoint was correlated with neoplasia development. In the preceding 5 years of surveillance, a mean RHI ≥ 8 had a 7.53-fold increased risk [95% CI 2.56-12.16, p < 0.001] and mean NHI ≥ 1.9 had a 5.89-fold increased risk [95% CI 2.18-15.92, p < 0.001] of developing colorectal neoplasia.

CONCLUSIONS

Persistent histologic activity during multiple surveillance episodes is an independent predictor of colorectal neoplasia. Mean RHI and mean NHI during a 5-year colonoscopic surveillance period can be used to assess risk for colorectal neoplasia and optimize UC surveillance.

The Correlation between Vitamin D Levels and the Risk of Postoperative Recurrence in Crohn's Disease

BACKGROUND AND AIMS

Vitamin D deficiency has been associated with disease activity in Crohn's disease (CD). We assessed whether there is a correlation between vitamin D levels and the risk of postoperative recurrence in CD.

METHODS

CD patients who underwent surgery were identified from a prospectively maintained database at the University of Chicago. The primary endpoint was the correlation of serum 25-hydroxy vitamin D levels measured at 6-12 months after surgery and the proportion of patients in endoscopic remission, defined as a simple endoscopic score for CD of 0. Clinical, biological (C-reactive protein), and histologic recurrences were also studied.

RESULTS

Among a total of 89 patients, 17, 46, and 26 patients had vitamin D levels of <15, 15-30, and >30 ng/mL, respectively. Patients with higher vitamin D levels were significantly more likely to be in endoscopic remission compared to those with lower levels (23, 42, and 67% in ascending tertile order; p = 0.028). On multivariate analysis, vitamin D >30 ng/mL (odds ratio [OR] 0.22, 95% confidence interval [CI] 0.07-0.66, p = 0.006) and anti-tumor necrosis factor agent treatment (OR 0.25, 95% CI 0.08-0.83, p = 0.01) were associated with reduced risk of endoscopic recurrence. Rates of clinical, biological, and histologic remission trended to be higher in patients with higher vitamin D levels (p = 0.17, 0.55, 0.062, respectively).

CONCLUSION

In the present study, higher vitamin D level was associated with lower risk of postoperative endoscopic CD recurrence. Further, studies are warranted to assess the role of vitamin D in postoperative CD recurrence.

AGA Clinical Practice Update on Endoscopic Surveillance and Management of Colorectal Dysplasia in Inflammatory Bowel Diseases: Expert Review

Improvements in disease management, as well as endoscopic technology and quality, have dramatically changed the way in which we conceptualize and manage inflammatory bowel disease-related dysplasia over the past 20 years. Based on evolving literature, we propose a conceptual model and best practice advice statements for the prevention, detection, and management of colorectal dysplasia in people with inflammatory bowel disease. This expert review was commissioned and approved by the American Gastroenterological Association Institute Clinical Practice Updates Committee and the American Gastroenterological Association Governing Board to provide timely guidance on a topic of high clinical importance to the American Gastroenterological Association membership. It underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology.

Pharmacological inhibition of MELK restricts ferroptosis and the inflammatory response in colitis and colitis-propelled carcinogenesis

INTRODUCTION

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic recurrent and incurable gastrointestinal diseases with an unknown etiology that leads to a high risk of developing colitis-associated colorectal cancer (CRC).

OBJECTIVES

In this study, we measured the expression characteristics of MELK in IBD and CRC tissues and explored the regulatory effect of OTSSP167 (a MELK-selective inhibitor) on the mice models of colitis and colitis-associated carcinogenesis and analyzed the specific molecular mechanisms.

METHODS

DSS-induced colitis and colitis-associated carcinogenesis (CAC) model were treated with MELK inhibitor OTSSP167 then the fight against effect of OTSSP167 in the clinical symptoms of colitis and CAC was measured. In addition, underlying mechanism of OTSSP167 treatment in vitro and vivo including anti-ferroptosis and anti-inflammatory response effect was further explored.

RESULTS

We found that pharmacological inhibition of MELK was indicated to significantly alleviate the inflammatory response in mice with colitis, reduce intestinal damage, and effectively inhibit the occurrence and progression of colitis-propelled carcinogenesis, which was closely related to the regulation of gut microbial composition, and OTSSP167-mediated fecal microbiota transplantation effectively alleviated DSS-induced colitis. In addition, OTSSP167 treatment obviously inhibited ferroptosis in the intestinal tissue and suppressed macrophage infiltration and M1 polarization, which reduced the secretion of pro-inflammatory factors. Further exploration of the molecular mechanism revealed that OTSSP167 inhibited AKT/IKK/P65 and ERK/IKK/P65 signaling cascades both in vivo and in vitro, which may help alleviate intestinal inflammation and control the occurrence of cancer.

CONCLUSION

Our findings lay a theoretical foundation for the use of OTSSP167 as a treatment for IBD and its inhibition of the occurrence of colitis-associated carcinogenesis; additionally, MELK may be a potentially effective target molecule, thus providing more options for clinical treatment.