The emerging role of histologic disease activity assessment in ulcerative colitis

Studies on the mechanism of local and extra-intestinal tissue manifestations in AOM-DSS-induced carcinogenesis in BALB/c mice: role of PARP-1, NLRP3, and autophagy

Colitis-associated colorectal cancer (CACC) is one of the devastating complications of long-term inflammatory bowel disease and is associated with substantial morbidity and mortality. Combination of azoxymethane (AOM) and dextran sulfate sodium (DSS) has been extensively used for inflammation-mediated colon tumor development due to its reproducibility, potency, histological and molecular changes, and resemblance to human CACC. In the tumor microenvironment and extra-intestinal tissues, PARP-1, NLRP3 inflammasome, and autophagy's biological functions are complicated and encompass intricate interactions between these molecular components. The focus of the present investigation is to determine the colonic and extra-intestinal tissue damage induced by AOM-DSS and related molecular mechanisms. Azoxymethane (10 mg/kg, i.p.; single injection) followed by DSS (3 cycles, 7 days per cycle) over a period of 10 weeks induced colitis-associated colon cancer in male BALB/c mice. By initiating carcinogenesis with a single injection of azoxymethane (AOM) and then establishing inflammation with dextran sulfate sodium (DSS), a two-stage murine model for CACC was developed. Biochemical parameters, ELISA, histopathological and immunohistochemical analysis, and western blotting have been performed to evaluate the colonic, hepatic, testicular and pancreatic damage. In addition, the AOM/DSS-induced damage has been assessed by analyzing the expression of a variety of molecular targets, including proliferating cell nuclear antigen (PCNA), interleukin-10 (IL-10), AMP-activated protein kinase (AMPK), poly (ADP-ribose) polymerase-1 (PARP-1), cysteine-associated protein kinase-1 (caspase-1), NLR family pyrin domain containing 3 (NLRP3), beclin-1, and interleukin-1β (IL-1β). Present findings revealed that AOM/DSS developed tumors in colon tissue followed by extra-intestinal hepatic, testicular, and pancreatic damages.

Comparing the efficacy of vedolizumab between males and females: a post-hoc analysis of GEMINI-1 and VARSITY

Vedolizumab is a first-line treatment option for ulcerative colitis. There are differences in incidence of ulcerative colitis between males and females, but whether sex affects treatment outcomes is less clear. We examined sex-based differences in patients with ulcerative colitis initiated on vedolizumab from two major randomized controlled trials (RCTs). We conducted a post-hoc analysis on participants with ulcerative colitis from the VARSITY and GEMINI-1 RCTs who received vedolizumab. Outcomes of interest were rates of clinical improvement, clinical remission, and endoscopic improvement at weeks 6, 14, and 52 in male and female participants, as were differences in concentrations of trough vedolizumab and C-reactive protein; 1009 persons in GEMINI-1 and VARSITY trials were included. Male and female patients had similar disease characteristics aside from males being more likely to have Mayo 3 grade endoscopic severity at baseline (62.8 vs. 48.9%, P  < 0.001). At week 6, females were more likely to have endoscopic improvement (47.4 vs. 35.2%, P  = 0.001) and increased vedolizumab trough levels [34.0 (23.0-44.5) vs. 28.9 (19.0-34.6), P  < 0.001]. The probability of achieving clinical remission (28.9 vs. 34.5%, P  = 0.057) or endoscopic improvement (35.5 vs. 39.3%, P  = 0.212) at week 52 was not different between males and females. Females with ulcerative colitis treated with vedolizumab appear more likely to achieve early endoscopic improvement than males, though longer-term outcomes demonstrated no difference. Further studies are required to better understand mechanisms through which sex or sex-associated factors could influence response to therapy in ulcerative colitis.

An artificial intelligence-driven scoring system to measure histological disease activity in ulcerative colitis

BACKGROUND AND AIMS

Assessment and scoring of histological images in Ulcerative colitis (UC) is prone to inter- and intra-observer variability. This study aimed to investigate whether an artificial intelligence (AI) system developed using image processing and machine learning algorithms could measure histological disease activity based on the Nancy index.

METHODS

A total of 200 histological images of patients with UC were used in this study. A novel AI algorithm was developed using state-of-the-art image processing and machine learning algorithms based on deep learning and feature extraction. The cell regions of each image, followed by the Nancy index, were manually annotated and measured independently by four histopathologists. Manual and AI-automated measurements of the Nancy index score were conducted and assessed using the intraclass correlation coefficient (ICC).

RESULTS

The 200-image dataset was divided into two groups (80% was used for training and 20% for testing). Intraclass correlation coefficient statistical analyses were performed to evaluate the AI tool and used as a reference to calculate the accuracy. The average ICC among the histopathologists was 89.3 and the average ICC between histopathologists and the AI tool was 87.2. The AI tool was found to be highly correlated with histopathologists.

CONCLUSIONS

The high correlation of performance of the AI method suggests promising potential for inflammatory bowel disease clinical applications. A standardized automated histological AI-driven scoring system can potentially be used in daily inflammatory bowel disease practice to reduce training needs and resource use, eliminate the subjectivity of the pathologists, and assess disease severity for treatment decisions.

Histological Disease Activity as Predictor of Clinical Relapse, Hospitalization, and Surgery in Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

BACKGROUND

The clinical impact of histological remission on short- and long-term clinical outcomes in patients with inflammatory bowel disease (IBD) is not well established. We assessed risk of clinical relapse, hospitalization, and need for surgery in patients achieving histological remission in comparison with active histological disease.

METHODS

A systematic review was conducted using MEDLINE, Scopus, Cochrane CENTRAL, EMBASE, and conference abstracts from inception to November 2022. Our main outcome was the rate of clinical relapse in patients with IBD who reached histological remission vs patients with active histological disease. Secondary outcomes were clinical complications of IBD such as hospitalization and need for surgery. The endpoints were investigated at 2 time points, 6 to 12 months (short term) and >12 months (long term).

RESULTS

Short-term outcome analysis showed that the risk of clinical relapse was significantly higher in ulcerative colitis patients with active histological disease in comparison with patients at histological remission (risk ratio [RR], 2.41; 95% confidence interval [CI], 1.69-3.44; P < .01). The risk of hospitalization in ulcerative colitis patients was not significant among the 2 groups (RR, 4.22; 95% CI, 0.91-19.62; P = .07). Long-term outcome analysis demonstrated that the risk of clinical relapse (RR, 2.07; 95% CI, 1.55-2.76; P < .01), need for surgery (RR, 3.14; 95% CI, 1.53-6.45; P < .01), and hospitalization (RR, 2.52; 95% CI, 1.59-4.00; P < .01) was significantly higher in patients with active histological disease.

CONCLUSIONS

Histological remission in IBD represents an important therapeutic goal that is not yet routinely pursued in clinical practice. In our study, patients who achieved histological remission have more favorable outcomes than those with active histological disease in ulcerative colitis.

Histology of IBD and related colitides in the elderly

Inflammatory bowel disease (IBD) are chronic relapsing diseases, affecting both children and adults with a life-long duration. An increased co-morbidity gives raise to fragility in the elderly. In this regard it should consider that several non-IBD colitides may mimic both ulcerative colitis and Crohn's disease. Moreover, chronic diseases represent a clinical challenge, mostly about treatment effectiveness. Finally, it is worth noting that patients with long-standing diseases - and elderly patients among them - have an increased malignancy risk when compared to general (non-IBD) population. Our paper aims to review the three main histological topics that play a role in the clinical management of IBD in the elderly, namely differential diagnosis, mucosal healing and IBD-associated dysplasia.

Identification of immune cell markers associated with ulcerative colitis histological disease activity in colonic biopsies

AIMS

Accurate determination of histological activity in ulcerative colitis (UC) is essential given its diagnostic and prognostic importance. Data on the relationship between histology and immune cell markers are limited. We aimed to evaluate the association between histological disease activity and immune cell marker concentration in colonic biopsies from patients with UC.

METHODS

Sigmoid colon biopsies from 20 patients with UC were retrospectively assessed using the Robarts Histopathology Index (RHI). Targeted mass spectrometry determined the concentration of 18 immune cell markers (cluster of differentiation (CD) 4, CD8, CD19, CD20, CD40, CD56, CD68, CD103, forkhead box p3 (FOXP3), human leucocyte antigen, DR alpha chain (HLA-DRA), interleukin 10 (IL-10), IL-23 subunit alpha (IL-23A), IL-23 receptor (IL-23R), IL-2 receptor alpha chain (IL-2RA), Ki67, lymphocyte-activation gene 3 (LAG-3), programmed cell death protein 1 (PD-1) and PD ligand 1 (PD-L1)). The association between RHI score and immune cell marker concentration was quantified using Spearman's rank correlation coefficient (ρ) and related 95% CIs.

RESULTS

Fourteen of the 18 immune cell marker proteins were detected, with tissue concentration ranging from 0.003 to 11.53 fmol/µg. The overall RHI score was positively correlated with CD19, CD20, CD40, FOXP3, LAG-3, PD-1 and PD-L1 concentration (ρ=0.596-0.799) and negatively correlated with CD56 concentration (ρ=-0.460). There was no significant association between RHI score and CD4, CD8, CD68, CD103, HLA-DRA or Ki67 concentration.

CONCLUSIONS

This study provides insight into the correlation between immune cell marker expression and histological disease activity and the possible molecular and immunological determinants underlying microscopic disease activity in UC.

Hypersampsonone H attenuates ulcerative colitis via inhibition of PDE4 and regulation of cAMP/PKA/CREB signaling pathway

BACKGROUND AND OBJECTIVES

Ulcerative colitis (UC) is a recurrent intestinal inflammatory disease which poses a serious threat to the life of patients. However, there are no specific drugs for UC yet. Hypericum sampsonii Hance (HS) is a Chinese herbal medicine traditionally used to treat enteritis and dysentery. Our previous studies have demonstrated that HS holds potential anti-UC effects, and a novel compound named Hypersampsonone H (HS-1) isolated from HS possesses significant anti-inflammatory activity. However, the beneficial effects of HS-1 on UC remain unclear. This study aimed to investigate the therapeutic effects of HS-1 on UC and its potential mechanisms, both in vitro and in vivo.

METHODS

The in vitro model was employed using LPS-induced RAW264.7 cells to investigate the anti-inflammatory effects of HS-1 and its possible mechanisms. Furthermore, the therapeutic efficacy and potential mechanisms of HS-1 against dextran sulfate sodium (DSS)-induced acute colitis were assessed through histopathological examination, biochemical analysis, and molecular docking.

RESULTS

In vitro, HS-1 significantly reduced LPS-induced inflammatory responses, as indicated by inhibiting NO production, down-regulating the overexpression of COX-2 and iNOS, as well as regulating the imbalanced levels of IL-6, TNF-α, and IL-10. Moreover, HS-1 also inhibited the expression of PDE4, elevated the intracellular cAMP level, and promoted the phosphorylation of CREB, thereby activating the PKA/CREB pathway in RAW264.7 cells. In vivo, HS-1 demonstrated therapeutic capacity against DSS-induced colitis by alleviating the symptoms of colitis mice, regulating the abnormal expression of inflammatory mediators, protecting the integrity of intestinal epithelial barrier, and reducing tissue fibrosis. Consistently, HS-1 was found to decrease the expression of PDE4 isoforms, subsequently activating the cAMP/PKA/CREB signaling pathway. Furthermore, the molecular docking results indicated that HS-1 exhibited a high affinity for PDE4, particularly PDE4D. Further mechanistic validation in vitro demonstrated that HS-1 possessed a synergistic effect on forskolin and an antagonistic effect on H-89 dihydrochloride, thereby exerting anti-inflammatory effects through the cAMP/PKA/CREB signaling pathway.

CONCLUSION

We disclose that HS-1 serves as a promising candidate drug for the treatment of UC by virtue of its ability to reduce DSS-induced colitis via the inhibition of PDE4 and the activation of cAMP/PKA/CREB signaling pathway.

Novel endoscopic scoring system for immune mediated colitis: a multicenter retrospective study of 674 patients

BACKGROUND AND AIMS

No endoscopic scoring system has been established for immune-mediated colitis (IMC). This study aimed to establish such a system for IMC and explore its utility in guiding future selective immunosuppressive therapy (SIT) use compared to clinical symptoms.

METHODS

This retrospective, international, 14-center study included 674 patients who developed IMC after immunotherapy and underwent endoscopic evaluation. Ten endoscopic features were selected by group consensus and assigned 1 point each to calculate an IMC endoscopic score (IMCES). IMCES cutoffs were chosen to maximize specificity for SIT use. This specificity was compared between IMCESs, and clinical symptoms were graded according to a standardized instrument.

RESULTS

A total of 309 (45.8%) patients received SIT. IMCES specificity for SIT use was 82.8% with a cutoff of 4. The inclusion of ulceration as a mandatory criterion resulted in higher specificity (85.0% for a cutoff of 4). In comparison, the specificity of a Mayo endoscopic subscore of 3 was 74.6%, and the specificity of clinical symptom grading was much lower at 27.4% and 12.3%, respectively. Early endoscopy was associated with timely SIT use (P < .001; r = 0.4084).

CONCLUSIONS

This is the largest multicenter study to devise an endoscopic scoring system to guide IMC management. An IMCES cutoff of 4 has a higher specificity for SIT use than clinical symptoms, supporting early endoscopic evaluation for IMC.

Histologic features and predicting prognosis in ulcerative colitis patients with mild endoscopic activity

BACKGROUND/AIMS

We aimed to evaluate the histologic features predictive of prognosis and correlate them with endoscopic findings in patients with ulcerative colitis (UC) having complete or partial mucosal healing (MH).

METHODS

We prospectively collected and reviewed data from patients with UC who underwent colonoscopy or sigmoidoscopy with biopsy. Complete and partial MH were defined as Mayo endoscopic subscores (MESs) of 0 and 1, respectively. Histologic variables, including the Nancy index (NI), predicting disease progression (defined as the need for medication upgrade or hospitalization/surgery), were evaluated and correlated with endoscopic findings.

RESULTS

Overall, 441 biopsy specimens were collected from 194 patients. The average follow-up duration was 14.7 ± 7.4 months. There were 49 (25.3%) and 68 (35.1%) patients with MESs of 0 and 1, respectively. Disease progression occurred only in patients with an MES of 1. NI ≥ 3 was significantly correlated with disease progression during follow-up. Mucosal friability on endoscopy was significantly correlated with NI ≥ 3 (61.1% in NI < 3 vs. 88.0% in NI ≥ 3; p = 0.013).

CONCLUSION

Histological activity can help predict the prognosis of patients with UC with mild endoscopic activity. Mucosal friability observed on endoscopy may reflect a more severe histological status, which can be a risk factor for disease progression.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials

INTRODUCTION

Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer.

AREAS COVERED

This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission.

EXPERT OPINION

Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

A Comparative Evaluation of the Measurement Properties of Three Histological Indices of Mucosal Healing in Ulcerative Colitis: Geboes Score, Robarts Histopathology Index and Nancy Index

BACKGROUND AND AIMS

To inform their future use in regulated clinical trials to evaluate treatment efficacy hypotheses, the measurement properties of three histological indices, Geboes Score [GS], Robarts Histopathology Index [RHI] and Nancy Index [NI], were evaluated among patients with ulcerative colitis.

METHODS

Analyses were conducted on data from a Phase 3 clinical trial of adalimumab [M14-033, n = 491] and focused on evaluating the measurement properties of the GS, RHI and NI. Specifically, internal consistency and inter-rater reliability, convergent, discriminant and known-group validity, and sensitivity to change were assessed at Baseline, and at Weeks 8 and 52.

RESULTS

Internal consistency for the RHI showed lower alpha [α] values at Baseline [α = 0.62] relative to Weeks 8 [α = 0.82] and 52 [α = 0.81]. The inter-rater reliability values of RHI [0.91], NI [0.64] and GS [0.53] were excellent, good and fair, respectively. Regarding validity, Week 52 correlations were moderate to strong between full and partial Mayo scores and Mayo subscale scores and the RHI and GS, and were weak to moderate for the NI. Significant differences between mean scores of all three histological indices were observed across known-groups based on Mayo endoscopy subscores and full Mayo scores at Weeks 8 and 52 [p < 0.001].

CONCLUSIONS

The GS, RHI and NI are each capable of producing reliable and valid scores that are sensitive to changes in disease activity over time, in patients with moderately to severely active ulcerative colitis. While all three indices demonstrated relatively acceptable measurement properties, the GS and RHI performed better than the NI.

Introducing a novel histopathological scoring system to assess disease activity and chronicity in cutaneous lichen planus: A proposal

BACKGROUND

Lichen planus (LP) is a chronic inflammatory disorder caused by an autoimmune attack by cytotoxic T-cells. The clinical course is variable, with episodes of remission and exacerbation. A clinicopathological scoring system for cutaneous LP is not available for effectively assessing disease severity and monitoring treatment response. This study was designed with the aim of proposing an objective and reproducible scoring system, comprising histopathological features of active and chronic disease, and to correlate these scores with clinical morphology groups.

METHODOLOGY

This is a retrospective study of 200 cases of cutaneous LP, which were categorized into five clinical groups (I-V) at the time of biopsy. The corresponding histopathological feature was assigned a score based on feature of active and chronic disease. Individual scores were summated to calculate a histopathological index (index [AI] and chronicity index [CI]). The comparison of indices between various clinical groups was performed by Mann-Whitney U test.

RESULTS

The median AI was lowest (1) for post-inflammatory hyperpigmentation (clinical group I) and highest (7) for the bullous group (clinical group IV). The median CI (7) was highest for the scarring group (clinical group V). The difference between median AI of clinical group I (post-inflammatory hyperpigmentation) and rest of the groups (clinical groups II, III, IV, and V) was statistically significant (p value <0.05).

CONCLUSION

We present this clinico-histopathological scoring system as a reliable and facile method of assessing the activity and severity of LP.

Inflammatory Bowel Diseases: Does One Histological Score Fit All?

Mucosal healing (MH) is the main treatment target in ulcerative colitis (UC) and Crohn's disease, and it is defined by the combination of complete endoscopic and histologic remission. The complete resolution of mucosal inflammation should be confirmed by histology but its assessment is not always univocal. Neutrophil infiltration represents the unique histological marker in discriminating the active vs. quiescent phases of the disease, together with crypt injuries (cryptitis and crypt abscesses), erosions, and ulcerations. On the contrary, basal plasmacytosis is not indicative of activity or the remission of inflammatory bowel diseases (IBDs) but instead represents a diagnostic clue, mostly at the onset. Several histological scoring systems have been developed to assess grade severity, particularly for UC. However, most are complex and/or subjective. The aim of this review was to summarize available scores, their characteristics and limitations, and to present the advantages of a simplified mucosa healing scheme (SHMHS) based on neutrophils and their distribution in the gut mucosa. Finally, we overview future developments including artificial intelligence models for standardization of disease assessments and novel molecular markers of inflammation with potential application in diagnostic practice.

Correlation Between the Nancy Histopathology Index and Markers of Disease Activity in Pediatric Ulcerative Colitis

The Nancy Histological Index (NHI) was developed to assess histological disease activity in adult ulcerative colitis (UC) patients. However, data in pediatrics is limited. Our aim was to determine whether the NHI correlates with different indices of disease activity in pediatric UC patients. We retrospectively reviewed the NHI in rectal biopsies from 61 pediatric UC patients (median age 14.3 years), of whom 34 (55.7%) were newly diagnosed. The median Pediatric Ulcerative Colitis Activity Index (PUCAI) score among participants was 30 (interquartile range 5-55). Most patients exhibited an NHI of 3 (41/61, 67.2%) or 4 (8/61, 13.1%), reflecting moderate-severe histologic inflammation. A moderate positive correlation was identified between the NHI and PUCAI, fecal calprotectin, and Mayo endoscopic scores ( r = 0.60, 0.54, and 0.56 respectively, P ≤ 0.001), but not with CRP or albumin. These results indicate that the NHI has a modest correlation with clinical, laboratory and endoscopic indices of disease activity in pediatric UC patients.

3-aminobenzamide protects against colitis associated diabetes mellitus in male BALB/c mice: Role of PARP-1, NLRP3, SIRT-1, AMPK

Diabetes and ulcerative colitis are chronic diseases associated with inflammation, dysbiosis, impaired immune function and infection risk. In patients with type 1 diabetes enteropathy, gastrointestinal manifestations are seen relatively frequently. The current investigation was aimed to decipher the role of 3-aminobenzamide (3-AB) in ulcerative colitis associated Diabetes mellitus in male BALB/c mice. Ulcerative colitis associated Diabetes mellitus experimental murine model was developed by 3 cycles (each cycle consists of seven days) of Dextran Sulphate Sodium (DSS; 2.5 %w/v) with recovery time of one week in-between along with Streptozotocin (STZ; 40 mg/kg; i.p. x 5 days; consecutively) was given at the I^st recovery period. As an intervention, 3-aminobenzamide (3-AB; 5 and 10 mg/kg; intraperitoneally) was given beginning with the second DSS cycle and then continue till sacrifice. 3-aminobenzamide treatment significantly reduced the severity of colitis-associated diabetes mellitus by altering the expression of a number of molecular targets, including sirtuin 1 (SIRT 1), proliferating cell nuclear antigen (PCNA), poly[ADP-ribose] polymerase 1 (PARP-1), cysteine protease-1 (Caspase-1), nuclear factor kappa-light-chain-enhancer of activated B cells (NFkBp65), NLR family pyrin domain containing 3 (NLRP3), insulin growth factor 1 (IGF-1), interleukin-1β (IL-1β), interleukin-10 (IL-10) and β-catenin. Further, 3-AB at high dose (10 mg/kg; intraperitoneally) significantly restored the epithelial tight junction integrity as evaluated by TEM analysis and restored occludin expression analysed by immunofluorescence analysis. Present study revealed that the high dose of 3-AB (10 mg/kg; intraperitoneally) showed significant and consistent protective effects against colitis associated Diabetes mellitus by modulating various molecular targets.

Identification of Specific Biomarkers and Pathways in the Treatment Response of Infliximab for Inflammatory Bowel Disease: In-Silico Analysis

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. In biological therapy, infliximab became the first anti-tumor necrosis factor (TNF) agent approved for IBD. Despite this success, infliximab is expensive, often ineffective, and associated with adverse events. Prediction of infliximab resistance would improve overall potential outcomes. Therefore, there is a pressing need to widen the scope of investigating the role of genetics in IBD to their association with therapy response. Methods: In the current study, an in-silico analysis of publicly available IBD patient transcriptomics datasets from Gene Expression Omnibus (GEO) are used to identify subsets of differentially expressed genes (DEGs) involved in the pathogenesis of IBD and may serve as potential biomarkers for Infliximab response. Five datasets were found that met the inclusion criteria. The DEGs for datasets were identified using limma R packages through the GEOR2 tool. The probes’ annotated genes in each dataset intersected with DGEs from all other datasets. Enriched gene Ontology Clustering for the identified genes was performed using Metascape to explore the possible connections or interactions between the genes. Results: 174 DEGs between IBD and healthy controls were found from analyzing two datasets (GSE14580 and GSE73661), indicating a possible role in the pathogenesis of IBD. Of the 174 DEGs, five genes (SELE, TREM1, AQP9, FPR2, and HCAR3) were shared between all five datasets. Moreover, these five genes were identified as downregulated in the infliximab responder group compared to the non-responder group. Conclusions: We hypothesize that alteration in the expression of these genes leads to an impaired response to infliximab in IBD patients. Thus, these genes can serve as potential biomarkers for the early detection of compromised infliximab response in IBD patients.

Role of Combination Treatment of Aspirin and Zinc in DMH-DSS-induced Colon Inflammation, Oxidative Stress and Tumour Progression in Male BALB/c Mice

Colitis-associated colorectal cancer serves as a prototype of inflammation-associated cancers which is linked with repeated cycles of inflammation and DNA repair deficits. Several preclinical and clinical data reported that aspirin has a chemo-preventive effect in colorectal cancer and is associated with dose-dependent side effects. Furthermore, it has been reported that zinc supplementation improves the quality of life in patients undergoing chemotherapy by alteration of colonic cancer cell gene expression. However, explication of the detailed molecular mechanisms involved in the combined administration of aspirin and zinc-mediated protection against colitis-associated colorectal cancer deserves further investigation. For the induction of colitis-associated colorectal cancer, male BALB/c mice were administered 1,2-dimethylhydrazine dihydrochloride (DMH) 20 mg/kg/bw thrice before the initiation of every DSS cycle (3%w/v in drinking water). One week after the initiation of DSS treatment, aspirin (40 mg/kg; p.o.) and zinc in the form of zinc sulphate (3 mg/kg; p.o.) were administered for 8 weeks. Combination of aspirin and zinc as intervention significantly ameliorated DAI score, myeloperoxidase activity, histological score, apoptotic cells and protein expression of various inflammatory markers including nuclear factor kappa light chain enhancer of activated B cells (NFκBp65), cycloxygenase-2 (COX-2) and interleukin-6 (IL-6); proliferation markers such as proliferating cell nuclear antigen (PCNA), signal transducer and activator of transcription 3 (STAT3) expression significantly decreased, and antioxidant enzymes nuclear factor erythroid 2-related factor 2 (Nrf-2), metallothionein, catalase and superoxide dismutase (SOD) significantly increased as evaluated by immunohistochemistry and western blot analysis.

SATB2 loss in inflammatory bowel disease-associated small intestinal metaplasia of the distal colon

Epithelial metaplasia is a common adaptation to chronic inflammatory processes and can be associated with increased risk of dysplasia and cancer. The distal colon of patients with inflammatory bowel disease (IBD) commonly shows crypt architectural distortion and Paneth cell metaplasia (PCM), and IBD patients also carry increased risk of colitis-associated dysplasia and cancer (CAC). Loss of SATB2 expression (Special AT-rich binding 2 protein, a colon-restricted chromatin remodeler) has recently been shown to distinguish colitis-associated dysplasia and CAC from sporadic disease. Here we report non-diffuse heterogeneous patterns of SATB2 loss across non-dysplastic distal colon biopsies from IBD patients (n=20). This cohort was specifically curated to include biopsies with well-developed histologic features of villiform growth and PCM. Notably, CDX2 was strongly expressed and P53 showed a wild-type immunolabeling pattern across our non-dysplastic cohort, regardless of SATB2 immunolabeling pattern. Our findings fit with recent murine studies in which colon-specific Satb2 deletion resulted in histologic conversion of colonic mucosa to small intestinal-like mucosa, including emergence of villi and Paneth cells. Taken together, we show that SATB2 loss is associated with a pre-neoplastic metaplastic response to chronic injury in human IBD and chronic colitis, reframing PCM more broadly as small intestinal metaplasia. We propose that inflammation-associated SATB2 loss mediates a remodeled chromatin landscape permissive for dysplasia and CAC.

Prognostic Value of Fecal Calprotectin to Inform Treat-to-Target Monitoring in Ulcerative Colitis

BACKGROUND & AIMS

We evaluated the value of post-induction fecal calprotectin (FCP) concentration as a biomarker in patients with ulcerative colitis (UC) treated with a biologic.

METHODS

This post hoc analysis of the GEMINI 1/GEMINI LTS (N = 620) and VARSITY (N = 771) trials evaluated the cross-sectional accuracy of post-induction FCP in identifying endoscopic activity and histologic inflammation, and the prognostic performance of FCP in identifying patients most likely to achieve endoscopic and histologic remission or require colectomy and UC-related hospitalization.

RESULTS

The cross-sectional accuracy of FCP in identifying endoscopic activity and histologic inflammation was modest (63%-79%). However, a post-induction FCP concentration of ≤250 μg/g vs >250 μg/g was associated with a substantially higher probability of achieving clinical remission (odds ratio [OR], 4.03; 95% confidence interval [CI], 2.78-5.85), endoscopic remission (OR, 4.26; 95% CI, 2.83-6.40), and histologic remission (Robarts Histopathology Index: OR, 5.54; 95% CI, 3.77-8.14; Geboes grade: OR, 6.42; 95% CI, 4.02-10.26) at week 52 and a lower probability of colectomy over 7 years (hazard ratio, 0.296; 95% CI, 0.130-0.677) and UC-related hospitalization (hazard ratio, 0.583; 95% CI, 0.389-0.874). The association with colectomy was significant even among patients in symptomatic remission or with endoscopic improvement post-induction, and among patients with elevated FCP at baseline.

CONCLUSIONS

Although FCP had only modest cross-sectional accuracy in identifying disease activity, an FCP concentration of ≤250 μg/g vs >250 μg/g was associated with increased probability of achieving long-term clinical, endoscopic, and histologic remission, and reduced probability of colectomy and UC-related hospitalization (ClinicalTrials.gov: NCT00783718, NCT00790933, NCT02497469).

Histologic healing and factors associated with complete remission following conventional treatment in ulcerative colitis

BACKGROUND

Endoscopic and histological activity scores in ulcerative colitis (UC) are associated with clinical outcomes and have become important targets of clinical trials. However, these endpoints have been scarcely investigated in patients receiving only conventional treatment.

OBJECTIVE

We aimed to assess the deep and complete remission rates after 3 months of conventional treatment in patients with newly diagnosed UC with moderate to severe endoscopic activity. We also aimed to investigate whether selected clinical and biochemical variables at baseline were associated with complete remission status after 3 months.

DESIGN

This was a prospective cohort study.

METHODS

Newly diagnosed patients with active UC commencing 5-aminosalicylate, corticosteroid, and/or azathioprine treatment were consecutively included. Clinical, biochemical, endoscopic, and histological data were collected at baseline and after 3 months. Rates of clinical remission (Partial Mayo Score ⩽ 2), mucosal healing (Mayo Endoscopic Score ⩽ 1), and histologic healing (Nancy Index ⩽ 1) were determined. Deep remission was assessed as clinical remission plus mucosal healing and complete remission as deep remission plus histologic healing. Predictors of complete remission were identified by logistic regression.

RESULTS

A total of 180 patients were included in the study. Deep remission and complete remission occurred in 62.8% and 42.2% of patients, respectively. Thus, of patients in deep remission one-third had persistent histologic activity. Histologic activity in mucosally healed patients was associated with higher symptom scores and faecal calprotectin levels. Of baseline variables, less endoscopic distribution and disease activity showed strongest association with achieving complete remission, and limited distribution in combination with moderate activity gave highest odds for complete remission (odds ratio: 4.1, 95% confidence interval: 7.69-2.18).

CONCLUSION

In patients with mucosal healing, persistent histologic activity was a common finding and was associated with increased disease activity. Pancolitis and severe inflammatory activity at baseline were associated with lower complete remission rates.

Histological remission in inflammatory bowel disease and risk of adverse pregnancy outcomes: A nationwide study

BACKGROUND

Inflammatory bowel disease (IBD) has been linked to adverse pregnancy outcomes, but it is unclear how risks vary by histological activity.

METHODS

We performed a nationwide study of Swedish women diagnosed with IBD 1990-2016 and a pre-pregnancy (<12 months) colorectal biopsy with vs. without histological inflammation (1223 and 630 births, respectively). We also examined pregnancy outcomes in 2007-2016 of women with vs. without clinically active IBD (i.e., IBD-related hospitalization, surgery, or medication escalation) <12 months before pregnancy (2110 and 4993 births, respectively). Accounting for smoking, socio-demographics, and comorbidities, generalized linear models estimated adjusted risk ratios (aRRs) for preterm birth (<37 gestational weeks) and small-for-gestational age (SGA, <10th percentile weight for age).

FINDINGS

Of infants to women with vs. without histological inflammation, 9.6% (n = 117) and 6.5% (n = 41) were preterm, respectively (aRR = 1.46; 95%CI = 1.03-2.06). Histological inflammation was associated with preterm birth in ulcerative colitis (UC) (aRR = 1.64; 95%CI = 1.07-2.52), especially extensive colitis (aRR = 2.37; 95%CI = 1.12-5.02), but not in Crohn's disease (aRR = 0.99; 95%CI = 0.55-1.78). Of infants to women with vs. without histological inflammation, 116 (9.6%) and 56 (8.9%), respectively, were SGA (aRR = 1.09; 95%CI = 0.81-1.47). Clinically active disease before pregnancy was linked to preterm birth (aRR = 1.42; 95%CI = 1.20-1.69), but not to SGA birth (aRR = 1.13; 95%CI = 0.96-1.32). Finally, of infants to women without clinical activity, histological inflammation was not significantly associated with preterm birth (aRR = 1.20; 95%CI = 0.68-2.13).

INTERPRETATION

Histological and clinical activity in IBD, especially in UC, were risk factors for preterm birth. Further research is needed to determine the importance of pre-pregnancy histological activity in women without clinically-defined disease activity.

FUNDING

The Swedish Society of Medicine.

Interobserver reliability of the Nancy index for ulcerative colitis: An assessment of the practicability and ease of use in a single-centre real-world setting

BACKGROUND

Histological disease severity assessment in ulcerative colitis (UC) has become a mainstay in clinical endpoints definition ("histologic remission") in clinical trials of UC. Several scores are established in the microscopical assessment of disease activity, but the Nancy index (NI) stands out being a histological index with the least amount of scoring items among these scores. To which extent histologic assessment using NI is affected by interobserver reliability in a real word setting, is poorly understood. We therefore performed a single-center retrospective analysis of NI assessment in patients with UC.

METHODS

We retrospectively evaluated the NI in two independent cohorts (total: 1085 biopsies, 547 UC patients) of clinically diagnosed UC patients, who underwent colonoscopy between 2007 and 2020. Cohort #1 consisted of 637 biopsies from 312 patients, Cohort #2 consisted of 448 biopsies from 235 patients. Two blinded pathologists with different levels of expertise scored all biopsies of each cohort. A consensus conference was held for cases with discrepant scoring results. Finally, an overall consensus scoring was obtained from both cohorts.

RESULTS

The interobserver-agreement of the NI was substantial after the assessment of 1085 biopsy samples (κ = 0.796 [95%-CI: 0.771-0.820]). An improvement of the interobserver-agreement was found with growing numbers of samples evaluated by both observers (Cohort #1: κ = 0.772 [95%-CI: 0.739-0.805]; Cohort #2: κ = 0.829 [95%-CI: 0.793-0.864]). The interobserver discordance was the highest in NI grade 1 (observer 1: n=128; observer 2: n=236). Interobserver discordance was the lowest in NI grades 0 (observer 1: n=504; observer 2: n=479) and 3 (observer 1: n=71; observer 2: n=66).

CONCLUSION

The NI is an easy-to-use index with high interobserver reliability to assess the histological disease activity of UC patients in a real-world setting. While NI grades 0 and 3 had a high level of agreement between the observers, NI grade 1 had a poorer agreement-level. This highlights the clinical need to specify histological characteristics leading to NI grade 1.

Mucus-Penetrating Silk Fibroin-Based Nanotherapeutics for Efficient Treatment of Ulcerative Colitis

Oral nanoparticles have been considered a prospective drug delivery carrier against ulcerative colitis (UC). To enhance the mucus-penetrating capacity and aqueous solubility, and strengthen the anti-inflammatory effect of resveratrol (RSV), we fabricated RSV-loaded silk fibroin-based nanoparticles with the functionalization of Pluronic F127 (PF-127). The obtained PF-127-functionalized RSV-loaded NPs had an average particle size around 170 nm, a narrow size distribution (polydispersity index < 0.2), and negative zeta potential (−20.5 mV). Our results indicated that the introduction of PF-127 strengthened the mucus-penetrating property of NPs. In vitro studies suggested that NPs with PF-127 enhanced the suppression of the secretion of proinflammatory cytokine TNF-α and reactive oxygen species (ROS) from RAW 264.7 macrophages under lipopolysaccharide stimulation in comparison with other counterparts. According to the evaluation of macro symptoms and main inflammatory cytokines, we further report preferable therapeutic outcomes achieved by PF-127 functionalized-NP-treated dextran sulphate sodium (DSS) groups in the colitis model compared with blank silk fibroin NPs and RSV-loaded NPs without the functionalization of PF-127. Taken together, this work suggests that the fabricated PF-127 NPs via the oral route are promising and useful RSV-loaded nanocarriers for UC treatment.

Histological Indices and Risk of Recurrence in Crohn's Disease: A Retrospective Study of a Cohort of Patients in Endoscopic Remission

BACKGROUND

Although histological healing is raising interest in ulcerative colitis to predict recurrence, its meaning in Crohn's disease (CD) remains unknown. We aimed to study the performances of different histological indices to predict recurrence of CD patients with mucosal healing.

METHODS

Crohn's disease patients with mucosal healing diagnosed between 2010 and 2018 were included if there was available clinical and endoscopical data. Nancy Histological index (NHI), Geboes score (GS), Robarts Histopathology index (RHI), Global Histological Disease Activity Score (GHAS), and Inflammatory Bowel Disease-Distribution Chronicity Activity score (IBD-DCA) were independently assessed by 3 pathologists.

RESULTS

Eighty-eight patients were included, of which 28 relapsed (32%) within 30.5 months. All 4 histological indices were associated with recurrence, with significant relapse risk (NHI, odds ratio [OR], 1.67; GHAS, OR, 2.33; RHI, OR, 1.19; GS, OR, 2.09; and IBD-DCA, OR, 2.14). Microscopic activity was significantly associated with relapse only with the IBD-DCA score. Predicting performances of all these scores were poor. Calibration curves indicate that the GHAS and IBD-DCA are the closest to the ideal predicted probability curve and thus could better predict recurrence than the other scores. Interobserver agreement varied from poor for GHAS (k = .39) to good for RHI (k = .68).

CONCLUSIONS

Histological scores are valuable indicators to predict recurrence. Histological assessment of activity seems insufficient to predict CD course with most of the score evaluated, highlighting the need for new indices or adaptation of actual scores to CD specificities.

(Re)Appraising Remission in Ulcerative Colitis

As the therapeutic targets in ulcerative colitis (UC) shift from control of symptoms to mucosal healing and prevention of disease complications like disability, colectomy, and cancer, the definition of remission has evolved. The current definition of clinical remission is variable and is determined by the clinical context in which it is being used. This results in skepticism and uncertainty about the true meaning of the term "clinical remission." In this review, the authors reexamine the definition of clinical remission and propose a novel approach to define remission in UC.

Ulcerative Colitis: Novel Epithelial Insights Provided by Single Cell RNA Sequencing

Ulcerative Colitis (UC) is a chronic inflammatory disease of the intestinal tract for which a definitive etiology is yet unknown. Both genetic and environmental factors have been implicated in the development of UC. Recently, single cell RNA sequencing (scRNA-seq) technology revealed cell subpopulations contributing to the pathogenesis of UC and brought new insight into the pathways that connect genome to pathology. This review describes key scRNA-seq findings in two major studies by Broad Institute and University of Oxford, investigating the transcriptomic landscape of epithelial cells in UC. We focus on five major findings: (1) the identification of BEST4 + cells, (2) colonic microfold (M) cells, (3) detailed comparison of the transcriptomes of goblet cells, and (4) colonocytes and (5) stem cells in health and disease. In analyzing the two studies, we identify the commonalities and differences in methodologies, results, and conclusions, offering possible explanations, and validated several cell cluster markers. In systematizing the results, we hope to offer a framework that the broad scientific GI community and GI clinicians can use to replicate or corroborate the extensive new findings that RNA-seq offers.

[Assessment of histologic activity in colitis]

The histological activity of the bowel inflammation is an extremely important morphological criterion that is encountered in the diagnosis of colitis. However, the determining of its degree is subjective and still does not have a generally accepted principle of gradation. The article describes the most common scale-schemes for assessing the severity of colitis, that include the degree of microscopic changes. The results of the analysis of the of histological activity degree on the material of colonobioptates in colitis of various etiologies (467 patients) are presented. It has been shown that the Geboes scale of ulcerative colitis can be used to assess histological activity in all forms of colitis. The histological features of inflammation should be reflected in the pathological diagnosis and are essential for clinical decision making. This index allows for a comparative analysis of clinical, endoscopic and morphological parameters and better control of the patient's condition during the treatment.

Molecular mechanisms of Huanglian jiedu decoction on ulcerative colitis based on network pharmacology and molecular docking

Huanglian jiedu decoction (HLJDD) is a heat-clearing and detoxifying agent composed of four kinds of Chinese herbal medicine. Previous studies have shown that HLJDD can improve the inflammatory response of ulcerative colitis (UC) and maintain intestinal barrier function. However, its molecular mechanism is not completely clear. In this study, we verified the bioactive components (BCI) and potential targets of HLJDD in the treatment of UC using network pharmacology and molecular docking, and constructed the pharmacological network and PPI network. Then the core genes were enriched by GO and KEGG. Finally, the bioactive components were docked with the key targets to verify the binding ability between them. A total of 54 active components related to UC were identified. Ten genes are very important to the PPI network. Functional analysis showed that these target genes were mainly involved in the regulation of cell response to different stimuli, IL-17 signal pathway and TNF signal pathway. The results of molecular docking showed that the active components of HLJDD had a good binding ability with the Hub gene. This study systematically elucidates the “multi-component, multi-target, multi-pathway” mechanism of anti-UC with HLJDD for the first time, suggesting that HLJDD or its active components may be candidate drugs for the treatment of ulcerative colitis.

Endoscopic Assessment of Inflammatory Bowel Disease Activity in Clinical Trials

In patients with Crohn's disease and ulcerative colitis, poor correlation between symptoms and active luminal inflammation has been well established. As a result, the field has moved towards the use of endoscopic assessment to evaluate inflammatory activity. Numerous endoscopic indices have been used for this purpose although none are completely validated. The Simple Endoscopic Score for Crohn's Disease and the Crohn's Disease Endoscopic Index of Severity have been used most frequently; however in addition to incomplete validation, they have important limitations for clinical use, including complexity of scoring and poor reliability of items such as stenosis. The Rutgeerts' score for postoperative Crohn's disease was developed primarily as a prognostic rather than evaluative tool and also requires additional validation. In ulcerative colitis, the Mayo endoscopic subscore has been used as the regulatory standard, although the Ulcerative Colitis Endoscopic Index of Severity may provide a more granular assessment of individual components of disease activity. The use of combined outcomes with patient reported outcomes (PROs) and endoscopic indices has received favor by regulatory bodies but require further validation. This review describes the indications for endoscopic assessment in trials, the indices most frequently utilized for these purposes, and potential future approaches to assessment of disease activity.

Utilizing Deep Learning to Analyze Whole Slide Images of Colonic Biopsies for Associations Between Eosinophil Density and Clinicopathologic Features in Active Ulcerative Colitis

BACKGROUND

Eosinophils have been implicated in the pathogenesis of ulcerative colitis and have been associated with disease course and therapeutic response. However, associations between eosinophil density, histologic activity, and clinical features have not been rigorously studied.

METHODS

A deep learning algorithm was trained to identify eosinophils in colonic biopsies and validated against pathologists' interpretations. The algorithm was applied to sigmoid colon biopsies from a cross-sectional cohort of 88 ulcerative colitis patients with histologically active disease as measured by the Geboes score and Robarts histopathology index (RHI). Associations between eosinophil density, histologic activity, and clinical features were determined.

RESULTS

The eosinophil deep learning algorithm demonstrated almost perfect agreement with manual eosinophil counts determined by 4 pathologists (interclass correlation coefficients: 0.805-0.917). Eosinophil density varied widely across patients (median 113.5 cells per mm2, interquartile range 108.9). There was no association between eosinophil density and RHI (P = 0.5). Significant differences in eosinophil density were seen between patients with Montreal E3 vs E2 disease (146.2 cells per mm2 vs 88.2 cells per mm2, P = 0.005). Patients on corticosteroids had significantly lower eosinophil density (62.9 cells per mm2 vs 124.1 cells per mm2, P = 0.006). No association between eosinophil density and biologic use was observed (P = 0.5).

CONCLUSIONS

We developed a deep learning algorithm to quantify eosinophils in colonic biopsies. Eosinophil density did not correlate with histologic activity but did correlate with disease extent and corticosteroid use. Future studies applying this algorithm in larger cohorts with longitudinal follow-up are needed to further elucidate the role of eosinophils in ulcerative colitis.

Systematic review and meta-analysis: the advantage of endoscopic Mayo score 0 over 1 in patients with ulcerative colitis

Background

Mucosal healing (MH) evaluated by endoscopy is a novel target of therapy in UC as it is associated with improved long-term outcomes. It is defined based on the Mayo endoscopic score (MES), but it is still to define whether a value of MES 0 or 1 should be the target. The purpose of this paper is to present the results of a systematic review with meta-analysis which compares long-term outcomes of patients in steroid-free clinical remission with MES 0 with those with MES 1.

Methods

A systematic electronic search of the literature was performed using Medline, Scopus, and CENTRAL through December 2020 (PROSPERO n:CRD42020179333). The studies concerned UC patients, in steroid-free clinical remission, with MES of 0 or 1, and with at least 12-months of follow-up.

Results

Out of 4611 citations, 15 eligible studies were identified. Increases in clinical relapse among patients with MES 1 were observed in all the studies included in this review, suggesting that MES of 1 have a higher risk of relapse than a score of 0. MES 0 patients displayed a lower risk of clinical relapse (OR 0.33; 95% CI 0.26–0.43; I² 13%) irrespective of the follow-up time (12-months or longer). On the other hand, no differences were found comparing MES 0 versus MES 1 about the risk of hospitalization or colectomy.

Conclusions

MES 0 is associated with a lower rate of clinical relapse than is MES 1. For this reason, MES 0, rather than MES 0–1, should be considered the therapeutic target for patients with UC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02157-5.

Intervention of 3-aminobenzamide against Dextran Sulphate Sodium induced colitis in mice: Investigations on molecular mechanisms

Various preclinical and clinical studies reported that Poly [ADP-ribose] polymerase 1 plays significant role in all acute and chronic inflammatory diseases with different etiopathogenesis. The present study aims to investigate the protective effect of 3-aminobenzamide in Dextran Sulphate Sodium induced ulcerative colitis and associated molecular mechanisms. Ulcerative colitis in male BALB/c mice was induced using Dextran sulphate sodium (3 %w/v) for 3 cycles with 7 days recovery period in-between. 3-aminobenzamide was administered at the doses of 5, 10 and 20 mg/kg starting from the I^st week of remission period and was continued till the termination of the experiment. The effect of 3-aminbenzamide was evaluated using biochemical parameters, histopathological evaluations, ELISA, immunohistochemistry, immunofluorescence and Western blot analysis. All the doses of 3-aminobenzamide (5 mg/kg; 10 mg/kg and 20 mg/kg) ameliorated the severity of ulcerative colitis by modulating various molecular targets such as poly[ADP-ribose] polymerase 1, nuclear factor kappa-light-chain-enhancer of activated B cells, NLR family pyrin domain containing 3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, cysteine aspartases, interleukin-1β, proliferating cell nuclear antigen, sirtuin 1, adenosine monophosphate-activated protein kinase, tumour necrosis factor-α and catalase. However, the lower doses (5 and 10 mg/kg) exerted more prominent effects in comparison to the high dose (20 mg/kg). Further, 3-aminobenzamide treatment restored the intestinal integrity by increasing the expression of occludin and significantly ameliorated ulcerative colitis associated elevated lipopolysaccharides, oxidative and nitrosative stress, cellular damage and apoptosis. Lower doses of 3-aminobenzamide showed more prominent protective effects against ulcerative colitis associated damage as compared to higher dose.

Histological Scores in Patients with Inflammatory Bowel Diseases: The State of the Art

The histological assessment has been advocated as a detailed and accurate measure of disease activity in inflammatory bowel diseases (IBD). In ulcerative colitis (UC), histological activity has been demonstrated to be associated with higher rates of relapse, prolonged corticosteroid use and long-term complications, even when endoscopic remission is achieved. Therefore, histological healing may represent a potential treatment target. Several histological scores have been developed and are available today. The Robarts histopathology index (RHI) and the Nancy index (NI) are the only two recommended by the European Crohn’s and Colitis Organization (ECCO) for use in patients with UC. Conversely, in Crohn’s disease (CD), the discontinuous nature of lesions has limited standardized histological assessment. Most of the available histological scoring systems in CD are complex and not validated. The aim of this review is to comprehensively summarize the latest evidence regarding histological scoring systems in IBD. We guide the reader through understanding the importance of an accurate microscopic evaluation using validated scoring systems, highlighting the strengths and pitfalls of each score. The priorities of future research needs are also addressed.

Randomised clinical trial: a phase 1b study of GB004, an oral HIF-1α stabiliser, for treatment of ulcerative colitis

BACKGROUND

Epithelial barrier dysfunction contributes to a dysregulated intestinal immune response in ulcerative colitis (UC). GB004 is an orally administered, small molecule, gut-targeted stabiliser of hypoxia-inducible factor-1α, a transcription factor with protective roles at the epithelial layer of the inflamed gut.

AIMS

To evaluate safety, pharmacokinetics, pharmacodynamics and efficacy of GB004 in patients with active UC.

METHODS

This double-blind, placebo-controlled study randomised patients 2:1 to receive an oral solution of GB004 120 mg or placebo once daily for 28 days. Eligible patients had a Robarts Histopathology Index score ≥4 with neutrophils in the epithelium, total Mayo Clinic score 3-12, Mayo Clinic endoscopic subscore ≥1, and blood in the stool, despite treatment with 5-aminosalicylates, corticosteroids or immunosuppressants.

RESULTS

Thirty-four patients were randomised. GB004 120 mg for 28 days was generally well-tolerated. Adverse events occurred in 27.3% (3/11) and 39.1% (9/23) of patients in the placebo and GB004 groups respectively. Nausea and dysgeusia were most commonly reported in the GB004 group (0% for placebo and 21.7% [5/23] and 13.0% [3/23] respectively for GB004). There were no treatment-related serious adverse events or deaths. GB004 exhibited minimal accumulation, with higher colonic concentrations relative to plasma. Exploratory pharmacodynamic and efficacy analyses demonstrated GB004 target engagement and numerically higher proportions of patients achieving improvement in multiple measures of disease activity, respectively, at day 28 for GB004 compared to placebo.

CONCLUSION

Results from this phase 1b trial support evaluation of the full therapeutic potential of GB004 for the treatment of UC. A phase 2 study (NCT04556383) is ongoing. Clinicaltrials.gov NCT03860896.

Medical Therapy in Chronic Refractory Ulcerative Colitis: When Enough Is Enough

Despite significant improvements in the management of ulcerative colitis (UC) in parallel with the evolution of therapeutic targets and novel biologics and small molecules, a subset of medically refractory patients still requires colectomy. Recent population-based studies demonstrate a trend toward a decrease in the rates of surgery for UC patients in the biological era, although the potential of disease modification with these agents is still debated. As the concept of irreversible bowel damage is underexplored in UC, refractory patients can be exposed to multiple treatments losing optimal timing for surgery and further developing complications such as dysplasia/cancer, dysmotility, microcolon, and other functional abnormalities. This review aims to discuss the concept of disease progression in UC, explore the limitations of medical treatment in refractory UC patients, and propose the application of a three-step algorithm that allows timely indication for surgery in clinical practice.

Targeting PDE4 as a promising therapeutic strategy in chronic ulcerative colitis through modulating mucosal homeostasis

Phosphodiesterase-4 (PDE4) functions as a catalyzing enzyme targeting hydrolyzation of intracellular cyclic adenosine monophosphate (cAMP) and inhibition of PDE4 has been proven to be a competitive strategy for dermatological and pulmonary inflammation. However, the pathological role of PDE4 and the therapeutic feasibility of PDE4 inhibitors in chronic ulcerative colitis (UC) are less clearly understood. This study introduced apremilast, a breakthrough in discovery of PDE4 inhibitors, to explore the therapeutic capacity in dextran sulfate sodium (DSS)-induced experimental murine chronic UC. In the inflamed tissues, overexpression of PDE4 isoforms and defective cAMP-mediating pathway were firstly identified in chronic UC patients. Therapeutically, inhibition of PDE4 by apremilast modulated cAMP-predominant protein kinase A (PKA)–cAMP-response element binding protein (CREB) signaling and ameliorated the clinical symptoms of chronic UC, as evidenced by improvements on mucosal ulcerations, tissue fibrosis, and inflammatory infiltrations. Consequently, apremilast maintained a normal intestinal physical and chemical barrier function and rebuilt the mucosal homeostasis by interfering with the cross-talk between human epithelial cells and immune cells. Furthermore, we found that apremilast could remap the landscape of gut microbiota and exert regulatory effects on antimicrobial responses and the function of mucus in the gut microenvironment. Taken together, the present study revealed that intervene of PDE4 provided an infusive therapeutic strategy for patients with chronic and relapsing UC.

Sampling and Reporting of Inflammatory Bowel Disease

Pathologists have an important and expanding role in the diagnosis and management of inflammatory bowel disease. This role includes the initial diagnosis of the disease, assessment of the response to treatment and the identification of short-term complications such as cytomegalovirus infection and long-term complications such as dysplasia. Furthermore, the assessment of resection specimens for complication of disease is important to determining the risk of subsequent disease or inflammation within an ileal pouch. Adequate sampling of the disease at endoscopy and from the surgical resection specimen is vital to determining the ultimate information that can be provided by the pathologist. This sampling is determined by the clinical scenario. Similarly, a standardized approach to reporting and synthesizing the histologic findings will improve patient management. This is best exemplified by the increasing interest in histologic activity indices, such as the Nancy index in ulcerative colitis, and in the standardized reporting for inflammatory bowel disease dysplasia recommended by the SCENIC international consensus.

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.

Association of Type 1 diabetes with ulcerative colitis in BALB/c mice: Investigations on sex-specific differences

Diabetes comorbidity in ulcerative colitis (UC) has relevant clinical and therapeutic implications. The link between hyperglycemia and intestinal barrier function with respect to infection and inflammation consequences exists in diabetes. The present study was designed to decipher the molecular mechanisms associated with Type 1 Diabetes mellitus and the UC in both male and female BALB/c mice. Dextran sulfate sodium (DSS; 2.5%w/v) dissolved in drinking water was given for three cycles (each cycle; 7 days) with 7 days recovery period in-between to both male and female BALB/c mice. At the first recovery period, Streptozotocin (40 mg/kg; i.p.) was administered for 5 consecutive days in the case of male BALB/c mice; whereas the same procedure was repeated at the beginning of each recovery period in female animals. In the DSS + DB group of male animals, disease activity index, myeloperoxidase activity, nitrite level, plasma lipopolysaccharides, interleukin-1β, histological score, % fibrotic area, % TUNEL positive cells were significantly increased. Furthermore, protein expression of phosphorylated nuclear factor kappa light chain enhancer of activated B cells (pNFκB65), proliferating cell nuclear antigen, interleukin-6, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and cysteine-containing aspartate-specific proteases-1 (caspase-1) significantly increased in the DSS + DB group of male animals as compared to female. The present study findings proved that hyperglycemic conditions exacerbated the pathological conditions in UC of male animals; whereas milder conditions developed in females.

Treatment of Inflammatory Bowel Disease: A Comprehensive Review

Inflammatory bowel disease (IBD), as a global disease, has attracted much research interest. Constant research has led to a better understanding of the disease condition and further promoted its management. We here reviewed the conventional and the novel drugs and therapies, as well as the potential ones, which have shown promise in preclinical studies and are likely to be effective future therapies. The conventional treatments aim at controlling symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures and/or surgical resection if necessary. However, a considerable fraction of patients do not respond to available treatments or lose response, which calls for new therapeutic strategies. Diverse therapeutic options are emerging, involving small molecules, apheresis therapy, improved intestinal microecology, cell therapy, and exosome therapy. In addition, patient education partly upgrades the efficacy of IBD treatment. Recent advances in the management of IBD have led to a paradigm shift in the treatment goals, from targeting symptom-free daily life to shooting for mucosal healing. In this review, the latest progress in IBD treatment is summarized to understand the advantages, pitfalls, and research prospects of different drugs and therapies and to provide a basis for the clinical decision and further research of IBD.

PTG-100, an Oral α4β7 Antagonist Peptide: Preclinical Development and Phase 1 and 2a Studies in Ulcerative Colitis

BACKGROUND & AIMS

Oral therapies targeting the integrin α4β7 may offer unique advantages for the treatment of inflammatory bowel disease. We characterized the oral α4β7 antagonist peptide PTG-100 in preclinical models and established safety, pharmacokinetic/pharmacodynamic relationships, and efficacy in a phase 2a trial in patients with ulcerative colitis (UC).

METHODS

In vitro studies measured binding properties of PTG-100. Mouse studies measured biomarkers and drug concentrations in blood and tissues. The phase 1 study involved healthy volunteers. In phase 2a, patients with moderate to severe active UC were randomized to receive PTG-100 (150, 300, or 900 mg) or placebo once daily for 12-weeks.

RESULTS

PTG-100 potently and selectively blocks α4β7. Oral dosing of PTG-100 in mice showed high levels of target engagement and exposure in gut-associated lymphoid tissues. In healthy volunteers, PTG-100 showed dose-dependent increases in plasma exposure and blood target engagement. Although this phase 2a study initially did not meet the primary endpoint, a blinded reread of the endoscopy videos by a third party indicated clinical efficacy in conjunction with histologic remission at doses correlating with less than 100% receptor occupancy in peripheral blood.

CONCLUSIONS

PTG-100 showed local gastrointestinal tissue target engagement and inhibition of memory T-cell trafficking in mice. It was safe and well tolerated in phase 1 and 2 studies. Phase 2a data are consistent with biological and clinical response and showed a dose response reflecting similar activities in preclinical models and healthy individuals. These data suggest that local gut activity of an oral α4β7 integrin antagonist, distinct from full target engagement in blood, are important for efficacy and the treatment of UC. (ClinicalTrials.gov, Number NCT02895100; EudraCT, Number 2016-003452-75).

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.

Treatment Targets in Ulcerative Colitis: Is It Time for All In, including Histology?

The main therapeutic goal of ulcerative colitis (UC) is to induce and maintain remission to prevent long-term disease progression. Treat-to-target strategies, first introduced by the STRIDE consensus and updated in 2021, have shifted focus from symptomatic control toward more stringent objective endpoints. Today, patient monitoring should be based on a combination of biomarkers and clinical scores, while patient-reported outcomes could be used as short-term targets in monitoring disease activity and therapeutic response. In addition, endoscopic healing was the preferred long-term goal in UC. A Mayo endoscopic score (MES) ≤ 1 can be recommended as a minimum target. However, recent evidence suggests that more stringent endoscopic goals (MES of 0) are associated with superior outcomes. Recently, emerging data support that histological remission (HR) is a superior prognostic factor to endoscopic healing in predicting long-term remission. Despite not yet being recommended as a target, HR may become an important potential therapeutic goal in UC. However, it remains questionable if histological healing should be used as a routine assessment in addition to clinical, biomarker, and endoscopic targets in all patients. Therefore, in this review, our aim was to discuss the current evidence for the different treatment targets and their value in everyday clinical practice.

The endoscopic diagnosis of mucosal healing and deep remission in inflammatory bowel disease

The therapeutic goal in inflammatory bowel disease (IBD) patients has shifted from controlling the clinical activity alone to managing other associated problems. The concept of mucosal healing (MH) and deep remission (DR) are advocated and regarded as new therapeutic goals in IBD. However, the definition of MH still remains controversial. It is unclear whether or not the histological structures or functional factors should be included in the definition of DR in addition to clinical remission and MH. The classifications of white-light imaging (e.g. Mayo endoscopic subscore, UCEIS, CD Endoscopic Index of Severity, simple Endoscopic Score-CD) have been proposed and are now widely used to assess the severity as well as the MH of inflammation in IBD. In ulcerative colitis, magnifying chromoendoscopy has been shown to be useful to assess the MH of inflammation while other types of image-enhanced endoscopy, such as narrow-band imaging, have not. Endocytoscopy and confocal laser endomicroscopy (CLE) are also applied to assess the activity in IBD. These endoscopic procedures can estimate MH with more precision through observing the details of superficial structures, such as crypt openings. In addition, CLE can partially assess the mucosal function by detecting fluorescence leakage. Molecular imaging can possibly detect the molecules associated with inflammation, intestinal regeneration and differentiation, and various functions including the intestinal barrier and mucus secretion. These novel procedures may improve the diagnosis strategy of DR through the assessment of DR-associated factors such as the histological structures and functional factors in the near future.

Histologic Outcomes With Vedolizumab Versus Adalimumab in Ulcerative Colitis: Results From An Efficacy and Safety Study of Vedolizumab Intravenous Compared to Adalimumab Subcutaneous in Participants With Ulcerative Colitis (VARSITY)

BACKGROUND AND AIMS

VARSITY (An Efficacy and Safety Study of Vedolizumab Intravenous [IV] Compared to Adalimumab Subcutaneous [SC] in Participants With Ulcerative Colitis) showed superior clinical remission and endoscopic improvement in ulcerative colitis with vedolizumab vs adalimumab. This analysis compared histologic outcomes.

METHODS

Patients in VARSITY were randomized 1:1 to maintenance with vedolizumab IV 300 mg every 8 weeks or adalimumab SC 40 mg every 2 weeks (both following standard induction). Geboes Index and Robarts Histopathology Index (RHI) scores were used to assess prespecified histologic exploratory end points of histologic remission (Geboes <2 or RHI ≤2) and minimal histologic disease activity (Geboes ≤3.1 or RHI ≤4) at weeks 14 and 52.

RESULTS

In total, 769 patients received vedolizumab (n = 383) or adalimumab (n = 386). Mean baseline histologic disease activity was similar between vedolizumab and adalimumab groups. Vedolizumab induced greater histologic remission than adalimumab at week 14 (Geboes: 16.7% vs 7.3%, Δ9.4% [95% confidence interval {CI}, 4.9%-13.9%], P < .0001; RHI: 25.6% vs 16.1%, Δ9.5% [95% CI, 3.8%-15.2%], P = .0011) and week 52 (Geboes: 29.2% vs 8.3%, Δ20.9% [95% CI, 15.6%-26.2%], P < .0001; RHI: 37.6% vs 19.9%, Δ17.6% [95% CI, 11.3%-23.8%], P < .0001) overall and in both anti-tumor necrosis factor (TNF)-naïve and -failure subgroups. Results were similar for minimal histologic disease activity. Histologic outcomes were generally better in anti-TNF-naïve vs -failure patients. At week 52, rates of mucosal healing (composite end point of histologic plus endoscopic improvement) were also higher with vedolizumab than adalimumab (Geboes: 25.6% vs 6.7%; RHI: 30.5% vs 14.5%).

CONCLUSIONS

Higher rates of histologic remission, minimal histologic disease activity, and combined histologic plus endoscopic outcomes were observed with vedolizumab than with adalimumab in ulcerative colitis in both anti-TNF-naïve and -failure subgroups.

REGISTRATION

ClinicalTrials.gov NCT02497469; EudraCT 2015-000939-33.

Ozanimod as Induction and Maintenance Therapy for Ulcerative Colitis

BACKGROUND

Ozanimod, a selective sphingosine-1-phosphate receptor modulator, is under investigation for the treatment of inflammatory bowel disease.

METHODS

We conducted a phase 3, multicenter, randomized, double-blind, placebo-controlled trial of ozanimod as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. In the 10-week induction period, patients in cohort 1 were assigned to receive oral ozanimod hydrochloride at a dose of 1 mg (equivalent to 0.92 mg of ozanimod) or placebo once daily in a double-blind manner, and patients in cohort 2 received open-label ozanimod at the same daily dose. At 10 weeks, patients with a clinical response to ozanimod in either cohort underwent randomization again to receive double-blind ozanimod or placebo for the maintenance period (through week 52). The primary end point for both periods was the percentage of patients with clinical remission, as assessed with the three-component Mayo score. Key secondary clinical, endoscopic, and histologic end points were evaluated with the use of ranked, hierarchical testing. Safety was also assessed.

RESULTS

In the induction period, 645 patients were included in cohort 1 and 367 in cohort 2; a total of 457 patients were included in the maintenance period. The incidence of clinical remission was significantly higher among patients who received ozanimod than among those who received placebo during both induction (18.4% vs. 6.0%, P<0.001) and maintenance (37.0% vs. 18.5% [among patients with a response at week 10], P<0.001). The incidence of clinical response was also significantly higher with ozanimod than with placebo during induction (47.8% vs. 25.9%, P<0.001) and maintenance (60.0% vs. 41.0%, P<0.001). All other key secondary end points were significantly improved with ozanimod as compared with placebo in both periods. The incidence of infection (of any severity) with ozanimod was similar to that with placebo during induction and higher than that with placebo during maintenance. Serious infection occurred in less than 2% of the patients in each group during the 52-week trial. Elevated liver aminotransferase levels were more common with ozanimod.

CONCLUSIONS

Ozanimod was more effective than placebo as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. (Funded by Bristol Myers Squibb; True North ClinicalTrials.gov number, NCT02435992.).

Application of Artificial Intelligence to Clinical Practice in Inflammatory Bowel Disease - What the Clinician Needs to Know

Artificial intelligence [AI] techniques are quickly spreading across medicine as an analytical method to tackle challenging clinical questions. What were previously thought of as highly complex data sources, such as images or free text, are now becoming manageable. Novel analytical methods merge the latest developments in information technology infrastructure with advances in computer science. Once primarily associated with Silicon Valley, AI techniques are now making their way into medicine, including in the field of inflammatory bowel diseases [IBD]. Understanding potential applications and limitations of these techniques can be difficult, in particular for busy clinicians. In this article, we explain the basic terminologies and provide a particular focus on the foundations behind state-of-the-art AI methodologies in both imaging and text. We explore the growing applications of AI in medicine, with a specific focus on IBD to inform the practising gastroenterologist and IBD specialist. Finally, we outline possible future uses of these technologies in daily clinical practice.