Introduction

The Simple US Score for Crohn's Disease (SIUS-CD) ultrasound index is a tool with high diagnostic accuracy for evaluating Crohn's disease (CD) activity^1,2. This index is distinguished by its prospective and multicenter validation, high interobserver agreement, and simple calculation. However, its usefulness for monitoring treatment response remains uncertain.

Aims & Methods

A prospective study was conducted in adult patients with CD who initiated treatment with Ustekinumab. All participants were evaluated by ultrasound and colonoscopy at baseline and again after 6 months of treatment. Patients who modified their therapy during the study or who presented with an impassable stricture on endoscopy were excluded.
Ultrasound examinations were performed by two gastroenterologists from the Inflammatory Bowel Disease (IBD) Unit with experience in ultrasonography, using Canon Aplio i800 equipment (Canon Medical Systems, Japan). Biological parameters (C-reactive protein [CRP] and fecal calprotectin [FC]) and ultrasound parameters of activity were recorded, with the SIUS-CD index calculated for the segment with the highest activity.
Endoscopy was performed by gastroenterologists from the same IBD Unit with extensive experience in endoscopic indices, using Olympus endoscopes (Olympus, Japan). Endoscopic remission was defined as SES-CD ≤ 3 or a Rutgeerts score < i2. Endoscopic response was considered as a >50% or ≥3-point reduction in SES-CD, or a ≥1-point decrease in the Rutgeerts score. Physicians were blinded to the results of the other test, and no physician performed both evaluations.

Results

A total of 19 patients were included; their baseline characteristics are summarized in Table 1. The median time between ultrasound and colonoscopy was 8 days (IQR = 56.5). Endoscopic response was observed in 9 patients (47.37%), 8 of whom were in endoscopic remission (42.11%).
In patients who achieved remission, SIUS-CD index values decreased significantly compared to those who did not (4.63 vs. 7.63; p < 0.0056). However, in this subgroup, no statistically significant differences were found in CRP (2.77 mg/L vs. 6.14 mg/L; p = 0.08) or FC levels (332.64 µg/g vs. 283.94 µg/g; p = 0.60).
Among patients with endoscopic response, a significant reduction of 3.43 ± 3.55 points in the SIUS-CD index was observed between baseline and 6-month evaluations (p < 0.0099). In contrast, no significant changes were found in patients without endoscopic response (8.46 ± 1.83).

Conclusion

According to preliminary results, a 3.4-point reduction in the SIUS-CD index was associated with endoscopic response, suggesting that this ultrasound index may be sensitive to changes following initiation of biological therapy, and could predict both remission and endoscopic response. Ultrasound and endoscopy showed better correlation in assessing disease activity than biomarkers (CRP and FC), supporting follow-up strategies that prioritize imaging techniques over laboratory markers alone.

References

1. Ripollés T., Poza J., Suárez Ferrer C., Martínez-Pérez M.J., Martín-Algíbez A., de las Heras Páez B. Evaluation of Crohn's Disease Activity: Development of an Ultrasound Score in a Multicenter Study. Inflamm Bowel Dis. 2021;27(1):145–154. doi:10.1093/ibd/izaa134
2. Ripollés T., Poza J., Martínez-Pérez M.J., Suárez Ferrer C., Blanc E., Paredes J.M. Assessment of Crohn’s Disease Activity: Validation of a Segmental Simple Ultrasound Score in a Multicenter Study. Inflamm Bowel Dis. 2024. doi:10.1093/ibd/izae213

Introduction

Intestinal ultrasound (IUS) is increasingly used as a point-of-care tool for patients with ulcerative colitis (UC). Non-invasive monitoring is essential for managing disease progression and therapeutic intervention in pediatric UC patients. The Milan Ultrasound criteria (MUC), ulcerative colitis intestinal ultrasound score (UC-IUS), and Civitelli score show promise as real-time disease activity assessment tools, potentially reducing the need for invasive procedures like endoscopy.

Aims & Methods

A prospective cohort of 34 pediatric UC patients underwent IUS and colonoscopy to assess disease activity using MUC, UCIUS, and Civitelli scores. Assessments were conducted within a 7-day interval, with no therapeutic changes between procedures. Diagnostic accuracy was determined using receiver operating characteristic (ROC) curves, with endoscopy as the reference
standard, and histological parameters assessed in a subset of patients using the Nancy Index.

Results

The study included 34 pediatric UC patients (median age: 14.7 years; 65% male) with varied disease severities and durations (median duration: 12.6 months; median PUCAI: 30; median fecal calprotectin: 1041 μg/g). Bowel wall thickness (BWT) correlated significantly with all IUS scores; however, no correlation was observed between BWT and baseline Mayo endoscopic disease activity. The area under the curve (AUC) was 0.528 (CI:0.348–0.704) for MUC, 0.602 (CI: 0.418–0.768) for UC-IUS, and 0.572 (CI: 0.388–0.742) for the Civitelli score, indicating moderate diagnostic accuracy. While differences among scores were not statistically significant, UC-IUS demonstrated the highest accuracy. In 16 patients with available Nancy Index data, the AUC values were 0.500 for MUC, 0.579 for Civitelli, and 0.563 for UC-IUS, further supporting moderate accuracy (Table 1).

Conclusion

Both MUC, Civitelli, and UC-IUS scores provide moderate diagnostic accuracy in assessing pediatric UC, though potentially less effective than in adult populations. UC-IUS, with its emphasis on vascularization, haustration and wall thickness, may offer enhanced sensitivity in pediatric patients. Lowering the cut-off for bowel wall thickness may improve accuracy in children, given their thinner, yet highly vascularized bowel walls, particularly in early disease stages.

References

1. van Wassenaer EA, van Rijn RR, Zwetsloot SLM, et al. Intestinal Ultrasound to Assess Ulcerative Colitis Disease Activity in Children: External Validation and Comparison of 2 Intestinal Ultrasound Activity Indices. Inflamm Bowel Dis. 2023;29:1217-1222.
2. Allocca M, Dell'Avalle C, Craviotto V, et al. Predictive value of Milan ultrasound criteria in ulcerative colitis: A prospective observational cohort study. United European Gastroenterol J. 2022;10:190-197

Introduction

Microscopic colitis (MC) is an inflammatory bowel disease (IBD) that causes chronic non-bloody watery diarrhea and abdominal pain that significantly reduces the quality of life¹. MC can be subdivided into collagenous colitis (CC) and lymphocytic colitis (LC), which are clinically indistinguishable but differ histologically². The activation of immune responses and the alteration of the intestinal epithelial barrier via water channel aquaporin downregulation and crypt hyperproliferation are characteristic features of MC³, often shared by other gastrointestinal disorders, such as “classical” IBD (Crohn’s disease and ulcerative colitis, UC), or irritable bowel syndrome (IBS). Enteric glial cells (EGC) are key regulators of gut homeostasis and epithelial permeability, that respond to inflammation by entering a reactive state, potentially driving epithelial dysfunction. Whether EGC promote resolution or perpetuate inflammation remains unclear.⁴

Aims & Methods

MC is poorly understood and EGC role in MC is still unknown. Therefore, our aim is to investigate the involvement of EGC – due to their neuroimmune functions and involvement in intestinal dysmotility – in patients with MC. In addition, mast cells will be investigated since altered interactions with EGC have been demonstrated during IBS⁵.
Paraffin-embedded colonic biopsies from patients with active CC, LC, UC, IBS-diarrhea (D) and healthy controls (HC) were collected (n=13-26 per cohort). In addition, a subset of CC patients was also sampled during successful treatment with glucocorticosteroid 9mg budesonide (n=13). The amount of EGC was quantified using glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100β). Mast cells were quantified using tryptase.

Results

Immunofluorescence analysis of EGC revealed an increased amount of EGC^GFAP+ in CC compared to HC (p<0.001). Of note, CC EGC^GFAP+ levels were comparable to those shown by biopsies from patients suffering from IBS-D and UC. Among the 13 CC patients with paired samples before and under budesonide treatment, we observed a trend toward reduced EGC^GFAP+ levels during treatment (p = 0.08). In contrast, LC patients displayed similar EGC^GFAP+ levels as to HC, but lower than those observed in biopsies from patients with CC, IBS-D, and UC (p<0.001). On the other hand, EGC^S100β+ were increased only in active CC (p<0.0001). Yet, UC patients displayed the highest level of EGC^S100β+ (p<0.0001). Mast cells analysis showed an increased counts for tryptase in CC before and under treatment compared to HC (p<0.01).

Conclusion

Our findings indicate that EGC and mast cells are involved in CC pathogenesis due to an increased reactivity of EGC and mast cells in the colonic mucosa. CC patients exhibit signs of EGC^GFAP+ levels comparable to those observed in UC and IBS-D. Oppositely, LC seems to be independent of neuroinflammation as EGC and mast cells presence was comparable to HC. These preliminary findings support the theory that CC and LC are distinct disease entities. Future work will include RNA sequencing of EGC-related genes, counts of eosinophils as well as in situ analysis of mast cells and eosinophils degranulation, and assessment of budesonide effects on EGC in vitro.

References

1. Nyhlin N, Wickbom A, Montgomery SM, et al. Long-term prognosis of clinical symptoms and health-related quality of life in microscopic colitis: a case-control study. Aliment Pharmacol Ther 2014; 39: 963-972. 20140311. DOI: 10.1111/apt.12685.
2. Carrasco A, Esteve M, Salas A, et al. Immunological Differences between Lymphocytic and Collagenous Colitis. J Crohns Colitis 2016; 10: 1055-1066. 20160229. DOI: 10.1093/ecco-jcc/jjw058.
3. Escudero-Hernandez C, Munch A, Ostvik AE, et al. The Water Channel Aquaporin 8 is a Critical Regulator of Intestinal Fluid Homeostasis in Collagenous Colitis. J Crohns Colitis 2020; 14: 962-973. DOI: 10.1093/ecco-jcc/jjaa020.
4. Gonzales J and Gulbransen BD. The Physiology of Enteric Glia. Annu Rev Physiol 2024 20241115. DOI: 10.1146/annurev-physiol-022724-105016.
5. Meira de-Faria F, Casado-Bedmar M, Marten Lindqvist C, et al. Altered interaction between enteric glial cells and mast cells in the colon of women with irritable bowel syndrome. Neurogastroenterol Motil 2021; 33: e14130. 20210402. DOI: 10.1111/nmo.14130.

Introduction

Dysregulated activation of myeloid cells, including monocytes and macrophages, contributes to intestinal inflammation in Inflammatory Bowel Disease (IBD) through excessive release of pro-inflammatory cytokines. Microbial-derived short-chain fatty acids (SCFAs) modulate the inflammatory and metabolic nature of these cells through activation of a wide-range of cellular signalling pathways. Several of these pathways—including targeting Free-fatty acid receptors (FFA1, FFA2, FFA3) and other metabolic pathways (Glycolysis and Oxidative phosphorylation) have exhibited potential by influencing the polarisation from inflammatory to regulatory macrophages. In this study, we aim to unravel these mechanisms and explore the interplay between myeloid cells and SCFAs in IBD.

Aims & Methods

We first investigated the immunomodulatory effects of SCFA on THP-1 and monocyte-derived macrophage (MDM) models of inflammation. These cells were polarised toward an M1-like phenotype (LPS+ IFN-γ) in the presence of SCFAs or pharmacological agonist of FFA3 (AR420626). We analysed how these treatments impacted cytokine secretion and markers of polarisation using ELISA and RT-qPCR. To gain insight with a disease context, CD14+ monocytes from the peripheral blood of IBD patients (n=6), were exposed to M1 polarising stimuli (LPS+IFN-γ), in the presence of SCFAs or AR420626. To explore potential disease-specific responses, monocytes from actively inflamed IBD patients (n=7) and healthy controls (HC) (n=3) were cultured in presence of butyrate (1mM) in the absence of inflammatory stimulus. In both instances, RT-qPCR and ELISA were conducted to assess secretion of pro-inflammatory cytokines and activation of metabolic pathways.

Results

In THP-1 and MDM models, treatment with butyrate (4 mM) markedly suppressed IL-6 secretion, an effect that was mimicked by the FFA3 agonist AR420626 (50 µM). These responses extended to IBD patient-derived monocytes, where strong induction of IL-6 and TNF-α were repressed by both butyrate and propionate (vs M1; p< 0.001). FFA3, which plays an important role in mediating responses to SCFAs, was also upregulated in M1 polarised patient monocytes (vs Unt; p< 0.05). However, this elevated expression was abrogated in monocytes that were exposed to butyrate (1mM), giving insight toward how butyrate can regulate SCFA sensing mechanisms under inflammatory conditions. Interestingly, this pro-inflammatory monocyte phenotype was accompanied by raised expression of the glycolysis markers HK2 and GLUT1 —which, again, were repressed by butyrate (vs Unt; p< 0.05). In untreated monocytes derived from IBD patients, we observed an elevated inflammatory state relative to HCs, suggesting prior disease-associated activation. While these cells displayed heightened baseline expression of HK2 than HC monocytes, this was attenuated by exposure to butyrate (vs Unt; p< 0.05), and cells were rescued from this hyper-inflammatory phenotype.

Conclusion

Taken together, these results highlight that butyrate helps to counteract inflammation in IBD monocytes —possibly stemming from an influence on glycolysis. This work demonstrates that monocyte metabolic activity and SCFA-sensing pathways are dysregulated under inflammatory conditions. These findings provide new insight into the altered immune-metabolic state of monocytes in IBD and highlight the important role of microbial-derived SCFAs to restoring immunometabolic balance.

Introduction

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the digestive tract. The introduction of targeted therapies has significantly improved patient outcomes, although a substantial proportion of patients still do not respond adequately. Genetic factors, including single nucleotide polymorphisms (SNPs), may influence therapeutic efficacy.

Aims & Methods

This study investigated the potential correlation between four SNPs in four cytokine genes and the response to targeted molecular therapies.
This prospective cohort study enrolled 197 patients with IBD (144 with Crohn’s disease CD and 55 with ulcerative colitis UC) receiving molecularly targeted therapies. The following SNPs were analyzed: TGF-β -cod10 T/C (rs1982073), IL-6 -174 G/C (rs1800795), TNF-α -308 G/A (rs1800629), and IL-10 -1082 G/A (rs1800896). These SNPs were assessed in relation to baseline patient characteristics. Therapeutic response to molecularly targeted therapies (adalimumab, infliximab, ustekinumab, vedolizumab and tofacitinib) was evaluated in two cohorts: 134 patients in the per-protocol analysis (who maintained the drug for 12 months) and 155 patients in the intention-to-treat analysis. Response was also assessed in the cohort receiving anti-TNF agents (infliximab and adalimumab), including 73 patients in the per-protocol cohort and 87 in the intention-to-treat cohort. After 12 months, response was defined as biochemical remission (absence of steroid therapy, CRP <5 mg/L, and fecal calprotectin <250 µg/g).

Results

The TNF-α -308 mutated allele was more frequently associated with CD than UC (the GA polymorphism was present in 33% of patients with CD and in 21% of patients with UC, while the AA polymorphism was present only in patients with CD, at 4.3%; p = 0.020). The wild-type IL-6 -174 SNP was associated with an older age at diagnosis, with a median age of 30y (22-41) vs 25y (19-36) (p = 0.049) and showed a partial association with a lower history of surgical interventions (p = 0.076). In the cohort of patients who had calprotectin and CRP values at T12, only the mutated IL-10 -1082 SNP was significantly associated with response in the per-protocol cohort (73.4% of patients who did not respond to therapy had the wild-type genotype; p = 0.041) [OR = 2.14 (95% CI 1.03–4.44)] and showed a trend toward significance in the intention-to-treat cohort (p = 0.053). Regarding anti-TNF therapy response, the mutated IL-10 -1082 SNP was associated with better therapeutic outcomes in the per-protocol cohort (84.8% of patients who did not respond to therapy had the wild-type genotype; p = 0.034) [OR = 3.36 (95% CI 1.07–10.58)], but not in the intention-to-treat cohort (p = 0.103). Additionally, a statistically significant correlation was found between TNF-α -308 SNP genotypes (wild-type, heterozygous mutated, and homozygous mutated) and response to anti-TNF therapy in the per-protocol cohort (p = 0.040) [OR = 2.82 (95% CI 1.01–7.85)].

Conclusion

Although four cytokine SNPs were analyzed, the most significant associations were observed with the IL-6 polymorphism, where the mutation was linked to a more aggressive disease course, and the IL-10 cytokine SNP, where the CC+GC genotypes appeared to be associated with a better response to target therapies.

Introduction

There is evidence linking inflammatory bowel disease (IBD) and cardiovascular diseases. However, the roles of histologic and clinical activity of IBD in the development of arrhythmias remain unknown.

Aims & Methods

In this nationwide cohort study in Sweden, we included IBD patients with histologic data (n = 61,383; diagnosed 1969–2017; classified as histologic inflammation vs. remission based on the Swedish version of the Systematized Nomenclature of Medicine codes) and clinical activity data (n = 96,154; diagnosed 1969–2020; classified as clinically active vs. quiescent IBD based on IBD-related hospitalization, surgery, and treatment escalation) and followed them through December 31, 2021. The primary outcome was incident arrhythmias (including atrial fibrillation/flutter, bradyarrhythmias, other supraventricular arrhythmias, and ventricular arrhythmias/cardiac arrest) within 2 years after documented histologic inflammation (vs. remission) or clinically active IBD (vs. quiescent IBD). Poisson regression models estimated incidence rates (IRs) of arrhythmias, while Cox proportional hazards models estimated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). We adjusted for age at IBD diagnosis, sex, calendar year at index date, county of residence, educational attainment, country of birth, number of health care visits, and history of CVD-related comorbidities in the model.

Results

Histologic inflammation was associated with an increased risk of developing any arrhythmias compared to histologic remission (IR: 62.0 vs. 47.2 per 10,000 person-years; aHR = 1.35, 95%CI: 1.18–1.54), corresponding to one additional event of arrhythmia per 338 IBD patients over 2 years after histologic inflammation. We found an excess risk for atrial fibrillation/flutter (aHR = 1.38, 95%CI: 1.18–1.62) and ventricular arrhythmias/cardiac arrest (aHR = 1.73, 95%CI: 1.22–2.44), but not for bradyarrhythmias or other supraventricular arrhythmias. Compared to clinically quiescent IBD, active IBD was also related to a higher risk of arrhythmias (IR: 67.4 vs. 108.4; aHR = 1.77, 95%CI: 1.66–1.88), affecting all subtypes except bradyarrhythmias. In patients with clinically quiescent IBD, histologic inflammation was also associated with an increased risk of arrhythmias (aHR = 1.16, 95%CI: 1.00–1.36, P=0.054).

Conclusion

Histologic and clinical activity were associated with a slightly increased risk of arrhythmias in patients with IBD.

Disclosure

All authors have completed the ICMJE uniform disclosure form and declare:
OO has been PI on projects at Karolinska Institutet financed by grants from Janssen, Pfizer, AbbVie, Takeda, Galapagos/Alfasigma, Ferring, and Bristol Myer Squibb. JH served as speaker or advisory board member for AbbVie, BMS, Celltrion, Eli Lilly, Ferring, Galapagos, Gilead, Index Pharma, Janssen, Medtronic, Merck, MSD, Novartis, Pfizer, Sandoz, Shire, Takeda, Thermo Fisher Scientific, Tillotts Pharma, and Vifor Pharma and received grant support from Takeda, Janssen, and MSD. FE has served as an advisory board member for Boehringer Ingelheim. JFL has coordinated a study for the Swedish IBD Quality Register (SWIBREG), which received funding from Janssen Corporation. JFL has also received financial support from MSD to develop a paper reviewing national healthcare registers in China. JFL has a research collaboration on celiac disease with Takeda and has a research collaboration on fibrosis in IBD with MSD. The other authors report no disclosures relevant to the manuscript.

Introduction

The intestinal microbiome is now broadly accepted as a key driver of Ulcerative Colitis (UC), but how the gut flora impacts key disease pathologies, such as epithelial barrier dysfunction, is poorly understood. MB310 is a live biotherapeutic product for the treatment of UC comprising 8 gut commensal bacteria. These were selected based on a strong association with clinical response in UC patients when engrafted from the donor in a fecal microbiota transplantation (FMT) clinical study. To understand how the MB310 strains drive clinical benefit, we tested their impact on gut barrier integrity and the epithelial inflammatory response.

Aims & Methods

Effects on barrier function were assessed by measuring electric impedance of Caco-2 cells in the presence or absence of lipopolysaccharide (LPS). Furthermore, effects on epithelial permeability were assessed by measuring the translocation of fluorescein isothiocyanate (FITC)-labelled dextran through a 2-dimensional human colonic organoid-derived monolayer, following treatment with the barrier disruptor dextran sodium sulfate (DSS). To gain a mechanistic insight, transcriptomic analysis of 3-dimensional human colonic organoids was performed, following micro-injection with the MB310 consortium in the presence of inflammatory cytokines (Tumor Necrosis Factor [TNF] and Interferon [IFN]γ).

Results

First, the impact of the MB310 consortium on barrier integrity was explored by co-culturing the strains individually or as a consortium with a monolayer of the gut epithelial cell line, Caco-2. Five MB310 strains, as well as the MB310 consortium, significantly increased the integrity of a gut epithelial cell monolayer. Next, the strains were tested on a Caco-2 monolayer that had been damaged by an inflammatory insult, namely LPS, to reflect active UC. 2 strains enhanced repair of the monolayer after LPS challenge, leading to increased integrity.
Human colonic organoids can be plated out to form a tight monolayer that is impervious to large molecules, such as FITC-dextran. DSS treatment disrupts the monolayer leading to translocation of FITC-dextran. Overnight treatment with the MB310 consortium almost completely reversed this effect, which again demonstrates an ability of MB310 to repair gut epithelium following insult.
Finally, the impact of MB310 on the inflammatory response of the gut epithelium was assessed, by stimulating organoids with inflammatory cytokines to mimic UC conditions. Transcriptomics analysis revealed that the cytokines upregulated several inflammatory genes and pathways. MB310 treatment reversed the activation of many of the inflammatory genes and pathways, including many pathways associated with UC.

Conclusion

The accumulated data suggest that MB310 interacts with the host epithelial barrier leading to improvement of its integrity, repair after damage and reduction of leakiness. Moreover, transcriptomic analysis demonstrated the ability of MB310 to rewire epithelial cells to an anti-inflammatory programme, under inflammatory conditions. COMPOSER-1 is an ongoing phase 1b trial testing MB310 in UC patients.