Introduction

Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal and extra-intestinal cancers. Specific therapies used to control inflammation in IBD may have a different impact on cancer risk. However, there are no long-term studies investigating cancer risk in patients with IBD.

Aims & Methods

In the present study we aimed to quantify the overall risk for of developing cancer and to identify specific risk factors for the occurrence of intestinal and extra-intestinal cancers in 560 consecutive patients with Crohn's disease (CD, N=310) or ulcerative colitis (UC, N=250) referred to our outpatient department between January 2021 and February 2022. Demographic data, smoking status, alcohol consumption, age at IBD diagnosis, disease location and course, therapies, and cancer development after IBD diagnosis were recorded. Odds ratios (OR) were estimated by logistic regression analysis. Standardized Incidence Ratios (SIRs) were estimated compared with the general population.

Results

During a median follow-up interval or time of 10 years (range 1-26 years), 6.6% of patients (37/550, female 65 %, mean age 51 years) developed cancer (SIR 1.94, 95%CI 1.4-2.6). The most common cancers were colorectal (12.3%), skin (8.2%), and breast cancer (7.2%). Female patients had an increased risk for all cancers (SIR 3.11, 95%CI 2.06-4.3), melanoma (SIR 5.6, 95%CI 1.14-16.2) and colorectal cancer (SIR 7.59, 95%CI 3-15.4). Male patients had an increased risk of lymphoma (SIR 26.15, 95%CI 3.2-95.7). Younger age at diagnosis of CD (A1 Montreal classification, OR 37.9, 95%CI 10-14), immunosuppressive monotherapy (OR 5.5, 95%CI 2.65- 11) or in combination with anti-TNFα (OR 9.9, 95%CI 3.3-29.09) were associated with an increased risk of cancer in the study population.

Conclusion

We have identified subgroups of IBD patients who would particularly benefit from screening programs. Our findings need to be validated in independent cohorts.

Introduction

Gastro-oesophageal reflux disease (GERD), caused by reflux of stomach contents into the oesophagus, results in discomfort and pain. Evidence suggests reflux- induced oxidative stress in oesophageal epithelial cells may have a role in GERD pathogenesis and symptom development. High mobility group box 1 (HMGB1), a nuclear protein found in most cell types, is actively released in response to oxidative stress. HMGB1 binds to TLR2, TLR4, and RAGE, leading to downstream inflammatory signalling.

Aims & Methods

Our aim was to investigate the potential role of epithelial-derived HMGB1 in the context of GERD.
Oesophageal biopsy tissue was obtained from consented healthy volunteers (N=10) and GERD patients categorised as functional heartburn (FH; N=7), non-erosive reflux disease (NERD; N=13), and erosive reflux disease (ERD; N=11) based on clinical assessment. Oesophageal HMGB1 mRNA was assessed by RT-qPCR. Tissue was used to assess protein expression of HMGB1, TLR2, TLR4, and RAGE using immunohistochemistry (IHC). Healthy oesophageal biopsies were used to assess HMGB1 release ex vivo following synthetic refluxate challenge (pH2, 1mM deoxycholate (DCA), 1mg/mL pepsin). Cellular translocation of HMGB1 was assessed using immunofluorescence in NE-1 cells in response to acidic bile salts (pH4, 1mM DCA).

Results

HMGB1 mRNA and epithelial protein expression were consistent between healthy control and GERD patients. TLR2 and TLR4 were expressed primarily on epithelial cells with cell quantification revealing TLR4 to be the predominantly expressed epithelial receptor. The proportion of TLR4+ cells was higher in ERD compared to healthy controls (1.4% ± 0.43 vs 7.2% ± 2.567; p<0.05). In contrast, RAGE was expressed exclusively on CD45+ leukocytes – predominantly in GERD phenotypes. Many RAGE+ immune cells in GERD tissue were in close apposition to sensory CGRP+ nerve fibres. Incubating NE-1 cells with acidic bile salts (10mins), but not acid alone, induced HMGB1 translocation to the cytosol (nuclear:cytosolic HMGB1 ratios: pH7 = 2.42 ± 0.19; pH4 = 2.66 ± 0.07; pH4 + DCA = 1.416 ± 0.06; p=0.0003). Challenging oesophageal biopsies with synthetic refluxate (5mins) led to release of HMGB1 over 18 hours compared to paired biopsies (218 ± 57 vs 586 ± 220 pg/mL/mg; p<0.05).

Conclusion

HMGB1 released by oesophageal epithelial cells following reflux may contribute to inflammatory pathways in GERD, particularly via TLR4 and RAGE on epithelial and immune cells, respectively. This is of particular interest in PPI-refractory GERD, due to the exaggerated role of bile salts in HMGB1 release. Further, the close proximity of RAGE+ leukocytes and CGRP+ nerve fibres may represent a cross-talk between epithelial cells, immune cells, and sensory nerves. HMGB1 may therefore be a potential new treatment target for GERD.

Introduction

High-resolution manometry (HRM) is routinely performed in an outpatient clinic setting. If intubation is not tolerated or if the LOS is not traversed, the test is often abandoned with no viable alternative option, thus impacting on therapeutic decisions. This study explores the option of intubating the catheter during endoscopy under the comfort of sedation and direct vision.

Aims & Methods

All patients who had HRM catheter insertion during endoscopy at a tertiary referral centre in London between Jan 2020 and April 2023 were collated and analysed. A consecutive equivalent number of standard unsedated HRM studies, as well as patients having standard diagnostic endoscopy at the same centre between Nov and Dec 2022 were included for comparison. Demographic data, symptom presentation, endoscopic technique and manometry diagnosis were analysed. All HRM studies attempted a full protocol of single water swallows and rice meal, undertaken only after confirmation that sedation had abated. The median integrated relaxation pressure (IRP) of single water swallows was used to categorise patients into those with and without a disorder of outflow. Oesophageal body function was defined according to the Chicago Classification of motility disorders¹.

Results

Of the 47 patients (68.1% F; 17-86 yrs) who were referred for endoscopic insertion (EI) of the HRM catheter, 42 (89.3%) were successfully intubated to the stomach. Of those, 33 (78.6%) were observed to pass through the pharynx and LOS with the endoscope, 4 (9.5%) required manual guidance through the oesophagus and LOS, whilst 5 (11.9%) required only observation of catheter passage through the pharynx. Overall, 41 (87.2%) patients completed the full swallow protocol. Indications for referral for EI included intolerance to standard insertion through the nares (52.4%), inability to breach the LOS resulting in a curled catheter (26.2%) and other reasons including septal deviation and psychiatric burden (21.4%). Similarly, of the contemporaneous 47 patients who had standard insertion (SI) of the HRM catheter in the outpatient setting (67.3% F, 23-80 yrs), 39 (82.9%) were successfully intubated and 33 (67.3%) completed the full swallow protocol. Symptoms were reproduced during the test protocol in both cohorts similarly (69.0% EI, n=42; 59.0% SI, n=39). EI patients required higher doses of sedation compared to a consecutive cohort of patients who attended for routine diagnostic endoscopy; mean Fentanyl 112.5µg (n=36) vs 78.7µg (n=47) p<.001, and Midazolam 4.9mg vs 3.4mg p<.001, respectively. The IRP was not significantly different between EI and SI regardless of LOS morphology; mean IRP in patients with no LOS outflow disorder (8.01mmHg, n=28 vs 6.05mmHg, n=35; p=.08), compared to those with an outflow obstruction (28.0mmHg, n=12 vs 23.1mmHg, n=5; p=.35). Overall motility diagnoses between the two cohorts are presented in Table 1.

Table 1: Diagnoses for HRM

Conclusion

Inserting the HRM catheter during endoscopy under sedation and direct vision enables oesophageal physiology testing for patients who might not have otherwise been able to receive motility assessment. The procedure is safe, feasible and is associated with no complications or adverse risk to date. Just as wireless pH monitoring can be a salvage for those who are unable to tolerate the pH catheter, this technique can fill an important gap in the investigation algorithm where motility testing would have otherwise been abandoned.

References

¹Yadlapati, Rena et al. “Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0^©.” Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society vol. 33,1 (2021): e14058. doi:10.1111/nmo.14058

Introduction

Recent societal guidelines suggest there is no role for hydrogen and methane breath testing (HMBT) to exclude small intestinal bacterial overgrowth (SIBO) in patients with diarrhoea predominant irritable bowel syndrome (IBS) and to treat symptoms with rifaximin empirically^1,2. However, a positive result for SIBO with lactulose HMBT has been shown to predict more favourable outcomes to rifaximin in patients with diarrhoea predominant IBS³. We wanted to investigate if symptoms and medical history can predict lactulose HMBT outcome hence justifying treatment of SIBO without a formal diagnosis.

Aims & Methods

A large questionnaire-based study was conducted in over 1000 patients of which 731 completed lactulose HMBT. The 26-item questionnaire included questions about medical history, symptoms, and pattern of symptoms, and we used this to identify any positive predictors for SIBO on HMBT. A positive lactulose HMBT was determined by a rise of ≥20 ppm in breath hydrogen from baseline within 90 minutes³. Breath samples were analysed using gas chromatography. Associations and predictors were calculated using chi square tests and logistic regression, respectively.

Results

Bloating (93.6%), abdominal pain (87.3%), and diarrhoea (80.3%) were the most common symptoms reported by those with a positive result for SIBO, but their duration, frequency and onset were no different to patients with a negative result (P > 0.05). There were no positive predictors for SIBO on lactulose HMBT based on symptoms, medications or medical history except for chronic low ferritin (P = 0.025).

Conclusion

This large questionnaire study has demonstrated that symptoms and medical history cannot predict HMBT outcomes for SIBO. Therefore, treatment of SIBO without a diagnosis confirmed on HMBT may lead to unnecessary antibiotic use and costs.

References

1. Vasant DH, Paine PA, Black CJ, Houghton LA, Everitt HA, Corsetti M, Agrawal A, Aziz I, Farmer AD, Eugenicos MP, Moss-Morris R, Yiannakou Y, Ford AC. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. Gut. 2021 Jul;70(7):1214-1240.
2. Savarino E, Zingone F, Barberio B, Marasco G, Akyuz F, Akpinar H, Barboi O, Bodini G, Bor S, Chiarioni G, Cristian G, Corsetti M, Di Sabatino A, Dimitriu AM, Drug V, Dumitrascu DL, Ford AC, Hauser G, Nakov R, Patel N, Pohl D, Sfarti C, Serra J, Simrén M, Suciu A, Tack J, Toruner M, Walters J, Cremon C, Barbara G. Functional bowel disorders with diarrhoea: Clinical guidelines of the United European Gastroenterology and European Society for Neurogastroenterology and Motility. United European Gastroenterol J. 2022 Jul;10(6):556-584.
3. Rezaie A, Heimanson Z, McCallum R, Pimentel M. Lactulose Breath Testing as a Predictor of Response to Rifaximin in Patients With Irritable Bowel Syndrome With Diarrhea. Am J Gastroenterol. 2019 Dec;114(12):1886-1893.

Introduction

Irritable bowel syndrome (IBS) is a complex multifactorial disorder characterized by recurrent abdominal pain associated with defecation or a change in bowel habits. Patients with IBS often complain of extra-intestinal symptoms resulting in impaired related quality of life. Growing evidence support the hypothesis that intestinal barrier dysfunction has a central role in the pathophysiology of IBS being the interface between the gut lumen and the deeper intestinal layers as well as the brain.

Aims & Methods

The aims of this study were: to characterize the epithelial and vascular barriers; to correlate molecular, morphological and functional aspects of epithelial and vascular barriers with IBS symptoms. 66 healthy subjects (AC) and 223 patients with IBS (112 IBS-D, 58 IBS-C and 53 IBS-M) were enrolled in the study. Rome IV criteria, Bowel disease questionnaire, Short Form 36, Hospital Anxiety Depression Scale were used to phenotype patients. Sugar test was used to evaluate in vivo permeability. The vascular barrier was characterized by using immunohistochemistry, western blot and electron microscopy. Vascular permeability was evaluated by assessing two markers: plasmalemma vesicle–associated protein-1 (PV1) and vascular endothelial cadherin (VEC). A translational model based on Caco-2 cells or HUVEC was used to evaluate permeability changes induced by mediators spontaneously released by mucosal biopsies and to highlight the underlying molecular mechanisms. Correlation analyses have been performed among experimental and clinical data.

Results

Compared to AC, lactulose (P<0.05), sucralose (P<0.01), sucrose (P<0.01) excretion and the L/M ratio (P<0.01) were significantly increased in IBS patients. Soluble mediators released by mucosal biopsies of IBS patients increased Caco-2 permeability compared to AC mediators (P<0.05) via a down-regulation of tight junction gene expression. Blood vessels were significantly increased by 1.5 fold in the colonic mucosa of IBS patients compared to AC (P<0.01). PV1 expression was increased (P<0.01) while VEC expression was decreased in the colonic mucosa of IBS group compared to AC (P<0.05). IBS mucosal mediators increased HUVEC permeability compared to AC mediators. The HUVEC changes associated with IBS samples were mediated by a protease-activated receptor (PAR)2 dependent mechanism resulting in VEC down-regulation. Significant correlations emerged among permeability changes and intestinal, extra-intestinal symptoms and health-related quality of life reported by IBS patients.

Conclusion

Epithelial and vascular barriers are compromised in IBS and are likely involved in symptom development.

Disclosure

Nothing to disclose

Introduction

A transmural oxidative imbalance, mainly affecting longitudinal muscle, has been reported in the different clinical phenotypes of Diverticular Disease (DD) (Pallotta L,2022; Cappelletti M,2022) but the genesis of the oxidative stress remains to be defined. Since the central role of the mitochondria for the cell metabolism and radicals production, aim of the study is to elucidate the involvement of mitochondria alterations in the different DD clinical phenotypes in order to improve the knowledge of the DD natural history and management.

Aims & Methods

Longitudinal smooth muscle tissues and cells were isolated separately from surgical specimens of complicated stenotic DD (cDD n=5), up-stream non-occlusive colon cancer with diverticula (DIV n=5) and without diverticula (controls n=5). Oxidized proteins, thioredoxin and, succinate deidrogenase (complex II) and complex IV (cytochrome c oxidase) of mitochondrial respiratory chain were evaluated on tissues by Western Blot. Mitochondrial mass, mitochondrial ROS, mitochondrial membrane potential and glutathione (GSH) were evaluated in cells by FACS. Functional cells activity was tested by image micrometry assessing maximal contraction to acetylcholine and relaxation to VIP, before and after 24h-incubation with 14mM polyphenols (Phenolea Active Complex L). Data (mean±SE) were expressed as fold variations or % decrease from controls, *p value<0.05 considered significant.

Results

In respect to control, oxidized proteins content in longitudinal muscle was increased both in DIV (5.0*±1.1) and cDD (2.6±0.6), associated to a progressive loss of the antioxidant thioredoxin molecule (DIV:70.9%±9.2;cDD:83.3%±3.4). The oxidative status resulted associated to a loss of the mitochondrial complex II succinate deidrogenase codified by nuclear DNA (DIV:43.4%±19.7;cDD:67.9%±10.3) suggestive of the electron respiratory chain impairement. Compensatory stress mechanisms likely occurred with an increase of the complex IV cytochrome c oxidase codified by mitochondrial DNA in muscle tissue (DIV:1.1±0.77;cDD:2.3±1.7) and mitochondrial mass increase (DIV:2.4±1.2;cDD:3.7*±1.3) in cells. Radicals over production was observed mainly in cDD with a cellular increase in mitochondrial ROS (cDD:1.50±0.57) and mitochondrial membrane potential (cDD:1.4±0.3). Antioxidant GSH cellular content progressively decreased from DIV (51.9%*±9.5) to cDD (72.2%*±1.5). These oxidative alterations were associated to an impairment of functional cellular activity with a reduction of contraction (DIV:51.3%*±4.5;cDD:52.5%*±8.5) and relaxation (DIV:34.9%*±14.3;cDD:37.6%*±10.6). The prominent role of oxidative stress in these functional alterations was confirmed by the ability of a 24/h polyphenols treatment to restore GSH content (DIV:1.1±0.06;cDD:1.4±0.3) and relaxation, in both DD phenotypes.

Conclusion

Oxidative stress-driven alterations are present in longitudinal muscle in DD, independently from the clinical stage. In accordance to the severity of the pathology, mitochondrial imbalance resulted more prevalent in complicated diverticular disease. The beneficial effects of the antioxidant treatment could open new tailored-therapeutic and prevention strategies still not tested in this disease.

Disclosure

No disclosure