bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Plasmodium falciparum Drug Resistance Markers pfcrt K76T and pfaat1 S258L in Southern Rwanda, 2010 to 2023
Authors: Schallenberg Emma , van Loon Welmoed , Mbarushimana Djibril , Igiraneza Clement , Glanz Karolina , Ngarambe Christian , Minega Ndoli Jules , Hendry Jason A , Mockenhaupt Frank P
Published: February 2025

Background

In many countries in Sub-Saharan Africa, the Plasmodium falciparum chloroquine resistance marker pfcrt K76T disappeared within a decade after use of chloroquine ceased. pfaat1 S258L has recently been implicated as another chloroquine resistance marker. Both genes may affect parasite susceptibility to partner drugs in artemisinin-based combination therapy. Rwanda abolished chloroquine use in 2001, and since 2006 the first-line antimalarial is artemether-lumefantrine. However, partial artemisinin resistance emerged in the region. We assessed the prevalence of pfcrt and pfaat1 markers in Huye district between 2010 and 2023, following trends and updating the status in southern Rwanda.

Methods

P. falciparum-positive blood samples from community children and malaria patients collected in 2010, 2014, 2018, 2019, and 2023 were examined. pfcrt K76T was genotyped by restriction fragment length polymorphism, and pfaat1 S258L by high-resolution melting curve (2010–2019). Samples from 2023 were subjected to nanopore sequencing.

Results

In 606 samples, pfcrt K76T prevalence declined from 76% (95% confidence interval [CI], 68%–83%) to 18% (95% CI, 11%–25%) between 2010 and 2018 but remained constant since at around 25% (P < .001). No other pfcrt markers were observed. pfaat1 S258L has remained at or near fixation. The artemisinin resistance marker pfk13 R561H was associated with pfcrt K76T (P = .02).

Discussion

The persistence of pfcrt K76T 20 years after abolishing chloroquine use indicates ongoing drug selection or importation. The fixation of pfaat1 S258L argues against a major fitness cost of this variant in Huye. Increases in partial artemisinin resistance in Rwanda and molecular markers indicate compromised lumefantrine efficacy. The observed pfcrt and pfaat1 signatures in the study area might be of use in guiding artemisinin partner drug alternatives.
Factors associated with harm in reported patient safety incidents and characteristics during health screenings in Korea: a secondary data analysis
Authors: Choe Jeongin , Woo Kyungmi
Published: February 2025

Background

Various health screenings are conducted in South Korea, including state-supported national health screenings, privately funded comprehensive health screenings, and employment-related or industry-specific screenings. Given the various risks of patient safety incidents during the health screening process and the lack of studies of incidents in this environment, this study aimed to analyse the types and characteristics of reported patient safety incidents during health screenings, the distribution of harm, and the impact of the incident types on harm.

Methods

We analysed patient safety incidents reported to the Korean Institute for Healthcare Accreditation (2017–22) using the World Health Organization’s framework for patient safety. We performed frequency analysis, chi-square tests, and binomial logistic regression analysis to identify the types and characteristics of reported patient safety incidents, the differences in the distribution of harm, and the impact of patient safety incident types on harm during health screenings.

Results

A total of 213 cases were included in the analysis. Over half of the patient safety incidents during health screenings resulted in harm to the patient, and examination-related incidents were the most frequent type of incident. Furthermore, reported patient safety incidents were more likely to occur during regular working hours, in the examination room, in hospitals with over 500 beds, and amongst patients in their 50s, with no significant differences in sex distribution. Significant differences were observed in the distribution of harm according to incident types (P <.001) and patient age (P =.023). Controlling for patient and incident characteristics, the incident type was a determinant of harm. Amongst the incident types, medication/drug administration [adjusted odds ratio (aOR) = 29.730, 95% confidence interval (CI) = 6.081, 145.368], anaesthesia/sedation/treatments and procedures (aOR = 5.121, 95% CI = 1.002, 26.178), falls (aOR = 4.903, 95% CI = 2.022, 11.890), infections/injuries (aOR = 11.898, 95% CI = 1.082, 130.839), and other types of incidents (aOR = 8.719, 95% CI = 2.602, 29.212) increased the probability of harm compared to examination-related incidents.

Conclusion

This study underscores the critical need to manage high-risk patient safety incidents and implement systemic harm reduction strategies during health screenings. Encouraging the reporting of incidents, including near misses, alongside developing targeted interventions, is essential for enhancing patient safety. Future research should leverage larger datasets, consistent classification systems, and standardized data collection to generalize findings and advance prevention strategies, thereby improving the quality and safety of health screening services.
A5 USING AIR-LIQUID INTERFACE ORGANOID MONOLAYERS TO DEFINE MUCOSAL-MICROBE DYSFUNCTION IN PATIENTS WITH ULCERATIVE COLITIS
Authors: Gilliland A , Chen Y , Ng I , Han X , Kalisky I , Sham H , Xiong W , Bressler B , vallance B
Published: February 2025

NOT PUBLISHED AT AUTHOR’S REQUEST

Please acknowledge all funding agencies listed below

Funding Agencies: CCC, CIHRWeston Family Foundation
A6 INVESTIGATING THE RELATIONSHIP BETWEEN MUCOSAL INFLAMMATION AND PROTEOLYTIC ACTIVITY IN CROHN’S DISEASE
Authors: Szeto J , Rueda G H , Hann A , Constante M , Wang X , Deraison C , Vergnolle N , Butcher J , Stintzi A , Bercik P , Galipeau H , Armstrong D , Verdu E
Published: February 2025

Background

Dysregulated proteolytic activity (PA) has been detected in intestinal biopsy samples of individuals with inflammatory bowel disease (IBD) compared to healthy controls. It is known that increased microbial fecal PA precedes ulcerative colitis (UC) diagnosis in an at-risk population. Intestinal inflammation in UC is characterized by continuous ulceration, inflammation in Crohn’s disease (CD) is patchy in nature. Sites of inflammation in CD has been associated with altered mucosa-associated microbes and higher permeability, suggesting these could be localized sites of increased microbial PA.

Aims

To investigate whether inflamed mucosal areas in CD are associated with proteolytic microbiota and increased permeability.

Methods

CD patients in flare (n=23) were recruited at McMaster University Medical Centre and matched (or paired) biopsies were collected at colonoscopy from inflamed and adjacent (within 5 cm) non-inflamed sites. Biopsy mucosal-to-serosal 51Cr-EDTA flux rate and tissue conductance were measured with Ussing chambers. Total proteolytic (trypsin), elastase-like (FITC-elastin), and mucolytic (0.05% mucin plates) activities were also assessed in biopsies from both sites and in situ zymography was used to measure and localize elastase-like activity in biopsy samples. Mucosal brushing samples from the same participants were also collected and total RNA purified for metatranscriptomic analysis to characterize active microbial pathways with a focus on identifying highly expressed microbial proteases.

Results

Paracellular permeability and tissue conductance were greater in biopsies from inflamed areas than in biopsies from matched non-inflamed areas (p<0.001). Elastase-like and mucolytic activities were higher in inflamed areas compared to matched non-inflamed areas (p<0.05 and p=0.04, respectively), no significance was detected in total proteolytic activity. In situ zymography revealed greater elastase-like activity in inflamed areas compared to non-inflamed areas (p=0.04), localized to both the epithelial and submucosa layers in inflamed tissues but only to the epithelial layer in matched non-inflamed tissue. Preliminary analysis of the metatranscriptomics results suggests that specific microbial proteases may be increased at inflamed sites in CD.

Conclusions

Our results suggest that localised variations in tissue inflammation, PA and mucosal permeability in CD may be causally linked, providing a rationale for the patchy distribution of mucosal injury. We, therefore, hypothesize that microbial elastase-like activity promotes mucosal inflammation through barrier disruption. This mechanism could be targeted locally to prevent or modulate microbially associated PA with the aim of enhancing mucosal healing in IBD.

Funding Agencies:
A20 DIETARY ANTIGENS DELIVERED TO MICE IN EARLY LIFE INDUCE ANTIGEN-SPECIFIC REGULATORY AND TH1 CELLS AND THE DEVELOPMENT OF ORAL TOLERANCE
Authors: FitzPatrick R D , Przydatek A M , Gatti D M , Cartwright R A , Norton N J , Lane J M , Reynolds L A
Published: February 2025

Background

Oral tolerance is the active suppression of immune responses to antigens that are first encountered in the gut. When this process fails, food allergies or celiac disease can arise. Oral tolerance develops largely in early life, but despite this it has historically been studied using adult rodent models.

Aims

Our research aims to develop a robust mouse model to elucidate mechanisms of oral tolerance development in early life.

Methods

Mice were orally gavaged with ovalbumin (OVA) as a model food antigen or water as a control in an early life, pre-weaning window (2-3 weeks old). Following systemic challenges with OVA, oral tolerance was assessed by measuring circulating antibody levels (ELISAs) and cytokine responses of ex vivo stimulated splenocytes and gut-draining mesenteric lymph node (MLN) cells (cytometric bead arrays). To characterize OVA–specific T helper cell responses, OT-II cells (OVA-specific CD4+ T cells) were adoptively transferred into mouse pups and their phenotypes were assessed in the MLNs and spleen by flow cytometry following oral gavages of OVA or control water.

Results

BALB/cJ and C57BL/6J mice orally gavaged with OVA in early life had reduced levels of OVA-specific antibodies compared to controls after systemic challenges with OVA, indicating that oral tolerance had developed. Further, we determined the minimum dosage of oral OVA required to confer oral tolerance during early life. We found a suppression of cytokine production in response to OVA-stimulation in cultures of MLN cells or splenocytes, from mice orally exposed to OVA (‘tolerized’) in early life compared to cell cultures from control mice.

We found an increased frequency of OVA-specific regulatory T cells in the MLNs and spleen in response to oral OVA exposure compared to mice exposed to control water. We also found an increase in the frequency of OVA-specific Th1 cells along with an increase in OVA-specific CD4+ T cells that are producing IFNγ when pups were exposed to oral OVA compared to control water.

Conclusions

We have developed a robust early life mouse model of oral tolerance. Our data suggests that oral tolerance is induced during early life in part following the central dogma of oral tolerance development elucidated in adult mice: with the induction of food-antigen specific regulatory T cells. However, we have also identified an increase in the frequency of food antigen-specific Th1 cells in the MLNs and spleen in response to oral antigen exposure during an early life, pre-weaning window. Future work will determine if IFNγ-expressing Th1 cells are essential for the development or maintenance of oral tolerance.

Oral tolerance development in early life.

Funding Agencies

CIHRTRIANGLE
A23 INVESTIGATING THE LINK OF BACTERIAL TRANSLOCATION AND BEHAVIORAL CHANGES IN A MOUSE RESTRAINT STRESS MODEL
Authors: Shimbori C , Khalil A , Kraimi N , Lu J , De Palma G , Hapfelmeier S , Collins S , Bercik P
Published: February 2025

Background

Bacterial translocation is defined as migration of bacteria or bacterial fragments from the intestinal lumen into extraintestinal tissues; this process has been implicated in the pathophysiology of gastrointestinal disorders and central nervous system disorders. However, the direct causal relationship between bacterial translocation and behavioral changes, as well as the mechanism of bacterial translocation remains unclear. In the previous study, we showed that commensal microbes can cross the intestinal barrier and access deeper layers of the gut and distal organs in the restraint stress model. In this study, we further investigated whether bacterial translocation contribute to behavioral changes in a mouse restraint stress model using invasive bacteria.

Aims

To investigate whether invasive bacteria can translocate and exacerbate behavioral alterations in a stress model.

Methods

SPF C57BL/6 mice were assigned to either the restraint stress group or the non-stress control group. Each group was further divided into two subgroups: one receiving a vehicle and the other inoculated with auxotrophic Salmonella enterica serovar Typhimurium HA630 via oral gavage three times per week during the stress period (n=6-14 per group). In a separate experiment, stressed and non-stressed mice were each split into 2 groups: vehicle or GFP-Salmonella; inoculated with GFP labeled wild type Salmonella enterica serovar typhimurium via single oral gavaging (n=6-7). After the last session of stress, we conducted light/dark preference and tail suspension tests. We collected jejunum, colon, myenteric lymph node, liver, spleen, and brain samples for histology and performed iterative bleaching extends multiplexity (IBEX) staining. We also sampled blood, liver, spleen, and brain for bacterial cultures under aseptic conditions.

Results

Transient salmonella inoculation enhanced stress-induced anxiety-like behaviour accompanied by higher rate of bacterial translocation. Histology analysis showed that intestinal bacteria were invade into the intestinal mucosa and co-localized with goblet cells in jejunum, and colon, and some of them were in close proximity with neurons in stress group. Interestingly, some bacteria appeared to be within the CD103+ cells in the colon, as well as in the hippocampus. GFP-salmonella inoculation enhanced stress-induced depression-like behaviour accompanied by higher rate of bacterial translocation.

Conclusions

This study indicates that intestinal bacteria translocation could contribute to the stress-induced behaviors. Our histology data suggest potential contribution of goblet and CD103+ cells in gut bacterial translocation in the restrained stress model.

Funding Agencies

CAG, CIHR
A26 PROFILE OF ACTIVATED B-CELL EXPANSION IN THE DISTAL COLON AND MESENTERIC LYMPH NODES OF COLITIC MICE
Authors: Sabzevary-Ghahfarokhi M , Marshall A , Ghia J
Published: February 2025

Background

Gut B cells maintain homeostasis by producing IgA antibodies that control the entry of commensal bacteria and pathogens. An increase in the number of B cells in the inflamed colon was detected in ulcerative colitis (UC) patients. Pro-inflammatory IgG antibodies binding to commensal bacteria are significantly elevated in UC, promoting intestinal inflammation.

Aims

To determine the effects of intestinal inflammation on the B cell compartment using a preclinical model of UC.

Methods

32 CD-1 WT males were treated for 6 days with 2.5% (w/v) dextran sulfate sodium (DSS), followed by 8 days of recovery (regular water). Disease activity index was monitored daily. Distal colonic mRNA expression of cytokine (tumor necrosis [TNF-α], B-cell activating factor [Baff]) and factors associated with B cell attraction (chemokine (C-X-C motif) ligand [CXCL]13) were assessed by qRT-PCR. Localization using B cells phenotype (B220, cluster of differentiation (CD) 19, CD138, GL7, and IgD) and activation markers (CD80 & CD86) were assessed by flow cytometry and immunofluorescence (IF) in Peyers’ patches, distal colon, and mesenteric lymph nodes (MLN). Levels of IgA, M, G1, G2b, and G2c in colon tissue and serum were determined by ELISA.

Results

In colitic mice, TNF-α, Baff, and CXCL-13 mRNA expression was significantly upregulated, and immunostaining demonstrated several aggregated sites of B cells with the phenotype of B220+, IgD+, and CD19+in the lamina propria. Aggregated B cells were positive for co-expression of IgD and CD19 markers and negative for expression of IgA and IgG antibodies. Flow cytometry data showed a significant increase in the percentage of B220+ and CD19+ B cells within the CD45+ live cell population in colitic mice’s distal colon and MLNs. In addition, in colitic mice, the percentage of B cells expressing CD86 significantly increased in the distal colon, Peyers’ patches, and MLN. Furthermore, in colitic conditions, the percentage of B cells producing IgG1 was increased in the Peyers’ patches and distal part of the colon but only in Peyers’ patches for IgA-producing B cells. In colitic mice, IgA/IgG2c ratio in colon tissue decreased, and serum IgG2b, IgG2c, and IgG1 antibody levels increased, with no difference for IgA and IgM.

Conclusions

Inflammatory conditions lead to B cell activation and recruitment with aggregated naïve B cells in the lamina propria that don’t switch to IgG or IgA. In colitis, systemic IgG subtypes increase, while Peyer’s patches may actively produce B cells expressing IgA or IgG1 during intestinal inflammation. These findings may guide the development of new UC therapies.

Funding Agencies

CCC
A28 PROFILE OF ACTIVATED B-CELL EXPANSION IN THE DISTAL COLON AND MESENTERIC LYMPH NODES OF COLITIC MICE
Authors: Sabzevary-Ghahfarokhi M , Marshall A , Ghia J
Published: February 2025

Background

Gut B cells maintain homeostasis by producing IgA antibodies that control the entry of commensal bacteria and pathogens. An increase in the number of B cells in the inflamed colon was detected in ulcerative colitis (UC) patients. Pro-inflammatory IgG antibodies binding to commensal bacteria are significantly elevated in UC, promoting intestinal inflammation.

Aims

To determine the effects of intestinal inflammation on the B cell compartment using a preclinical model of UC.

Methods

32 CD-1 WT males were treated for 6 days with 2.5% (w/v) dextran sulfate sodium (DSS), followed by 8 days of recovery (regular water). Disease activity index was monitored daily. Distal colonic mRNA expression of cytokine (tumor necrosis [TNF-α], B-cell activating factor [Baff]) and factors associated with B cell attraction (chemokine (C-X-C motif) ligand [CXCL]13) were assessed by qRT-PCR. Localization using B cells phenotype (B220, cluster of differentiation (CD) 19, CD138, GL7, and IgD) and activation markers (CD80 & CD86) were assessed by flow cytometry and immunofluorescence (IF) in Peyers’ patches, distal colon, and mesenteric lymph nodes (MLN). Levels of IgA, M, G1, G2b, and G2c in colon tissue and serum were determined by ELISA.

Results

In colitic mice, TNF-α, Baff, and CXCL-13 mRNA expression was significantly upregulated, and immunostaining demonstrated several aggregated sites of B cells with the phenotype of B220+, IgD+, and CD19+in the lamina propria. Aggregated B cells were positive for co-expression of IgD and CD19 markers and negative for expression of IgA and IgG antibodies. Flow cytometry data showed a significant increase in the percentage of B220+ and CD19+ B cells within the CD45+ live cell population in colitic mice’s distal colon and MLNs. In addition, in colitic mice, the percentage of B cells expressing CD86 significantly increased in the distal colon, Peyers’ patches, and MLN. Furthermore, in colitic conditions, the percentage of B cells producing IgG1 was increased in the Peyers’ patches and distal part of the colon but only in Peyers’ patches for IgA-producing B cells. In colitic mice, IgA/IgG2c ratio in colon tissue decreased, and serum IgG2b, IgG2c, and IgG1 antibody levels increased, with no difference for IgA and IgM.

Conclusions

Inflammatory conditions lead to B cell activation and recruitment with aggregated naïve B cells in the lamina propria that don’t switch to IgG or IgA. In colitis, systemic IgG subtypes increase, while Peyer’s patches may actively produce B cells expressing IgA or IgG1 during intestinal inflammation. These findings may guide the development of new UC therapies.

Funding Agencies:
A30 THROUGH-THE-SCOPE CLIP WITH ANCHOR PRONGS FOR PROPHYLACTIC CLIP CLOSURE AFTER GI LESION RESECTION: A PROSPECTIVE COHORT STUDY
Authors: von Renteln D , Rex D , Pohl H , Kumta N , Chan S , Ryou M , Zaheer N , Zhou P H , Inoue H , Peetermans J , Rousseau M , Mosko J
Published: February 2025

Background

Endoscopic clipping following gastrointestinal (GI) lesion resection provides prophylaxis for delayed bleeding. A rotatable, anchor-pronged through-the-scope endoscopic clip (TTSC) underwent limited prospective study since commercialization in the USA in 2022.

Aims

We prospectively studied 30-day delayed bleeding rates after prophylactic clip closure of lesions using the new TTSC.

Methods

We conducted a multicenter, prospective cohort study of the anchor-pronged MANTISTM clip (Boston Scientific Corporation, Marlborough, Massachusetts, USA) used for prophylactic clipping after lesion resection at 10 sites in 6 countries (ClinicalTrials.gov number, NCT05653843). Outcomes were 1) complete defect closure without delayed bleeding at the original resection site, 2) rate of delayed bleeding at the original resection site, defined as a severe bleeding event requiring hospitalization, blood transfusion (>5 units), or another invasive intervention ≤30 days after study clip placement, 3) rate of serious device or procedure-related adverse events (SAEs).

Results

Among 191 enrolled participants, the mean age was 65.4±12.2 (range 23-89) years, and 110 (57.6%) were male. Median maximum lesion diameter was 25.0 (range 5.0-100.0) mm. Of 199 attempted clipping procedures, 190 (95.5%) defects had complete closure without delayed bleeding at the original lesion site (Table). Delayed bleeding occurred in 1 (0.5%) patient by 30 days after the index procedure. Seven (3.7%) patients had at least one SAE, including bleeding (2 patients), perforation (1), aspiration (1), nausea (1), pneumoperitoneum (1), postpolypectomy syndrome (1). No SAEs were considered device-related.

Conclusions

A rotatable, anchor-pronged TTSC showed high rates of procedural completion and sustained lesion closure, and low rates of delayed bleeding or other SAEs by 30 days after the index procedure.

Table. Main outcomes (N=199 lesions in 191 patients)

*Bleeding SAEs within 7 days were counted as failures of the primary efficacy endpoint.

Funding Agencies

Boston Scientific Corporation
A33 DIAGNOSTIC YIELD AND QUALITY OF EUS-GUIDED LIVER BIOPSIES IN A 142-PATIENT COHORT - THE KELOWNA EXPERIENCE
Authors: Jowhari F , Neong S , Berg K
Published: February 2025

Background

EUS-guided liver biopsy (EUS-LB) is a safe & effective technique, consistently yielding diagnostic accuracy with adequate tissue samples. However, most studies are limited by small sample sizes, leaving gaps in data. Despite growing international evidence, a comprehensive Canadian experience remains unreported. To address this, we present our institutional data on EUS-LB, emphasizing diagnostic yield, safety & procedural benefits.

Aims

To evaluate the diagnostic yield, safety & procedural efficacy of EUS-guided liver biopsies in a large cohort of patients from a Canadian healthcare setting.

Methods

This is a retrospective analysis of patients who underwent EUS-LB over a 4 year period. All procedures were performed with a linear echoendoscope using a 1-2 pass,selective-actuation,wet suction technique & a 19-G Franseen-tip needle using our own institutional protocol. All patients received either conscious or deep sedation. Specimen adequacy was assessed by a GI histopathologist evaluating key parameters including the number of complete portal tracts (CPT),length of longest intact core (LIC),total specimen length (TSL) & degree of fragmentation, using guideline specific cutoffs where applicable. Comprehensive demographic, clinical & procedural data were also collected for detailed analyses.

Results

A total of 142 consecutive patients underwent EUS-LB at Kelowna General Hospital, British Columbia, from April 2020 to October 2024. The median age was 62 years (IQR 52–70), with 109 women (77%) and 33 men (23%). The median BMI was 27 kg/m2 (IQR 24–32). The diagnostic yield was 99.3%, with all but one specimen being diagnostic. Adequate histological specimens were obtained in 136 patients (95.7%), and a conclusive diagnosis was reached in 141 patients (99.3%). The most common diagnosis was metabolic dysfunction-associated steatohepatitis (MASH) in 42 patients (29%), followed by drug-induced liver injury (14.5 %), autoimmune hepatitis (13.1%), and primary biliary cholangitis (PBC) (10.3%). At the time of this submission, detailed histopathologic analyses were available for a subset of patients. The median total specimen length (TSL) was 4.4 cm (IQR 3.3–5.2), the median number of complete portal tracts (CPTs) was 13 (IQR 11.5–23.5), and the median longest intact core was 1.3 cm (IQR 1.1–1.7). No major adverse events were observed.

Conclusions

Our study reinforces the evolving role of EUS-guided liver biopsy in liver diagnostics, demonstrating its safety, efficacy, and high diagnostic yield. This technique not only ensures procedural success but also enhances the autonomy of gastroenterologists, promoting more timely and integrated patient care. As the largest study of EUS-guided liver biopsies conducted in a Canadian healthcare setting, it addresses a critical gap in the literature and further validates the role of EUS-LB in modern hepatology practice.

Gross intact core EUS-LB specimens collected in formalin.

Funding Agencies

None
A35 ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) OUTCOMES IN GASTROINTESTINAL SUBMUCOSAL TUMORS (SMT): A RETROSPECTIVE STUDY
Authors: Youssef M , Ching Hui Yee C , Bechara R
Published: February 2025

Background

Gastrointestinal submucosal tumors (SMTs) range from benign entities to malignant tumors that require surveillence or resection. The role of ESD in management of SMTs remains unclear.

Aims

We aim to evaluate the clinical and technical outcomes of ESD in the management of SMTs.

Methods

This study included patients with SMTs who underwent ESD at the Kingston Health Sciences Center (KHSC) between May 2017 to September 2024. Data was collected on patient demographics and tumor characteristics including size, pathology, differentiation, depth, and lymphovascular invasion (LVI). Technical outcomes were analyzed with respect to procedure time (min), technical efficiency (min/cm2), en-bloc and R0 resection rates. En-bloc resection was defined as resection of the lesion piecemeal and R0 indicated negative margins on microscopic examination. We also reported clinical outcomes including length of stay, perioperative adverse events (e.g. bleeding or perforation), strictures, and tumor recurrence rates at the time of follow-up. Descriptive analysis was used to summarize the data.

Results

This case series included 22 patients (7 males, 15 females) with SMTs (6 esophageal, 16 gastric). 40.1% of patients (9/22) had endoscopic biopsy prior to ESD. The median specimen area was 3.8 cm2 (min-max range 0.38-18.2 cm2). Procedure times ranged between 5-138 mins with a mean time of 49.6 mins (SD= 33.1 mins) and mean efficiency of 13.7 min/cm2. 100% of patients had en-bloc resections and 86.3% (19/22) had R0 resections. There were no perioperative adverse events and most patients (21/22) were discharged the same day with the exception of one patient who stayed for 6 days postoperatively for (chronic) pain management. The pathology of the six esophageal tumors showed 3 leiomyomas, 2 Granular Cell Tumors (GCT), and 1 lipoma. Of the sixteen gastric lesions, 6 were Gastrointestinal Stromal Tumors (GIST), 6 were neuroendocrine tumors (NET), 1 leiomyoma, 1 lipoma, 1 inflammatory fibroid polyp, and 1 heterotopic pancreatic tissue. In both GIST and NET tumors, 5/6 lesions were Grade 1 (well-differentiated) and 1/6 was Grade 2 (moderately differentiated). The depth of the lesions was into the submucosa and there was no lymphovascular invasion (LVI). With regards to the esophageal tumors that required endoscopic follow-up (n= 4), the mean follow-up time was 8.5 months and there was no tumor recurrence. Of the gastric lesions that required endoscopic follow-up (n= 14), the mean follow-up time was 26.2 months and there was no tumor recurrence. There were no strictures observed on endoscopic follow-up for any of the lesions.

Conclusions

ESD for SMTs is a safe procedure with high en-bloc and R0 resection rates, along with low recurrence rates on follow-up. Larger scale studies are needed to further explore the efficacy and safety of ESD in the management of SMTs.

Funding Agencies

None
A47 VIRTUAL REALITY SIMULATION TRAINING IN GASTROINTESTINAL ENDOSCOPY: A COCHRANE REVIEW
Authors: Khan R , Sabrie N , Plahouras J , Johnston B , Scaffidi M , Grover S , Walsh C
Published: February 2025

Background

Training with virtual reality (VR) simulation is increasingly used for health professions training to allow novices to practice in a learner-centered, risk-free environment. This review was performed to evaluate the effectiveness of VR simulation training in gastrointestinal endoscopy.

Aims

To determine whether virtual reality simulation training can supplement and/or replace early conventional endoscopy training in diagnostic endoscopy for health professions trainees with limited or no prior endoscopic experience.

Methods

We searched 17 databases from inception until October 18, 2023. We included randomised and quasi-randomised trials that compared VR simulation training with no training, conventional training, another form of simulation training, or an alternative method of VR training. We screened and abstracted data through Cochrane methodology. The primary outcome was composite score of competency. Secondary outcomes were procedure completion, procedure time, adverse events, patient discomfort, global rating of competency, and mucosal visualization. We calculated risk ratio for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) for continuous outcomes with 95% CI. We used GRADE to assess the certainty of evidence.

Results

We included 20 trials (500 participants; 3975 endoscopic procedures). There was insufficient evidence to determine the effect of VR training on composite score of competency compared to no training or conventional training. VR training was advantageous over no training based for independent procedure completion (RR 1.62, 95% CI 1.15 to 2.26; moderate certainty evidence), overall rating of performance (mean difference [MD] 0.45, 95 %CI 0.15 - 0.75, very low certainty evidence), and mucosal visualization (MD 0.60, 95 %CI 0.20 - 1.00, very low certainty evidence). VR training resulted in fewer independent procedure completions compared to conventional training (RR = 0.45, 95 %CI 0.27 - 0.74, low certainty evidence). We found no differences between VR training and no training or conventional training for other outcomes. Based on qualitative analysis, we found no significant differences between VR training and other forms of simulation training. VR curricula based in educational theory provided benefit with respect to composite score of competency, compared with unstructured curricula. Based on qualitative analysis, we found no significant differences between VR training and other forms of simulation training. VR curricula based in educational theory provided benefit with respect to composite score of competency, compared with unstructured curricula.

Conclusions

VR simulation training in endoscopy can supplement conventional endoscopy training and provides benefit compared to no training.

Risk of bias summary

Funding Agencies

None
A48 PATIENT OUTCOMES OF A COMPLEX POLYP ASSESSEMNT COMMITTEE IMPLEMENTATION
Authors: Gallagher P , Petropolis H , Stewart M , Patel S , Farina D , Kohansal A
Published: February 2025

Background

Over the past two decades, the endoscopic approach to managing complex colonic polyps has shifted from surgery to advanced endoscopic techniques, including endoscopic mucosal resection (EMR) and Endoscopic Submucosal Dissection. Endoscopic methods are less invasive than surgery, reducing morbidity, mortality, and cost, but require additional time, training, and expertise. Despite guidelines recommending EMR as the first line option, surgical resection for complex non-invasive polyps remains common in Canada. A 2019 retrospective study revealed that 12.5% of large non-malignant polyps in Nova Scotia were treated with surgical resection. Subsequently, a Complex Polyp Assessment Committee (CxPAC) was established to assess polyps suitable for endoscopic resection, aiming to reduce unnecessary surgical procedures.

Aims

The project aims to examine the early outcomes of programmatic assessment and management of complex colorectal polyps though CxPAC.

Methods

A retrospective chart review was completed on all patients referred to Nova Scotia’s CxPAC between January 2022 and February 2024. Descriptive statics were calculated.

Results

In a 24-month study period, 99 patients were referred to the CxPAC, with 88 suitable for complex polypectomy. Among the 10 patients not deemed appropriate for the procedure, 7 were directed to surgery prior to any endoscopic intervention. The referral indication was polyp size (65.7%), size with challenging position (16.2%), challenging position alone (6.1%), residual/recurrent polyp (7.1%), and scarring/poor lift (5.1%). The mean patient age was 66 (SD, 12), and the mean polyp size was 37mm (SD, 17). There were 18 patients referred for surgical management: 2 based on referral image review, 10 after endoscopic or post-resection pathology appearance positive for invasive carcinoma, 1 after perforation, and 5 after incomplete resection. Follow-up endoscopies have been performed on 61 patients. Among the 40 patients deemed clear during follow-up endoscopy, 8 did not have a biopsy at the polypectomy site. Of the 32 patients who did undergo biopsies, 20 exhibited normal mucosa, 8 showed reactive changes/scarring post-polypectomy, 2 were diagnosed with tubular adenomas, 1 with a sessile serrated adenoma, and 1 with a hyperplastic polyp. There were 9 instances of severe adverse events related to complex polypectomy: 5 cases of post-polypectomy bleeding, 2 perforations, and 2 emergency department visits due to abdominal pain.

Conclusions

The CxPAC has been effective for assessing and managing complex non-malignant colonic polyps, with 88.6% of patients able to avoid surgery. While endoscopic resection of complex polyps is a safer alternative to surgery, procedural risks remain, highlighting the importance of additional training on the part of the endoscopists and a detailed discussion and consent process with the patients.

Funding Agencies

None
A52 OVERNUTRITION IN TREATED CELIAC DISEASE (CED) PATIENTS: THE NEED FOR PERSONALIZED NUTRITIONAL ASSESSMENT TO MANAGE THE METABOLIC SEQUELAE OF A GLUTEN-FREE DIET (GFD)
Authors: Verma A K , Khaouli M , Abdi F , Blom J , Echagüe F J , Alessa F , Aman A , Armstrong D , pinto-sanchez M
Published: February 2025

Background

Overnutrition, leading to overweight and obesity, is increasingly prevalent in celiac disease (CeD). A nutritionally imbalanced diet may contribute to overnutrition and the development of Metabolic Syndrome (MS) and Metabolic Dysfunction Associated Steatotic Liver Disease (MASLD).

Aims

To investigate the factors contributing to the metabolic shift in treated CeD.

Methods

We enrolled patients with biopsy-proven CeD on a GFD and non-CeD (Inflammatory Bowel Disease and Irritable Bowel Syndrome) attending a tertiary care center adult Nutrition Assessment Clinic. We collected data on nutritional assessment (SGA), energy requirements determined by resting energy expenditure (REE: indirect calorimetry, QNRG, COSMED, US) and activity factor (IPAQ), body composition (3D scanner; Styku CA, US) and obesity risk (EOSS: Edmonton Obesity Staging System) to assess risk based on metabolic comorbidities such as diabetes, fatty liver, and cardiovascular disease. SPSS (version 22, US) was used for statistical analysis. Data are reported as median (IQR); Mann-U-Whitney was used for comparison between groups.

Results

From November 2021 to October 2024, 124 CeD [Female: 76%; Age: 45 (27) yr; time since diagnosis: 5 (6) yr] and 96 non-CeD [F:74%; 48 (27) yr] patients were enrolled. Nutritional assessment identified undernutrition (BMI<19) in 8% vs 20%, overweight (BMI 26-30) in 24% vs 14%, and obesity (BMI>30) in 49% vs 34% of CeD vs non-CeD (p<0.001). REE adjusted for weight was significantly lower in obese CeD compared with non-obese CeD [17 (3) vs 22 (4) kcal/kg/day; p<0.001]. Fat mass was significantly greater [19 (7) vs 40 (10) kg; p<0.001], and fat-free mass was significantly reduced [FFM:43 (11) vs 54 (10) kg; p=0.005] in CeD with overweight/obesity compared to normal BMI. FFM was positively correlated with REE (r=0.71; p<0.001). Metabolic comorbidities occurred in 26% of obese-CeD patients. MASLD was more frequent in CeD with overweight and obesity compared to normal BMI (81% vs 43%; p=0.04).

Conclusions

The high rate of overnutrition and reduced muscle mass in treated CeD patients is concerning, as this is associated with metabolic comorbidities. Personalized nutrition assessment with accurate measurements is crucial for nutritional guidance and will likely improve health in CeD.

Funding Agencies:
A66 MICROSCOPIC COLITIS: AN EPIDEMIOLOGICAL ANALYSIS OF MANITOBA’S POPULATION
Authors: Shah P , Al-Bayati K , Parkinson K , Fischer G , Singh H , Bernstein C N , Shaffer S
Published: February 2025

Background

Microscopic colitis (MC) is an inflammatory disease of the colon, causing chronic diarrhea, with 2 histologic sub-types, collagenous colitis and lymphocytic colitis. It tends to affect older individuals, with a female predominance. MC is diagnosed in 10% of patients across all age groups, and in 20% in those over the age of 70 among persons undergoing colonoscopy for chronic watery diarrhea. However, there is a paucity of data in Canadian populations, thus we performed a population-based study in Manitoba to assess the prevalence of MC.

Aims

Determine of the prevalence of MC in Manitoba from 2006 - 2018.

Methods

Pathology reports which mentioned MC (or one of the histologic sub-types) were obtained from the Shared Health Pathology Database, which includes a portion of the pathology reports issued in Manitoba for the years 2006 to 2018. These pathology reports were then examined manually to detect true cases of MC. Patient demographics including age, year of diagnosis, and histologic sub-type (collagenous versus lymphocytic) were obtained. Continuous variables were analyzed using means.

Results

9377 pathology reports were initially identified. Of these, 916 people (9.8%) were identified with MC, with 74 having had more than 1 colonoscopy during this time period. Of the 916 cases of MC, 53.5% (490) had collagenous colitis, 44.8% (410) had lymphocytic colitis, and 1.7% (16) did not have a specified sub-type reported. There was a female predominance: collagenous colitis at 83.9%, lymphocytic colitis at 77.1%, and unspecified subtype at 81.3%. The mean age of diagnosis for collagenous colitis, lymphocytic colitis, and unspecified, was 62.0 years old (SD 13.2), 59.8 years old (SD 14.6) and 60.5 years ols (SD 15.6,), respectively. The age range of diagnoses was 18 to 91.

Of the 70 people who had more than 1 colonoscopy during this time period, 4 people initially had a diagnosis of collagenous colitis which was later switched to lymphocytic colitis, 7 had an initial diagnosis of lymphocytic colitis which was later switched to collagenous colitis, and 1 patient had an initial diagnosis of lymphocytic colitis, then switched to collagenous colitis, and later switched back to lymphocytic colitis.

Conclusions

In Manitoba over a 13 year time-period, 916 (9.8% of those where MC was considered) were diagnosed from colonic biopsy. Collagenous colitis was more common than lymphocytic colitis, with a similar age at the time of colonoscopy, along with both having a female predominance. Further research is needed to understand whether the clinical courses of collagenous and lymphocytic colitis differ, and how each sub-type responds to conventional treatment.

Funding Agencies

None
A80 TIME-RESTRICTED FEEDING IMPROVES INFLAMMATORY AND METABOLIC BIOMARKERS IN CROHN’S DISEASE WITH OVERWEIGHT: A RANDOMIZED, PLACEBO-CONTROLLED PILOT TRIAL
Authors: Haskey N , Lewis A G , Lavallee C , Yousuf M , Taylor L , Jilani S , Gold S , Lu C , Ghosh S , Panaccione R , Raman M
Published: February 2025

Background

Time-restricted feeding (TRF), a form of intermittent fasting (IF), has shown promise for weight loss and metabolic health. Up to 40% of patients with Crohn’s disease (CD) have a BMI >25, which together with increased visceral adipose tissue (VAT) are independent risk factors for increased hospitalizations, early surgical interventions, and reduced responsiveness to pharmacotherapy. Effects of IF regarding metabolic and inflammatory biomarkers in CD remain limited.

Aims

To assess whether a TRF, compared to standard management (SM), affects inflammatory and metabolic biomarkers in CD patients with a BMI >25.

Methods

We conducted a 12-week (12W) pilot randomized controlled trial, recruiting patients with CD and overweight from Calgary/Kelowna. Participants were randomly assigned in a 1:1 ratio to either TRF or SM. The TRF group fasted for 16 hours daily and ate within an 8-hour window (16:8) for 6 days per week, without altering their habitual diet. The SM group continued their habitual diet.

Results

35 patients completed the protocol (TRF=20; SM=15). Baseline characteristics were similar between groups, with a median BMI 28.0 kg/m2 [IQR:26-33.1]; median age 49 years [IQR:37-60]; 63% female with a median fecal calprotectin (FCP) 115 mcg/g [IQR:42-543]. There were no significant differences between groups in terms of diet, clinical disease activity or inflammatory and metabolic biomarkers at baseline. At 12W, the TRF group experienced a significant reduction in BMI (-0.9 kg/m2, P=0.007) and VAT (-194 cm3, P=0.008) while the SM group saw an increase in BMI (+0.2 kg/m2) and VAT (+78 cm3). FCP levels were either maintained or reduced (P=0.046), serum amyloid A significantly decreased (P<0.0001), with a trend toward improvement in the Harvey Bradshaw Index (P=0.061) in the TRF group, whereas in the SM group FCP, serum amyloid A, and the Harvey Bradshaw Index increased over the 12W. Serum markers leptin (P=0.002), adipsin (P=0.023), and plasminogen activator inhibitor-1 (P=0.045), significantly decreased in the TRF group. These changes were not observed in the SM group; the SM group saw an increase in IL-6 levels over the 12 weeks (P=0.001).

Conclusions

TRF led to significant improvements in BMI, VAT, and key metabolic markers, as well as decreases in systemic and gut inflammation, not observed in the SM group. These results highlight the potential of TRF as a complementary strategy for improving metabolic health and reducing inflammation in CD patients, warranting further investigation in larger studies. (NCT05230160).

Funding Agencies

Crohn’s & Colitis Foundation
A106 PATIENTS’ BARRIERS TO OPTIMIZING DIETARY INTERVENTIONS IN INFLAMMATORY BOWEL DISEASE (IBD): A DESCRIPTIVE QUALITATIVE STUDY
Authors: Noejovich V , Verma R , Miranda P M , Szeto J , Verdu E , Armstrong D
Published: February 2025

Background

Diet is a key influence on symptoms and disease activity in IBD patients, but effective dietary intervention relies on patient adherence, which is often sub-optimal in clinical practice and research. Adherence is shaped by individual barriers, beliefs and behaviours that must be addressed when recommending personalized dietary interventions, but these barriers are not well understood for IBD patients.

Aims

To identify IBD patients’ self-identified barriers to dietary modification and to understand their experiences and expectations for dietary interventions.

Methods

Adult patients with confirmed IBD attending a tertiary care centre IBD Clinic were invited to join heterogeneous focus group sessions with 2-6 participants or individual interviews moderated by a psychologist over a video communication platform (Zoom). Participants completed a demographics survey (REDCap). Audio files for all sessions were transcribed, de-identified and reviewed for accuracy by two reviewers, followed by thematic analysis (NVIVO).

Results

Between May 2022 and May 2023, 47 IBD patients were enrolled; 38 took part in 11 focus groups and 9 in individual interviews. Most participants (mean age 42 yrs; 60% female) were Caucasian (87%); 42% had a self-reported history of mental health disorders. Mean IBD duration was 16 yrs (0.5–44 yrs); 73% were in remission, and 68% had Crohn’s disease. Participants identified multiple barriers, which were consolidated using thematic analysis into 4 key themes, which encompassed 12 subthemes and related barriers (Table). Some patients (n= 30) reported adjusting their diet when diagnosed with IBD without following a specific diet, while some reported that diet was not discussed with their doctors (n=30).

Conclusions

IBD patients report multiple barriers to modifying their diet, highlighting the need to integrate specialized dietary advice into their healthcare. These findings could be used to develop screening questionnaires to guide personalized dietary interventions that address individuals’ barriers to dietary adoption

Funding Agencies

None