Clinical Case Summary

A 64-year-old women, without known family history of colorectal cancer (CRC), underwent a colonoscopy due to iron deficiency anemia. In the colonoscopy, with an adequate bowel preparation, an ulcerated lesion in the ascending colon was identified. Multiple biopsies were performed, and the colon was tattooed distally to the lesion. Histology confirmed adenocarcinoma. Staging was performed and the CT-scan identified parietal thickening of the distal ascending colon and multiple infracentrimetric nodules at the root of the mesentery, without description of other suspicious lesions. After a multidisciplinary team meeting, a right hemicolectomy was proposed, which occurred 12 weeks after endoscopic diagnosis. Macroscopic evaluation of the surgical specimen didn’t identify lesions compatible with the described neoplasia, despite the colic tattoo being observed. Also, in the anatomopathological evaluation, there was no evidence of tumor. The resected nodes were negative for neoplasia. The colonoscopy was repeated 8 weeks after surgery, with no identifiable lesions. The list of patients who underwent colonoscopy on the same day was reviewed, and the hypothesis of misidentification of the patient was excluded. Finally, biopsies of the neoplasia and the colectomy specimen were compared by capillary electrophoresis, confirming the compatibility of the genetic profile between them.
We present a rare case of a spontaneous remission of CRC. This phenomenon has been described in several neoplasms, but is rare in CRC, corresponding to <2% of all cases. The pathophysiology is not well understood, with several etiologic mechanisms proposed. With this exemplary case, we emphasize the measures to avoid identification errors, how to investigate cases of disagreement between pre- and post-operative diagnoses and the importance of recognizing that spontaneous remission of CRC is not synonymous of cure, being necessary to maintain the recommended follow-up.

Introduction

Glucose breath test (GBT) is the most commonly used method for the diagnosis of small intestinal bacterial overgrowth (SIBO). SIBO is a common condition with very unspecific symptoms (bloating, abdominal pain, diarrhea or constipation). Recently, American and European recommandations have been published to standardize the indications and the conditions to perform these tests.^1,2 However, some discrepancies remain between the European and American recommandations, and many statements were supported by low quality of evidence.^1,2 Moreover, several counfounding factors related to the patient’s condition may impact the result of the test, leading to a difficult interpretation.

Aims & Methods

This study aimed to assess the factors that could impact the results of a GBT. Therefore, we retrospectively reviewed the results of the GBT performed in our physiology department from 2013 to 2023. The test was performed after ingestion of 75g of glucose, with breath samples collected every 15min during 2 hours. The result was considered positive for hydrogen (H₂) if a rise ≥ 20ppm was observed or positive for methane (CH4) if a rise ≥ 10ppm was observed. Demographic data were collected, such as symptoms and questionnaires during the exam including Rome questionnaire, and the Gastro-Intestinal Quality of Life Index (GIQLI). Severity of symptoms was based on the GIQLI questionnaire, where a higher score represents a better condition. Medical and surgery history, such as drug treatments were then retrospectively collected from medical records, using a computerized research.

Results

A total of 2373 tests from different patients were included. The mean age was 46.0 ± 15.8 years old, with 1727 females (73.7%). The number of positive GBT was 576 tests (24.3%), with 294 tests positive for H₂ only, 214 tests positive for CH₄ only, and 69 tests positive for both. In univariate analysis, a higher age, female sex, and a lower body mass index (BMI) were associated with a positive GBT (Table). A history of diabetes, and a previous gastric surgery (sleeve, or bypass) were associated with a positive test, while proton pump inhibitors (PPI) or opioids intake did not change the outcome (Table). Regarding the symptoms, more severe abdominal bloating and constipation were associated with a positive test (1.28 ± 1.0 vs 1.41 ± 1.1; p=0.02, and 2.67 ± 1.3 vs 2.82 ± 1.2; p=0.03), while abdominal pain and diarrhea were not statistically different (1.57 ± 1.1 vs 1.67 ± 1.1; p=0.07; and 2.23 ± 1.3 vs 2.33 vs 1.4; p=0.14). In multivariate analysis, age (Odds Ratio (OR) = 1.02 [1.01 – 1.03]; p<0.001), BMI (OR=0.93 [0.90 – 0.96]; p<0.001), a previous gastric surgery (OR=9.32 [3.74 – 24.86]; p<0.001) and more severe constipation (OR=0.88 [0.79 – 0.98]; p=0.02) were associated with a positive GBT.

	Negative GBT (n=1797)	Positive GBT (n=576)	p value
Age (years)	44.7 ± 15.5	50.0 ± 16.2	<0.001
Sex (female)	1280 (71.2%)	447 (77.6%)	0.005
BMI (kg/m²)	25.0 ± 5.5	23.9 ± 5.2	<0.001
Diabetes	62 (3.5%)	30 (5.2%)	0.02
Gastric sleeve	8 (0.4%)	14 (2.4%)	<0.001
PPI intake	361 (20.1%)	123 (21.4%)	0.50
Opioids intake	183 (10.2%)	57 (9.9%)	0.91
Irritable bowel syndrome	561 (31.2%)	148 (25.7%)	0.09
Functional dyspepsia	704 (39.2%)	190 (33.0%)	0.08

Conclusion

The result of GBT is more likely to be positive in patients with constipation. A previous gastric surgery is a cofounding factor, leading to a non-interpretable result of the test. A diagnosis of irritable bowel syndrome or functional dyspepsia did not change the result of the test, such as PPI or opioid intake.

References

1. Hammer HF, Fox MR, Keller J, et al. European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus. United European Gastroenterol J 2022;10:15-40.
2. Pimentel M, Saad RJ, Long MD, et al. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. Am J Gastroenterol 2020;115:165-178.

Introduction

Clinical trials in coeliac disease require reliable histological metrics to quantify mucosal damage and demonstrate improvement with treatment. Regulatory agencies are recognizing this and expect some form of histological assessment in coeliac disease trials. Qualitative scoring systems are highly variable among readers. It has been suggested that quantitative scoring provides better consistency among different readers.

Aims & Methods

This study aimed to assess the variability that occurs when quantifying villus height (Vh), crypt depth (Cd) and the Vh:Cd ratio, and identified approaches to improve correlation among observers at different institutions. A set of 236 slides stained with haematoxylin and eosin from 28 patients with coeliac disease on a gluten-free diet (NCT03738475) were used. Quantitative scoring of Vh, Cd, Vh:Cd ratio and the sum of Vh and Cd were initially compared between different institutions that prioritized ocular microscopy or digital pathology. Additionally, the change from baseline with gluten ingestion for each of these measurements was compared between institutions. Improvements to inter-reader correlations were assessed by implementing a common digital pathology software and using agreed upon criteria for making quantitative measurements. Data sets were subjected to statistical analysis to understand correlation and significance. Regression slopes were calculated and the coefficient of determination, R², was derived as a measure of linearity. The concordance correlation coefficient was calculated as an index of agreement beyond linearity. Pairwise Pearson correlation coefficients between readers from different institutions were calculated to demonstrate the degree of association between readers.

Results

Initial inter-reader analysis found that Vh:Cd ratios had a similar, linear trend between readers, regardless of ocular or digital pathology usage, but that there was a consistent systematic difference partially due to differences in reader assessment of the location of the crypt–villus border. Use of a common digital pathology platform and clear scoring criteria greatly improved inter-reader correlations, even when scoring was done by a non-pathologist. Importantly, the assessment of change from baseline in the quantitative measurements after gluten exposure was also highly concordant (Table). The software also enabled visual comparison of readers’ individual measurements of the crypt and villous lengths allowing potential reasons for differences in these measurements to be identified.

Table 1. Changes from baseline in Vh and Cd metrics obtained via ocular microscopy and digital pathology after gluten challenge.

Metric	Substudy 1		Substudy 2	Difference from institution 2
	Digital pathology (institution 2)	Ocular microscopy (institution 1)	Digital pathology + training (institution 1)	Substudy 1 (institution 1)	Substudy 2 (institution 1)
Vh, μm	−95.25 (−130.84, −59.66)**	−38.01 (−72.90, −3.12)*	−87.3 (−137.5, −37.0)†	−57.24**	−7.95†
Cd, μm	50.61 (35.87, 65.34)**	7.73 (−0.26, 15.72)†	40.7 (16.6, 64.8)†	42.88**	9.91†
Vh:Cd ratio	−0.79 (−1.03, −0.54)**	−0.38 (−0.61, −0.15)*	−0.7 (−1.0, −0.4)†	−0.41**	−0.09†
Vh+Cd, μm	−44.64 (−74.62, −14.67)*	−30.28 (−67.44, 6.88)†	−46.5 (−83.9, −9.1)†	−14.36†	1.90†
*p < 0.05 for difference between digital and ocular reads. **p < 0.001 for difference from baseline (0). †p values were not significant (> 0.05). Data are mean (95% CI). Vh, Cd, Vh:Cd ratio and Vh+Cd measurements were obtained by ocular microscopy by one reader from institution 1 and by digital pathology by three readers from institution 2. Shown here are the changes in Vh and Cd metrics between baseline and Day 14 after gluten challenge and the changes (improvement) in the performance of the reader (same reader in each substudy) between substudies 1 and 2. Cd, crypt depth; CI, confidence interval; NR, not reported; Vh, villus height; Vh+Cd, sum of the villus height and crypt depth; Vh:Cd, villus height:crypt depth.

Conclusion

The results suggest that quantitative histology in coeliac disease is reliable and can be improved through digital pathology, software measurement aids and attention to selecting optimally oriented sections. Given the ease with which pathologists without training in the use of quantitative histology software can produce results similar to those from experienced central laboratories, quantitative histology may be feasible outside the clinical trial setting.

Disclosure

AV has nothing to disclose. DAL, DR, DC, GS, JM and QL are employees of Takeda Development Center Americas, Inc. and receive stock or stock options. JI is the founder and owner of Jilab, Inc.; is a Full Professor at Tampere University, Medical Faculty; and has a consulting agreement with Takeda. JAM has grants from Nexpep/ImmusanT, National Institutes of Health, Immunogenix, Takeda Pharmaceutical, Allakos, Oberkotter, Cour; and has received consultancy fees from Bionix, Lilly Research Laboratory, Johnson & Johnson, Dr. Schar USA, UCB Biopharma, Celimmune, Intrexon Corporation, Dren Bio, Reistone Pharma, Chugai Pharma, Kanyos, Boehringer Ingelheim, Equillium and Torax Medical. MR is a consultant for Takeda and Bristol Myers Squibb. MZC has nothing to disclose. TTW has nothing to disclose.
Funding statement: This study was sponsored by Takeda Development Center Americas, Inc. Medical writing support was provided by Oxford PharmaGenesis, Oxford, UK and was funded by Takeda Pharmaceuticals.

Introduction

Diagnostics of enteropathy with membrane digestion disturbance (EMDD) is based on the evaluation of carbohydrase activity in duodenal mucosa (DM). There is no information about diagnostic value of ileum mucosa (IM) carbohydrases.
Study objective. Assess the diagnostic value of carbohydrases activity in mucous membrane of duodenum and distal ileum in patients with EMDD and irritable bowel syndrome (IBS).

Aims & Methods

The study includes 12 patients with EMDD, 16 patients with IBS and 12 relatively healthy persons (control group). Study design included analysis of food tolerance and evaluation of activity of sucrase (S), glucoamylase (GA), maltase (М) and lactase (L) in mucous membrane of duodenum and ileum based on the method of Dahlquist with N.I.Belostotsky modification. Microsoft Office Excel and STATISTICA 10.0 were used for statistical evaluation of material. Mann-Whitney criterion was used to evaluate the differences between quantitative parameters. The differences were considered to be significant at p <0.05. Control group was used for comparison.

Results

Ratio of carbohydrase activity in duodenum and ileum in control group and patients with IBS and EMDD.

In control group the carbohydrases activity in duodenum mucosa was not significantly statistically different from the one in ileum mucosa.
In patients with IBS glucoamylase and maltase activity parameters in IM were significantly different from activity in DM, which can be interpreted as functional inequality of enzyme activity of various departments of small intestine.
In patients with EMDD GA level in ileum mucosa is 5.2 times higher, maltase level is 3.8 times higher and sucrose level is 2 times higher than duodenum enzyme levels, which demonstrates the possibility of formation of compensatory reaction of adaptive shift type towards distal segments of small intestine, initially described by A.M. Ugolev et al. in 1985

Conclusion

Enzyme activity distribution along small intestine is an adaptor function of its segments. Our study confirmed the need and promising outlook of further investigations in terms of evaluation of proximo-distal gradients of enzyme activity to study compensatory reactions which can be fulfilled by distal segment of small intestine in case of duodenum damage.
The evaluation of carbohydrase activity in ileum mucosa provides additional opportunities for diagnostics of EMDD and its differentiation from IBS, which can be used to improve therapeutic approaches.

Introduction

Intestinal ischemia-reperfusion injury (IRI) is a life-threatening condition caused by an abrupt obstruction of mesenteric blood flow. Reestablishing blood flow (reperfusion) is necessary to save intestinal tissue but unintentionally exacerbates damage induced by ischemia. Mitochondria are sensitive to IRI; if damaged, they release cytotoxic molecules that can aggravate injury. Therefore, removal of damaged mitochondria is essential for cellular survival. The selective clearance of mitochondria via autophagy, mitophagy, has been reported to protect against IRI in other organs, but its role in the intestine remains unknown.

Aims & Methods

The main objective of this study was to assess mitochondrial damage and evaluate signs of mitophagy in response to hypoxia-reoxygenation in a human small intestinal organoid (SIO) model and the differences therein between crypt-like (CL) and villus-like (VL) organoids. Both SIOs phenotypes were exposed to hypoxia-reoxygenation, and mitochondrial damage was assessed by live-cell imaging of mitochondrial membrane potential using fluorescent dye tetramethylrhodamine methyl ester (TMRM). In addition, ultrastructural changes in mitochondria were evaluated by transmission electron microscopy (TEM). Finally, mitochondrial content, autophagy, and mitophagy markers were assessed using quantitative PCR (qPCR) and Western blot.

Results

A drastic decrease in TMRM fluorescence, indicating impaired mitochondrial activity, was mainly observed in VL organoids and not in CL organoids. Mitochondrial ultrastructural changes were observed in both phenotypes, including mitochondrial swelling and disrupted cristae following hypoxia, whereas after 480 minutes reoxygenation, mitochondria exhibited a tubular or small round shape. Mitochondrial content markers were decreased in both organoid phenotypes following hypoxia-reoxygenation. Most importantly, only CL organoids showed a significant increase in autophagy and mitophagy markers.

Conclusion

Mitochondria of VL organoids are more severely damaged by hypoxia-reoxygenation, whereas CL organoids might be protected by inducing mitophagy. The occurrence of mitophagy is currently further validated with live-cell imaging.

Introduction

Histopathological assessment remains the gold standard for evaluating diminutive colorectal polyps, despite the potential of optical diagnosis (OD) to reduce colonoscopy-associated costs (1). However, implementing OD strategies remains limited in clinical practice (2). This study aimed to evaluate patient acceptance of truly replacing pathology evaluation of diminutive polyps with resect and discard (RD) and diagnose and leave (DL) strategies using computer-aided polyp diagnosis (CADx).

Aims & Methods

In this prospective clinical pilot study at the Montreal University Hospital Center, 102 patients undergoing colonoscopy were invited to participate in the study. Patients received information on CADx, RD, DL and were informed that if they agree to participate in the study, we will diagnose all polyps using CADx during the colonoscopy, but polyps will be discarded or left in place and no pathology exams will be performed. For consenting patients, blue light imaging (BLI)-assisted CADx was used and endoscopists made the final histology determination and rated their confidence level (high vs. low) in the OD. Endoscopists also determined if high-risk features were present before using RD or DL strategies. Then all diminutive polyps optically diagnosed with high confidence as adenomas were resected and discarded and all diminutive rectosigmoid polyps optically diagnosed as hyperplastic with high confidence were left in situ. All polyps >5mm, with disagreement between endoscopists and CADx OD, low-confidence OD, or high-risk features (JNET 2b or higher) were sent for pathology evaluation. All cases were video recorded, and a quality review of the diagnoses performed with two expert endoscopists (DR and HP).

Results

Among the 102 patients approached, 97 (95%) accepted participating and utilization of CADx instead of pathology. Three stated that they did not want to participate in any research, and two patients stated that they did not trust OD or CADx as the reason for refusal. Overall, 164 diminutive polyps were removed in 97 patients (mean age=67.2 years), of which 36% were in the rectosigmoid and 64% in the proximal colon. CADx-assisted OD was performed on 97% of the polyps. The proportion of polyps with a low-confidence OD or disagreement between endoscopists' and CADx-based OD was 19/159 (11.9%). Overall, 98/159 (61.6%) polyps underwent the RD strategy, of which 4 polyps were discarded by the endoscopist's discretion despite disagreement between endoscopists and CADx OD. One of these 4 polyps had to undergo the DL strategy but was RD because of serrated features. One polyp in the proximal colon was resected and retrieved because of serrated features. 40 polyps were DL in the rectosigmoid, of which 1 polyp was neoplastic based on CADx and endoscopist's OD.

Conclusion

We observed a very high patient acceptance for truly replacing diminutive polyp histopathology with CADx-assisted OD. CADx-based OD was used to RD 98/159 (61.6%) or DL 40/159 (25.2%) diminutive polyps found in the cohort.

References

1) Rex, Douglas K. It’s not lack of evidence holding back resect and discard. Gastrointestinal Endoscopy, Volume 96, Issue 6, 1033 - 1035.
2) Willems P, Djinbachian R, Ditisheim S, Orkut S, Pohl H, Barkun A, Bouin M, Faulques B, von Renteln D. Uptake and barriers for implementation of the resect and discard strategy: an international survey. Endosc Int Open. 2020 May;8(5):E684-E692.

Disclosure

Dr Rex is a consultant for Olympus Corporation, Boston Scientific, Aries Pharmaceutical, Braintree Laboratories, Lumendi Ltd., Norgine, Endokey, GI Supply,
Medtronic, and Acacia Pharmaceuticals; the recipient of research support from EndoAid, Olympus Corporation, Medivators, Erbe USA Inc, and Braintree Laboratories; and a shareholder in Satisfai Health. Dr Pohl has received research funding from Steris, Cosmo, and is an advisory board member of InterVenn. Dr von Renteln has received research funding from ERBE Elektromedizin GmbH, Ventage, Pendopharm, Fujifilm, and Pentax and has received consultant or speaker fees from Boston Scientific Inc, ERBE Elektromedizin GmbH, and Pendopharm. The remaining authors disclose no conflicts.