Number of intraepithelial lymphocytes and presence of a subepithelial band in normal colonic mucosa differs according to stainings and evaluation method.

Chronic watery diarrhea is a frequent symptom. In approximately 10% of the patients, a diagnosis of microscopic colitis (MC) is established. The diagnosis relies on specific, but sometimes subtle, histopathological findings. As the histology of normal intestinal mucosa vary, discriminating subtle features of MC from normal tissue can be challenging and therefore auxiliary stainings are increasingly used. The aim of this study was to determine the variance in number of intraepithelial lymphocytes (IELs) and presence of a subepithelial band in normal ileum and colonic mucosa, according to different stains and digital assessment. Sixty-one patients without diarrhea referred to screening colonoscopy due to a positive feacal blood test and presenting with endoscopically normal mucosa were included. Basic histological features, number of IELs, and thickness of a subepithelial band was manually evaluated and a deep learning-based algorithm was developed to digitally determine the number of IELs in each of the two compartments; surface epithelium and cryptal epithelium, and the density of lymphocytes in the lamina propria compartment. The number of IELs was significantly higher on CD3-stained slides compared with slides stained with Hematoxylin-and-Eosin (HE) (p<0.001), and even higher numbers were reached using digital analysis. No significant difference between right and left colon in IELs or density of CD3-positive lymphocytes in lamina propria was found. No subepithelial band was present in HE-stained slides while a thin band was visualized on special stains. Conclusively, in this cohort of prospectively collected ileum and colonic biopsies from asymptomatic patients, the range of IELs and detection of a subepithelial collagenous band varied depending on the stain and method used for assessment. As assessment of biopsies from patients with diarrhea constitute a considerable workload in the pathology departments digital image analysis is highly desired. Knowledge provided by the present study highlight important differences that should be considered before introducing this method in the clinic.

Risk of cancer in patients with bile acid diarrhoea: a Danish nationwide matched cohort study.

OBJECTIVE: Bile acid diarrhoea is a common cause of chronic diarrhoea. Increased levels of potentially carcinogenic bile acids in faeces, theoretically, may increase the risk of colorectal cancer in particular, but the long-term disease course is unknown. We aimed to investigate the overall and site-specific cancer risk in bile acid diarrhoea. DESIGN: Adult patients with bile acid diarrhoea were identified using nationwide Danish registries from 2003 to 2020 by a diagnostic gold-standard 75-selenium tauroselcholic acid procedure followed within 6 months by sequestrant prescription. The risk of overall and site-specific cancers in cases with bile acid diarrhoea was compared with sex, age and comorbidity-adjusted matched controls. A competing risk model estimated cumulative incidence functions and cause-specific HRs. RESULTS: We identified 2260 patients with bile acid diarrhoea with a mean follow-up of 5.5 years (SD 4.2). The overall cancer risk was increased by an HR of 1.32 (95% CI 1.12 to 1.54). The risk of site-specific cancer was increased in 3 of 10 cancer groups: haematological, HR 2.41 (1.36 to 4.02); skin, HR 1.33 (1.01 to 1.71); and male genital cancers, HR 1.85 (1.11 to 2.92). No increased risk of colorectal cancer was detected in patients with bile acid diarrhoea, HR 0.73 (0.34 to 1.63). CONCLUSIONS: Bile acid diarrhoea was associated with an increased overall risk of cancer, especially haematological cancers, but the risk of colorectal cancer was not increased. The lack of a diagnostic code for bile acid diarrhoea and potential residual confounding are limitations, and the findings should be replicated in other cohorts.

Prospective comparison of diagnostic tests for bile acid diarrhoea.

BACKGROUND: Bile acid diarrhoea is often missed because gold standard nuclear medicine tauroselcholic [75-Se] acid (SeHCAT) testing has limited availability. Empirical treatment effect has unknown diagnostic performance, whereas plasma 7α-hydroxy-4-cholesten-3-one (C4) is inexpensive but lacks sensitivity. AIMS: To determine diagnostic characteristics of empirical treatment and explore improvements in diagnostics with potential better availability than SeHCAT. METHODS: This diagnostic accuracy study was part of a randomised, placebo-controlled trial of colesevelam. Consecutive patients with chronic diarrhoea attending SeHCAT had blood and stool sampled. Key thresholds were C4 > 46 ng/mL and SeHCAT retention ≤10%. A questionnaire recorded patient-reported empirical treatment effect. We analysed receiver operating characteristics and explored machine learning applied logistic regression and decision tree modelling with internal validation. RESULTS: Ninety-six (38%) of 251 patients had SeHCAT retention ≤10%. The effect of empirical treatment assessed with test results for bile acid studies blinded had 63% (95% confidence interval 44%-79%) sensitivity and 65% (47%-80%) specificity; C4 > 46 ng/mL had 47% (37%-57%) and 92% (87%-96%), respectively. A decision tree combining C4 ≥ 31 ng/mL with ≥1.1 daily watery stools (Bristol type 6 and 7) had 70% (51%-85%) sensitivity and 95% (83%-99%) specificity. The logistic regression model, including C4, the sum of measured stool bile acids and daily watery stools, had 77% (58%-90%) sensitivity and 93% (80%-98%) specificity. CONCLUSIONS: Diagnosis of bile acid diarrhoea using empirical treatment was inadequate. Exploration suggested considerable improvements in the sensitivity of C4-based testing, offering potential widely available diagnostics. Further validation is warranted. CLINICALTRIALS: gov: NCT03876717.

Efficacy and safety of colesevelam for the treatment of bile acid diarrhoea: a double-blind, randomised, placebo-controlled, phase 4 clinical trial.

BACKGROUND: Bile acid diarrhoea is a common but overlooked cause of chronic watery diarrhoea. Plasma 7α-hydroxy-4-cholesten-3-one (C4) is an alternative to the gold standard tauroselcholic [75Se] acid (SeHCAT) test. Low-certainty evidence supports sequestrant treatment, including colesevelam. We aimed to determine the efficacy and safety of colesevelam in bile acid diarrhoea. METHODS: In this randomised, double-blind, placebo-controlled, investigator-initiated phase 4 trial of the sequestrant colesevelam in bile acid diarrhoea (SINBAD), we enrolled consecutive patients aged 18-79 years without inflammatory bowel disease attending SeHCAT testing for suspected bile acid diarrhoea at four Danish secondary care centres. Participants were randomly allocated 1:1 to receive 12 days of treatment with colesevelam (overencapsulated tablets of 625 mg) or placebo, with the starting dose of two capsules twice daily and titrated to effect during the first 5 days of treatment. A pharmacist independent of the clinical investigators generated a randomisation list on the web page randomization.com using block randomisation (randomisation was not stratified). C4 and SeHCAT diagnostic results were blinded during treatment. We treated all patients with diarrhoea, with a daily mean of 3·0 or more bowel movements or 1·0 or more watery bowel movements (Bristol stool scale type 6 and 7). Remission was defined as the absence of both these criteria during treatment days 6-12. The primary outcome was the intention-to-treat remission rate in bile acid diarrhoea diagnosed by C4 concentration greater than 46 ng/mL. A secondary outcome was the intention-to-treat remission rate in bile acid diarrhoea diagnosed by SeHCAT retention of 10% or less. This trial is registered with ClinicalTrials.gov, NCT03876717. FINDINGS: Between Oct 25, 2018, and July 1, 2021, 168 patients were randomly assigned to receive colesevelam (n=84) or placebo (n=84). 41 patients had C4 concentration greater than 46 ng/mL (22 assigned to the colesevelam group and 19 to the placebo group). For the C4-defined primary outcome, 14 (64%) of 22 participants receiving colesevelam versus three (16%) of 19 participants receiving placebo achieved remission (adjusted odds ratio 9·1, 95% CI 1·9-62·8; p=0·011). For the SeHCAT-defined secondary outcome, 75 of the 168 participants had retention of less than 10% (37 assigned to the colesevelam group and 38 assigned to the placebo group); 22 (59%) of 37 participants receiving colesevelam achieved remission versus five (13%) of 38 participants receiving placebo (adjusted odds ratio 11·1, 95% CI 3·4-45·6; p=0·00020). There were no serious adverse events. Common adverse events were transient. For patients receiving colesevelam within the primary outcome population, five had abdominal pain, nine had bloating, and four had nausea. For patients receiving placebo, four had abdominal pain, four had bloating, and one had nausea. No participants with bile acid diarrhoea withdrew due to adverse events. INTERPRETATION: Colesevelam was superior to placebo at inducing remission of bile acid diarrhoea diagnosed with C4 concentration greater than 46 ng/mL. Secondary outcome data suggest similar efficacy treating SeHCAT-defined bile acid diarrhoea. Colesevelam was safe during the treatment. FUNDING: Fabrikant Vilhelm Pedersen og hustrus mindelegat; recommended by the Novo Nordisk Foundation.

The Process of Developing a Disease Activity Index in Microscopic Colitis.

BACKGROUND AND AIMS: Patient-reported outcome measures [PROMs] aim to measure patients' perception of how their disorder influences everyday functioning. The objective of this study was to develop a PROM to assess disease activity in microscopic colitis [MC] fulfilling the requirements of the Food and Drug Administration [FDA]. METHODS: The European Microscopic Colitis Activity Index [E-MCAI] was developed in four steps. [1] A list of symptoms associated with active MC was created by a group of experts in the field. [2] Content validity of the symptoms was performed by experts [n = 14] and patients [n = 79] using the Content Validity Index. [3] Questions and response alternatives were created for each symptom, and validity of the E-MCAI was evaluated with cognitive interviews with patients [n = 7] and by the experts. [4] A pilot postal survey was performed to ensure usability. RESULTS: Seven of the symptoms related to active MC fulfilled the criteria for content validity and were included in the E-MCAI: stool consistency, stool frequency, stools at night, feel a need to pass more stools shortly after a bowel movement, urgent need to empty the bowel, leakage of stool and abdominal pain. The development and validation process resulted in the current version of the E-MCAI consisting of six questions related to MC. CONCLUSIONS: The E-MCAI was developed using the methods advocated by the FDA. The evaluation indicates good content validity. Further evaluation will be performed to achieve construct validity, reliability and responsiveness in future cross-sectional and longitudinal studies.

Autoimmune diseases in microscopic colitis: A Danish nationwide case-control study.

BACKGROUND: The association between autoimmune diseases and microscopic colitis remains uncertain. AIMS: To describe the association between autoimmune diseases and microscopic colitis by using a matched case-control design based on nationwide registry data. METHODS: All adult Danish patients with a diagnosis of microscopic colitis from 2001 to 2018 were identified from nationwide registries. Odds of autoimmune diseases were compared between cases with microscopic colitis and sex- and age-matched controls from the background population in a 1:10 ratio and evaluated by logistic regression calculating odds ratios (OR) with 95% confidence intervals (CI) adjusted for comorbidity. Analyses were stratified according to sex, age and the subtypes of lymphocytic and collagenous colitis. RESULTS: We identified 15 597 cases with microscopic colitis and matched to 155 910 controls. In total, 3491 (22%) of patients with microscopic colitis had concomitant autoimmune disease compared to 16 521 (11%) of controls (OR, 2.46; 95% CI, 2.36-2.56). Adjusting for comorbidities reduced the OR to 2.09 (95% CI, 2.01-2.19). Analyses showed increased ORs with 16 different autoimmune diseases, particularly of gastrointestinal and endocrine origin, and connective tissue disorders. The highest ORs were for coeliac disease (OR = 10.15; 95% CI, 8.20-12.6), Crohn's disease (OR = 2.47; 95% CI, 2.10-2.91) and ulcerative colitis (OR = 6.73; 95% CI, 6.20-7.30). In stratified analyses younger age at diagnosis and collagenous colitis were associated with higher odds. CONCLUSION: Using nationwide registry data, microscopic colitis was associated with a wide range of autoimmune diseases, especially of gastrointestinal origin. The results suggest an autoimmune predisposition to microscopic colitis.

Budesonide as induction therapy for incomplete microscopic colitis: A randomised, placebo-controlled multicentre trial.

BACKGROUND AND AIMS: Incomplete microscopic colitis (MCi) is a subtype of microscopic colitis (MC). Budesonide is recommended as a first-line treatment for MC. However, randomised trials on efficacy of treatment in MCi are missing. We therefore performed a randomised, placebo-controlled trial to evaluate budesonide as induction therapy for MCi. METHODS: Patients with active MCi were randomly assigned to either budesonide 9 mg once daily or placebo for 8 weeks in a double-blind, double-dummy design. The primary endpoint was clinical remission, defined as a mean of <3 stools/day and a mean of <1 watery stool/day in the 7 days before week 8. RESULTS: Due to insufficient patient recruitment, the trial was discontinued prematurely. The intention-to-treat analysis included 44 patients (21 budesonide and 23 placebo). The primary endpoint of clinical remission at week 8 was obtained by 71.4% on budesonide and 43.5% on placebo (p = 0.0582). All clinical secondary endpoints were in favour of budesonide. Budesonide decreased the number of soft or watery stools (16.3 vs. 7.7, p = 0.0186) and improved health-related quality of life for all four dimensions of the short health scale. Adverse events with a suspected relation to study drug were reported in one patient in the budesonide group and two patients in the placebo group. Neither serious nor severe adverse events occurred during the double-blind phase. CONCLUSIONS: Budesonide decreased the frequency of soft or watery stools and improved the patients' quality of life significantly in MCi, but the primary endpoint was not met due to the low sample size (type 2 error). Budesonide was safe and well tolerated during the 8-weeks treatment course.

Histological disease activity in patients with microscopic colitis is not related to clinical disease activity or long-term prognosis.

BACKGROUND: Microscopic colitis (MC) is a common cause of chronic watery diarrhea. Biopsies with characteristic histological features are crucial for establishing the diagnosis. The two main subtypes are collagenous colitis (CC) and lymphocytic colitis (LC) but incomplete forms exist. The disease course remains unpredictable varying from spontaneous remission to a relapsing course. AIM: To identify possible histological predictors of course of disease. METHODS: Sixty patients from the European prospective MC registry (PRO-MC Collaboration) were included. Digitised histological slides stained with CD3 and Van Gieson were available for all patients. Total cell density and proportion of CD3 positive lymphocytes in lamina propria and surface epithelium were estimated by automated image analysis, and measurement of the subepithelial collagenous band was performed. Histopathological features were correlated to the number of daily stools and daily watery stools at time of endoscopy and at baseline as well as the clinical disease course (quiescent, achieved remission after treatment, relapsing or chronic active) at 1-year follow-up. RESULTS: Neither total cell density in lamina propria, proportion of CD3 positive lymphocytes in lamina propria or surface epithelium, or thickness of collagenous band showed significant correlation to the number of daily stools or daily watery stools at any point of time. None of the assessed histological parameters at initial diagnosis were able to predict clinical disease course at 1-year follow-up. CONCLUSIONS: Our data indicate that the evaluated histological parameters were neither markers of disease activity at the time of diagnosis nor predictors of disease course.

Quantifying intraepithelial lymphocytes and subepithelial collagen band in microscopic colitis, extracting insights into the interrelationship of lymphocytic and collagenous colitis.

Microscopic colitis (MC) is the umbrella term for the conditions termed lymphocytic colitis (LC) and collagenous colitis (CC). LC with thickening of the subepithelial collagen band or CC with increased number of intraepithelial T- lymphocytes (IELs) is often seen in MC and may lead to difficulties in correct histological classification. We investigated the extent of overlapping features of CC and LC in 60 cases of MC by measuring the exact thickness of the subepithelial collagen band in Van Gieson stained slides and quantifying number of IELs in CD3 stained slides by digital image analysis. A thickened collagen band was observed in nine out of 29 cases with LC (31%) and an increased number of IELs in all 23 cases of CC (100%). There was no correlation between the thickness of the collagen band and number of IELs. Due to the increased number of IELs in all cases of CC we consider the lymphocytic inflammatory infiltration of the mucosa to be the essential histopathological feature of MC. However, although LC and CC are related due to the lymphocytic inflammation, the non-linear correlation of number of IELs and thickness of the collagenous band indicate differences in their pathogenesis.

[Healing of severe morbus Crohn-related pyoderma gangrenosum after colectomy].

This case report describes a patient with colonic Crohn's disease and perianal disease. The patient experienced extensive and severe pyoderma gangrenosum after colectomy. Steroids and anti-inflammatory medication had no effect on pyoderma or the persistent perianal and rectal disease. All pyoderma lesions eventually healed after proctectomy and excision of perianal fistulae. The relevance and effect of surgically induced remission on medically resistant inflammatory bowel disease-associated pyoderma gangrenosum is highlighted.

European guidelines on microscopic colitis: United European Gastroenterology and European Microscopic Colitis Group statements and recommendations.

INTRODUCTION: Microscopic colitis is a chronic inflammatory bowel disease characterised by normal or almost normal endoscopic appearance of the colon, chronic watery, nonbloody diarrhoea and distinct histological abnormalities, which identify three histological subtypes, the collagenous colitis, the lymphocytic colitis and the incomplete microscopic colitis. With ongoing uncertainties and new developments in the clinical management of microscopic colitis, there is a need for evidence-based guidelines to improve the medical care of patients suffering from this disorder. METHODS: Guidelines were developed by members from the European Microscopic Colitis Group and United European Gastroenterology in accordance with the Appraisal of Guidelines for Research and Evaluation II instrument. Following a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of the evidence. Statements and recommendations were developed by working groups consisting of gastroenterologists, pathologists and basic scientists, and voted upon using the Delphi method. RESULTS: These guidelines provide information on epidemiology and risk factors of microscopic colitis, as well as evidence-based statements and recommendations on diagnostic criteria and treatment options, including oral budesonide, bile acid binders, immunomodulators and biologics. Recommendations on the clinical management of microscopic colitis are provided based on evidence, expert opinion and best clinical practice. CONCLUSION: These guidelines may support clinicians worldwide to improve the clinical management of patients with microscopic colitis.

Physiological Genetics Reformed: Bridging the Genome-to-Phenome Gap by Coherent Chemical Fingerprints - the Global Coordinator.

Forward-focused molecular genetics is successfully framing DNA diversity and mapping primary gene functions. However, abandoning the classic Linnaean fingerprint link between the phenome and genome by suppressing gene interaction (pleiotropy), has resulted in a genome-to-phenome gap and poor utilization of molecular data. We demonstrate how to bridge this gap by using an example of a barley mutant seed model, where pleiotropy is observed as covarying global molecular patterns that define each endosperm. Global coherence was discovered as a covariate coordinator within and between local genotype specific fingerprints. This implies that any of these fingerprints can select its recombinant global phenotype variant, including composition. Introducing the law of coherence, and the movement of gene complexes by chemical fingerprint traits as selectors, introduces a revolution in understanding physiological molecular genetics and plant-breeding.

Course of Disease in Patients with Microscopic Colitis: A European Prospective Incident Cohort Study.

BACKGROUND AND AIMS: The disease course of microscopic colitis [MC] is considered chronic but benign. However, this assumption is based on mainly retrospective studies, reporting on incomplete follow-up of selective cohorts. Systematic, prospective and unbiased data to inform patients and healthcare professionals on the expected course of the disease and real-life response to therapy are warranted. METHODS: A prospective, pan-European, multi-centre, web-based registry was established. Incident cases of MC were included. Data on patient characteristics, symptoms, treatment and quality of life were systematically registered at baseline and during real-time follow-up. Four disease course phenotypes were discriminated and described. RESULTS: Among 381 cases with complete 1-year follow-up, 49% had a chronic active or relapsing disease course, 40% achieved sustained remission after treatment and 11% had a quiescent course. In general, symptoms and quality of life improved after 3 months of follow-up. A relapsing or chronic active disease course was associated with significantly more symptoms and impaired quality of life after 1 year. CONCLUSIONS: A minority of MC patients follow a quiescent disease course with spontaneous clinical improvement, whereas the majority suffer a chronic active or relapsing disease course during the first year after diagnosis, with persisting symptoms accompanied by a significantly impaired quality of life.

Distribution of histopathological features along the colon in microscopic colitis.

PURPOSE: The diagnosis microscopic colitis (MC) consisting of collagenous colitis (CC) and lymphocytic colitis (LC) relies on histological assessment of mucosal biopsies from the colon. The optimal biopsy strategy for reliable diagnosis of MC is controversial. The aim of this study was to evaluate the distribution of histopathological features of MC throughout the colon. METHODS: Mucosal biopsies from multiple colonic segments of patients with MC who participated in one of the three prospective European multicenter trials were analyzed. Histological slides were stained with hematoxylin-and-eosin, a connective tissue stain, and CD3 in selected cases. RESULTS: In total, 255 patients were included, 199 and 56 patients with CC and LC, respectively. Both groups exhibited a gradient with more pronounced inflammation in the lamina propria in the proximal colon compared with the distal colon. Similarly, the thickness of the subepithelial collagenous band in CC showed a gradient with higher values in the proximal colon. The mean number of intraepithelial lymphocytes was > 20 in all colonic segments in patients within both subgroups. Biopsies from 86 to 94% of individual segments were diagnostic, rectum excluded. Biopsies from non-diagnostic segments often showed features of another subgroup of MC. CONCLUSION: Conclusively, although the severity of the histological changes in MC differed in the colonic mucosa, the minimum criteria required for the diagnosis were present in the random biopsies from the majority of segments. Thus, our findings show MC to be a pancolitis, rectum excluded, questioning previously proclaimed patchiness throughout the colon.