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

Factors associated with long-term clinical outcome in microscopic colitis

BACKGROUND AND AIMS

Microscopic colitis has been increasingly recognized as a cause of chronic diarrhoea. We aimed to characterize the role of disease-related factors and treatments on the clinical outcomes of microscopic colitis.

METHODS

We retrospectively reviewed the medical records of patients with microscopic colitis who were treated at the University of Chicago and Oregon Health & Science University between August 2010 and May 2016. Patient characteristics and treatments were evaluated as predictors of clinical outcomes using univariate and multivariate analyses. Clinical remission was defined as no symptoms associated with microscopic colitis based on physician assessment and histologic remission was defined as no evidence of histological inflammation of microscopic colitis.

RESULTS

Seventy-two patients with microscopic colitis were included in the study (28 with lymphocytic colitis and 44 with collagenous colitis). Non-steroidal anti-inflammatory drugs, proton pump inhibitors and selective serotonin reuptake inhibitors were used in 23 (31.9%), 14 (19.4%) and 15 (20.8%), respectively, at the time of diagnosis. Among 46 patients with adequate follow-up data, 25 (54.3%) patients achieved clinical remission. Response to budesonide (p = .0002) and achieving histologic remission (p = .0008) were associated with clinical remission on univariate analysis. On multivariate analysis, budesonide response (p = .0052) was associated with clinical remission (odds ratio 25.00, 95% confidence interval 2.63-238.10). Among 22 patients who underwent a follow-up colonoscopy, five patients (22.7%) achieved histologic remission. All patients with histologic remission maintained clinical remission without medication, whereas only two patients (11.8%) were able to discontinue medical therapy when histologic inflammation was present (p = .0002).

CONCLUSIONS

In the present cohort of patients with microscopic colitis, a favourable response to budesonide was significantly associated with long-term clinical remission, and all patients achieving histological remission were able to maintain clinical remission without further medical therapy. Larger studies are required to confirm these findings.

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.

PROTON-PUMP INHIBITORS ARE ASSOCIATED WITH AN INCREASED RISK OF MICROSCOPIC COLITIS: A POPULATION-BASED STUDY AND REVIEW OF THE LITERATURE

BACKGROUND

•The study evaluated the risk of developing microscopic colitis and its subtypes in patients on PPI therapy.

BACKGROUND

•Using a large multicenter database, a retrospective cohort analysis was conducted, excluding patients with autoimmune diseases, and adjusting for confounders.

BACKGROUND

•An increased risk of developing microscopic colitis was associated with female gender, smoking, and the use of PPI, SSRI, and NSAIDs.

BACKGROUND

•The use of PPI represented the highest odds of developing microscopic colitis.

BACKGROUND

Microscopic colitis is a relatively new diagnosis that was first described in the 1980s. Patients usually present with chronic watery and non-bloody diarrhea and are typically characterized by an unremarkable gross appearance of the colon on lower endoscopy while having evidence of lymphocytic infiltration of the lamina propria and the epithelium on histology. Two subtypes have been described in the literature: Collagenous colitis, with marked thickening of the subepithelial layer, and Lymphocytic colitis. Multiple risk factors such as female gender, older age and celiac disease have been associated with this entity. A few studies have found an association between microscopic colitis and proton-pump inhibitor (PPI). The aim of our study was to evaluate the risk of developing microscopic colitis and its subtypes for patients who are on PPI therapy.

METHODS

A validated multicenter and research platform database of more than 360 hospitals from 26 different healthcare systems across the United States from 1999 to September 2022 was utilized to construct this study. Patients aged 18 years and above were included. Individuals who have been diagnosed with any autoimmune disease have been excluded. A multivariate regression analysis was performed to assess risk of developing microscopic, lymphocytic, and collagenous colitis by accounting for potential confounders including female gender, smoking history, and the use of proton pump inhibitor, nonsteroidal anti-inflammatory drugs, and selective serotonin receptor inhibitors. A two-sided P value <0.05 was considered as statistically significant, and all statistical analyses were performed using R version 4.0.2 (R Foundation for Statistical Computing, Vienna, Austria, 2008).

RESULTS

78,256,749 individuals were screened in the database and 69,315,150 were selected in the final analysis after accounting for inclusion and exclusion criteria. The baseline characteristics of patients with microscopic, lymphocytic, and collagenous colitis is seen in table 1. Using a multivariate regression analysis, the risk of developing microscopic, lymphocytic, and collagenous colitis was calculated and illustrated in table 2.

DISCUSSION

Our study showed that the risk of microscopic colitis, lymphocytic colitis and collagenous colitis was higher in females and smokers. Although medications like SSRI and NSAIDs showed a positive correlation with colitis, the highest likelihood of developing this disease was associated with PPIs. Lansoprazole has been documented to be associated with microscopic colitis as it is believed to inhibit colonic proton pumps, and subsequently promote diarrhea and inflammation. Interestingly, the prevalence of lymphocytic colitis and collagenous colitis was similar in the cohort of patients treated with PPIs, indicating no specific predisposition to either subtype. This study further confirms the risk factors associated with microscopic colitis. It can help guide physicians to recognize and eliminate these risk factors prior to initiating treatment for this disease. Future studies can focus on identifying the incidence of microscopic colitis with the different types of PPIs in the market.

Chronic Diarrhea Owing to Microscopic Colitis: A Cohort Study with Insights into Diagnostic Challenges and Size of the Problem

BACKGROUND

Microscopic colitis (MC) is a recognized cause of chronic diarrhea and is often underestimated when a colonoscopy appears normal. This study aims to accurately diagnose chronic diarrhea through histopathological examination of colonoscopic mucosal biopsies and assess the prevalence of microscopic colitis and the diagnostic value of biomarkers.

METHODS

A hospital-based cohort study was conducted on 116 patients with chronic diarrhea. Colonoscopies and colonic mucosal biopsies were performed and analyzed, along with various tests including fecal calprotectin (FC) level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), stool analysis, routine laboratory tests, and clinical data related to nocturnal diarrhea, abdominal pain, and unexplained weight loss.

RESULTS

In the study group, 32.8% had MC, with 25.9% having lymphocytic colitis (LC) and 6.9% having collagenous colitis (CC). Patients with MC had significantly higher FC, ESR, and CRP levels than those without colitis (p < 0.001). Factors associated with MC included nocturnal diarrhea (OR = 4.26; 95% CI [1.64-11.08]; p-value = 0.003) and abdominal pain (OR = 4.62; 95% CI [1.85-11.54]; p-value = 0.001). ESR at a cutoff >14 mm/h and FC at a cutoff >64 mcg/g showed excellent validity in diagnosing MC with area under the curve (AUC) values of 0.94 and 0.97, respectively.

CONCLUSIONS

Microscopic colitis, particularly LC-type, is not an uncommon cause of chronic diarrhea, especially when accompanied by symptoms such as abdominal pain and nocturnal diarrhea, warranting further investigation, including inflammatory markers and colonic biopsy. Inflammatory markers can be useful in diagnosing MC with proper values and approaches; however, further studies are needed.

Microscopic Colitis: An Underestimated Disease of Growing Importance

The aim of this paper is to raise awareness of MC as a clinically significant condition and to highlight its under-recognition, risk factors, diagnosis, management, and complications. This paper underlines the diagnostic and therapeutic challenges associated with the often nonspecific symptoms of MC. In order to create this article, we reviewed available articles found in the PubMed database and searched for articles using the Google Scholar platform. Microscopic colitis (MC) is a chronic inflammatory bowel disease, classified into three types: lymphocytic, collagenous, and unspecified. The average age of onset of MC is around 62-65 years and the disease is more common in women than men (nine times more common). The main symptom of MC is watery diarrhoea without blood, other symptoms include defecatory urgency, faecal incontinence, abdominal pain, nocturnal bowel movements, and weight loss. Once considered a rare disease, MC is now being diagnosed with increasing frequency, but diagnosis remains difficult. To date, a number of causative factors for MC have been identified, including smoking, alcohol consumption, medications (including NSAIDs, PPIs, SSRIs, and ICPIs), genetic factors, autoimmune diseases, bile acid malabsorption, obesity, appendicitis, and intestinal dysbiosis. It may be difficult to recognize and should be differentiated from inflammatory bowel diseases (Crohn's disease and ulcerative colitis), irritable bowel syndrome (IBS), coeliac disease, infectious bowel disease, and others. Diagnosis involves biopsy at colonoscopy and histopathological evaluation of the samples. Treatment consists of budesonide oral (the gold standard) or enema. Alternatives include bile acid sequestrants (cholestyramine, colesevelam, and colestipol), biologics (infliximab, adalimumab, and vedolizumab), thiopurines, methotrexate, and rarely, surgery.

Update on the Epidemiology and Management of Microscopic Colitis

Microscopic colitis is an inflammatory bowel disease that commonly presents with debilitating chronic watery diarrhea. Recent epidemiologic studies and randomized trials of therapeutics have improved the understanding of the disease. Medications, such as nonsteroidal anti-inflammatories, proton pump inhibitors, and antidepressants, have traditionally been considered as the main risk factors for microscopic colitis. However, recent studies have challenged this observation. Additionally, several epidemiologic studies have identified other risk factors for the disease including older age, female sex, smoking, alcohol use, immune-mediated diseases, and select gastrointestinal infections. The diagnosis of microscopic colitis requires histologic assessment of colon biopsies with findings including increased in intraepithelial lymphocytes with or without expansion of the subepithelial collagen band. The pathophysiology is poorly understood but is thought to be related to an aberrant immune response to the luminal microenvironment in genetically susceptible individuals. Antidiarrheal medications, such as loperamide or bismuth subsalicylate, may be sufficient in patients with mild symptoms. In patients with more severe symptoms, treatment with budesonide is recommended. Maintenance therapy is often necessary and several potential treatment strategies are available. Biologic and small molecule treatments seem to be effective in patients who have failed budesonide. There is an unmet need to further define the pathophysiology of microscopic colitis. Additionally, trials with novel therapies, particularly in patients with budesonide-refractory disease, are needed.

Effectiveness of Bile Acid Sequestrants in Microscopic Colitis and Utility of Bile Acid Testing: A Systematic Review and Meta-analysis

INTRODUCTION

Bile acid sequestrants (BAS) are an option for microscopic colitis (MC) refractory or intolerant to budesonide. There are inconsistent data on the prevalence of bile acid malabsorption (BAM) and utility of bile acid testing in MC. The aim of this systematic review and meta-analysis was to evaluate these outcomes.

METHODS

A systematic search of randomized control trials and observational studies of adults with MC treated with BAS was conducted using MEDLINE, Embase, Cochrane, and Scopus from inception to January 22, 2024. Data were extracted on (i) prevalence of BAM, (ii) clinical response and adverse events, and (iii) recurrence after BAS discontinuation. Data were pooled using random-effects models to determine weighted pooled estimates and 95% confidence intervals (CIs).

RESULTS

We included 23 studies (1 randomized control trial, 22 observational), with 1,011 patients with MC assessed for BAM and 771 treated with BAS. The pooled prevalence of BAM was 34% (95% CI 0.26-0.42, I2 = 81%). The pooled response rate with BAS induction for all patients with MC, irrespective of BAM, was 62% (95% CI 0.55-0.70, I2 = 71%). There was a higher pooled response rate in patients with BAM compared with those without BAM ( P < 0.0001). The pooled rate of BAS-related adverse effects was 9% (95% CI 0.05-0.14, I2 = 58%).

DISCUSSION

One-third of patients with MC had BAM, and almost two-thirds of all patients responded to BAS with limited side effects. Patients with MC and BAM were more likely to respond to therapy, supporting the value of bile acid testing.

Potential association between M694V homozygous mutation in familial Mediterranean fever and eosinophilic intestinal inflammation: a pediatric case series

Familial Mediterranean fever (FMF) is the most common hereditary systemic auto-inflammatory disease. Digestive complaint is a common feature during FMF attacks. Nevertheless, digestive complaint in attack-free period has scarcely been studied. This retrospective monocentric study aimed to describe the clinical, histological, and genetic features of pediatric patients with FMF who underwent endo-colonoscopy in this setting. Out of 115 patients with a diagnosis of FMF, 10 (8, 7%) underwent endoscopy or colonoscopy. All displayed homozygote MEFV M694V mutation and presented chronic abdominal pain, iron deficiency, and/or growth retardation. On the histological level, all patients displayed low-grade mucosal inflammation, characterized by a moderate eosinophilic infiltrate in the lamina propria sometimes associated with increased crypt apoptosis. The proportion of patients explored with endoscopy or colonoscopy was 0.4 patients per year in our center, compared with 5.7 patients per year nationwide. This study identified a specific intestinal phenotype that does not respond to the criteria of classical inflammatory bowel disease: pediatric FMF pediatric patients with homozygous MEFV M694V, abdominal pain, iron deficiency, and growth retardation should benefit from specialized gastroenterological advice.

Co-occurrence of collagenous gastrointestinal disease in siblings in early childhood: New insight into a rare condition

Collagenous gastrointestinal (GI) disease is a rare inflammatory condition characterized by subepithelial collagen deposition and inflammatory cell infiltrates of the GI mucosa, which typically occurs in the stomach in children. There are few published reports of more extensive involvement in children, and descriptions of familial involvement are rare, with no previous reported cases of affected siblings in early childhood. We describe two siblings with contrasting medical backgrounds, who were simultaneously diagnosed with collagenous GI disease in early childhood. Both children demonstrated gastric and colonic involvement on serial endoscopies, however, had distinct patterns of clinical presentation, disease course, and histological progression, providing new insights into the pediatric phenotype of collagenous GI disease and further, its relationship to microscopic colitis. Although rare, this condition should be considered as a differential in children presenting with severe or refractory iron deficiency anemia, chronic non-bloody watery diarrhea, or unexplained nonspecific chronic abdominal pain.

Budesonide Versus Mesalamine in Microscopic Colitis: A Comparative Meta-analysis of Randomized Controlled Trials

BACKGROUND

Microscopic colitis (MC) is an inflammatory bowel disease of autoimmune origin that causes chronic watery diarrhea. Medications, including budesonide, mesalamine, loperamide, cholestyramine, and bismuth subsalicylate, are first-line therapies. Meanwhile, azathioprine, 6-mercaptopurine, and methotrexate are indicated for refractory MC.

OBJECTIVE

We aim to assess the efficacy and safety of budesonide compared with mesalamine for induction of remission in MC patients.

METHODS

We searched the Cochrane Library, Scopus, Web of Science, and PubMed for relevant clinical trials comparing either mesalamine or budesonide with a control group. We included the following outcomes: clinical remission (3 or fewer stools/day), daily stool weight, daily stool frequency, number of patients with clinical response <50% in the disease activity, and daily stool consistency. Safety end points included: any adverse event, serious adverse events, any adverse event-related discontinuation, abdominal discomfort, constipation, flatulence, nausea, dizziness, headache, bronchitis, nasopharyngitis, and depression. We conducted a meta-analysis model using the generic inverse variance method and performed a subgroup analysis based on the intervention administered.

RESULTS

Nineteen randomized clinical trials were included. We found that after 6 weeks of follow-up, budesonide is associated with increased clinical remission rates compared with mesalamine [RR=2.46 (2.27, 2.67), and RR=2.24 (1.95, 2.57), respectively]. However, the test of subgroup difference revealed that the difference is not significant (P=0.25). After 8 weeks of follow-up, budesonide showed significantly higher clinical remission rates than mesalamine RR=2.29 (2.14, 2.45), and RR=1.7 (1.41, 2.05), respectively (P=0.003). Regarding the daily stool weight, patients in the budesonide group showed nonsignificant less stool weight [MD=-351.62 (-534.25, -168.99)] compared with mesalamine [MD=-104.3 (-372.34, 163.74)], P=0.14. However, daily stool frequency was significantly less in the budesonide group compared with mesalamine (P<0.001). Budesonide is associated with a significantly lower incidence of adverse events compared with mesalamine (P=0.002). Analysis of other safety endpoints was not significant between both groups.

CONCLUSIONS

Budesonide was found to be better than mesalamine in MC patients in terms of clinical remission rate, especially after 8 weeks of follow-up. Budesonide also showed less incidence of adverse events. There is an urgent need for randomized, double-blinded clinical trials to provide direct and reliable evidence.

Microscopic Colitis and Celiac Disease: Sharing More than a Diagnostic Overlap

Microscopic colitis (MC) is an emergent group of chronic inflammatory diseases of the colon, and celiac disease (CD) is a chronic gluten-induced immune-mediated enteropathy affecting the small bowel. We performed a narrative review to provide an overview regarding the relationship between both disorders, analyzing the most recent studies published at the epidemiological, clinical and pathophysiological levels. In fact, MC and CD are concomitantly prevalent in approximately 6% of the cases, mainly in the subset of refractory patients. Thus, physicians should screen refractory patients with CD against MC and vice versa. Both disorders share more than a simple epidemiological association, being multifactorial diseases involving innate and adaptive immune responses to known or unknown luminal factors based on a rather common genetic ground. Moreover, autoimmunity is a shared characteristic between the patients with MC and those with CD, with autoimmunity in the latter being quite well-established. Furthermore, CD and MC share some common clinical symptoms and risk factors and overlap with other gastrointestinal diseases, but some differences exist between both disorders. More studies are therefore needed to better understand the complex mechanisms involving the common pathogenetic ground contributing to the CD and MC epidemiological association.

Effectiveness and Safety Profile of Budesonide Maintenance in Microscopic Colitis: A Systematic Review and Meta-Analysis

BACKGROUND

Microscopic colitis (MC) is a common cause of chronic diarrhea. Randomized controlled trials (RCTs) have demonstrated the efficacy of budesonide treatment for MC. However, relapse is frequent after discontinuation of budesonide, and data on maintenance therapy are limited. We performed a systematic review and meta-analysis evaluating these outcomes in clinical trials and real-world settings.

METHODS

A systematic search was performed on October 31, 2022, of Medline, Embase, Cochrane, and Scopus. Case series, case-control, cohort studies, and RCTs of adults with MC were included. Data were pooled using random effects models to calculate weighted pooled estimates and 95% confidence intervals. Heterogeneity was assessed using the I2 statistic.

RESULTS

We included 35 studies (11 RCTs, 24 observational studies) with 1657 MC patients treated with budesonide induction and 146 for maintenance. The overall pooled clinical remission rate with budesonide treatment was similar between RCTs and observational studies. The pooled remission rate with budesonide maintenance therapy was 84% (95% CI, 0.60-1.00; I2 = 91%). After budesonide discontinuation, the pooled relapse rate was 53% (95% CI, 0.42-0.63; I2 = 76%). On maintenance therapy, no differences were noted in adverse events (eg, metabolic bone disease, hypertension, hyperglycemia, cataracts/glaucoma) in those on budesonide vs placebo or other noncorticosteroid medications for MC (P = .9).

CONCLUSIONS

Budesonide is an effective maintenance treatment for MC. There is a high risk of recurrence after budesonide discontinuation, but long-term use at the lowest effective dose appears to be relatively safe and have limited adverse effects.

A 1-year follow-up study on checkpoint inhibitor-induced colitis: results from a European consortium

BACKGROUND

Data regarding the clinical outcome of patients with immune checkpoint inhibitor (ICI)-induced colitis are scant. We aimed to describe the 12-month clinical outcome of patients with ICI-induced colitis.

MATERIALS AND METHODS

This was a retrospective, European, multicentre study. Endoscopy/histology-proven ICI-induced colitis patients were enrolled. The 12-month clinical remission rate, defined as a Common Terminology Criteria for Adverse Events diarrhoea grade of 0-1, and the correlates of 12-month remission were assessed.

RESULTS

Ninety-six patients [male:female ratio 1.5:1; median age 65 years, interquartile range (IQR) 55.5-71.5 years] were included. Lung cancer (41, 42.7%) and melanoma (30, 31.2%) were the most common cancers. ICI-related gastrointestinal symptoms occurred at a median time of 4 months (IQR 2-7 months). An inflammatory bowel disease (IBD)-like pattern was present in 74 patients (77.1%) [35 (47.3%) ulcerative colitis (UC)-like, 11 (14.9%) Crohn's disease (CD)-like, 28 (37.8%) IBD-like unclassified], while microscopic colitis was present in 19 patients (19.8%). As a first line, systemic steroids were the most prescribed drugs (65, 67.7%). The 12-month clinical remission rate was 47.7 per 100 person-years [95% confidence interval (CI) 33.5-67.8). ICI was discontinued due to colitis in 66 patients (79.5%). A CD-like pattern was associated with remission failure (hazard ratio 3.84, 95% CI 1.16-12.69). Having histopathological signs of microscopic colitis (P = 0.049) and microscopic versus UC-/CD-like colitis (P = 0.014) were associated with a better outcome. Discontinuing the ICI was not related to the 12-month remission (P = 0.483). Four patients (3.1%) died from ICI-induced colitis.

CONCLUSIONS

Patients with IBD-like colitis may need an early and more aggressive treatment. Future studies should focus on how to improve long-term clinical outcomes.

Lymphocytic colitis can be transcriptionally divided into channelopathic and inflammatory lymphocytic colitis

BACKGROUND

The pathobiology of the non-destructive inflammatory bowel disease (IBD) lymphocytic colitis (LC) is poorly understood. We aimed to define an LC-specific mucosal transcriptome to gain insight into LC pathology, identify unique genomic signatures, and uncover potentially druggable disease pathways.

METHODS

We performed bulk RNA-sequencing of LC and collagenous colitis (CC) colonic mucosa from patients with active disease, and healthy controls (n = 4-10 per cohort). Differential gene expression was analyzed by gene-set enrichment and deconvolution analyses to identify pathologically relevant pathways and cells, respectively, altered in LC. Key findings were validated using reverse transcription quantitative PCR and/or immunohistochemistry. Finally, we compared our data with a previous cohort of ulcerative colitis and Crohn's disease patients (n = 4 per group) to distinguish non-destructive from classic IBD.

RESULTS

LC can be subdivided into channelopathic LC, which is governed by organic acid and ion transport dysregulation, and inflammatory LC, which is driven by microbial immune responses. Inflammatory LC displays an innate and adaptive immunity that is limited compared to CC and classic IBD. Conversely, we noted a distinct induction of regulatory non-coding RNA species in inflammatory LC samples. Moreover, compared with CC, water channel and cell adhesion molecule gene expression decreased in channelopathic LC, whereas it was accentuated in inflammatory LC and associated with reduced intestinal epithelial cell proliferation.

CONCLUSIONS

We conclude that LC can be subdivided into channelopathic LC and inflammatory LC that could be pathomechanistically distinct subtypes despite their shared clinical presentation. Inflammatory LC exhibits a dampened immune response compared to CC and classic IBDs. Our results point to regulatory micro-RNAs as a potential disease-specific feature that may be amenable to therapeutic intervention.

Coeliac Disease and Microscopic Colitis: The Largest Study Assessing Prognosis and Risk of Hospital Admission

Microscopic colitis (MC) and coeliac disease (CD) are common associated gastrointestinal conditions. We present the largest study assessing hospitalisation in patients with MC and the effect of a concomitant diagnosis of CD. Data were retrospectively collected between January 2007 and December 2021 from all patients diagnosed with MC and compared to a database of patients with only CD. In total, 892 patients with MC (65% female, median age 65 years (IQR: 54-74 years) were identified, with 6.4% admitted to hospital due to a flare of MC. Patients admitted were older (76 vs. 65 years, p < 0.001) and presented with diarrhoea (87.7%), abdominal pain (26.3%), and acute kidney injury (17.5%). Treatment was given in 75.9% of patients, including intravenous fluids (39.5%), steroids (20.9%), and loperamide (16.3%). Concomitant CD was diagnosed in 3.3% of patients and diagnosed before MC (57 versus 64 years, p < 0.001). Patients with both conditions were diagnosed with CD later than patients with only CD (57 years versus 44 years, p < 0.001). In conclusion, older patients are at a higher risk of hospitalisation due to MC, and this is seen in patients with a concomitant diagnosis of CD too. Patients with MC are diagnosed with CD later than those without.

Celiac Disease-Related Conditions: Who to Test?

Celiac disease (CeD) is a chronic immune-mediated condition triggered by gluten consumption in genetically predisposed individuals. Approximately 1% of the general population is affected by the disorder. Disease presentation is heterogeneous and, despite growing awareness among physicians and the public, it continues to be underestimated. The most effective strategy for identifying undiagnosed CeD is proactive case finding through serologic testing in high-risk groups. We reviewed the most recent evidence on the association between CeD and more than 20 conditions. In light of this review, CeD screening is recommended in individuals with (1) autoimmune disease and accompanying symptoms suggestive of CeD; (2) diseases that may mimic CeD (eg, irritable bowel syndrome [IBS], inflammatory bowel disease [IBD], and microscopic colitis); and (3) among patients with conditions with a high CeD prevalence: first-degree relatives, idiopathic pancreatitis, unexplained liver enzyme abnormalities, autoimmune hepatitis, primary biliary cholangitis, hyposplenism or functional asplenia with severe bacterial infection, type 1 diabetes mellitus, Hashimoto's thyroiditis and Graves' disease, Sjögren's syndrome, dermatitis herpetiformis, recurrent aphthous syndrome and enamel defects, unexplained ataxia, peripheral neuropathy, delayed menarche or premature menopause, Down syndrome, Turner syndrome, Williams syndrome, chronic fatigue syndrome, IgA nephropathy, and IgA deficiency. CeD serology should be the initial step in the screening process. However, for patients with any of the aforementioned disorders who are undergoing upper endoscopy, biopsies should be performed to rule out CeD.

The Metabolomic Profile of Microscopic Colitis Is Affected by Smoking but Not Histopathological Diagnosis, Clinical Course, Symptoms, or Treatment

Microscopic colitis (MC) is classified as collagenous colitis (CC) and lymphocytic colitis (LC). Genetic associations between CC and human leucocyte antigens (HLAs) have been found, with smoking being a predisposing external factor. Smoking has a great impact on metabolomics. The aim of this explorative study was to analyze global metabolomics in MC and to examine whether the metabolomic profile differed regarding the type and course of MC, the presence of IBS-like symptoms, treatment, and smoking habits. Of the 240 identified women with MC aged ≤73 years, 131 completed the study questionnaire; the Rome III questionnaire; and the Visual Analog Scale for Irritable Bowel Syndrome (VAS-IBS). Blood samples were analyzed by ultra-high-performance liquid chromatograph mass spectrometry (UHLC-MS/UHPLC-MSMS). The women, 63.1 (58.7-67.2) years old, were categorized based on CC (n = 76) and LC (n = 55); one episode or refractory MC; IBS-like symptoms or not; use of corticosteroids or not; and smoking habits. The only metabolomic differences found in the univariate model after adjustment for false discovery rate (FDR) were between smokers and non-smokers. Serotonin was markedly increased in smokers (p < 0.001). No clear patterns appeared when conducting a principal component analysis (PCA). No differences in the metabolomic profile were found depending on the type or clinical course of the disease, neither in the whole MC group nor in the subgroup analysis of CC.

The association between drugs and repeated treatment with budesonide in patients with microscopic colitis: a retrospective observational study

Background

Smoking and the use of non-steroidal anti-inflammatory drugs (NSAIDs) acetylsalicylic acid (ASA), proton pump inhibitors (PPIs), serotonin reuptake inhibitors (SSRIs), and statins have been associated with microscopic colitis (MC).

Objectives

We investigated whether these factors were associated with repeated budesonide treatments in patients diagnosed with MC.

Design

Retrospective observational study.

Methods

All patients with a histologically verified diagnosis of MC at our clinic between the years 2006 and 2022 were identified. Baseline factors and drugs prescribed before and after diagnosis were registered. The influence of risk factors on the odds of having a prescription of oral budesonide and the odds of having a second course of budesonide was studied.

Results

Patients with MC (n = 183) with a mean age of 62.3 years [standard deviation (SD): 13.3 years] were followed for a median of 5 years (25th-75th percentile 4-10 years) after diagnosis. In all, 138 patients (75%) had at least one prescription of budesonide after diagnosis, and 90 patients (49%) had at least one clinical relapse treated with budesonide. Patients who had been prescribed NSAIDs within 1 year before clinical relapse had higher odds for clinical relapse [odds ratio (OR): 3.70, 95% confidence interval (CI): 1.06-12.9] but there was no increased risk for clinical relapse for the use of ASA (OR: 0.99, 95% CI: 0.39-2.90), PPIs (OR: 1.09, 95% CI: 0.45-2.63), SSRI (OR: 1.41, 95% CI: 0.82-2.44), or statins (OR: 0.83, 95% CI: 0.35-1.99). No association was seen between being a smoker and/or being prescribed NSAID, ASA, PPI, SSRI, and statins at baseline and the odds of having a prescription of oral budesonide within 1 year after diagnosis.

Conclusion

The risk of being prescribed a second course of budesonide is associated with receiving a prescription of NSAIDs but not with the use of ASA, PPIs, SSRIs, and statins.

Association of microscopic colitis and enteropathy due to olmesartan

We report the case of a patient with severe chronic diarrhea. He was admitted on multiple occasions for this reason, with the cause remaining undetected. After obtaining a detailed medical history and performing several studies, the patient was diagnosed with microscopic colitis and enteropathy due to Olmesartan. In the literature, both diseases appear concurrently only in a few cases. Here we highlight the importance of conducting a comprehensive medical history and maintaining high clinical suspicion to avoid delays in the diagnosis of these uncommon pathologies, as well as unnecessary tests and empirical treatments.

WARNING TO DELAY IN DIAGNOSING MICROSCOPIC COLITIS IN OLDER ADULTS. A SERIES OF CASES

BACKGROUND

Microscopic colitis (MC) is a chronic inflammatory bowel disease causing non-bloody diarrhea, and several cases are undiagnosed as a hidden cause of chronic diarrhea.

OBJECTIVE

We aimed to report the symptoms, delay diagnosis and the treatment of MC in a case series.

METHODS

All patients were treated at a Gastroenterology reference office from May 2022 to June 2023. Personal history including preexisting disorders, use of medications and smoking habits were collected. The delay between the onset of symptoms and the correct diagnosis was informed. All patients consented to use budesonide MMX (Corament®) off label.

RESULTS

During the study period, six Caucasoid patients were diagnosed with MC, five females and one male, between the ages of 65 and 74. All patients had comorbities and were taking multiple prescription drugs. Laboratory findings showed negative serology for celiac disease for all patients, normal levels of albumin and vitamin B12. The delay between the symptoms and the MC diagnosis varied from 2 months to 6 years. All patients had a previous diagnosis of irritable bowel syndrome. All patients were in complete clinical remission during the treatment and referred no side effects of the drug.

CONCLUSION

Older females using high-risk medications are suggestive of MC. Preventing delay in the diagnosis of MC is crucial to improvement in patients´ quality of life. Budesonide MMX appears to be effective, safe and well-tolerated.

Clinicopathologic Characterization of Lymphocytic Colitis in the Pediatric Population

BACKGROUND

Lymphocytic colitis (LC) in the pediatric population has been associated with immune dysregulation.

METHODS

Single-center retrospective study of pediatric LC.

RESULTS

50 patients (35 female, 70%) with a median age of 12 years at diagnosis (interquartile range: 5.7-15.8) of LC were identified. At presentation, 11 patients (22%) had malnutrition, 16 (32%) had a known underlying immune dysregulation, 4 (8%) had celiac disease (CD), and none had a diagnosis of inflammatory bowel disease. The most common medications prior to diagnosis were non-steroidal anti-inflammatory drugs, proton pump inhibitor, and selective serotonin reuptake inhibitors (10% each). Colonic biopsies showed a median number of intraepithelial lymphocytes (IELs)/100 epithelial cells of 48 (range: 25-85), and only 10% of cases had neutrophilic cryptitis. Upper gastrointestinal tract findings included lymphocytic esophagitis (4%), and duodenal IELs without and with villous blunting (9% each) (n: 47). Ten patients (23%) had increased IELs in the terminal ileum (n: 43). Treatments including 5-ASA, budesonide, prednisone, and gluten-free diet improved symptoms in <50% of patients (n: 42), and all follow-up colonoscopies showed persistent LC (n: 13).

CONCLUSION

Our study supports the association of LC with immune-mediated conditions, most commonly celiac disease. Symptomatic improvement was seen in <50% of patients with none of the patients with repeat colonoscopy showing histologic improvement.

Human Leukocyte Antigen Signatures as Pathophysiological Discriminants of Microscopic Colitis Subtypes

BACKGROUND AND AIMS

Microscopic colitis [MC] is currently regarded as an inflammatory bowel disease that manifests as two subtypes: collagenous colitis [CC] and lymphocytic colitis [LC]. Whether these represent a clinical continuum or distinct entities is, however, an open question. Genetic investigations may contribute important insight into their respective pathophysiologies.

METHODS

We conducted a genome-wide association study [GWAS] meta-analysis in 1498 CC, 373 LC patients, and 13 487 controls from Europe and the USA, combined with publicly available MC GWAS data from UK Biobank and FinnGen [2599 MC cases and 552 343 controls in total]. Human leukocyte antigen [HLA] alleles and polymorphic residues were imputed and tested for association, including conditional analyses for the identification of key causative variants and residues. Genetic correlations with other traits and diagnoses were also studied.

RESULTS

We detected strong HLA association with CC, and conditional analyses highlighted the DRB1*03:01 allele and its residues Y26, N77, and R74 as key to this association (best p = 1.4 × 10-23, odds ratio [OR] = 1.96). Nominally significant genetic correlations were detected between CC and pneumonia [rg = 0.77; p = 0.048] and oesophageal diseases [rg = 0.45, p = 0.023]. An additional locus was identified in MC GWAS analyses near the CLEC16A and RMI2 genes on chromosome 16 [rs35099084, p = 2.0 × 10-8, OR = 1.31]. No significant association was detected for LC.

CONCLUSION

Our results suggest CC and LC have distinct pathophysiological underpinnings, characterised by an HLA predisposing role only in CC. This challenges existing classifications, eventually calling for a re-evaluation of the utility of MC umbrella definitions.

Therapeutic Effects of Tretinoin and Caffeine-Treated Bone Marrow-Derived Mesenchymal Stem Cell on Immunological Features of Ulcerative Colitis: An Animal Model Study

Background

Ulcerative colitis (UC) is one of the inflammatory gastrointestinal diseases. It causes irritation, inflammation, and ulcers in the digestive tract. UC is distinguished clinically by abdominal and rectal pain and intestinal secretion abnormalities. Mesenchymal stem cell (MSC) therapy could be the underlying treatment for UC. This study aimed to compare the results of MSC therapy with tretinoin and caffeine in an animal model.

Materials and Methods

Sixty male BALB/c mice were randomly divided into six equal groups. Five groups were exposed to acetic acid-induced colitis, and one healthy negative control group was designed. The positive control group was UC-induced mouse model with no treatment. Besides, treatment groups were MSCs (n = 2×106) that received tretinoin and caffeine. The treatment group was given mesalazine orally. The decision to begin treatment was taken after monitoring the symptoms of the UC.

Results

MSCs, tretinoin, and caffeine-treated MSCs significantly decrease inflammatory cytokines (interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α) and inflammatory mediators (myeloperoxidase (MPO) and nitric oxide (NO)) compared with the positive control group. However, the alleviated effects of tretinoin-treated MSCs significantly were more than those of MSCs and caffeine-treated MSCs.

Conclusion

MSC therapy is an effective option for UC and can prevent disease progression. The results represented a high developmental rate and simple cell application of MSC therapy in UC patients. Also, MSC therapy's ability for immunomodulation is strengthened by drugs that improve their microenvironment by binding to their receptors.

Microscopic colitis found together with celiac disease in a female population is associated with one episode of lymphocytic colitis

BACKGROUND

Microscopic colitis (MC) is considered a chronic disease associated with autoimmune disease, smoking, and drugs. The aim was to examine the association between MC and celiac disease, adjusted for smoking, considering subtypes and clinical course of the disease in a retrospectively collected female cohort.

METHODS

Women (n = 240), ≤ 73 years, diagnosed as MC in medical records or pathological registers were invited. One hundred and fifty-eight women accepted to be included. Participants completed a study questionnaire about sociodemographic factors, lifestyle habits, and medical history; the Rome III questionnaire; and the visual analog scale for irritable bowel syndrome (VAS-IBS). Participants were categorized into collagenous colitis (CC) (n = 92) and lymphocytic colitis (LC) (n = 66) or MC with one episode of the disease (n = 70) and refractory MC (n = 88). Presence of IBS-like symptoms were noted. Blood samples were collected and analyzed for anti-transglutaminase antibodies. Differences between groups were calculated and logistic regression was adjusted for smoking habits.

RESULTS

MC and celiac disease debuted simultaneously in half of the cases. Celiac disease was most prevalent in LC (12.1% vs. 3.3%; p = 0.05) and MC with one episode (12.9% vs. 2.3%; p = 0.01). Anti-transglutaminase antibodies were found in one patient with one episode of MC. Corticosteroid use was most often found in CC (37.0% vs. 21.2%; p = 0.037) and refractory MC (38.6% vs. 20.0%; p = 0.015). Past smokers were most prevalent in patients with one episode of MC (54.3 vs. 29.5%; p = 0.007). Current smoking was the smoking habit with highest prevalence of IBS-like symptoms. When adjusted for smoking habits, celiac disease was associated with LC (OR: 4.222; 95% CI: 1.020-17.469; p = 0.047) and tended to be inversely associated with refractory MC (OR: 0.210; 95% CI: 0.042-1.506; p = 0.058).

CONCLUSION

Celiac disease is most common in patients with one episode of LC. The question remains whether LC in combination with celiac disease should be classified as celiac disease or two different entities.

Practice Implications of Colonoscopic Investigation of Microscopic Colitis in Patients Above 50 Years of Age Presenting With Chronic Diarrhoea: A Multi-Centre Review

Background Patients with an unknown cause for chronic diarrhoea will usually undergo a colonoscopy as part of the investigative work-up, and it is acceptable practice for the patients to undergo random biopsies. The optimum number of biopsies has yet to be established. This study investigated the implications of routine random biopsies for diagnosing microscopic colitis in patients 50 years and older who presented with chronic diarrhoea. Methodology A retrospective cohort study of a prospectively maintained internal hospital database across three tertiary teaching hospitals in Perth, Western Australia, on participants >50 years old who presented for an elective colonoscopy to investigate chronic diarrhoea between January 2016 and June 2019. Data was captured from medical records, imaging, colonoscopy, and histopathology reports, and patient follow-up was analysed using SPSS v.29 (IBM Corp., Armonk, NY). Results There were 216 patients, with the majority female (67%) and a mean age of 64.6 (SD±9.9). Microscopic colitis was identified in 7.4% (95% CI = 3.9-10.9%). Most positive biopsies (81.3%) were from the left colon. The median number of biopsies per case was seven (IQR=5). The median procedure duration and scope withdrawal time were 23 and eight minutes, respectively. Most of the procedures were done by a consultant (77%). Bowel was adequately prepped in 76.9% of the cases. Univariate analysis demonstrated that the rate of identification of microcolitis was associated with the number of biopsies taken; microcolitis positivity had a higher mean number of biopsies, 10.8 vs 6.7 (p<0.001). Key complications were a 30-day readmission rate, seven-day re-presentation with acute colitis, post-procedure bleeding, requiring further imaging or angioembolisation and increased length of stay on readmission. Conclusion The prevalence of positive biopsies for microcolitis is low (7.4%). Biopsies during colonoscopy are associated with clinically significant morbidity and health care costs. Most positive biopsies were attained from the left colon. It may be time to standardise practice in investigating microscopic colitis as a cause of chronic diarrhoea in patients > 50 years old.

Diagnosis and Pharmacological Management of Microscopic Colitis in Geriatric Care

Microscopic colitis, a diagnosis under the umbrella term of inflammatory bowel disease, is a prevalent cause of watery diarrhea, often with symptoms of urgency and bloating, typically observed in older adults aged ≥ 60 years. Its incidence has been reported to exceed those of ulcerative colitis and Crohn's disease in some geographical areas. Although nonpathognomonic endoscopic abnormalities, including changes of the vascular mucosal pattern; mucosal erythema; edema; nodularity; or mucosal defects, e.g., "cat scratches" have been reported, a colonoscopy is typically macroscopically normal. As reliable biomarkers are unavailable, colonoscopy using random biopsies from various parts of the colon is compulsory. Based on the histological examination under a microscope, the disease is divided into collagenous (with a thickened subepithelial collagenous band) and lymphocytic (with intraepithelial lymphocytosis) colitis, although incomplete forms exist. In routine clinical settings, the disease has a high risk of being misdiagnosed as irritable bowel syndrome or even overlooked. Therefore, healthcare providers should be familiar with clinical features and rational management strategies. A 6-8-week oral budesonide treatment course (9 mg/day) is considered the first-line therapy, but patients often experience relapse when discontinued, or might become intolerant, dependent, or even fail to respond. Consequently, other therapeutic options (e.g., bismuth subsalicylate, biologics, loperamide, bile acid sequestrants, and thiopurines) recommended by available guidelines may be prescribed. Herein, clinically meaningful data is provided based on the latest evidence that may aid in reaching a diagnosis and establishing rational therapy in geriatric care to control symptoms and enhance the quality of life for those affected.

Collagenous Colitis with Escitalopram Use: A Case Report and Literature Review

We present the case of a 42-year-old female whose escitalopram use potentially contributed to a diagnosis of collagenous colitis. The patient presented with significant watery, nonbloody diarrhea, abdominal cramping and pain, and weight loss. Established risk factors of microscopic colitis in this patient include a history of smoking and female gender. The patient underwent a colonoscopy, which confirmed histological changes consistent with collagenous colitis. Prescribed therapy included oral budesonide and omeprazole, continued for eight and twelve weeks, respectively. Escitalopram was continued, with a discussion regarding changing to an alternative therapy. Based on the patient's history of escitalopram use, this case suggests a relationship between escitalopram and microscopic colitis. Though case reports of patients diagnosed with microscopic colitis after antidepressant use are published, this case appears to be the only report of collagenous colitis without macroscopic complications following escitalopram use. This case adds further support in that antidepressants may contribute to microscopic colitis. Despite an undefined frequency of association, healthcare providers who prescribe antidepressants should be cognizant of the theorized association and understand risk factors, screening, and treatment approaches.

The colitis may be microscopic, but the diarrhea is not: update on the treatment of microscopic colitis and immune checkpoint inhibitor colitis

PURPOSE OF REVIEW

Microscopic colitis is an inflammatory disease of the colon that presents as watery diarrhea with minimal to normal endoscopic changes on colonoscopy. It encompasses two common subtypes, lymphocytic colitis and collagenous colitis, which are both treated similarly.Immune checkpoint inhibitor colitis is among the most common immune-related adverse events. Endoscopic and histological findings range from normal colonic mucosa to inflammatory bowel like changes. This review article provides update in treatment and management of microscopic colitis and immune checkpoint inhibitor colitis (ICPi colitis).

RECENT FINDINGS

Recent studies on microscopic colitis have focused on the successful use of immunomodulators such as biologics for treatment of budesonide refractory microscopic colitis cases. Microscopic colitis does not confer an added risk for colorectal cancer.With the increasing usage of immunotherapy agents, immune checkpoint inhibitor colitis is becoming more common. ICPi colitis can be successfully managed with steroids, with treatment stepped up to biologics for moderate to severe cases or for mild cases that do not respond to steroids. Immunotherapy agents can be carefully re-introduced in mild cases, after treatment of ICPi colitis.

SUMMARY

Biologics can be used to treat budesonide refractory microscopic colitis. ICPi colitis can be managed with steroids and biologics in moderate to severe cases.

[Clinical cases of microscopic colitis: Diagnosis and treatment issues. Case report]

Currently, there is an increase in the incidence of microscopic colitis. There are difficulties in diagnosing this disease due to the variability of histological signs, variability of morphological changes in the mucous membrane of the colon in different parts of the colon, and the combination in one patient of not only various forms of microscopic colitis, but also other intestinal diseases. The article describes the differential diagnosis, an example of its staging and successful treatment of various forms of microscopic colitis with budesonide (two clinical cases presented).

Follow-Up of Microscopic Colitis Patients and Diarrhea Controls at 1 Year

BACKGROUND AND AIMS

Microscopic colitis (MC) is a common cause of chronic diarrhea; however, the clinical course of this disease is poorly understood. We aimed to investigate how patients diagnosed with MC were treated in routine clinical practice and how their symptoms compared to patients with other causes of chronic diarrhea at one year follow-up.

METHODS

We conducted a case-control study of patients undergoing outpatient colonoscopy to evaluate diarrhea. The study pathologist determined whether patients were classified as MC cases or non-MC controls. One year after colonoscopy, we interviewed cases (n = 74) and controls (n = 162) about their diagnosis, medications for diarrhea, and symptom burden.

RESULTS

At 1-year follow-up after colonoscopy, 10% of MC cases were unaware of the diagnosis, 60% had been prescribed a medication for diarrhea, 40% had fecal urgency, 32% had weight loss, and 21% had fecal incontinence. Among cases, 46% were treated with budesonide. Compared to cases, controls had worse symptoms based on the Microscopic Colitis Disease Activity Index score with a median score of 3.0 (interquartile range 1.9-4.2) vs 2.3 (interquartile range 1.4-3.2) at 1-year follow-up. Controls had more frequent stools, urgency, fecal incontinence, and abdominal pain.

CONCLUSION

In a cohort of patients with biopsy-confirmed MC and diarrhea controls, we found that some cases remained unaware of their diagnosis, many cases had persistent symptoms, and controls had worse symptoms than cases. These findings suggest there are opportunities to improve management of this chronic disease.

Patients With Microscopic Colitis Are at Higher Risk of Major Adverse Cardiovascular Events: A Matched Cohort Study

BACKGROUND AND AIMS

Inflammatory diseases are associated with an increased risk of incident major adverse cardiovascular events (MACE). However, data on MACE are lacking in large population-based histopathology cohorts of microscopic colitis (MC).

METHODS

This study included all Swedish adults with MC without previous cardiovascular disease (1990-2017; N = 11,018). MC and subtypes (collagenous colitis and lymphocytic colitis) were defined from prospectively recorded intestinal histopathology reports from all pathology departments (n = 28) in Sweden. MC patients were matched for age, sex, calendar year, and county with up to 5 reference individuals (N = 48,371) without MC or cardiovascular disease. Sensitivity analyses included full sibling comparisons, and adjustment for cardiovascular medication and healthcare utilization. Multivariable-adjusted hazard ratios for MACE (any of ischemic heart disease, congestive heart failure, stroke, and cardiovascular mortality) were calculated using Cox proportional hazards modelling.

RESULTS

Over a median of 6.6 years of follow-up, 2181 (19.8%) incident cases of MACE were confirmed in MC patients and 6661 (13.8%) in reference individuals. MC patients had a higher overall risk of MACE outcomes compared with reference individuals (adjusted hazard ratio [aHR], 1.27; 95% confidence interval [CI], 1.21-1.33) and higher risk of its components: ischemic heart disease (aHR, 1.38; 95% CI, 1.28-1.48), congestive heart failure (aHR, 1.32; 95% CI, 1.22-1.43), and stroke (aHR, 1.12; 95% CI, 1.02-1.23) but not cardiovascular mortality (aHR, 1.07; 95% CI, 0.98-1.18). The results remained robust in the sensitivity analyses.

CONCLUSIONS

Compared with reference individuals, MC patients had a 27% higher risk of incident MACE, equal to 1 extra case of MACE for every 13 MC patients followed for 10 years.

Bile Acid Sequestrants in Microscopic Colitis: Clinical Outcomes and Utility of Bile Acid Testing

BACKGROUND & AIMS

Bile acid sequestrants (BAS) may be a treatment in microscopic colitis (MC), but efficacy data are limited. We evaluated the effectiveness of BAS in MC and assessed the utility of bile acid testing to predict response.

METHODS

Adults with MC treated with BAS (2010-2020) at Mayo Clinic were identified. Bile acid malabsorption was defined by elevated serum 7⍺-hydroxy-4-cholesten-3-one or by fecal testing using previously validated cutoffs. Response was defined at 12 ± 4 weeks after BAS initiation as: complete (resolution of diarrhea), partial (≥50% improvement in diarrhea), nonresponse (<50% improvement), and intolerance (discontinuation due to side effects). Logistic regression was used to identify predictors of response to BAS.

RESULTS

We identified 282 patients (median age, 59 years [range, 20-87 years]; 88.3% women) with median follow-up of 4.5 years (range, 0.4-9.1 years). Patients were treated with the following BAS: 64.9% cholestyramine, 21.6% colesevelam, and 13.5% colestipol. Clinical outcomes were: 49.3% complete response, 16.3% partial response, 24.8% nonresponse, and 9.6% intolerance. There were no differences in outcomes between those on BAS alone or BAS combined with other medications (P = .98). The dose of BAS was not associated with response (P = .51). Bile acid testing was done in 31.9% of patients, and 56.7% were positive. No predictors of response to BAS were identified. After BAS discontinuation, 41.6% had recurrence at a median of 21 weeks (range, 1-172 weeks).

CONCLUSION

In one of the largest cohorts evaluating BAS treatment in MC, nearly two-thirds had a partial or complete response. Additional research is needed to determine the role of BAS and bile acid malabsorption in MC.

Microscopic Colitis: A Review Article

Microscopic colitis (MC) is a chronic inflammatory disease that affects the older population. Its clinical presentation includes a variety of gastrointestinal manifestations. The main symptom is chronic watery, nonbloody diarrhea. The disease has a female predominance. The diagnosis might be challenging since the symptoms are similar to other differential diagnoses, such as celiac disease, irritable bowel syndrome, Crohn's disease, bacterial overgrowth, and infectious colitis. The golden diagnostic tool for diagnosis is performing colonoscopy to obtain the colonic biopsy, which demonstrates the characteristic histological evidence needed for diagnosis. The treatment starts with an accurate diagnosis and trial of any possible offending medications. Alternatively, there are many medications, such as bismuth or budesonide, which are very effective in treating this disease. The primary objective of this detailed review is to enhance knowledge and understanding of this condition among healthcare providers to guide them with detailed information regarding epidemiology, clinical presentation, diagnosis, and appropriate management. In the assessment of individuals presenting with persistent chronic diarrhea, it is essential for healthcare providers to consider MC as a probable differential diagnosis.

Misinterpreting Diarrhea-Predominant Irritable Bowel Syndrome and Functional Diarrhea: Pathophysiological Highlights

Irritable bowel syndrome with predominant diarrhea (IBS-D) and functional diarrhea (FD) are disorders of gut-brain interaction characterized by recurring symptoms which have a serious impact on the patient's quality of life. Their pathophysiology is far from being completely understood. In IBS-D growing evidence suggests that bile acid malabsorption (BAM) could be present in up to 30% of patients. Microscopic colitis (MC) is a well-known cause of watery diarrhea and some patients, at first, can be diagnosed as IBS-D or FD. Both BAM and MC are often responsible for the lack of response to conventional treatments in patients labelled as "refractory". Moreover, because BAM and MC are not mutually exclusive, and can be found in the same patient, they should always be considered in the diagnostic workout when a specific treatment for BAM or MC is unsatisfactory. In the present review the possible shared pathogenetic mechanisms between BAM and MC are discussed highlighting how MC can induce a secondary BAM. Moreover, a brief overview of the current literature regarding the prevalence of their association is provided.

Colon perforation due to collagenous colitis: A case report

Collagenous colitis (CC) is generally benign, and serious complications are rare. It is important to note that spontaneous perforation of CC is a possible complication. In the case of colon perforation of unknown origin, CC should be considered.

Complementary and alternative medicine mention and recommendations in inflammatory bowel disease guidelines: systematic review and assessment using AGREE II

BACKGROUND

Many patients with inflammatory bowel disease (IBD) use complementary and alternative medicine (CAM) for disease management. There is, however, a communication gap between patients and healthcare professionals regarding CAM use, where patients are hesitant to disclose CAM use to providers. The purpose of this study was to identify the quantity and assess the quality of CAM recommendations in IBD clinical practice guidelines (CPGs) using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument.

METHODS

MEDLINE, EMBASE, and CINAHL were systematically searched from 2011 to 2022 to find CPGs for the treatment and/or management of IBD. The Guidelines International Network (GIN) and National Center for Complementary and Integrative Health (NCCIH) websites were also searched. Eligible CPGs were assessed using the AGREE II instrument.

RESULTS

Nineteen CPGs made CAM recommendations for IBD and were included in this review. Average scaled domain percentages of CPGs were as follows (overall CPG, CAM section): scope and purpose (91.5%, 91.5%), clarity of presentation (90.3%, 64.0%), editorial independence (57.0%, 57.0%), stakeholder involvement (56.7%, 27.8%), rigour of development (54.7%, 45.9%), and applicability (14.6%, 2.1%).

CONCLUSIONS

The majority of CPGs with CAM recommendations were of low quality and their CAM sections scored substantially lower relative to other therapies in the overall CPG. In future updates, CPGs with low scaled-domain percentages could be improved in accordance with AGREE II and other guideline development resources. Further research investigating how CAM therapies can best be incorporated into IBD CPGs is warranted.

Microscopic Colitis: Pathogenesis and Diagnosis

Microscopic colitis is a type of inflammatory bowel disease and is classified as either collagenous colitis or lymphocytic colitis. The typical presentation is chronic watery diarrhea. The disease occurs more frequently in women aged 60-65 years and is increasing in incidence. The pathophysiology of microscopic colitis remains poorly understood and has not been well-described with possible several pathogeneses. To date, the diagnosis of microscopic colitis depends on histological tissue obtained during colonoscopy. Other non-invasive biomarkers, such as inflammatory markers and fecal biomarkers, have been studied in microscopic colitis, but the results remains inconclusive. The approach to chronic diarrhea is important and being able to differentiate chronic diarrhea in patients with microscopic colitis from other diseases, such as inflammatory bowel disease, functional diarrhea, and malignancy, by using non-invasive biomarkers would facilitate patient management. The management of microscopic colitis should be based on each individual's underlying pathogenesis and involves budesonide, bile acid sequestrants, or immunosuppressive drugs in refractory cases. Cigarette smoking and certain medications, especially proton pump inhibitors, should be eliminated, when possible, after the diagnosis is made.

What do we know today about drug-induced microscopic colitis? A case of lymphocytic colitis on olmesartan

Microscopic colitis is part of the differential diagnosis of chronic watery diarrhea. Colonoscopy discloses a normal looking mucosa, therefore its diagnosis is based on histology of colonic biopsies. Two main phenotypes are distinguished: collagenous colitis and lymphocytic colitis. A third entity, incomplete microscopic colitis or unspecified microscopic colitis has been reported in the literature. It affects preferentially women over 60 years of age and its association with certain drugs is increasingly established. In case of suspected drug-induced microscopic colitis, identification of the responsible drug is a key to management. After discontinuation of the suspected drug, the gold standard of treatment is budesonide both for induction and for maintenance in case of clinical relapse, as is often the case after discontinuation. Therapy with immunomodulators, biologics, or surgery is reserved for refractory forms of microscopic colitis after multidisciplinary consultation. Through the clinical case of colitis on olmesartan, we will review the latest recommendations on drug-induced microscopic colitis.

Effectiveness of Non-Budesonide Therapies in Management of Microscopic Colitis: A Systematic Review and Meta-analysis

BACKGROUND

Budesonide is accepted as first-choice therapy for microscopic colitis (MC); however, symptoms often recur and some patients may be dependent, intolerant, or even fail budesonide. We performed a systematic review and meta-analysis to determine the effectiveness of non-budesonide therapies (thiopurines, bismuth subsalicylate [BSS], bile acid sequestrants [BAS], loperamide and biologics) for MC suggested by international guidelines.

METHODS

We searched the CENTRAL, MEDLINE, and EMBASE databases from their inception to 18 April 2023 for the above-mentioned therapeutics in MC. We pooled the response and remission rates by medication using a random-effects model.

RESULTS

Twenty-five studies comprising 1475 patients were included in the meta-analysis. Treatment with BSS showed the highest response rate of 75% (95% confidence interval [CI] 0.65-0.83; I² = 70.12%), with 50% achieving remission of symptoms (95% CI 0.35-0.65; I² = 71.06%). Treatment with tumor necrosis factor (TNF) inhibitors (infliximab and adalimumab) demonstrated a response rate of 73% (95% CI 0.63-0.83; I² = 0.00%), with a remission rate of 44% (95% CI 0.32-0.56; I² = 0.00%). The response rate for those treated with vedolizumab was similar; 73% responded to treatment (95% CI 0.57-0.87; I² = 35.93%), with a remission rate of 56% (95% CI 0.36-0.75; I² = 46.30%). Loperamide was associated with response and remission rates of 62% (95% CI 0.43-0.80; I² = 92.99%) and 14% (95% CI 0.07-0.25), respectively, whereas BAS use was associated with response and remission rates of 60% (95% CI 0.51-0.68; I² = 61.65%) and 29% (95% CI 0.12-0.55), respectively. Finally, the outcomes for thiopurine use were 49% (95% CI 0.27-0.71; I² = 81.45%) and 38% (95% CI 0.23-0.54; I² = 50.05%), respectively DISCUSSION: The present systematic review and meta-analysis provides rates of effectiveness of non-budesonide therapies for MC based on available data in the field. Studies in the meta-analysis showed a large amount of heterogeneity due to the variability in assessing the clinical effects of intervention between the studies caused by differences in the definitions of response or remission rates between the studies included. This may likely result in overestimating the benefit of a treatment. Furthermore, the number of participants and drug dosages varied, and only a few studies applied disease-specific activity indices. Only one randomized controlled trial (RCT) was identified. All other 24 included studies were either case series or (retrospective) cohort studies, which complicated efforts to perform further sensitivity analyses to adjust for potential confounders and risk of bias. In addition, the overall evidence on the effect of these treatment options was judged as low, mostly due to comparability bias and the observational nature of the available studies, which limited statistically robust comparisons of rates of effectiveness of the different non-budesonide agents ranked against each other. However, our observational findings may inform clinicians regarding the most rational selection of non-budesonide therapies to patients with MC.

CLINICAL TRIALS REGISTRATION

PROSPERO protocol #CRD42020218649.

Microscopic colitis is a risk factor for low bone density: a systematic review and meta-analysis

Background

Microscopic colitis (MC) is a chronic inflammatory disease of the large bowel characterized by watery diarrhea, substantially decreasing the patient's quality of life. Scarce data suggest that MC is associated with low bone density (LBD).

Objectives

We aimed to assess whether MC is a risk factor for LBD and the proportion of patients with MC having LBD.

Design

A systematic review and meta-analysis of studies reporting bone density measurements in MC patients.

Data Sources and Methods

We systematically searched five databases from inception to October 16, 2021 (Pubmed, Embase, Cochrane, Scopus, and Web of Science). We used the random-effect model to calculate pooled odds ratios (ORs) and pooled event rates with 95% confidence intervals (CIs). To ascertain the quality of evidence of our outcomes, we followed the recommendations of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group.

Results

The systematic search yielded a total of 3046 articles. Four articles were eligible for quantitative synthesis. All of them used age- and sex-matched controls to evaluate LBD occurrence among patients with MC. The odds of having LBD were twofold increased (OR = 2.13, CI: 1.42-3.20) in the presence of MC, the odds of osteopenia occurrence were 2.4 (OR = 2.45, CI: 1.11-5.41), and of osteoporosis 1.4 (OR = 1.42, CI: 0.65-3.12). The proportion of LBD was 0.68 (CI: 0.56-0.78), osteopenia was 0.51 (CI: 0.43-0.58), and osteoporosis was 0.11 (CI: 0.07-0.16) among the MC population. Our findings' certainty of the evidence was very low following the GRADEPro guideline.

Conclusion

Our data demonstrate that MC is associated with a twofold risk for LBD. Based on our findings, we suggest screening patients for bone mineral density upon diagnosis of MC. Further prospective studies with higher patient numbers and longer follow-up periods on this topic are needed.

Registration

Our protocol was prospectively registered with PROSPERO (CRD42021283392).

Fecal calprotectin level in microscopic colitis: a systematic review and meta-analysis

Background

There are no specific biomarkers for microscopic colitis (MC), and the diagnosis depends on histopathological tissue obtained during colonoscopy. Studies on the role of fecal calprotectin (FCP) in MC are limited. A literature search of PubMed, Embase, and Scopus was conducted from each database's inception through September 2022.

Methods

A DerSimonian-Liard random-effects meta-analysis was performed to examine the standardized mean difference (SMD) in FCP levels between patients with MC and control patients with chronic diarrhea.

Results

Six studies with 96 active MC patients and 200 controls were included in the meta-analysis. Random effects meta-analysis revealed that FCP was significantly and moderately elevated in patients with MC compared to the control group (SMD = 0.6 [95% CI 0.3, 1.0], P = 0.001). Imputing one effect size confirmed the observation that FCP is significantly higher in patients with MC than control subjects with chronic diarrhea (SMD = 0.5 [95% CI 0.2, 0.9], P = 0.004). Study heterogeneity between the SMDs was not significant (I2 = 41%, P = 0.1).

Conclusion

These results indicate that FCP levels in patients with chronic diarrhea can help identify patients with MC. More studies with serial measurements of FCP would provide a better understanding of its utility in MC.

Dietary Calcium and Risk of Microscopic Colitis

BACKGROUND

Microscopic colitis (MC) is an increasingly common cause of watery diarrhea particularly in older individuals. The role of diet in MC has received little study.

METHODS

We conducted a case-control study at a single institution enrolling patients referred for elective outpatient colonoscopy for diarrhea. Patients were classified as cases with MC or non-MC controls after a review of colon biopsies by 1 research pathologist. Study subjects were interviewed by a trained telephone interviewer using a validated food frequency questionnaire. Adherent microbes were evaluated from colonic biopsies using 16s rRNA sequencing.

RESULTS

The study population included 106 cases with MC and 215 controls. Compared with controls, the cases were older, better educated, and more likely to be female. Cases with MC had lower body mass index and were more likely to have lost weight. Subjects in the highest quartile of dietary calcium intake had a lower risk of MC compared with those in the lowest quartile (adjusted odds ratio 0.22, 95% confidence interval 0.07-0.76). The findings were not explained by dairy intake, body mass index, or weight loss. We found that dietary calcium intake had significant associations with the abundance of Actinobacteria and Coriobacteriales in the microbial community of colonic biopsies.

DISCUSSION

Compared with patients with diarrhea, cases with MC had a lower intake of dietary calcium. Diet can be associated with alterations in the gut microbiota and with luminal factors that could affect the risk of MC.

The Role of Genetic and Epigenetic Regulation in Intestinal Fibrosis in Inflammatory Bowel Disease: A Descending Process or a Programmed Consequence?

Inflammatory bowel diseases (IBDs) are a group of chronic diseases characterized by recurring periods of exacerbation and remission. Fibrosis of the intestine is one of the most common complications of IBD. Based on current analyses, it is evident that genetic factors and mechanisms, as well as epigenetic factors, play a role in the induction and progression of intestinal fibrosis in IBD. Key genetic factors and mechanisms that appear to be significant include NOD2, TGF-β, TLRs, Il23R, and ATG16L1. Deoxyribonucleic acid (DNA) methylation, histone modification, and ribonucleic acid (RNA) interference are the primary epigenetic mechanisms. Genetic and epigenetic mechanisms, which seem to be important in the pathophysiology and progression of IBD, may potentially be used in targeted therapy in the future. Therefore, the aim of this study was to gather and discuss selected mechanisms and genetic factors, as well as epigenetic factors.

Predominant Antibody Deficiency and Risk of Microscopic Colitis: a Nationwide Case-Control Study in Sweden

PURPOSE : Predominant antibody deficiency (PAD) disorders, including common variable immunodeficiency (CVID), have been linked to increased risk of gastrointestinal infections and inflammatory bowel diseases. However, there are limited data on the relationship between PAD, specifically CVID, and risk of microscopic colitis (MC).

METHODS

We performed a nationwide case-control study of Swedish adults with MC diagnosed between 1997 and 2017 (n = 13,651). Data on biopsy-verified MC were retrieved from all of Sweden's pathology departments through the Epidemiology Strengthened by histoPathology Reports in Sweden (ESPRESSO) study. We defined predominant antibody deficiency using International Union of Immunologic Societies (IUIS) phenotypic classification. Individuals with MC were matched to population controls by age, sex, calendar year, and county. We used logistic regression to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

The prevalence of PAD in MC was 0.4% as compared to 0.05% in controls. After adjustment for potential confounders, this corresponded to an aOR of 7.29 (95%CI 4.64-11.63). The magnitude of the association was higher for CVID (aOR 21.01, 95% 5.48-137.44) compared to other antibody deficiencies (aOR 6.16, 95% CI 3.79-10.14). In exploratory analyses, the association between PAD and MC was particularly strong among males (aOR 31.73, 95% CI 10.82-135.04).

CONCLUSION

In this population-based study, predominant antibody deficiency was associated with increased risk of MC, particularly among males. Clinicians who encounter these patients should consider a detailed infectious history and screening for antibody deficiency.