Diagnosis and Management of Microscopic Colitis

Efficacy and Safety of Vedolizumab and Tumor Necrosis Factor Inhibitors in the Treatment of Steroid-refractory Microscopic Colitis: A Systematic Review and Meta-analysis

BACKGROUND

Tumor necrosis factor (TNF-α) inhibitors and the α4β7 integrin antagonist, vedolizumab, have been investigated as treatment options for patients with steroid-refractory microscopic colitis.

AIMS

To evaluate the benefit of vedolizumab and TNF-α inhibitors in patients with steroid-refractory microscopic colitis.

METHODS

Retrospective studies and case series involving patients with steroid-refractory MC who either received vedolizumab, adalimumab, or infliximab were eligible for inclusion. Pooled proportional meta-analyses were used to calculate the rate of clinical remission at induction, clinical response, maintenance of remission, histologic remission, and overall medication related adverse effects. Statistical analysis was performed in R using the metafor and meta packages.

RESULTS

A total of 14 studies involving 164 patients were included. Pooled analysis showed a clinical remission rate of 63.5% [95% CI (0.483; 0.776), I 2 =43% P =0.08], 57.8% [95% CI (0.3895; 0.7571), I 2 =0%, P =0.7541], and 39.3% [95% CI (0.0814; 0.7492), I 2 =66%, P =0.02] for vedolizumab, infliximab, and adalimumab, respectively. The maintenance of remission rates were 65.9% [95% CI (0.389; 0.889), I 2 =67%, P =0.02], 45.3% [95% CI (0.1479; 0.7747), I 2 =0%, P =0.36] and 32.5% [95% CI (0.000; 0.8508), I 2 =53%, P =0.14] in patients who received vedolizumab, infliximab, and adalimumab, respectively. Rate of biological-related adverse events warranting discontinuation of therapy was 12.2%, 32.9%, and 23.0% for the vedolizumab, infliximab, and adalimumab groups, respectively.

CONCLUSION

Vedolizumab and anti-TNF-α agents demonstrated a clinical benefit in the treatment of steroid-refractory microscopic colitis and with a tolerable safety profile. Future randomized controlled trials are needed to compare vedolizumab with TNF-α inhibitors and examine treatment effect on patients' quality of life.

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.

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.

Evaluation of colitis induced by immune-checkpoint inhibitors therapy in melanoma patients by an overall grading scale

BACKGROUND

Colitis was the third most common immune-related adverse effect in melanoma patients treated with immune-checkpoint inhibitor (ICI). With the limitation of real-world data in the UK population, this study was conducted in a UK hospital where a fresh colitis guidance was introduced to evaluate the overall grading (OG) to assess colitis severity and guide the treatment.

AIMS

This study aimed to investigate colitis severity by Common Terminology Criteria for Adverse Events (CTCAE) grade and overall grade at time of presentation. Colitis treatment and outcome were evaluated to compare the impact of these two categories.

METHODS

A single-center, retrospective observational study was performed in melanoma patient developing colitis symptoms.

RESULTS

A total of 44 advanced melanoma patient with colitis symptoms were included. Median time to colitis onset was 67 days (range 4-890). Majority of patients developed G1/ G2 of CTCAE scale (70.4%) but moderate or severe overall grade (84.1%). There were 65.9% of patients treated with steroids, and 38.2% with infliximab and 4.5% with vedolizumab. The median time of colitis resolution was 28 days (range 0-282). Both treatment modality and time to resolution were associated with severity of colitis assessed by complete OG(p<0.0001) rather than CTCAE grading (p>0.05).

CONCLUSIONS

This study provided a comprehensive description about ICI-induced colitis management in a single center of the UK. The more completed OG was proposed to stratify colitis patient and guide the investigation and treatment decision at presenting time, replacing the old CTCAE grading.

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.

A Literature Review of Microscopic Colitis

Although the clinical importance of microscopic colitis (MC) is highly increasing, however, the disease is still mysterious due to several challenges. Recent MC data depend mainly on doubts and uncertainties leading to misclassification. This review discussed the current knowledge gaps about MC and various controversies regarding its subtypes, pathogenesis, and management. The diagnosis of MC is based mainly on histology and immunohistopathology which can discriminate two subtypes. However, transitional forms are often associated with misclassification. The site and number of the colon biopsies have been agreed upon as at least three from each side of the colon (right and left) with a total of six. There is no credible, clear explanation for the increased incidence. The etiopathogenesis is possibly multifactorial with a high impact on the immunological background. It is proposed that MC would be the initiative of irritable bowel disease, which needs further data clarification. Although budesonide is an effective treatment in most cases, budesonide-refractory MC represents a significant clinical challenge. Therefore, immunomodulators and biologics are now well-thought to be the second-line choice for treatment.

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.

Trans-Anethole Alleviates DSS-Induced Ulcerative Colitis by Remodeling the Intestinal Flora to Regulate Immunity and Bile Acid Metabolism

Ulcerative colitis (UC) is the most common inflammatory bowel disease (IBD); it is incurable, and the treatment is expensive. Trans-anethole (TA), the main component of fennel, exhibits various biological activities. An increasing number of studies have demonstrated the efficacy of herbal active ingredients in the treatment of UC. This study aimed to investigate the effect and mechanism of TA in UC. In this study, we have experimented on mice with dextran sulfate sodium salt (DSS)-induced UC. The TA group was gavaged with 62.5 mg/kg TA by gavage once daily on days 8-14. To observe the effect of TA on the colon tissue, various investigations were performed, including western blot and immunohistochemistry for intestinal barrier protein expression, TUNEL staining for apoptosis, western blot, and ELISA for inflammation level, flow cytometry for Th17/Treg, LC-MS for blood bile acid content, GC-MS for blood fatty acid content, and 16s RNA for intestinal contents. TA alleviated weight loss in mice with UC; increased colon length; alleviated intestinal mucosal damage; upregulated claudin-1, occludin, and ZO-1 protein expression levels; reduced inflammatory factors in the colon and serum; and alleviated apoptosis. TA reduced fatty acid and bile acid levels by inhibiting colony abundance and reducing Th17/Treg cell differentiation in the colon. We found that TA alleviates DSS-induced UC by remodeling the intestinal flora to regulate immunity and bile acid metabolism.

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.

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.

Reduced Intake of Dietary Tryptophan Improves Beneficial Action of Budesonide in Patients with Lymphocytic Colitis and Mood Disorders

Lymphocytic colitis (LC) is a gastrointestinal (GI) tract disease with poorly known pathogenesis, but some environmental and lifestyle factors, including certain dietary components, may play a role. Tryptophan is an essential amino acid, which plays important structural and functional roles as a component of many proteins. It is important in the development and maintenance of the body, in which it is metabolized in two main pathways: kynurenine (KYN) and serotonin. In this work, we explored the effect of reducing of TRP in the diet of patients with LC with mood disorders. We enrolled 40 LC patients who had a normal diet, 40 LC patients with the 8-week diet with TRP content reduced by 25% and 40 controls. All LC patients received budesonide at 9 mg per day, and the severity of their GI symptoms was evaluated by the Gastrointestinal Symptoms Rating Scale. Mood disorders were evaluated by the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D). The concentration of TRP and its metabolites, 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN), kynurenic acid (KYNA) and quinolinic acid (QA), in urine were determined. Budesonide improved the GI and mental states of LC patients, and the diet with reduced TRP content further amended these symptoms. Dietary intervention decreased the concentration of 5-HIAA by about 50% (3.4 vs. 6.3) and QA by about 45% (3.97 vs. 7.20). These changes were correlated with a significant improvement in the profitable action of budesonide on gastrointestinal and mental health of LC patients as they displayed significantly lower GSRS, HAM-A and HAM-B scores after than before the intervention—10.5 vs. 32, 11.0 vs. 21 and 12 vs. 18, respectively. In conclusion, a reduction in TRP intake in diet may improve GI and mental symptoms in LC patients treated with budesonide and these changes may be mediated by the products of TRP metabolism.

The natural history of histological changes in microscopic colitis

Background

Microscopic colitis (MC) causes chronic diarrhea. It has two histologic subtypes: lymphocytic colitis (LC) and collagenous colitis (CC). Little is known about the natural progression of disease with time and with treatment.

Objectives

We aimed to assess histological changes over time.

Design

We designed a retrospective study including adults diagnosed with MC from January 1992 to January 2020 at Mayo Clinic.

Methods

Pathology reports were reviewed until 31 October 2020. Histological assessments at least 8 weeks apart were considered as adequate follow-up. Histological change from one subtype to the other and resolution were tracked with univariate and multivariable Cox proportional hazards models.

Results

Overall, 416 patients with a median age at diagnosis of 63.9 years with >1 histopathological assessment were identified. Histology at initial diagnosis was CC in 218 (52.4%) patients and LC in 198 (47.6%). No medications were associated with a histological change. However, histological resolution was more likely with the use of aspirin [hazard ratio (HR): 2.10, 95% confidence interval (CI): 1.34-3.31, p = 0.001) and proton-pump inhibitors (PPIs; HR: 2.01, 95% CI: 1.34-3.02, p = 0.001). Histological resolution was more likely with budesonide treatment (HR: 1.86, 95% CI: 1.16-3.00, p = 0.010) and less likely with mesalamine (HR: 0.40, 95% CI: 0.19-0.83, p = 0.014), compared to medications such as prednisone, loperamide, and bismuth. Patients with CC were less likely to change their histology compared to patients with LC (HR: 0.24, 95% CI: 0.14-0.42, p < 0.001). There was no difference in histological resolution between the two subtypes (HR: 0.70, 95% CI: 0.47-1.05, p = 0.084).

Conclusion

Patients with LC have a higher chance of changing their histology as compared to CC. However, histological resolution was associated with the use of PPIs and aspirin, and treatment with budesonide.

Are Drugs Associated with Microscopic Colitis? A Systematic Review and Meta-Analysis

There is growing evidence of the association of Microscopic Colitis (MC) with the use of specific medications such as proton pump inhibitors (PPIs), Selective serotonin reuptake inhibitors (SSRIs), Non-Steroidal anti-inflammatory drugs (NSAIDs), Statins and H2-receptor antagonists (H2RA). In our study, we calculated the pooled odds of MC in patients using these drugs. We performed a detailed search of major databases, including PubMed/Medline, Scopus, web of science, and Embase, to include the studies in which odds of MC were reported after using above mentioned drugs. A random-effects model was used to pool the estimates. Thirteen studies were included in our analysis consisting of 304,482 patients (34,194 cases and 270,018 controls). In eight studies, the control group consisted of a random population selected based on age, gender and same birth year, whereas 3 studies recruited patients who presented with diarrhea and underwent colonoscopy and biopsy to rule out MC. Two studies reported odds of MC for both diarrhea and random control groups. Patients taking PPIs were more likely to develop MC, AOR 2.65 (95% CI 1.81-3.50, I² 98.13%). Similarly, higher odds of association were found in patients taking SSRIs (OR 2.12, 95% CI 1.27-2.96, I² 96.46%), NSAIDs (OR 2.02, 95% CI 1.33-2.70, I² 92.70%) and Statins (OR 1.74, 95% CI 1.19-2.30, I² 96.36%). No difference in odds of developing MC was seen in patients using H2RA compared to the control group (OR 2.70, 95% CI 0.32-5.08, I² 98.67%). We performed a subgroup analysis based on the control group and found higher odds of MC in patients on PPIs compared to the random control group (OR 4.55, 95% CI 2.90-6.19, I² 98.13%). Similarly, higher odds of MC were noted for SSRI (OR 3.23, 95% CI 1.54-4.92, I² 98.31%), NSAIDs (OR 3.27, 95% CI 2.06-4.48, I² 95.38%), and Statins (OR 2.23, 95% CI 1.41-3.06, I² 98.11%) compared to the random control group. Contrary lower odds of MC were seen in the PPI and H2RA group compared to the diarrhea control group (OR 0.68, 95% CI 0.48-0.88, I² 7.26%), (OR 0.46, 95% CI 0.14-0.78, I² 0%) respectively. We found no difference in odds of MC in patients on SSRIs (OR 0.96, 95% CI 0.49-1.42, I² 37.89%), NSAIDs (OR 1.13, 95% CI 0.49-1.76, I² 59.37%) Statins (OR 0.91, 95% 0.66-1.17, I² 0%) and H2RA (OR 3.48, 95% CI -0.41-7.36, I² 98.89%) compared to the diarrhea control group. We also analyzed the association use of PPIs and NSAIDs with the development of collagenous colitis (CC) and lymphocytic colitis. Only the use of NSAIDs was associated with increased odds of developing collagenous colitis (OR 1.61, 95% CI 1.50-1.72, I² 0%). No increased odds of CC and LC were seen in PPI users. PPIs, NSAIDs, SSRIs, and Statins are associated with an increased risk of MC compared to the random control group. On the contrary, the use of PPIs, NSAIDs, SSRIs, and Statins is not associated with an increased risk of MC when compared to the diarrhea control group.

Biologic Therapy for Budesonide-refractory, -dependent or -intolerant Microscopic Colitis: a Multicentre Cohort Study from the GETAID

BACKGROUND

Budesonide remains the backbone therapy for microscopic colitis [MC]; however, relapses are frequent, and some patients are intolerant or dependent. Anti-TNF therapy is increasingly used to treat these patients, but available evidence is still limited. The aim of this study was to evaluate the effectiveness and safety of anti-TNF therapy in MC patients failing budesonide.

METHODS

In a multicentre retrospective cohort study, budesonide-refractory, -dependent, or -intolerant MC patients treated with anti-TNF agents were included. Clinical remission was defined as fewer than three bowel movements per day, and clinical response was defined as an improvement in stool frequency of at least 50%.

RESULTS

Fourteen patients were included. Median age was 58.5 years, median disease duration was 25 months, and median follow-up was 29.5 months. Seven patients were treated with infliximab [IFX], and seven with adalimumab. Clinical remission without steroids at 12 weeks was reached in 5/14 [35.7%] patients; all of these received IFX. Clinical response at 12 and 52 weeks, was obtained in 9/14 [64.3%] and 7/14 [50%] patients, respectively. Five patients switched to another anti-TNF agent. When considering both first- and second-line anti-TNF therapies, 7 [50%] patients were in clinical remission at Week 52. Mild to moderate adverse events were reported in six ptients. Two patients were treated with vedolizumab, of whom one had clinical response; one patient treated with ustekinumab had no response.

CONCLUSIONS

This is the first multicentre cohort study showing that half of patients treated with anti-TNF therapy for MC achieved clinical remission in case of budesonide failure.

Collagenous Colitis Possibly Associated with Dipeptidyl Peptidase-4 Inhibitor

A 60-year-old man with type 2 diabetes mellitus treated with a dipeptidyl peptidase-4 (DPP-4) inhibitor was referred to our hospital because of his refractory watery diarrhea. Ileocolonoscopy revealed increased capillary growth, fine granular mucosa, and longitudinal mucosal tears mainly in the left side of the colon. A bioptic examination revealed thickened subepithelial collagen bands, thus confirming the diagnosis of collagenous colitis. Systemic steroid therapy was initiated, but his symptoms recurred when tapering the steroid. However, withdrawal of the DPP-4 inhibitor was successful even after the cessation of steroid therapy. We therefore considered his collagenous colitis to have been caused by the DPP-4 inhibitor.

Temporal changes in the histology of microscopic colitis

BACKGROUND

In a subgroup of patients with microscopic colitis [MC], its histopathology changed from lymphocytic [LC] to collagenous colitis [CC] and vice versa. Previous studies have also observed histopathological transitions between MC and inflammatory bowel disease [IBD].

AIMS

The aim of the present study was to analyse the prevalence of such transitions in a large population of MC patients.

METHODS

The Inform Diagnostics database is an electronic repository of histopathology records of patients distributed throughout the USA. In a cross-sectional study, we analysed the prevalence of changes in MC histology. Each prevalence was expressed as the rate per 100 MC patients with its 95% Poisson confidence interval.

RESULTS

In a total population of 29 307 MC patients, our cross-sectional study focused on a subgroup of 4363 patients who underwent two or more consecutive colonoscopies between December 2008 and March 2020. Overall, 1.6% [95% CI 1.2-2.0%] of patients changed their MC phenotype from LC to CC, and 0.5% [0.3-0.7%] from CC to LC. Of 4363 MC patients, 414 [9.5%] were also diagnosed with IBD. In 2.9% [2.4-3.5%], MC and IBD were diagnosed as synchronous mucosal lesions. In 2.1% [1.7-2.6%], MC changed to IBD, and in 4.5% [3.9-5.2%] IBD changed to MC.

CONCLUSIONS

The analysis confirmed the synchronous occurrence of MC and IBD and transitions between the two diagnoses. In patients who fail therapy for either one of the two diseases, the gastroenterologist should search for changes in the underlying phenotype as a possible explanation.

Rheumatologic Associations of Microscopic Colitis: A Narrative Review

Extra-intestinal manifestations are frequent complications of the classical inflammatory bowel diseases, Crohn's disease and ulcerative colitis. However, in addition to the classical diseases, there is a spectrum of conditions, often termed "microscopic colitis", in which extra-intestinal manifestations are less well described. Our objective was to review the literature regarding the extra-intestinal manifestations complicating microscopic colitis and describe the association with systemic autoimmune rheumatic diseases. A comprehensive search and review of peer-reviewed English-language and international journals and reports was completed based on key terms, including "microscopic colitis", "lymphocytic colitis", "collagenous colitis", "inflammatory bowel disease", "extraintestinal manifestations", and the specific disease associations utilizing the PubMed Central database and MEDLINE. A broad spectrum of rheumatologic manifestations has been reported in patients with microscopic colitis. The identification of rheumatoid arthritis and limited scleroderma as co-morbidities with microscopic colitis was noteworthy. Inflammatory arthropathy was frequently seen in microscopic colitis, usually preceding or occurring in conjunction with the onset of gastrointestinal symptoms. A variety of presentations of associated arthritis were reported: migratory, symmetric or asymmetric, peripheral or axial, oligoarticular or polyarticular, erosive or non-erosive. There was a high incidence of autoantibodies in these patients, supporting a potential autoimmune association. On the basis of these anecdotal reports, we would suggest development of a clinical registry to help define the incidence of extra-intestinal manifestations and systemic autoimmune rheumatic diseases among microscopic colitis patients to help elucidate shared predispositions, pathogenic mechanisms and therapeutic opportunities.

Budesonide Maintenance in Microscopic Colitis: Clinical Outcomes and Safety Profile From a Population-Based Study

INTRODUCTION

Outcomes and safety of budesonide maintenance therapy in microscopic colitis (MC) are not well known.

METHODS

Adult residents of Olmsted County, Minnesota, diagnosed with MC (2002-2019) and treated with budesonide were identified using the Rochester Epidemiology Project. Response was assessed at 12 ± 4 weeks after initiation of therapy and defined as complete (resolution of diarrhea), partial (≥50% improvement in the number of bowel movements), nonresponse (&lt;50% improvement), and intolerance (discontinued because of side effects). For safety outcomes, cases (budesonide maintenance) and MC controls (no budesonide therapy) were matched by sex and age at diagnosis (±2 years).

RESULTS

A total of 450 patients were identified, of whom 162 (36.0%) were treated with budesonide for induction of clinical remission (median age 67 [23-91] years and 126 women [77.8%] ). Clinical outcomes for induction were as follows: 130 (80.2%) complete response, 22 (13.6%) partial response, 8 (4.9%) no response, and 2 (1.2%) intolerance. After induction, 96 (63.2%) had recurrence after discontinuation, of whom 27 (28.1%) required further budesonide induction treatment without maintenance, 56 (58.3%) required long-term budesonide maintenance, and 13 (13.5%) were treated with other therapies. Of those receiving budesonide maintenance, all responded (55 [98.2%] complete and 1 [1.8%] partial). No patient stopped maintenance from adverse events. The median duration of follow-up was 5.6 years (0.3-18.9). There was no significant difference between cases and controls in the incidence of osteopenia/osteoporosis, diabetes mellitus, hypertension, glaucoma, or cataracts.

DISCUSSION

The long-term use of budesonide in MC seems to be effective and generally well tolerated with limited adverse effects.

Microscopic colitis: Etiopathology, diagnosis, and rational management

Microscopic colitis is an inflammatory bowel disease divided into two subtypes: collagenous colitis and lymphocytic colitis. With an increasing incidence of microscopic colitis exceeding those of ulcerative and Crohn's disease among elderly people in some countries, microscopic colitis is a debilitating life experience. Therefore, physicians should be familiar with its clinical features and management strategies because the disease deserves the same attention as the classical inflammatory bowel diseases. Here, state-of-the-art knowledge of microscopic colitis is provided from a global perspective with reference to etiopathology and how to establish the diagnosis with the overall aim to create awareness and improve rational management in clinical practice. The immune system and a dysregulated immune response seem to play a key role combined with risk factors (e.g. cigarette smoking) in genetically predisposed individuals. The symptoms are characterized by recurrent or chronic nonbloody, watery diarrhea, urgency, weight loss, and a female preponderance. As biomarkers are absent, the diagnosis relies on colonoscopy with a histological assessment of biopsy specimens from all parts of the colon. Although the disease is not associated with a risk of colorectal cancer, a recent nationwide, population-based cohort study found an increased risk of lymphoma and lung cancer. Budesonide is the first-line therapy for management, whereas immunomodulatory drugs (including biologics) and drugs with antidiarrheal properties may be indicated in those failing, dependent, or intolerant to budesonide. In microscopic colitis induced by checkpoint inhibitors, a drug class used increasingly for a wide range of malignancies, a more aggressive therapeutic approach with biologics introduced early seems reasonable. However, particular attention needs to be drawn to the existence of incomplete forms of microscopic colitis with the risk of being overlooked in routine clinical settings.

Microscopic colitis in older adults: impact, diagnosis, and management

Microscopic colitis (comprising lymphocytic and collagenous colitis, albeit an incomplete variant is gaining recognition as well) is a chronic, immune-mediated inflammatory state of the lower gastrointestinal tract (colon). The diagnosis requires diagnostic colonoscopy with characteristic histopathological findings. They have a propensity to present in senior populations (above 60 years of age), particularly women – who are approximately 2.5–3 times more likely to develop microscopic colitis. Preexisting other immune-inflammatory diseases are also shown to predispose patients for the development of microscopic colitis. The classic presentation is profuse watery diarrhea, often during the night or early morning hours. Fecal incontinence and abdominal pain are frequent as well. Thus, the disease impacts patients’ quality of life and well-being. The first described cases date back to the seventies and eighties of the twentieth century, thereby they can be considered fairly recently discovered disease states. Our understanding of the disease and its pathophysiology is still incomplete. Although there is a lack of unified recommendation for treatment, most clinicians prefer the use of budesonide, and most published guidelines regard this locally acting glucocorticoid as the therapy of choice. In our article, we aimed for a brief, noncomprehensive overview of the clinical significance, diagnosis, and management of microscopic colitis.

Increased Fecal Bile Acid Excretion in a Significant Subset of Patients with Other Inflammatory Diarrheal Diseases

BACKGROUND

Increased fecal bile acid excretion (IBAX) occurs in a third of patients with functional diarrhea.

AIMS

To assess the prevalence of IBAX in benign inflammatory intestinal and colonic diseases presenting with chronic diarrhea.

METHODS

All patients with known inflammatory diseases or resections who underwent 48 h fecal fat and BA testing for chronic diarrhea at a single center were included. Quiescent disease was based on clinical evaluation and serum, endoscopic and imaging studies. IBAX was defined by: > 2337 µmol total BA/48 h; or primary fecal BAs > 10%; or > 4% primary BA plus > 1000 µmol total BA /48 h. Demographics, fecal weight, fecal fat, stool frequency and consistency were collected. Nonparametric statistical analyses were used for group comparisons.

RESULTS

Sixty patients had celiac disease (51 quiescent, 9 active), 66 microscopic colitis (MC: 34 collagenous, 32 lymphocytic), 18 ulcerative colitis (UC), and 47 Crohn's disease (CD). Overall, fecal fat, 48 h stool weight, frequency and consistency were not different among subgroups except for inflammatory bowel disease (IBD) based on disease location. Almost 50% patients with celiac disease and MC had IBAX, with a greater proportion with increased primary fecal BA. Among UC patients, rates of IBAX were higher with pancolonic disease. A high proportion of patients with ileal resection or CD affecting ileum or colon had IBAX. IBAX was present even with quiescent inflammation in UC or CD.

CONCLUSIONS

A significant subset of patients with MC, quiescent celiac disease and IBD had increased fecal BA excretion, a potential additional therapeutic target for persistent diarrhea.

The Epidemiology of Microscopic Colitis in Olmsted County, Minnesota: Population-Based Study From 2011 to 2019

BACKGROUND & AIMS

Epidemiologic studies from Europe and North America have reported an increasing incidence of microscopic colitis (MC) in the late 20th century, followed by a plateau. This population-based study assessed recent incidence trends and the overall prevalence of MC over the past decade.

METHODS

Residents of Olmsted County, MN, diagnosed with collagenous colitis (CC) or lymphocytic colitis (LC) between January 1, 2011, and December 31, 2019 were identified using the Rochester Epidemiology Project. Clinical variables were abstracted by chart review. Incidence rates were age- and sex-adjusted to the 2010 US population. Associations between incidence and age, sex, and calendar periods were evaluated using Poisson regression analyses.

RESULTS

A total of 268 incident cases of MC were identified with a median age at diagnosis of 64 years (range, 19-90 y); 207 (77%) were women. The age- and sex-adjusted incidence of MC was 25.8 (95% CI, 22.7-28.9) cases per 100,000 person-years. The incidence of LC was 15.8 (95% CI, 13.4-18.2) and CC was 9.9 (95% CI, 8.1-11.9) per 100,000 person-years. A higher MC incidence was associated with increasing age and female sex (P < .01). There was no significant trend in age- and sex-adjusted incidence rate over the study period (P = .92). On December 31, 2019, the prevalence of MC, LC, and CC (including cases diagnosed before 2011) was 246.2, 146.1, and 100.1 per 100,000 persons, respectively.

CONCLUSIONS

The incidence of MC and its subtypes was stable between 2011 and 2019, but its prevalence was higher than in previous periods. The incidence of MC continues to be associated with increasing age and female sex.

Bile Acid Diarrhea in Adults and Adolescents

BACKGROUND

Bile acids are central to enterohepatic signaling pathways activated through natural receptors, farnesoid X receptor [FXR mediates synthesis of fibroblast growth factor-19 (FGF-19)], and G protein-coupled bile acid receptor 1 (GPBAR1, also known as TGR5). Although bile acid diarrhea (BAD) is more commonly encountered in ileal resection or disease, there is evidence documenting "idiopathic" BAD in about 20% of adolescents and 30% of adults presenting with chronic, non-bloody diarrhea often attributed to irritable bowel syndrome. Mechanism(s) leading to increased hepatic synthesis and colonic bile acid levels in "idiopathic" BAD include reduced synthesis of FGF-19 by the ileal mucosa, or genetic variation in hepatocyte proteins klotho β and FGF receptor 4 (FGFR4) that mediate negative feedback of bile acid synthesis.

PURPOSE

The objective of this review is to summarize the diagnosis of BAD in adults and adolescents. In addition to ⁷⁵ SeHCAT retention for diagnosis of BAD, studies have validated fasting serum 7αC4 and FGF-19, respectively, by-product and inhibitor of hepatic bile acid synthesis, as well as fecal bile acid measurements. These assays are widely available through reference laboratories, and they are being simplified (eg, measurement of primary fecal bile acids in a random stool sample). BAD has also been identified as a co-factor contributing to persistent diarrhea in other diseases in remission including inflammatory bowel disease, microscopic colitis, celiac disease, and neuroendocrine tumors. In summary, advances in diagnosis of BAD provide opportunities for generalists and pediatric and adult gastroenterologists to provide targeted treatment for BAD presenting as chronic non-bloody diarrhea.

Endoscopic and histopathologic features of Anti‐PD‐1‐related collagenous colitis

Objectives

Cancer patients treated with immune checkpoint inhibitors occasionally show persistent diarrhea accompanied by endoscopic features of ulcerative colitis. The endoscopic mucosal inflammation may appear mild in some patients compared to the clinical severity, which can make choosing a treatment challenging. In this study, we evaluated the factors that support the continuation of chemotherapy by assessing the endoscopic and histopathological characteristics of patients who experienced diarrhea after immune checkpoint inhibitor administration.

Methods

This study included eight patients who were diagnosed with collagenous colitis based on pathological assessments. We retrospectively investigated these patients’ backgrounds, laboratory data, and computed tomography images that were extracted from their medical records. We also summarized their endoscopic and pathologic findings.

Results

All eight patients were being treated with anti‐programmed cell death‐1/programmed cell death‐ligand 1 therapeutic agents and had a recent history of oral proton pump inhibitor therapy. The anti‐programmed cell death‐1‐related collagenous colitis in these cases was characterized by endoscopically mild mucosal inflammation, high fecal calprotectin levels, and a lower frequency of intestinal wall thickening on computed tomography. Histological assessments showed CD8⁺ lymphocytes predominantly infiltrating the lamina propria and crypts of the colonic mucosa. Suspending the proton pump inhibitor therapy relieved the patients’ symptoms and allowed the continuation of the anti‐programmed cell death‐1/programmed cell death‐ligand 1 therapy.

Conclusions

Anti‐programmed cell death‐1‐related collagenous colitis is reversible; appropriate diagnosis of adverse events is crucial for the continuation of immune checkpoint inhibitor therapy.

Microscopic Colitis and Risk of Colon Adenomas: A Multicenter Retrospective Cohort Study

Microscopic colitis (MC) is a common cause of chronic watery diarrhea, with the highest incidence in women over age 50.¹ Cross-sectional studies have suggested that patients with MC have a lower incidence of adenomatous colon polyps compared with those without MC.^2-4 The existing literature is limited by cross-sectional design, small sample sizes, lack of longitudinal follow-up, and the use of average-risk patients, rather than those with chronic diarrhea, as controls. We aimed to explore the association between MC and colon adenomas.

Abnormal findings on abdominopelvic cross-sectional imaging in patients with microscopic colitis: a retrospective, multicenter study

OBJECTIVES

Patients with microscopic colitis may have subtle macroscopic findings on colonoscopy such as erythema, edema, or altered vascular pattern; however, radiographic abnormalities on cross-sectional imaging have not been investigated. We aimed at identifying the abdominopelvic radiographic abnormalities in patients with microscopic colitis, as well as possible correlation with endoscopic findings and the need for extended duration of treatment.

MATERIALS AND METHODS

This was a retrospective study of patients with biopsy-proven microscopic colitis at two tertiary centers between 1 January 2010 and 30 April 2020. Patients underwent computed tomography scan or magnetic resonance imaging within 30 days of a diagnostic flexible sigmoidoscopy or colonoscopy. Patients with colon ischemia and other causes of colitis were excluded. Radiographic abnormalities from imaging reports included bowel wall thickening, mucosal hyperenhancement and mesenteric fat stranding. Univariate and multivariable logistic regression models were used to identify predictors of radiographic abnormalities.

RESULTS

498 patients with microscopic colitis underwent abdominopelvic cross-sectional imaging within 30 days of flexible sigmoidoscopy/colonoscopy. Lymphocytic colitis was diagnosed in 54.6% of patients, and collagenous colitis in 45.4%. Endoscopic and radiographic abnormalities were identified in 16.1% and 12.4% of patients, respectively. Radiographic abnormalities were associated with the need for budesonide therapy (p = .029) and budesonide therapy long-term (p = .0028). Budesonide therapy long-term (p = .047) was associated with radiographic abnormalities in multivariate analysis.

CONCLUSIONS

Radiographic abnormalities may be present on abdominopelvic cross-sectional imaging in a minority of patients with biopsy-proven microscopic colitis, suggesting cross-sectional imaging has low clinical value in the evaluation and treatment of this disease.

Vedolizumab Therapy in Refractory Microscopic Colitis: A Single Center Case Series

Microscopic colitis (MC) is a disease characterized by chronic watery diarrhea secondary to colonic inflammation. Endoscopically, the mucosa is usually normal but biopsies show characteristic histologic findings.¹.

Bile Acid Sequestrant Therapy in Microscopic Colitis

GOALS

There is an unmet need in investigating corticosteroid-sparing treatments for induction and maintenance of remission in microscopic colitis (MC). The authors' aim was to evaluate the outcomes of patients with MC treated with bile acid sequestrants (BAS).

BACKGROUND

MC is a common chronic diarrheal illness. Budesonide is effective induction therapy, but relapses are high after cessation of treatment.

STUDY

Our cohort consisted of patients enrolled in our institutional MC registry, a biorepository of histology-confirmed diagnoses of MC. Patients receiving BAS for the treatment of MC were reviewed at each clinical visit for efficacy or ability to decrease budesonide maintenance dosing.

RESULTS

The authors included 79 patients (29 collagenous colitis and 50 lymphocytic colitis) with a median follow-up period of 35 months (range, 1 to 120). Most patients were female individuals (78%) and the median age was 69 years (range, 29 to 87). BAS therapy was used in 21 patients who were budesonide-naive, with a response rate of 76% (16/21). In patients treated previously with budesonide, 46 patients were budesonide-dependent and given BAS as maintenance therapy. Of these patients, 23 (50%) were able to decrease their budesonide dosing and 9 (20%) were able to stop budesonide completely. Seven of 46 patients (15%) stopped BAS because of intolerance, perceived lack of benefit, or treatment of concomitant diarrhea illness.

CONCLUSIONS

BAS may be an effective corticosteroid-sparing option in the treatment of MC and should be considered after budesonide induction. Larger controlled studies are needed to confirm the efficacy for long-term maintenance and tolerability of BAS in patients with MC.

Clinical Characteristics and Treatment Response in Microscopic Colitis Based on Age at Diagnosis: A Multicenter Retrospective Study

BACKGROUND

Microscopic colitis (MC) primarily affects older adults; thus, data in younger patients are scarce.

AIMS

To compare clinical characteristics and treatment response by age at diagnosis.

METHODS

This retrospective cohort study was performed at Mayo Clinic and Massachusetts General Hospital. Patients were chosen consecutively using established databases. Patients were 'younger' if age at diagnosis was ≤ 50 years and 'older' if age > 50 years. Treatment outcomes were captured for induction (12 ± 4 weeks), based on the total number of daily stools, and defined as remission (complete resolution), response (≥ 50% improvement), non-response (< 50% improvement), and intolerance. Patients were considered 'responders' if they had remission or response and 'non-responders' if they had non-response or intolerance.

RESULTS

We included 295 patients (52 younger, 243 older). There were no differences in sex, race, MC subtype, and diarrhea severity between groups (all P > 0.05). Younger patients were more likely to have celiac disease (17.3% vs. 5.8%, P = 0.01), while older patients had higher BMI (mean 25.0 vs. 23.8 kg/m², P = 0.04) were more likely smokers (53.9% vs. 34.6%, P = 0.01) and use NSAIDs (48.6% vs. 15.4%, P < 0.01) and statins (22.6% vs. 3.8%, P < 0.01). Overall treatment response was highest for budesonide (88.3%) and did not differ when comparing older to younger patients (90.6% vs. 77.8%, P = 0.12) or by MC subtype (LC, 81.5% vs. CC, 92.9%, P = 0.07).

CONCLUSIONS

There are no significant differences in MC treatment response based on age or disease subtype. These findings support treating patients with MC based on symptom severity rather than age.

Primary Gastrointestinal T-Cell Lymphoma and Indolent Lymphoproliferative Disorders: Practical Diagnostic and Treatment Approaches

Simple Summary

It is challenging for pathologists to diagnose primary gastrointestinal T-cell neoplasms. Besides the rarity of the diseases, the small biopsy material makes it more difficult to differentiate between non-neoplastic inflammation and secondary involvement of extra gastrointestinal lymphoma. Since this group of diseases ranges from aggressive ones with a very poor prognosis to indolent ones that require caution to avoid overtreatment, the impact of the diagnosis on the patient is enormous. Although early treatment of aggressive lymphoma is essential, the treatment strategy is not well established, which is a problem for clinicians. This review provides a cross-sectional comparison of histological findings. Unlike previous reviews, we summarized up-to-date clinically relevant information including the treatment strategies as well as practical differential diagnosis based on thorough literature review.

Abstract

Primary gastrointestinal (GI) T-cell neoplasms are extremely rare heterogeneous disease entities with distinct clinicopathologic features. Given the different prognoses of various disease subtypes, clinicians and pathologists must be aware of the key characteristics of these neoplasms, despite their rarity. The two most common aggressive primary GI T-cell lymphomas are enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. In addition, extranodal natural killer (NK)/T-cell lymphoma of the nasal type and anaplastic large cell lymphoma may also occur in the GI tract or involve it secondarily. In the revised 4th World Health Organization classification, indolent T-cell lymphoproliferative disorder of the GI tract has been incorporated as a provisional entity. In this review, we summarize up-to-date clinicopathological features of these disease entities, including the molecular characteristics of primary GI T-cell lymphomas and indolent lymphoproliferative disorders. We focus on the latest treatment approaches, which have not been summarized in existing reviews. Further, we provide a comprehensive review of available literature to address the following questions: How can pathologists discriminate subtypes with different clinical prognoses? How can primary GI neoplasms be distinguished from secondary involvement? How can these neoplasms be distinguished from non-specific inflammatory changes at an early stage?

Cost Analysis of Diagnostic Endoscopic Procedures for Chronic Diarrhoea

Chronic diarrhoea is a common condition that affects up to 5% of the population which heavily affects the quality of life for the patient. The British Society of Gastroenterology guidelines recommend that for those who suffer with chronic diarrhoea, a colonoscopy with a biopsy is recommended to exclude microscopic colitis. This retrospective audit included 147 patients who received endoscopic procedures in 2019 at Walsall Manor Hospital for chronic diarrhoea. The results show that a total of £56,797 was incurred through endoscopic and histological investigation with four patients (2.6%) diagnosed with microscopic colitis. Given the lack of diagnostic yield, there is room for advancement in the current guidelines for managing persistent diarrhoea.

Controversials of Microscopic Colitis

Microscopic colitis (MC) has become a disease with increased awareness due to the availability of new data about the pathogenesis, diagnosis and therapy of this disease. The incidence of MC is increasing, reaching the incidence of the inflammatory bowel disease (IBD) in some populations. However, some aspects of MC are still controversial. It is unknown whether the changes of microbiome play a role in the pathogenesis and what is in the background of the different subtypes of disease that can transform into each other. Is there a connection between MC and IBD or why the histological changes do not follow the clinical activity? We do not know what the etiology of the incomplete MC is, and what its natural course is. The association of MC with celiac disease is well-known- is there a common pathogenesis? The MC treatment is budesonide. Its effectiveness is high, but the relapse rate is high, as well. Why would biologics be effective in these cases when budesonide is not? This mini-review makes an attempt to summarize the data about MC and highlight that there are still unanswered questions in the pathogenesis, diagnosis and therapy of the disease, which can initiate further investigations in the future.

Microscopic Colitis Is Not an Independent Risk Factor for Low Bone Density

BACKGROUND

Microscopic colitis (MC) is a subtype of inflammatory bowel disease (IBD) with overlapping risk factors for low bone density (LBD). While LBD is a known complication of IBD, its association with MC is not well-established.

AIMS

Assess the prevalence of LBD in MC compared to control populations, and evaluate if MC predicts LBD when controlling for confounders.

METHODS

Retrospective, observational case control study of adult patients with pathologically confirmed MC from 2005 to 2015. Bone density measurements were abstracted from dual-energy X-ray absorptiometry (DEXA) reports, and bone density was classified using T-score: normal (T ≥ - 1.0), osteopenia (- 1.0 > T > -2.5) or osteoporosis (T ≤ - 2.5). Demographics, disease, medication history and LBD risk factors were obtained from chart review. Prevalence of LBD was compared to national and local controls. A matched control cohort to MC patients without prior diagnosis of LBD was analyzed with logistic regression to assess the relationship of MC to LBD.

RESULTS

One hundred and eighteen patients with MC were identified. Osteopenia in women with MC was more prevalent compared to national controls (67% vs. 49%, p = 0.0004), and LBD was more prevalent in MC patients compared to local controls (82% vs. 55%, p < 0.0001). In MC patients without prior diagnosis of LBD matched to controls, there was a higher prevalence of osteopenia (53.2% vs. 36.7%, p = 0.04). However, after controlling for confounders, MC was not associated with LBD (OR 0.83, 95% CI 0.22, 3.16, p = 0.8).

CONCLUSIONS

While LBD was more prevalent in MC patients compared to control populations, with adjustment for key confounders (including BMI, steroids, smoking, vitamin D and calcium use), MC was not an independent predictor of LBD.

Mucosal and faecal neutrophil gelatinase-associated lipocalin as potential biomarkers for collagenous colitis

BACKGROUND

Collagenous colitis (CC) is an inflammatory bowel disease where chronic diarrhoea is the main symptom. Diagnostic markers distinguishing between CC and other causes of chronic diarrhoea remain elusive. This study explores neutrophil gelatinase-associated lipocalin (NGAL) and its mRNA lipocalin2 (LCN2) as histological and faecal disease markers in CC.

METHODS

NGAL/LCN2 were studied in colonic biopsies from CC patients before and during budesonide treatment using RNA sequencing (n = 9/group), in situ hybridization (ISH) (n = 13-22/group) and immunohistochemistry (IHC) (n = 14-25/group). Faecal samples from CC (n = 3-28/group), irritable bowel syndrome diarrhoea (IBS-D) (n = 14) and healthy controls (HC) (n = 15) were assayed for NGAL and calprotectin.

RESULTS

NGAL/LCN2 protein and mRNA expression were upregulated in active CC vs HC, and vs paired samples of treated CC in clinical remission. IHC and ISH localized increased NGAL/LCN2 mainly to epithelium of active CC, compared to almost absence in HC and treated CC. In contrast, calprotectin was solely expressed in immune cells. Despite great individual differences, faecal NGAL was significantly increased in active CC compared to HC, IBS-D and treated CC and had high test sensitivity. Faecal calprotectin levels were variably increased in active CC, but the values remained below usual clinical cut-offs.

CONCLUSION

NGAL/LCN2 is upregulated in the epithelium of active CC and reduced during budesonide-induced clinical remission to the level of HC and IBD-S. This was reflected in NGAL faecal concentrations. We propose NGAL as an IHC marker for disease activity in CC and a potential faecal biomarker discriminating CC from HC and IBS-D.

Development of Anti-fibrotic Therapy in Stricturing Crohn's Disease: Lessons from Randomized Trials in Other Fibrotic Diseases

Intestinal fibrosis is considered an inevitable complication of Crohn's disease (CD) that results in symptoms of obstruction and stricture formation. Endoscopic or surgical treatment is required to treat the majority of patients. Progress in the management of stricturing CD is hampered by the lack of effective anti-fibrotic therapy; however, this situation is likely to change because of recent advances in other fibrotic diseases of the lung, liver and skin. In this review, we summarized data from randomized controlled trials (RCT) of anti-fibrotic therapies in these conditions. Multiple compounds have been tested for the anti-fibrotic effects in other organs. According to their mechanisms, they were categorized into growth factor modulators, inflammation modulators, 5-hydroxy-3-methylgultaryl-coenzyme A (HMG-CoA) reductase inhibitors, intracellular enzymes and kinases, renin-angiotensin system (RAS) modulators and others. From our review of the results from the clinical trials and discussion of their implications in the gastrointestinal tract, we have identified several molecular candidates that could serve as potential therapies for intestinal fibrosis in CD.

No Microscope Needed: A Macroscopic Presentation of Collagenous Colitis

Microscopic colitis (MC) is a common cause of chronic secretory diarrhea with variable etiologies, including nonsteroidal anti-inflammatory drugs. As its name implies, the diagnosis requires consistent histopathologic findings that typically accompany normal-appearing mucosa. However, accumulating evidence suggests that the presence of distinct endoscopic features is associated with MC. We present a case of MC that highlights the importance of recognizing these macroscopic findings because they can aid in diagnosis and have significant management implications.

Alcohol Consumption is Associated With An Increased Risk of Microscopic Colitis: Results From 2 Prospective US Cohort Studies

BACKGROUND

No dietary factors have yet been shown to conclusively impact the incidence of microscopic colitis (MC). Here, we sought to examine the relationship between alcohol intake and the risk of MC.

METHODS

We conducted a prospective cohort study of 209,902 participants (age range, 28.5-66.7 years) enrolled in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII). Validated data on alcohol consumption were collected at baseline in 1986 in the NHS and 1991 in the NHSII and updated every 4 years. Diagnoses of MC were confirmed via review of histopathology data. We used Cox proportional hazards modeling to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Through 2016 in the NHS and 2017 in the NHSII, we confirmed 352 incident cases of MC over 4,994,324 person-years. Higher alcohol consumption was associated with an increased risk of MC (Ptrend < .001). Compared to non-users, the aHRs of MC were 1.20 (95% CI, 0.86-1.67) for consumers of 0.1-4.9 g/day of alcohol, 1.90 (95% CI, 1.34-2.71) for consumers of 5-14.9 g/day, and 2.31 (95% CI, 1.54-3.46) for consumers of ≥15 g/day. The associations were consistent across the histologic subtypes of collagenous and lymphocytic colitis (Pheterogeneity = .523). When stratified by alcohol type, the risk according to every 2 servings/week appeared to be strongest with consumption of wine (aHR, 1.08; 95% CI, 1.04-1.12) as compared to beer (aHR, 1.01; 95% CI, 0.91-1.12) or liquor (aHR, 1.00; 95% CI, 0.92-1.09).

CONCLUSIONS

Alcohol consumption was associated with an increased risk of MC. Further studies are needed to determine the mechanism underlying these associations, as well as the impact of reducing alcohol intake in patients with MC.

Drug-Induced Colitis

Drug-induced colitis encompasses a wide spectrum of colon disorders that can manifest microscopically or macroscopically. Patients present with new-onset colitis or exacerbations of inflammatory bowel diseases; in some cases, colitis resolves with discontinuation of medication. Mucosal injury can be focal or extensive, involving the entire colonic mucosa, and sometimes involves other parts of the gastrointestinal tract. It has been a challenge to determine the proportion of new-onset colitis caused by medication and there are few data on the overall prevalence. We review the drugs that have been linked with development of drug-induced colitis and strategies for physicians who believe their patients have this disorder-usually discontinuation of the drug believed to cause colitis and treatment with steroids or immune-modulating therapies. Physicians must be aware of medications that can cause colitis.

Approach to the adult patient with chronic diarrhea: A literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Approach to the adult patient with chronic diarrhea: a literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Normal gastrointestinal tract inflammatory cells and review of select benign hematolymphoid proliferations

The luminal gastrointestinal tract can be a site of robust immune response in which reactive lymphoproliferative processes can sometimes be difficult to distinguish from lymphoma. In this article, we review gastrointestinal tract normal resident inflammatory cells and common nonneoplastic lymphoproliferative responses with emphasis on their differential and links to lymphoma. Topics that are covered include lymphocytic esophagitis, gastric chronic inflammation, mucosa-associated lymphoid tissue, and ulceration, small intestinal lymphoid hyperplasia, celiac disease, microscopic colitis, inflammatory bowel disease, primary immunodeficiency, graft-versus-host disease, and anti-programmed cell death protein-1 effect. We additionally present the less common differential of histiocytic processes within the gastrointestinal tract. The aim of this paper is to serve as a reference for practicing pathologists facing lymphoid, lymphoplasmacytic, or histiocytic processes in the luminal gastrointestinal tract. We hope to help the practicing pathologist distinguish benign from malignant entities and identify features requiring further workup.

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.

Random colonic biopsies in macroscopically normal colonoscopies: is there any benefit? A two-centre audit of current practice

BACKGROUND

Recent guidelines from the British Society of Gastroenterology published in April 2018, recommended performing random colonic biopsies (RCB) in endoscopically normal colonic mucosa when investigating chronic diarrhoea in adults to rule out microscopic colitis; however, cost effectiveness was not accounted for due to poor evidence base. There is now more evidence that RCBs are of low yield and of significant cost.

METHODS

A two-centre audit of current practice was conducted at Rockingham General Hospital and Fremantle Hospital in Western Australia, aiming to determine the yield of RCB in macroscopically normal mucosa for microscopic colitis, from 1 January 2009 to 30 June 2018, with comparisons of practice and results between gastroenterologists and general surgeons. Variability in the indications (diarrhoea and non-diarrhoea indications) for RCBs was determined and the cost of consumables, additional endoscopy time and histopathology analysis were calculated.

RESULTS

A total of 872 normal colonoscopies with RCBs were included; 48.7% of colonoscopies with RCB were for diarrhoea. Only 1.5% of RCBs were positive for microscopic colitis; 3.1% of patients with diarrhoea had microscopic colitis. Only one patient received pharmacologial treatment as a result of the test. The calculated cost per positive diagnosis of microscopic colitis was $10 862.42.

CONCLUSION

RCBs from normal colonic mucosa have poor yield and are costly. Local guidelines should be updated, so RCBs are performed only in patients with a high degree of suspicion of an organic cause of chronic diarrhoea.