Azathioprine and mercaptopurine in the management of patients with chronic, active microscopic colitis

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.

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.

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.

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), I2=43% P=0.08], 57.8% [95% CI (0.3895; 0.7571), I2=0%, P=0.7541], and 39.3% [95% CI (0.0814; 0.7492), I2=66%, P=0.02] for vedolizumab, infliximab, and adalimumab, respectively. The maintenance of remission rates were 65.9% [95% CI (0.389; 0.889), I2=67%, P=0.02], 45.3% [95% CI (0.1479; 0.7747), I2=0%, P=0.36] and 32.5% [95% CI (0.000; 0.8508), I2=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 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.

Mucosa associated invariant T and natural killer cells in active and budesonide treated collagenous colitis patients

Introduction

Collagenous colitis (CC) is an inflammatory bowel disease, which usually responds to budesonide treatment. Our aim was to study the immunological background of the disease.

Methods

Analyses of peripheral and mucosal MAIT (mucosa associated invariant T cells) and NK (natural killer) cells were performed with flow cytometry. Numbers of mucosal cells were calculated using immunohistochemistry. We studied the same patients with active untreated CC (au-CC) and again while in remission on budesonide treatment. Budesonide refractory patients and healthy controls were also included. The memory marker CD45R0 and activation marker CD154 and CD69 were used to further study the cells. Finally B cells, CD4⁺ and CD8⁺ T cells were also analysed.

Results

The percentages of circulating CD56^dimCD16⁺ NK cells as well as MAIT cells (CD3⁺TCRVa7.2⁺CD161⁺) were decreased in au-CC compared to healthy controls. This difference was not seen in the mucosa; where we instead found increased numbers of mucosal CD4⁺ T cells and CD8⁺ T cells in au-CC. Mucosal immune cell numbers were not affected by budesonide treatment. In refractory CC we found increased mucosal numbers of MAIT cells, CD4⁺ and CD8⁺ T cells compared to au-CC.

Discussion

Patients with active collagenous colitis have lower percentages of circulating MAIT and NK cells. However, there was no change of these cells in the colonic mucosa. Most mucosal cell populations were increased in budesonide refractory as compared to au-CC patients, particularly the number of MAIT cells. This may indicate that T cell targeting therapy could be an alternative in budesonide refractory CC.

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.

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.

Diagnosis and Management of Microscopic Colitis in Pediatric Patients

Microscopic colitis (MC) is an inflammatory disease of the colon, characterized by chronic watery diarrhea with distinguishing histologic findings despite normal endoscopic appearance of the colonic mucosa. MC is a common cause of diarrhea in older adults, though it has been infrequently reported in children and adolescents. As MC is rare in the pediatric population, and the clinical presentation is non-specific, increased awareness of this disease amongst pediatric clinicians and pathologists is essential for timely diagnosis, which requires performing colonoscopy with biopsy. The etiology of MC is incompletely understood, but current theories in pathogenesis inform management strategies. The goals of management in pediatric MC should be to achieve symptomatic improvement while minimizing adverse effects of treatment. Many patients who achieve clinical response have symptomatic recurrence after discontinuation of initial therapy, and may require maintenance medication therapy to sustain remission. This review aims to summarize the epidemiology and risk factors, clinical features, diagnosis, theories regarding pathogenesis, and suggested management approaches for MC in the pediatric population.

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.

Microscopic colitis

Microscopic colitis (MC) is an inflammatory disease of the large intestine associated with urgent watery diarrhoea. MC may occur in people of all ages, although the disease primarily affects older women. Once believed to be rare, MC is now known to be a common cause of chronic watery diarrhoea in high-income countries, affecting 1 in 115 women and 1 in 286 men during their lifetime in Swedish population-based estimates. An inappropriate immune response to disturbances in the gut microenvironment is implicated in the pathogenesis of MC. Evidence also supports an underlying genetic basis for disease. The diagnosis of MC relies on clinical symptoms and microscopic assessment of colonic biopsy samples. MC is categorized histologically into collagenous colitis, lymphocytic colitis and their incomplete forms. The mainstay of treatment includes the use of budesonide, with or without adjunctive therapies, and withdrawal of offending drugs. Emerging studies suggest a role for biologicals and immunosuppressive therapies for the management of budesonide-refractory or budesonide-dependent disease. MC can have a substantial negative effect on patient quality of life. The outlook for MC includes a better understanding of the immune response, genetics and the microbiome in disease pathogenesis along with progress in disease management through robust clinical trials.

Disease Activity Patterns, Mortality, and Colorectal Cancer Risk in Microscopic Colitis: A Danish Nationwide Cohort Study, 2001 to 2016

BACKGROUND AND AIMS

The disease course of microscopic colitis [MC], encompassing collagenous colitis [CC] and lymphocytic colitis [LC], is not well known. In a Danish nationwide cohort, we evaluated the disease activity patterns as well as the risk of colorectal cancer [CRC] and mortality based on disease severity.

METHODS

All incident MC patients [n = 14 302] with a recorded diagnosis of CC [n = 8437] or LC [n = 5865] in the Danish Pathology Register, entered between 2001 and 2016, were matched to 10 reference individuals [n = 142 481]. Incident cases of CRC after the index date were captured from the Danish Cancer Registry. Mortality data were ascertained from the Danish Registry of Causes of Death, and information about treatment was obtained from the Danish National Prescription Registry. The risk of CRC and mortality analyses were investigated by Cox regression and Kaplan-Meier estimates.

RESULTS

We identified a self-limiting or transient disease course in 70.6% of LC patients and in 59.9% of CC patients, p <0.001. Less than 5% of MC patients experienced a budesonide-refractory disease course and were treated with immunomodulators or biologic treatment. A total of 2926 [20.5%] MC patients and 24 632 [17.3%] reference individuals died during the study period. MC patients with a severe disease had a relative risk [RR] of mortality of 1.41 (95% confidence interval [CI]: 1.32-1.50) compared with reference individuals. Only 90 MC patients were diagnosed with CRC during follow-up, corresponding to an RR of 0.48 [95% CI: 0.39-0.60].

CONCLUSIONS

A majority of MC patients experience an indolent disease course with a lower risk of developing CRC compared with the background population.

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.

Treatment of microscopic colitis: the role of budesonide and new alternatives for refractory patients

Microscopic colitis is a common cause of chronic watery diarrhea with a great impact on patient quality of life. Microscopic colitis includes two histological subtypes: collagenous colitis and lymphocytic colitis. Due to the increasing incidence and awareness of this disease over the last decades, several international guidelines have been recently published. However, there is still significant heterogeneity in the management of these patients, and treatments without solid scientific evidence support are often used in clinical practice. This article reviews the therapeutic role of budesonide in microscopic colitis and summarizes the current evidence regarding other treatments available for this disease, especially for the management of refractory patients. Finally, an updated treatment algorithm is proposed.

Lymphocytic and collagenous colitis in children and adolescents: Comprehensive clinicopathologic analysis with long-term follow-up

Microscopic colitis (MC) is characterized by chronic watery diarrhea, endoscopically normal findings, and abnormal histology. While mostly encountered in adults, pediatric cases are rare and may show varying presentations. Our pathology data system was searched from 1984 to 2019 for patients ≤18 years of age with a lymphocytic colitis (LC) or collagenous colitis (CC) pattern of injury. Twenty-seven cases (23 LC and 4 CC) were retrieved. LC was more prevalent than CC (85% vs 15%, respectively) and affected slightly younger individuals (mean, 9.8 years versus 12.25 years). Immune dysregulation was documented in 11 (41%) patients. Most patients presented with watery diarrhea (n = 26, 96%) and either abdominal pain (n = 18, 67%), nausea/vomiting (n = 5, 19%), flatulence (n = 6, 22%), and/or weight loss (n = 1, 4%). A subset of patients (n = 10, 37%) demonstrated endoscopic abnormalities. Histologically, some patients with LC and CC displayed focal cryptitis or crypt abscess formation (n = 7, 26%) and focally increased crypt apoptosis (n = 9, 33%) in the absence of chronic injury. Clinical follow-up data were available for 23 (85%) patients with variable clinical responses recorded. Only 8 patients experienced complete symptom resolution. Twelve patients (11 LC and 1 CC) had subsequent biopsy material; of which, one developed histologic features of inflammatory bowel disease and another was found to have a CTLA-4 deficiency. Our study shows that pediatric patients with MC may have atypical clinical, histologic, and endoscopic findings and variable clinical responses. Underlying inflammatory and/or genetic conditions may be eventually unmasked, and genetic testing may be helpful in a small subset of patients.

Overview of microscopic colitis

Microscopic colitis encompasses both collagenous and lymphocytic colitis and is a relatively common condition with rising incidence. Diagnosis is by colonoscopy (which is usually normal but may show some mild changes) and biopsies which reveal characteristic histological findings. Symptoms include non-bloody diarrhoea with urgency which may be associated with faecal incontinence and abdominal pain. Microscopic colitis is associated with a reduced health-related quality of life, and treatment is aimed at symptom control. Medications linked with the development of microscopic colitis, including proton pump inhibitors, non-steroidal anti-inflammatory drugs and selective serotonin-reuptake inhibitors, should be discontinued. If symptoms persist, budesonide is a licensed treatment for microscopic colitis which has been shown to be effective in clinical trials and real-world practice.

Les colites microscopiques

Microscopic colitis is frequently found as a cause of chronic watery diarrhea in women after menopause. The disease can be associated with a medication side effect in half of the patients (non-steroidal anti-inflammatory drugs or proton pump inhibitors for instance). Colonic biopsies are mandatory for the diagnosis of microscopic colitis and should be performed in several locations of the colon. Management of microscopic colitis is first based on avoiding iatrogenic factors and smoking together with symptomatic treatment of diarrhea (loperamide, cholestyramine). In case of failure or severe symptoms, budesonide is the key treatment. The aim of the treatment is to achieve clinical remission, defined as less than 3 liquid stools per day, to improve quality of life. After a first course of budesonide, recurrence of diarrhea is frequent and a maintenance therapy can be prescribed for several months. In case of intolerance or refractoriness, second-line therapy (immunosuppressants, biological therapy, surgery) should be discussed in multidisciplinary team meeting.

Microscopic colitis: pathophysiology and clinical management

Microscopic colitis is a chronic inflammatory disease of the colon that frequently causes chronic watery diarrhoea that might be accompanied by abdominal pain, nocturnal diarrhoea, urgency, and faecal incontinence. These symptoms lead to poor quality of life and increased health-care costs. Diagnosis relies on histological examination of multiple biopsy samples from the colonic mucosa, which often show no or only few abnormalities on endoscopy. Two major histological subtypes can be distinguished-collagenous colitis and lymphocytic colitis-but incomplete and variant forms with fewer characteristic features have been reported. Here we summarise the latest evidence on epidemiology, pathogenesis, and risk factors, and discuss established and novel therapeutic options for clinical remission. Finally, we propose an updated treatment algorithm. Further prospective studies are needed to clarify the natural history of microscopic colitis, supported by validated criteria for the assessment of disease activity.

Microscopic colitis: diagnosis and management

Microscopic colitis (MC) is a common cause of chronic, non-bloody, watery diarrhoea in older patients. The diagnosis depends on characteristic histological findings. Bile acid malabsorption and autoimmune conditions, including coeliac disease, are more frequently found in patients with MC, but colorectal neoplasia and mortality are not increased. Non-steroidal anti-inflammatory drugs, proton-pump inhibitors, selective serotonin reuptake inhibitors and smoking tobacco confer an increased risk of developing MC. Although a so-called benign disease, which rarely causes serious complications, it does have an impact on the quality of life. Several treatment options exist, but budesonide is the only treatment proven in randomised-controlled trials to be effective and safe for induction and maintenance of remission. This article provides a practical overview for the gastroenterologist looking after patients with MC.

Single-centre experience with anti-tumour necrosis factor treatment in budesonide-refractory microscopic colitis patients

Background

Microscopic colitis is an inflammatory bowel disease that causes chronic, watery diarrhoea. Microscopic colitis is usually effectively treated with budesonide, but some patients are refractory. Data on alternative treatments are sparse.

Aims

The purpose of this study was to retrospectively evaluate outcome of microscopic colitis patients receiving anti-tumour necrosis factor therapy at our centre.

Methods

Treatment results, including side effects, for all microscopic colitis patients receiving anti-tumour necrosis factor therapy were registered at week 12 and at end of follow-up. Clinical remission was defined as a mean of <3 stools and <1 watery stools/day/week and clinical response as a 50% reduction of mean stool frequency/day/week. Induction and maintenance treatment was either adalimumab or infliximab.

Results

The study cohort comprised 18 patients; mean age at diagnosis was 47 years (range 19-77). Ten and eight patients, respectively, received adalimumab and infliximab as first-line anti-tumour necrosis factor; seven patients received second-line anti-tumour necrosis factor due to non-response, loss of response or side effects. At week 12, 9/18 patients had achieved remission, 6/18 were responders and 3/18 were non-responders. Of the nine remission patients, 3/18 (16%) had long-lasting clinical remission post-induction therapy alone. Five patients (28%) (one first-line, four second-line anti-tumour necrosis factor) were in remission and one patient (6%) responded to maintenance treatment; follow-up was mean 22 (range 4-60) months. Six patients (33%) had minor, reversible side effects.

Conclusions

Over half of budesonide-refractory microscopic colitis patients can achieve clinical remission or response on anti-tumour necrosis factor agents. Prospective studies are mandatory to evaluate the efficacy and safety of anti-tumour necrosis factor treatments in budesonide-refractory microscopic colitis.

Budesonide treatment for microscopic colitis: systematic review and meta-analysis

Microscopic colitis (MC), encompassing lymphocytic and collagenous colitis, is a common cause for chronic nonbloody diarrhoea, which impacts significantly on the quality of life for patients. Despite increasing awareness of the condition and its treatment, there is considerable variation in therapeutic approaches. To conduct a systematic review and meta-analysis on the efficacy and safety of budesonide in the treatment of MC. We searched Medline, Embase and Central databases using predefined search methodology for randomised trials using budesonide in the treatment of MC. We extracted data, on the efficacy and safety of budesonide, from studies identified that met the feasibility for analysis criteria. These data were pooled with a fixed effects model. Nine studies met the inclusion criteria for analysis. The pooled odds ratios (ORs) for a response to budesonide therapy at induction and maintenance were 7.34 [95% confidence interval (CI): 4.08-13.19] and 8.35 (95% CI: 4.14-16.85) respectively. Histological response rates were superior in budesonide-treated patients compared to placebo following induction (OR: 11.52; 95% CI: 5.67-23.40) and maintenance treatment (OR: 5.88; 95% CI: 1.90-18.17). There was no difference in adverse events. Significant relapse rates (>50%) were observed following treatment cessation with no difference noted between the budesonide or the placebo-treated patients. Budesonide is an effective treatment option for MC for achieving induction and maintenance of both clinical and histological response. High relapse rates on treatment cessation were observed.

Vedolizumab in Refractory Microscopic Colitis: An International Case Series

BACKGROUND

Evidence for second-line therapy in patients with microscopic colitis [MC] failing budesonide is scarce, although anti-tumour necrosis factors [anti-TNFs], methotrexate and azathioprine have been reported to be effective in small cohort studies. Vedolizumab, a monoclonal antibody targeting α4β7-integrin, prevents homing of T-cells to the gut. We evaluated clinical remission with vedolizumab in budesonide-refractory MC patients.

METHODS

We solicited gastroenterologists in Europe and Canada for cases of MC treated with vedolizumab. Vedolizumab 300 mg IV was administered at weeks 0, 2 and 6, and then every 8 weeks. Clinical remission and histological remission were defined as less than three stools per day and normalization of histology, respectively, after induction treatment.

RESULTS

Eleven cases were retrieved (nine females, lymphocytic colitis [LC] n = 5, collagenous colitis [CC] n = 6). Median [interquartile range] disease duration at vedolizumab initiation was 51 [29-70] months. Nine of 11 patients had failed one immunosuppressant and ten of 11 at least one anti-TNF agent. After three infusions of vedolizumab, clinical remission was observed in 5/11 patients [two LC and three CC] of whom three remained well with maintenance therapy [median duration of 13 months]. Biopsies were obtained from 9/11 patients. Histological remission was observed in 3/4 patients with clinical remission [2/3 CC, 1/1 LC] and 0/5 patients without clinical improvement.

CONCLUSION

In a series of highly refractory MC patients, vedolizumab induced clinical remission in 5/11 subjects, of whom 75% showed normalized histology. Larger randomized trials are needed to assess the efficacy of vedolizumab in patients with MC.

Microscopic colitis: a narrative review with clinical approach

Microscopic colitis (MC) is diagnosed in presence of microscopic alterations of colonic mucosa, in patients without macroscopic lesions who referred for chronic diarrhea. The two types of MC are lymphocytic colitis (LC) and collagenous colitis (CC), but it is unclear whether these are the different expression of one unique disease or if they are distinct conditions. Today, although MC represents a consistent health problem, being responsible for a large part of gastroenterological consultations for diarrhea, it remains often underestimated. The detailed pathogenesis of MC has not been determined yet. Probably, it is the result of an interaction between individual, environmental and genetic factors. The most relevant risk factor for the development of MC is the use of certain drugs (such as non-steroidal anti-inflammatory drugs [NSAIDs], proton pump inhibitors [PPIs], selective serotonin reuptake inhibitors, beta-blockers, statins). Smoking is another relevant factor reported as associated with the development of MC. Diagnosis needs the execution of a colonoscopy in patients complaining about chronic diarrhea and abdominal pain. The crucial role is played by histology: MC is characterized by the presence of colonic mucosal lymphocytic infiltrate, with intraepithelial lymphocytes ≥20 per 100 enteric surface cells, in CC there is a typical subepithelial collagen layer, whose thickness is ≥10 μm. We carried out a review of the current literature to rule out what is new on epidemiology, diagnosis and therapy of MC.

Management of microscopic colitis: challenges and solutions

Microscopic colitis (MC) is a chronic inflammatory bowel disease characterized by nonbloody diarrhea in the setting of normal appearing colonic mucosa. MC has two main subtypes based on histopathologic features, collagenous colitis and lymphocytic colitis. Management of both subtypes is the same, with treatment goal of reducing the number of bowel movements and improving consistency. First-line treatment involves counseling the patient about decreasing their risk factors, like discontinuing smoking and avoiding medications with suspected association such as NSAIDs, proton pump inhibitor, ranitidine, and sertraline. Starting loperamide for immediate symptomatic relief is used as an adjunct to therapy with glucocorticoids. Budesonide is considered first-line treatment for MC given its favorable side effect profile and good efficacy, though relapse rates are high. Systemic glucocorticoids should be reserved to patients unable to take budesonide. In glucocorticoid refractory disease, medications that have been tried include cholestyramine, bismuth salicylate, antibiotics, probiotics, aminosalicylates, immunomodulators, and anti-tumor necrosis factor-alpha inhibitors. More research is needed for the creation of a systematic stepwise approach for relapsing and refractory disease.

Research progress and perspectives of microscopic colitis

Microscopic colitis (MC) is a common cause of chronic diarrhea. Over the past 20 years, the prevalence of MC has been increasing rapidly, which has aroused the close attention of digestive physicians. The etiology of MC is still unknown, and immune abnormalities are the main pathogenesis, followed by some drugs. MC is clinically characterized by chronic non-bloody watery diarrhea, spastic abdominal pain, weight loss, and fatigue, but colonoscopy is often normal or roughly normal. Colonic biopsy often shows mucosal inflammation or subepithelial collagen band thickening, based on which a diagnosis can be made. At present, there has been no special treatment for MC, with steroid budesonide and immunosuppressive agents being the main treatments. As a self-limiting disease, MC has a good prognosis. Studies have found that MC has a protective effect against colorectal cancer. However, it was recently found that innate immune abnormalities may have carcinogenic effects.

Collagenous panenteritis: a rare cause of chronic diarrhoea

Collagenous panenteritis is a rare inflammatory condition that causes profound diarrhoea and weight loss. There has only been a handful of cases reported in the literature. We report this rare case and the diagnostic difficulties encountered in securing the diagnosis. A 59-year-old woman presented with an 8-month history of diarrhoea and weight loss on a background of a family history of coeliac disease. Her presentation was complicated with acute kidney injury secondary to prerenal losses. Repeated gastroscopies and colonoscopies along with biopsies were inconclusive. It was not until histology of biopsies taken at endoscopies were reviewed that a diagnosis of collagenous panenteritis was secured. Her management revolved around combination of budesonide, gluten-free diet and antidiarrhoeals, which has achieved clinical remission.

Collagenous colitis: Requirement for high-dose budesonide as maintenance treatment

BACKGROUND

Controlled studies show high efficacy of budesonide in inducing short-term clinical remission in collagenous colitis (CC), but relapses are common after its withdrawal.

AIM

To evaluate the need for high-dose budesonide (≥6mg/d) to maintain clinical remission in CC.

METHODS

Analysis of a multicentre retrospective cohort of 75 patients with CC (62.3±1.5years; 85% women) treated with budesonide in a clinical practice setting between 2013 and 2015. Frequency of budesonide (9mg/d) refractoriness and safety, and the need for high-dose budesonide to maintain clinical remission, were evaluated. Drugs used as budesonide-sparing, including azathioprine and mercaptopurine, were recorded. Logistic regression analysis was performed to evaluate the risk factors associated with the need for high-dose budesonide (≥6mg/d) to maintain clinical remission.

RESULTS

Budesonide induced clinical remission in 92% of patients, with good tolerance. Fourteen of 68 patients (21%; 95% CI, 13-32%) needed high-dose budesonide to maintain remission. Only intake of NSAIDs at diagnosis (OR, 8.6; 95% CI, 1.6-44) was associated with the need for high-dose budesonide in the multivariate analysis.

TREATMENT

with thiopurines was effective in 5 out of 6 patients (83%; 95% CI, 44-97%), allowing for withdrawal from or a dose decrease of budesonide.

CONCLUSIONS

One fifth of CC patients, especially those with NSAID intake at diagnosis, require high-dose budesonide (≥6mg/d) to maintain clinical remission. In this setting, thiopurines might be effective as budesonide-sparing drugs.

Immune modulator therapy for microscopic colitis in a case series of 73 patients

BACKGROUND

Microscopic colitis (MC) is a common cause of chronic diarrhoea. Various treatment options have been described, but there are limited data describing outcomes of corticosteroid-sparing treatments.

AIM

To evaluate the outcomes of patients with active MC treated with immune modulators.

METHODS

All patients seen at Mayo Clinic, Rochester between January 1, 1997 and November 30, 2016 with a histological diagnosis of MC were identified. Patients treated with an immune modulator of interest were selected and clinical outcomes recorded.

RESULTS

Seventy-three MC patients (50 collagenous colitis and 23 lymphocytic colitis) with a median disease duration of 24 months (range, 7-60) were included. The indications for treatment were budesonide-refractoriness in 66%, budesonide dependence in 29%, and budesonide intolerance in 5%. Median age was 51.8 years (range, 43.4-63.1) and 61 (84%) were female. Thiopurines were used in 49 patients (67%) for a median of 4 months (range, 1.5-15). Complete and partial response occurred in 43% and 22% respectively. Adverse effects resulting in therapy cessation occurred in 17 patients (35%). Twelve patients (16%) were treated with methotrexate for a median of 14 months (3-18.8). Complete and partial response occurred in 58% and 17%, respectively. Anti-TNF therapy was used in 10 patients (14%) for a median of 4 months (range, 2.3-5.5). Complete response occurred in four patients and partial response in four patients.

CONCLUSIONS

The majority of patients with active MC responded to thiopurines, methotrexate, or anti-TNF therapy. Larger controlled studies are required to confirm the efficacy and safety of these medications in MC.

显微镜结肠炎的诊疗进展

显微镜结肠炎(microscopic colitis, MC)是一种以反复发作的、非出血性、分泌性水样腹泻为主要临床表现, 结肠镜下结肠黏膜正常, 病理显微镜下见特异性病理、组织学改变的一组临床、病理综合征, 其主要包括淋巴细胞性结肠炎和胶原性结肠炎两种类型. 近十余年来MC的发病率有所增高, 相关研究愈来愈多, 但临床医师对其认识有限. 本文就收集到的国内、外的相关研究文献, 对该病的流行病学、病因、临床症状、结肠镜诊断、病理学诊断及治疗方面的研究进展作一概述.

Current Approach to the Evaluation and Management of Microscopic Colitis. Curr Gastroenterol Rep. 2017;19:8. [PMID: 28265892 DOI: 10.1007/s11894-017-0551-3]

PURPOSE OF REVIEW

Microscopic colitis is a common cause of chronic watery diarrhea, particularly in the elderly. The accompanying symptoms, which include abdominal pain and fatigue, can markedly impair patients' quality of life. Diagnosis is based upon characteristic histologic findings of the colonic mucosa. This review focuses on the current approach to evaluation and management of patients with microscopic colitis.

RECENT FINDINGS

Although the incidence of microscopic colitis has been increasing over time, recent epidemiological studies show stabilization at 21.0-24.7 cases per 100,000 person-years. Recent research has further expanded our knowledge of the underlying pathophysiology and emphasized the entity of drug-induced microscopic colitis and the association with celiac disease. Two recent randomized studies have confirmed the effectiveness of oral budesonide for both induction and maintenance treatment of microscopic colitis and is now endorsed by the American Gastroenterological Association as first-line treatment. The incidence of microscopic colitis has stabilized at just over 20 cases per 100,000 person-years. Celiac disease and drug-induced microscopic colitis should be considered in all patients diagnosed with microscopic colitis. There are a number of treatments available for patients with microscopic colitis; however, budesonide is the only option well studied in controlled trials and is effective for both induction and maintenance treatment.

Budesonide-Related Iatrogenic Cushing's Syndrome in Microscopic Colitis

Budesonide is the treatment of choice for microscopic colitis because of its excellent risk to benefit ratio. It is a potent, well-absorbed corticosteroid, but because of a high rate of first-pass metabolism in the liver, its systemic bioavailability is low. It has fewer corticosteroid-related adverse effects than prednisone, and adrenal suppression is considered to be rare. We present a middle-aged woman with lymphocytic colitis whose symptoms responded to budesonide but developed budesonide-related iatrogenic Cushing’s syndrome. Withdrawal of budesonide led to restoration of normal pituitary-adrenal responsiveness but at the price of recurrent diarrhea due to re-emergence of lymphocytic colitis.

Diagnosis and Management of Microscopic Colitis

Microscopic colitis (MC) is a relatively common cause of chronic watery diarrhea, especially in older persons. Associated symptoms, including abdominal pain and arthralgias, are common. The diagnosis is based upon characteristic histological findings in the presence of diarrhea. The two types of MC, collagenous and lymphocytic colitis, share similar clinical features, with the main difference being the presence or absence of a thickened subepithelial collagen band. There are several treatment options for patients with MC, although only budesonide has been well studied in multiple controlled clinical trials. This review will describe the clinical features, epidemiology, pathophysiology, diagnostic criteria, and treatment of patients with MC.

Optimal management of collagenous colitis: a review

Collagenous colitis (CC) is an increasingly recognized cause of chronic inflammatory bowel disease characterized by watery non-bloody diarrhea. As a lesser studied inflammatory bowel disease, many aspects of the CC's natural history are poorly understood. This review discusses strategies to optimally manage CC. The goal of therapy is to induce clinical remission, <3 stools a day or <1 watery stool a day with subsequent improved quality of life (QOL). Antidiarrheal can be used as monotherapy or with other medications to control diarrhea. Budesonide therapy has revolutionized treatment and is superior to prednisone, however, the treatment is associated with high-relapse rates and the management of refractory disease is challenging. Ongoing trials will address the safety and efficacy of low-dose maintenance therapy. For those with refractory disease, case reports and case series support the role of biologic agents. Diversion of the fecal stream normalizes colonic mucosal changes and ileostomy may be considered where anti-tumor necrosis factor (TNF)-α agents are contraindicated. Underlying celiac disease, bile salt diarrhea, and associated thyroid dysfunction should be ruled out. The author recommends smoking cessation as well as avoidance of nonsteroidal anti-inflammatories as well as other associated medications.

Current concepts on microscopic colitis: evidence-based statements and recommendations of the Spanish Microscopic Colitis Group

BACKGROUND

Microscopic colitis (MC) is an underdiagnosed inflammatory bowel disease.

AIM

To develop an evidence-based clinical practice guide on MC current concepts.

METHODS

Literature search was done on the Cochrane Library, EMBASE and MEDLINE electronic databases, which were consulted covering the period up until March 2015. Work groups were selected for each of the reviewed topics, with the purpose of drafting the initial statements and recommendations. They subsequently underwent a voting process based on the Delphi method. Each statement/recommendation was accompanied by the result of the vote the level of evidence, and discussion of the corresponding evidence. The grade of recommendation (GR) using the GRADE approach was established for diagnosis and treatment recommendations.

RESULTS

Some key statements and recommendations are: advancing age increases the risk of developing MC, mainly in females. The symptoms of MC and IBS-D may be similar. If MC is suspected, colonoscopy taking biopsies is mandatory. Treatment with oral budesonide is recommended to induce clinical remission in patients with MC. Oral mesalazine is not recommended in patients with collagenous colitis for the induction of clinical remission. The use of anti-TNF-alpha drugs (infliximab, adalimumab) is recommended for the induction of remission in severe cases of MC that fail to respond to corticosteroids or immunomodulators, as an alternative to colectomy.

CONCLUSIONS

This is the first consensus paper on MC based on GRADE methodology. This initiative may help physicians involved in care of these patients in taking decisions based on evidence.

Contemporary methods for the diagnosis and treatment of microscopic colitis

Microscopic colitis is a common cause of chronic diarrhea. It is characterized by non-bloody watery diarrhea with macroscopically normal colonic mucosa. Its specific histological characteristics confirm the diagnosis. Two distinct histological forms can be identified, namely, collagenous colitis and lymphocytic colitis. In collagenous colitis, a thick colonic subepithelial collagenous deposit can be observed, whereas in lymphocytic colitis, a pronounced intraepithelial lymphocytic inflammation in the absence of a thickened collagen band can be identified. Microscopic colitis occurs more frequently in elderly females and its etiology is believed to be multifactorial, although smoking and consumption of several drugs have been identified as risks factors for the development of the disease. The treatment is based on avoiding the risks factors and administration of oral budesonide.

Microscopic colitis: A review of etiology, treatment and refractory disease

Microscopic colitis is a common cause of chronic, nonbloody diarrhea. Microscopic colitis is more common in women than men and usually affects patients in their sixth and seventh decade. This article reviews the etiology and medical management of microscopic colitis. The etiology of microscopic colitis is unknown, but it is associated with autoimmune disorders, such as celiac disease, polyarthritis, and thyroid disorders. Smoking has been identified as a risk factor of microscopic colitis. Exposure to medications, such as non-steroidal anti-inflammatory drugs, proton pump inhibitors, and selective serotonin reuptake inhibitors, is suspected to play a role in microscopic colitis, although their direct causal relationship has not been proven. Multiple medications, including corticosteroids, anti-diarrheals, cholestyramine, bismuth, 5-aminosalicylates, and immunomodulators, have been used to treat microscopic colitis with variable response rates. Budesonide is effective in inducing and maintaining clinical remission but relapse rate is as high as 82% when budesonide is discontinued. There is limited data on management of steroid-dependent microscopic colitis or refractory microscopic colitis. Immunomodulators seem to have low response rate 0%-56% for patients with refractory microscopic colitis. Response rate 66%-100% was observed for use of anti-tumor necrosis factor (TNF) therapy for refractory microscopic colitis. Anti-TNF and diverting ileostomy may be an option in severe or refractory microscopic colitis.

Microscopic colitis

Microscopic colitis (MC) is the common denominator for lymphocytic and collagenous colitis (CC). It is now recognized as a relatively frequent cause of diarrhea that equals the prevalence of inflammatory bowel disease. Patients are typically middle-aged women, but disease may occur at every age. Patients with MC report watery, non-bloody diarrhea in the absence of endoscopic and radiologic abnormalities. Lymphocytic colitis is characterized by an increased number of intraepithelial lymphocytes, and CC by a thickened subepithelial collagen band, whereas in both an increased mononuclear infiltration of the lamina propria is found. The pathogenesis of MC is largely unknown, but may relate to autoimmunity, adverse reactions to drugs or (bacterial) toxins, and abnormal collagen metabolism in the case of CC. Budesonide is so far the only drug that has proven efficacy in randomized controlled trials both for the induction and maintenance of remission. Patients who are nonresponsive, dependent or who experience side effects on budesonide may benefit from thiopurine or anti-TNF treatment, but these options are still experimental. The long-term prognosis of MC is good; it does not appear to predispose to malignancies and can in some cases be self-limiting. Further research and randomized clinical trials are required to expand our understanding of the natural course and the pathogenesis of MC.

Microscopic colitis: clinical and pathologic perspectives

Microscopic colitis is a chronic inflammatory bowel disease characterized by chronic nonbloody diarrhea and specific histopathology features. Active disease, defined as 3 or more stools or 1 or more watery stools per day, significantly reduces quality of life. Epidemiologic studies have found the incidence and prevalence of microscopic colitis to be comparable with those of Crohn's disease and ulcerative colitis. Nevertheless, microscopic colitis is still under-recognized in clinical practice-most health care workers know little about its etiology and pathophysiology. Furthermore, there are many challenges to the diagnosis and treatment of patients. We review the epidemiologic and clinical features of this disorder and discuss its pathogenesis. We also outline the criteria for histopathologic evaluation of microscopic colitis, recently published by the European Consensus on Inflammatory Bowel Disease, and discuss a treatment algorithm created by the European Microscopic Colitis Group. Treatment options for patients with budesonide-refractory disease are discussed.

VSL#3 induces and maintains short-term clinical response in patients with active microscopic colitis: a two-phase randomised clinical trial

BACKGROUND

The probiotic mixture VSL#3 has proven efficacious in inflammatory bowel diseases and irritable bowel syndrome; however, its efficacy in microscopic colitis (MC) is being investigated.

OBJECTIVE

To evaluate the safety and efficacy of a multistrain probiotic, VSL#3, in inducing clinical remission and achieving clinical response, as compared with mesalamine, in patients with active MC.

METHODS

A randomised, open labelled study comparing the efficacy of 900 billion colony-forming units/day of VSL#3 (group (Gp) A) or 1.6 g of mesalamine/day (Gp B) for 8 weeks in 30 patients with MC was conducted. After a washout period of 2 weeks, Gp B received 8 weeks of VSL#3 and Gp A was off medication for the next 8 weeks. The primary end points were clinical remission and clinical response at 8 weeks.

RESULTS

Of 30 patients, 15 were randomised in each arm. 11 patients in Gp A and 13 patients in Gp B completed 8 weeks of treatment. 5 (46%) of 11 patients in Gp A and 1 (8%) of 13 patients in Gp B attained clinical remission (p=0.022). Clinical response was seen in Gp A, as evidenced by a lower stool weight (377.6±104.5 g) as compared with Gp B (507±168.2 g; p=0.03). VSL#3 was effective in maintaining clinical response up to 10 weeks, even after discontinuation of therapy. Secondary end points like stool parameters, histology and well-being improved in both treatment groups.

CONCLUSIONS

The probiotic VSL#3 was found to offer the benefit of inducing as well as maintaining short-term clinical response in patients with active MC.

TRIAL REGISTRATION NUMBER

The clinical trial is registered with CLINICAL TRIAL REGISTRY INDIA; http://ctri.nic.in, CTRI No. "CTRI/2008/091/000086" (registered on: 23/06/2008).

Microscopic colitis: a review

AIM

In recent years, microscopic colitis has been increasingly diagnosed. This review was carried out to evaluate demographic factors for microscopic colitis and to perform a systematic assessment of available treatment options.

METHOD

Relevant publications up to December 2013 were identified following searches of PubMed and Google Scholar using the key words 'microscopic colitis', 'collagenous colitis' and 'lymphocytic colitis'. Two-hundred and forty-eight articles were identified.

RESULTS

The term microscopic colitis includes lymphocytic colitis and collagenous colitis. Both have common clinical symptoms but are well defined histopathologically. The clinical course is usually benign, but serious complications, including death, may occur. A peak incidence from 60 to 70 years of age with a female preponderance is observed. Although most cases are idiopathic, associations with autoimmune disorders, such as coeliac disease and hypothyroidism, as well as with exposure to nonsteroidal anti-inflammatory drugs and proton-pump inhibitors, have been observed. The incidence and prevalence of microscopic colitis is rising and good-quality epidemiological research is needed. Treatment is currently largely based on anecdotal evidence and on results from limited clinical trials of budesonide. Long-term follow-up of these patients is not well established.

CONCLUSION

The review synthesizes work on the definition of microscopic colitis and the relationship between collagenous and lymphocytic colitis. It reviews the international epidemiology and work on aetiology. In addition, it critically considers the efficacy of a range of treatments.

Diagnosis and management of microscopic colitis: current perspectives

Collagenous colitis and lymphocytic colitis, together constituting microscopic colitis, are common causes of chronic diarrhea. They are characterized clinically by chronic nonbloody diarrhea and a macroscopically normal colonic mucosa where characteristic histopathological findings are seen. Previously considered rare, they now have emerged as common disorders that need to be considered in the investigation of the patient with chronic diarrhea. The annual incidence of each disorder is five to ten per 100,000 inhabitants, with a peak incidence in 60- to 70-year-old individuals and a predominance of female patients in collagenous colitis. The etiology and pathophysiology are not well understood, and the current view suggests an uncontrolled mucosal immune reaction to various luminal agents in predisposed individuals. Clinical symptoms comprise chronic diarrhea, abdominal pain, fatigue, weight loss, and fecal incontinence that may impair the patient's health-related quality of life. An association is reported with other autoimmune disorders, such as celiac disease, thyroid disorders, diabetes mellitus, and arthritis. The best-documented treatment, both short-term and long-term, is budesonide, which induces clinical remission in up to 80% of patients after 8 weeks' treatment. However, after successful budesonide therapy is ended, recurrence of clinical symptoms is common, and the best possible long-term management deserves further study. The long-term prognosis is good, and the risk of complications, including colonic cancer, is low. We present an update of the epidemiology, pathogenesis, diagnosis, and management of microscopic colitis.

Microscopic colitis: epidemiology, pathophysiology, diagnosis and current management-an update 2013

Microscopic colitis is a common cause of chronic diarrhea. Over the last years the incidence and the prevalence of microscopic colitis are rising and this rise is largely attributed to a rising awareness, and concomitantly an increasing number of diagnoses are made. Patients with microscopic colitis report watery, nonbloody diarrhea of chronic, intermittent, or chronic recurrent course. Following an unremarkable physical examination the diagnosis of microscopic colitis is made by colonoscopy, which shows essentially a normal colonic mucosa. Biopsies taken during the colonoscopy procedure will then finally establish the correct diagnosis. Histological workup can then confirm a diagnosis of microscopic colitis and can distinguish the two distinct histological forms, namely, collagenous colitis and lymphocytic colitis. Presently both forms are diagnosed and treated in the same way; thus the description of the two forms is not of clinical value, though this may change in future. Depending on the patients age and gender 10-30% of patients investigated for chronic diarrhea will be diagnosed with microscopic colitis if biopsies are taken. Microscopic colitis is most common in older patients, especially in female patients and is frequently associated with autoimmune disorders and the consumption of several drugs. This review summarizes the present knowledge of the epidemiology, the pathophysiology, and the diagnosis of microscopic colitis and discusses the former and the present treatment options.