Budesonide treatment and expression of inducible nitric oxide synthase mRNA in colonic mucosa in collagenous colitis

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pathogenesis of Microscopic Colitis: A Systematic Review

BACKGROUND

Whereas the exact aetiology of microscopic colitis [MC] remains unknown, a dysregulated immune response to luminal factors or medications is the most accepted pathogenesis hypothesis.

METHODS

We conducted a systematic review of the pathogenesis of MC. We applied the Joanna Briggs Institute methodologies and the PRISMA statement for the reporting of systematic reviews [PROSPERO Trial Identifier: CRD42020145008]. Populations, Exposure of interest, and Outcome [PEO] questions were used to explore the following topics in MC: 1] intestinal luminal factors; 2] autoimmunity; 3] innate immunity; 4] adaptive immunity; 5] extracellular matrix; 6] genetic risk factors; and 7] mechanism of diarrhoea. A search was done in PubMed, Embase, and Web of Science up to February 2020. A narrative description was performed explaining the findings for each aspect of MC aetiopathogenesis.

RESULTS

Thirty-eight documents provided evidence for PEO1, 100 for PEO2, 72 for PEO3 and 4, 38 for PEO5, 20 for PEO6, and 23 for PEO7. The majority of documents were cohorts, case reports, and case series, with a few case-control and some experimental studies. Consistency among data provided by different studies was considered to support pathogenetic hypotheses. MC is a multifactorial disease believed to involve innate and adaptive immune responses to luminal factors, genetic risk, autoimmunity, and extracellular matrix alterations, all contributing by varied mechanisms to watery diarrhoea.

CONCLUSIONS

This is the first systematic review on the aetiology of MC supporting the notion that MC is a multifactorial disease. However, high-profile studies are lacking, and most evidence derives from small heterogeneous studies.

Interventions for treating collagenous colitis

BACKGROUND

Collagenous colitis is a cause of chronic diarrhea. This updated review was performed to identify therapies for collagenous colitis that have been assessed in randomized controlled trials (RCTs).

OBJECTIVES

The primary objective was to assess the benefits and harms of treatments for collagenous colitis.

SEARCH METHODS

We searched CENTRAL, the Cochrane IBD Group Specialized Register, MEDLINE and EMBASE from inception to 7 November 2016.

SELECTION CRITERIA

We included RCTs comparing a therapy with placebo or active comparator for the treatment of active or quiescent collagenous colitis.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two authors. The primary outcome was clinical response or maintenance of response as defined by the included studies. Secondary outcome measures included histological response, quality of life and the occurrence of adverse events. Risk ratios (RR) and 95% confidence intervals (CI) were calculated for dichotomous outcomes. The Cochrane risk of bias tool was used to assess bias. The overall quality of the evidence was assessed using the GRADE criteria.

MAIN RESULTS

Twelve RCTs (476 participants) were included. These studies assessed bismuth subsalicylate, Boswellia serrata extract, mesalamine, cholestyramine, probiotics, prednisolone and budesonide therapy. Four studies were low risk of bias. One study assessing mesalamine and cholestyramine was judged to be high risk of bias due to no blinding. The other studies had an unclear risk of bias for random sequence generation (five studies) allocation concealment (six studies), blinding (one study), incomplete outcome data (one study) and selective outcome reporting (one study). Clinical response occurred in 100% (4/4) of patients who received bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks) compared to 0% (0/5) of patients who received placebo (1 study; 9 participants; RR 10.80, 95% CI 0.75 to 155.93; GRADE = very low). Clinical response occurred in 44% (7/16) of patients who received Boswellia serrata extract (three 400 mg/day capsules for 8 weeks) compared to 27% (4/15) of patients who received placebo (1 study; 31 participants; RR 1.64, 95% CI 0.60 to 4.49; GRADE = low). Clinical response occurred in 80% (24/30) of budesonide patients compared to 44% (11/25) of mesalamine patients (1 study; 55 participants; RR 1.82, 95% CI 1.13 to 2.93; GRADE = low). Histological response was observed in 87% (26/30) of budesonide patients compared to 44% (11/25) of mesalamine patients (1 study, 55 participants; RR 1.97, 95% CI 1.24 to 3.13; GRADE = low). There was no difference between the two treatments with respect to adverse events (RR 0.69, 95% CI 0.43 to 1.10; GRADE = low), withdrawals due to adverse events (RR 0.09, 95% CI 0.01 to 1.65; GRADE = low) and serious adverse events (RR 0.12, 95% CI 0.01 to 2.21; GRADE = low). Clinical response occurred in 44% (11/25) of mesalamine patients (3 g/day) compared to 59% (22/37) of placebo patients (1 study; 62 participants; RR 0.74, 95% CI 0.44 to 1.24; GRADE = low). Histological response was observed in 44% (11/25) and 51% (19/37) of patients receiving mesalamine and placebo, respectively (1 study; 62 participants; RR 0.86, 95% CI 0.50 to 1.47; GRADE = low). There was no difference between the two treatments with respect to adverse events (RR 1.26, 95% CI 0.84 to 1.88; GRADE = low), withdrawals due to adverse events (RR 5.92, 95% CI 0.70 to 49.90; GRADE = low) and serious adverse events (RR 4.44, 95% CI 0.49 to 40.29; GRADE = low). Clinical response occurred in 63% (5/8) of prednisolone (50 mg/day for 2 weeks) patients compared to 0% (0/3) of placebo patients (1 study, 11 participants; RR 4.89, 95% CI 0.35 to 68.83; GRADE = very low). Clinical response occurred in 29% (6/21) of patients who received probiotics (2 capsules containing 0.5 x 10¹⁰ CFU each of L. acidophilus LA-5 and B. animalis subsp. lactis strain BB-12 twice daily for 12 weeks) compared to 13% (1/8) of placebo patients (1 study, 29 participants, RR 2.29, 95% CI 0.32 to 16.13; GRADE = very low). Clinical response occurred in 73% (8/11) of patients who received mesalamine (800 mg three times daily) compared to 100% (12/12) of patients who received mesalamine + cholestyramine (4 g daily) (1 study, 23 participants; RR 0.74, 95% CI 0.50 to 1.08; GRADE = very low). Clinical response occurred in 81% (38/47) of patients who received budesonide (9 mg daily in a tapering schedule for 6 to 8 weeks) compared to 17% (8/47) of placebo patients (3 studies; 94 participants; RR 4.56, 95% CI 2.43 to 8.55; GRADE = low). Histological response was higher in budesonide participants (72%, 34/47) compared to placebo (17%, 8/47) (RR 4.15, 95% CI 2.25 to 7.66; GRADE = low). Clinical response was maintained in 68% (57/84) of budesonide patients compared to 20% (18/88) of placebo patients (3 studies, 172 participants, RR 3.30 95% CI 2.13 to 5.09; GRADE = low). Histological response was maintained in 48% (19/40) of budesonide patients compared to 15% (6/40) of placebo patients (2 studies; 80 participants; RR 3.17, 95% CI 1.44 to 6.95; GRADE = very low). No difference was found between budesonide and placebo for adverse events (5 studies; 290 participants; RR 1.18, o95% CI 0.92 to 1.51; GRADE = low), withdrawals due to adverse events (5 studies, 290 participants; RR 0.97, 95% CI 0.43 to 2.17; GRADE = very low) or serious adverse events (4 studies, 175 participants; RR 1.11, 95% CI 0.15 to 8.01; GRADE = very low). Adverse effects reported in the budesonide studies include nausea, vomiting, neck pain, abdominal pain, excessive sweating and headache. Adverse effects reported in the mesalamine studies included nausea and skin rash. Adverse effects in the prednisolone study included abdominal pain, headache, sleep disturbance, mood change and weight gain.

AUTHORS' CONCLUSIONS

Low quality evidence suggests that budesonide may be effective for inducing and maintaining clinical and histological response in patients with collagenous colitis. We are uncertain about the benefits and harms of therapy with bismuth subsalicylate, Boswellia serrata extract, mesalamine with or without cholestramine, prednisolone and probiotics. These agents and other therapies require further study.

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.

Lymphocytic and collagenous colitis: an overview of so-called microscopic colitis

The entity of 'microscopic colitis' is being diagnosed with increasing frequency and is a well-established clinicopathological diagnosis that is underpinned by a triad of watery diarrhea, normal results on endoscopy and characteristic microscopic findings. Careful histopathological evaluation and awareness of its numerous associations (especially with drugs and celiac disease) and mimics will lead to the correct diagnosis of microscopic colitis. The etiology of microscopic colitis remains enigmatic and is multifactorial with different elements being more influential in different individuals. Treatment includes antidiarrheal agents and anti-inflammatory drugs (including steroids). The purpose of this article is to provide some clarity on nomenclature, discuss the multitude of conditions that can occur synchronously or metachronously with microscopic colitis and their role in the etiopathogenesis of this condition, provide a detailed review of the pathological aspects of the disease and to briefly discuss treatment trends.

Epithelial barriers in intestinal inflammation

The gastrointestinal epithelium transports solutes and water between lumen and blood and at the same time forms a barrier between these compartments. This highly selective and regulated barrier permits ions, water, and nutrients to be absorbed, but normally restricts the passage of harmful molecules, bacteria, viruses and other pathogens. During inflammation, the intestinal barrier can be disrupted, indicated by a decrease in transcellular electrical resistance and an increase in paracellular permeability for tracers of different size. Such inflammatory processes are accompanied by increased oxidative stress, which in turn can impair the epithelial barrier. In this review, we discuss the role of inflammatory oxidative stress on barrier function with special attention on the epithelial tight junctions. Diseases discussed causing barrier changes include the inflammatory bowel diseases Crohn's disease, ulcerative colitis, and microscopic colitis, the autoimmune disorder celiac disease, and gastrointestinal infections. In addition, the main cytokines responsible for these effects and their role during oxidative stress and intestinal inflammation will be discussed, as well as therapeutic approaches and their mode of action.

The collagenous gastroenteritides: similarities and differences

Collagenous gastritis, collagenous sprue, and collagenous colitis share striking histologic similarities and occur together in some patients. They also share some drug and disease associations. Pediatric cases of collagenous gastritis, however, lack most of these associations. The etiologies of the collagenous gastroenteritides are not known, so it is not clear whether they are similar because they share pathogeneses, or because they indicate a common histologic response to varying injuries. The features, disease and drug associations, and the inquiries into the pathogenesis of these disorders are reviewed.

Collagenous gastritis: histopathologic features and association with other gastrointestinal diseases

Collagenous gastritis (CG) characterized by the deposition of a subepithelial collagen band and accompanying inflammatory infiltrate is a rare disorder. The natural history and pathogenesis of CG remain unclear. We describe the histologic features (23 gastric, 18 duodenal, and 4 colonic biopsies) and clinical findings of an additional 12 cases. Histologic features including active or chronic inflammation, surface epithelial injury, intraepithelial lymphocytosis, intestinal metaplasia, and Helicobacter pylori, and measurement of thickness of subepithelial collagenous band were evaluated in gastric biopsies. The clinical features, endoscopic findings, and follow-up were obtained and correlated with histologic features. There was an even number of males (n=6) and females (n=6). Four patients were children/young adults, 3 of whom (75%) presented with anemia and gastric nodularity. Eight patients were adults, 6 of whom (75%) had an associated autoimmune disease (1 with Hashimoto thyroiditis and polymyositis) or other intestinal disease (3 with celiac sprue, 1 with collagenous colitis, 1 with collagenous sprue), in contrast to none in the 4 children/young adults, P=0.06. The range of subepithelial collagen thickness was 15 to 120 microm in CG. The collagenous layer showed surface epithelial injury and entrapped inflammatory cells. On presentation, the thickened collagen distribution in the antrum and body was variably patchy and diffuse. Four (33%) patients showed lymphocytic gastritis (3 within the same biopsy); one of these patients also had celiac sprue and another had collagenous sprue. Three (25%) patients had celiac sprue (2 had duodenal biopsy proven and 1 had a clinical diagnosis of celiac sprue). An additional patient had duodenal biopsies showing collagenous sprue. Four patients had follow-up biopsies during a 3 to 119-month period after the diagnosis of CG. CG persisted on the follow-up gastric biopsies in 3 (75%) of the 4 patients, and the other patient had lymphocytic gastritis, a finding not seen in previous biopsies. CG is a rare disorder with a distinct presentation and association in pediatric and adult patients. An absence of associated intestinal and autoimmune diseases characterizes the pediatric population. Association with lymphocytic gastritis, celiac or collagenous sprue, collagenous colitis, and autoimmune disorders are frequently seen in adult patients.

Microscopic colitis: an update

Microscopic colitis (MC) causes chronic diarrhea, abdominal cramping, nausea, and weight loss. Colonic mucosa appears normal on endoscopy; however, biopsies show abnormalities such as intraepithelial lymphocytosis in lymphocytic colitis, and a thickened subepithelial collagen band in collagenous colitis. Epidemiologic data demonstrates that MC is a more common cause of diarrhea than previously shown. Although the etiology of this condition is unclear, certain well-defined risk factors exist. Recently there has been more research on the pathophysiology of MC, and studies on treatment have demonstrated budesonide to be most effective, although other treatments also hold promise.

Diagnosis and management of microscopic colitis

Microscopic colitis, comprising collagenous and lymphocytic colitis, is characterized clinically by chronic watery diarrhea, and a macroscopically normal colonic mucosa where diagnostic histopathological features are seen on microscopic examination. The annual incidence of each disorder is 4-6/100,000 inhabitants, with a peak incidence in 60-70-year-old individuals and a noticeable female predominance for collagenous colitis. The etiology is unknown. Chronic diarrhea, abdominal pain, weight loss, fatigue and fecal incontinence are common symptoms, which impair the health-related quality of life of the patient. There is an association with other autoimmune disorders such as celiac disease, diabetes mellitus, thyroid disorders and arthritis. Budesonide is the best-documented short-term treatment, but the optimal long-term strategy needs further study. The long-term prognosis is good and the risk of complications including colonic cancer is low.

A unique case of collagenous colitis presenting as protein-losing enteropathy successfully treated with prednisolone

A 76-year-old woman with a 5-mo history of recurrent diarrhea and generalized edema was admitted to our hospital. Colonoscopy revealed edematous mucosa, and histopathological examination was compatible with collagenous colitis. Protein leakage from the colon, particularly in the ascending portion, was identified on 99mTc-human serum albumin scintigraphy. Collagenous colitis associated with protein-losing enteropathy (PLE) without small bowel disease was diagnosed. Prednisolone treatment ameliorated diarrhea and hypoproteinemia. Collagenous colitis should be included in the differential diagnosis of chronic diarrhea with hypoproteinemia for appropriate management.

Interventions for treating collagenous colitis

BACKGROUND

Collagenous colitis is a cause of chronic diarrhea. Treatment has been based mainly on anecdotal evidence. This review was performed to identify therapies for collagenous colitis that have been proven in randomized trials.

OBJECTIVES

To determine effective treatments for patients with collagenous colitis.

SEARCH STRATEGY

Relevant papers published between 1970 and December 2007 were identified via the MEDLINE and PUBMED databases. Manual searches from the references of identified papers, as well as review papers on collagenous or microscopic colitis were performed to identify additional studies. Abstracts from major gastroenterological meetings were searched to identify research submitted in abstract form only. Finally, the Cochrane Controlled Trials Register and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Ten randomized trials were identified. Seven of these compared active treatment to placebo for treating active disease. Of these, 1 trial studied bismuth subsalicylate, 1 trial studied Boswellia serrata extract, 3 trials studies budesonide, 1 trial studied prednisolone, and 1 trial studied probiotics. One trial compared mesalamine to mesalamine + cholestyramine for treating active disease. Two trials compared budesonide to placebo in maintaining response induced by budesonide.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by each author onto 2x2 tables (treatment versus comparator and response versus no response). For therapies assessed in one trial only, P-values were derived using the chi-square test. For therapies assessed in more than one trial, summary test statistics were derived using the Peto odds ratio and 95% confidence intervals. Data were combined for analysis only if the outcomes were sufficiently similar in definition.

MAIN RESULTS

In treating active disease, there were 9 patients with collagenous colitis in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks). Clinical response occurred in 100% of patients who received bismuth subsalicylate compared to 0% of patients who received placebo (P = 0.03). Thirty-one patients were enrolled in the trial studying Boswellia serrata extract (three 400 mg capsules daily for 8 weeks). Clinical response occurred in 44% of patients who received Boswellia serrata extract compared to 27% of patients who received placebo (P = 0.32). A total of 94 patients were enrolled in 3 trials studying budesonide (9 mg daily or in a tapering schedule for 6 to 8 weeks). Clinical response occurred in 81% of patients who received budesonide compared to 17% of patients who received placebo (P < 0.00001). The pooled odds ratio for clinical response to treatment with budesonide was 12.32 (95% CI 5.53 to 27.46), with a number needed to treat of 2 patients. Statistically significant histological response occurred with treatment in all 3 trials studying budesonide therapy. Eleven patients were enrolled in the trial studying prednisolone (50 mg daily for 2 weeks). Clinical response occurred in 63% of patients who received prednisolone compared to 0% who received placebo (P = 0.15). Twenty-nine patients were enrolled in the trial studying probiotics (2 capsules containing 0.5 x 10(10) CFU each of L. acidophilus LA-5 and B. animalis subsp. lactis strain BB-12 twice daily for 12 weeks). Clinical response occurred in 29% of patients who received probiotics compared to 13% of patients who received placebo (P = 0.38). Twenty-three patients were enrolled in the trial studying mesalamine (800 mg three times daily) with or without cholestyramine (4 g daily) for 6 months. Clinical response occurred in 73% of patients who received mesalamine alone compared to 100% of patients who received mesalamine + cholestyramine (P = 0.14). In maintaining response, 80 patients who had responded to open-label budesonide were enrolled in 2 trials studying budesonide (6 mg daily for 6 months). Clinical response was maintained in 83% of patients who received budesonide compared to 28% of patients who received placebo (P = 0.0002). The pooled odds ratio for maintenance of clinical response to treatment with budesonide was 8.40 (95% CI 2.73 to 25.81), with a number needed to treat of 2 patients. Histological response was maintained in 48% of patients who received budesonide compared to 15% of patients who received placebo (P = 0.002).

AUTHORS' CONCLUSIONS

Budesonide is effective for inducing and maintaining clinical and histological response in patients with collagenous colitis. The evidence for benefit with bismuth subsalicylate and for mesalamine with or without cholestyramine is weak. There is no evidence for the effectiveness of Boswellia serrata extract, prednisolone, or probiotics. These agents and other therapies require further study.