Microscopic colitis

Levodopa/dopa decarboxylase inhibitor associated microscopic colitis: An under-recognized drug reaction

BACKGROUND

Microscopic colitis is a form of inflammatory bowel disease characterized by profuse non-bloody watery diarrhea. Macroscopic abnormality is not present on colonoscopy, and it requires biopsy for diagnosis. Few cases have been attributed to levodopa/dopa-decarboxylase inhibitor therapy.

METHOD

A retrospective cohort study of 21 patients on levodopa/benserazide and one patient on levodopa-carbidopa intestinal gel with clinically suspected or biopsy proven microscopic colitis.

RESULTS

All 21 patients on oral levodopa/benserazide had resolution of diarrhea with cessation of the medication. Four patients discontinued levodopa permanently. Two were rechallenged with levodopa/benserazide without symptom recurrence. One patient on oral levodopa/carbidopa developed diarrhea only with intermittent dispersible levodopa/benserazide. 14 were switched to levodopa/carbidopa with resolution of diarrhea in 9 but symptom recurrence in 5. One patient on oral levodopa/benserazide developed profuse diarrhea when switched to levodopa-carbidopa intestinal gel. Of 7/22 patients who had colonoscopy and biopsy, 5 had histopathological proven microscopic colitis.

CONCLUSION

levodopa/dopa-decarboxylase inhibitor induced microscopic colitis may be more common than previously suspected, with the potential to affect treatment compliance and therapeutic options.

Incidence and Prevalence of Microscopic Colitis Between 2001 and 2016: A Danish Nationwide Cohort Study

BACKGROUND AND AIMS

Epidemiological studies suggest an increasing global incidence of microscopic colitis, including collagenous colitis and lymphocytic colitis. We aimed to investigate the incidence and prevalence of microscopic colitis in Denmark.

METHODS

In a nationwide cohort study, we included all incident patients with a recorded diagnosis of collagenous colitis or lymphocytic colitis in the Danish Pathology Register between 2001 and 2016.

RESULTS

A total of 14 302 patients with microscopic colitis-8437 [59%] with collagenous and 5865 [41%] with lymphocytic colitis-were identified during the study period. The prevalence in December 2016 was estimated to be 197.9 cases per 100 000 inhabitants. Microscopic colitis was more prevalent among females (n = 10 127 [71%]), with a mean annual incidence of 28.8, compared with 12.3 per 100 000 person-years among males. The overall mean incidence during the study period was 20.7 per 100 000 person-years. Mean age at time of diagnosis was 65 years (standard deviation [SD]:14) for microscopic colitis, 67 [SD:13] for collagenous colitis, and 63 [SD:15] for lymphocytic colitis. The overall incidence increased significantly from 2.3 cases in 2001 to 24.3 cases per 100 000 person-years in 2016. However, the highest observed incidence of microscopic colitis was 32.3 cases per 100 000 person-years in 2011. Large regional differences were found, with the highest incidence observed in the least populated region.

CONCLUSIONS

The incidence of microscopic colitis in Denmark has increased 10-fold during the past 15 years and has now surpassed that of Crohn's disease and ulcerative colitis. However, incidence has stabilised since 2012, suggesting that a plateau has been reached.

Microscopic ileitis in diverted and nondiverted enteric segments: an underrecognized condition with a multifactorial etiology

Microscopic ileitis has been infrequently reported in the literature with the few reported cases usually associated with concurrent microscopic colitis. Having encountered a case of collagenous ileitis involving the diverted distal limb of a loop ileostomy and sparing the proximal limb, we examined additional cases of loop ileostomy, end ileostomy, colostomy, and the accompanying diverted colorectal segment for features of microscopic ileitis and colitis. A total of 101 cases of diverted and nondiverted enteric segments were examined from 37 loop ileostomies, 16 end ileostomies, and 12 colostomies status post-Hartmann's procedure. The patients' clinical histories, including demographics and risk factors for microscopic colitis, were obtained from electronic medical records. The index case and an additional case showed collagenous ileitis: the former in the diverted distal limb, and the latter in the nondiverted proximal limb of the loop ileostomy. The latter was associated with high ileostomy output with watery diarrhea. Two additional cases showed lymphocytic ileitis: one in the nondiverted proximal limb of loop ileostomy and the other in the end ileostomy. All 4 patients had one or more risk factors for microscopic colitis. The etiology of microscopic ileitis seems to be multifactorial, and microscopic ileitis may be underdiagnosed. The diverted enteric segment may be involved by microscopic enteritis, suggesting that additional factors other than fecal stasis and altered bacterial flora may be contributing to its pathogenesis. When microscopic ileitis is encountered, identifying associated risk factors, recognizing incipient clinical symptoms of microscopic colitis, and considering other associated diseases or conditions are warranted.

Interventions for treating lymphocytic colitis

BACKGROUND

Lymphocytic colitis is a cause of chronic diarrhea. It is a subtype of microscopic colitis characterized by chronic, watery, non-bloody diarrhea and normal endoscopic and radiologic findings. The etiology of this disorder is unknown.Therapy is based mainly on case series and uncontrolled trials, or by extrapolation of data for treating collagenous colitis, a related disorder. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate the efficacy and safety of treatments for clinically active lymphocytic colitis.

SEARCH METHODS

The MEDLINE, PUBMED and EMBASE databases were searched from inception to 11 August 2016 to identify relevant papers. Manual searches from the references of included studies and relevant review articles were performed.Abstracts from major gastroenterological meetings were also searched to identify research submitted in abstract form only. The trial registry web site www.ClinicalTrials.gov was searched to identify registered but unpublished trials. Finally, the Cochrane Central Register of Controlled Trials and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register were searched for other studies.

SELECTION CRITERIA

Randomized controlled trials assessing medical therapy for patients with biopsy-proven lymphocytic colitis were considered for inclusion DATA COLLECTION AND ANALYSIS: Data was independently extracted by at least two authors. Any disagreements were resolved by consensus. Data were analyzed on an intention-to-treat (ITT) basis. The primary outcome was clinical response as defined by the included studies. Secondary outcome measures included histological response as defined by the included studies, quality of life as measured by a validated instrument and the occurrence of adverse events. Risk ratios (RR) and 95% confidence intervals (CI) were calculated for dichotomous outcomes. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting the primary outcome and selected secondary outcomes was assessed using the GRADE criteria. Data were combined for analysis if they assessed the same treatments. Dichotomous data were combined using a pooled RR along with corresponding 95% CI. A fixed-effect model was used for the pooled analysis.

MAIN RESULTS

Five RCTs (149 participants) met the inclusion criteria. These studies assessed bismuth subsalicylate versus placebo, budesonide versus placebo, mesalazine versus mesalazine plus cholestyramine and beclometasone dipropionate versus mesalazine. The study which assessed mesalazine versus mesalazine plus cholestyramine and the study which assessed beclometasone dipropionate versus mesalazine were judged to be at high risk of bias due to lack of blinding. The study which compared bismuth subsalicylate versus us placebo was judged as low quality due to a very small sample size and limited data. The other 3 studies were judged to be at low risk of bias. Budesonide (9 mg/day for 6 to 8 weeks) was significantly more effective than placebo for induction of clinical and histological response. Clinical response was noted in 88% of budesonide patients compared to 38% of placebo patients (2 studies; 57 participants; RR 2.03, 95% CI 1.25 to 3.33; GRADE = low). Histological response was noted in 78% of budesonide patients compared to 33% of placebo patients (2 studies; 39 patients; RR 2.44, 95% CI 1.13 to 5.28; GRADE = low). Forty-one patients were enrolled in the study assessing mesalazine (2.4 g/day) versus mesalazine plus cholestyramine (4 g/day). Clinical response was noted in 85% of patients in the mesalazine group compared to 86% of patients in the mesalazine plus cholestyramine group (RR 0.99, 95% CI 0.77 to 1.28; GRADE = low). Five patients were enrolled in the trial studying bismuth subsalicylate (nine 262 mg tablets daily for 8 weeks versus placebo). There were no differences in clinical (P=0.10) or histological responses (P=0.71) in patients treated with bismuth subsalicylate compared with placebo (GRADE = very low). Forty-six patients were enrolled in the trial studying beclometasone dipropionate (5 mg/day or 10 mg/day) versus mesalazine (2.4 g/day). There were no differences in clinical remission at 8 weeks (RR 0.97; 95% CI 0.75 to 1.24; GRADE = low) and 12 months of treatment (RR 1.29; 95% CI 0.40 to 4.18; GRADE = very low). Although patients receiving beclometasone dipropionate (84%) and mesalazine (86%) achieved clinical remission at 8 weeks, it was not maintained at 12 months (26% and 20%, respectively). Adverse events reported in the budesonide studies include nausea, vomiting, neck pain, abdominal pain, hyperhidrosis and headache. Nausea and skin rash were reported as adverse events in the mesalazine study. Adverse events in the beclometasone dipropionate trial include nausea, sleepiness and change of mood. No adverse events were reported in the bismuth subsalicylate study.

AUTHORS' CONCLUSIONS

Low quality evidence suggests that budesonide may be effective for the treatment of active lymphocytic colitis. This benefit needs to be confirmed by a large placebo -controlled trial. Low quality evidence also suggests that mesalazine with or without cholestyramine and beclometasone dipropionate may be effective for the treatment of lymphocytic colitis, however this needs to be confirmed by large placebo-controlled studies. No conclusions can be made regarding bismuth subsalicylate due to the very small number of patients in the study, Further trials studying interventions for lymphocytic colitis are warranted.

Association of Serotonin Transporter Promoter Polymorphism (5-HTTLPR) with Microscopic Colitis and Ulcerative Colitis

BACKGROUND

Serotonin (5-HT) release and serotonin reuptake transporter (5-HTT) expression have been reported to be decreased in experimental colitis, in interleukin-10 knockout-associated colitis, and in patients with ulcerative colitis. Serotonin is known to play an important role in the pathogenesis of colitis, but individual genetic variants of 5-HTT gene in microscopic colitis and ulcerative colitis are not known.

AIM

This study aimed to evaluate the association between the serotonin transporter gene promoter polymorphism (5-HTTLPR) and 5-HT concentration in microscopic colitis (MC) and ulcerative colitis (UC) patients.

METHOD

This prospective case-control study included 41 patients with microscopic colitis (age 19-82 years, mean 35 ± 13.6), 75 patients with ulcerative colitis (age 16-65 years, mean 38.5 ± 11.6), and 100 controls (age 20-64 years, mean 38 ± 11). 5-HTTLPR gene polymorphism was studied by polymerase chain reaction-based assay. 5-HT levels were measured by ELISA.

RESULTS

The frequency of the 5-HTTLPR (SS) genotype was significantly lower in MC (12 %) patients compared to controls (30 %) (p < 0.05). When the L/L and L/S genotypes were combined into one group, the frequencies of the non-S genotype were significantly higher than those of S/S genotype between the MC patients and the controls (p < 0.05). 5-HT levels were significantly higher in UC and MC patients compared to healthy controls (p < 0.01).

CONCLUSIONS

A significant association was observed between LL genotype of 5-HTTLPR polymorphism and microscopic colitis, suggesting that 5-HTTLPR is a potential candidate gene involved in the pathogenesis of microscopic colitis. Serotonin levels were significantly higher in microscopic colitis and ulcerative colitis patients compared to healthy controls.

Lymphocytic colitis associated with lansoprazole treatment

INTRODUCTION

There have been several reported cases of lansoprazole-associated collagenous colitis (CC) reported in the literature but only 1 reported case of lansoprazole-associated lymphocytic colitis (LC) in the literature. Both CC and LC are considered inflammatory bowel diseases, but they are distinctly classified based on the condition of the colon, which is typically confirmed through biopsy.

CASE SUMMARIES

A 52-year-old white male (Patient 1), with a height of 178 cm and weight of 75 kg, presented to Gazi University Hospital, Ankara, Turkey, with a 3-month history of abdominal pain and nonbloody, watery diarrhea. The patient reported receiving PO lansoprazole 30 mg/d to treat heartburn ~1 week prior to the onset of diarrhea. The patient's medical history revealed that he did not have any preexisting conditions, other than gastroesophageal reflux disease (GERD) for which lansoprazole was prescribed. The medical history report also revealed that the patient was not receiving any concomitant medications or treatments at the time. A colon biopsy confirmed LC. Additionally, a 43-year-old white female (Patient 2), with a height of 168 cm and weight of 61 kg, presented to the same facility with a 6-month history of nonbloody, watery diarrhea and mild lower abdominal cramping. The patient reported that initial onset began ~2 months after receiving a 10-day Helicobacter pylori eradication combination treatment regimen that included lansoprazole, amoxicillin, and clarithromycin, followed by lansoprazole monotherapy to treat GERD. The patient's medical history revealed no other concomitant medications were being adminstered at the time. A colon biopsy confirmed LC.

DISCUSSION

A search of the literature using the MEDLINE database and all relevant English-language articles with key words lansoprazole and lymphocytic colitis, found that there were several cases of lansoprazole-associated CC reported and 1 reported case of lansoprazole-associated LC. Histologic findings from laboratory tests and colon biopsies confirmed diagnoses of LC in both patients in this case report. Patient 1 presented with diarrhea and cramping, which the patient reported had been ongoing for ~3 months, following lansoprazole administration. However, after lansoprazole was discontinued, the symptoms completely resolved within 7 days. Patient 2 presented with diarrhea and cramping, which had been occurring for ~6 months. That patient reported that initial onset commenced ~2 months after a 10-day H pylori eradication combination treatment regimen that included lansoprazole, amoxicillin, and clarithromycin, followed by lansoprazole monotherapy to treat GERD. However, after sulfasalazine (3 g/d) was prescribed for 2 months immediately upon diagnosis of LC, there was little improvement in the effort to control the diarrhea in this patient. After omeprazole 20 mg/d was substituted for lansoprazole, the patient's diarrhea ceased. Follow-up sigmoidoscopy 2 months later revealed normal mucosa and complete normalization of histologic findings. The patient remains diarrhea-free while on omeprazole. A causality assessment using the Naranjo adverse reaction algorithm produced scores of 6 for both patients, suggesting that LC was probably associated with lansoprazole treatment.

CONCLUSIONS

Here we report 2 cases of LC in patients probably associated with the administration of lansoprazole treatment. Complete remission occurred after lansoprazole was discontinued.

Microscopic colitis

Microscopic colitis may be defined as a clinical syndrome, of unknown etiology, consisting of chronic watery diarrhea, with no alterations in the large bowel at the endoscopic and radiologic evaluation. Therefore, a definitive diagnosis is only possible by histological analysis. The epidemiological impact of this disease has become increasingly clear in the last years, with most data coming from Western countries. Microscopic colitis includes two histological subtypes [collagenous colitis (CC) and lymphocytic colitis (LC)] with no differences in clinical presentation and management. Collagenous colitis is characterized by a thickening of the subepithelial collagen layer that is absent in LC. The main feature of LC is an increase of the density of intra-epithelial lymphocytes in the surface epithelium. A number of pathogenetic theories have been proposed over the years, involving the role of luminal agents, autoimmunity, eosinophils, genetics (human leukocyte antigen), biliary acids, infections, alterations of pericryptal fibroblasts, and drug intake; drugs like ticlopidine, carbamazepine or ranitidine are especially associated with the development of LC, while CC is more frequently linked to cimetidine, non-steroidal antiinflammatory drugs and lansoprazole. Microscopic colitis typically presents as chronic or intermittent watery diarrhea, that may be accompanied by symptoms such as abdominal pain, weight loss and incontinence. Recent evidence has added new pharmacological options for the treatment of microscopic colitis: the role of steroidal therapy, especially oral budesonide, has gained relevance, as well as immunosuppressive agents such as azathioprine and 6-mercaptopurine. The use of anti-tumor necrosis factor-α agents, infliximab and adalimumab, constitutes a new, interesting tool for the treatment of microscopic colitis, but larger, adequately designed studies are needed to confirm existing data.

Microscopic colitis: Current status, present and future challenges: statements of the European Microscopic Colitis Group

Microscopic colitis (MC) is an inflammatory bowel disease presenting with chronic, non-bloody watery diarrhoea and few or no endoscopic abnormalities. The histological examination reveals mainly two subtypes of MC, lymphocytic or collagenous colitis. Despite the fact that the incidence in MC has been rising over the last decades, research has been sparse and our knowledge about MC remains limited. Specialists in the field have initiated the European Microscopic Colitis Group (EMCG) with the primary goal to create awareness on MC. The EMCG is furthermore a forum with the intention to promote clinical and basic research. In this article statements and comments are given that all members of the EMCG have considered being of importance for a better understanding of MC. The paper focuses on the newest updates in epidemiology, symptoms and diagnostic criteria, pathophysiology and highlights some unsolved problems. Moreover, a new treatment algorithm is proposed on the basis of new evidence from well-designed, randomized control trials.

Biopsy interpretation of colonic biopsies when inflammatory bowel disease is excluded

The interpretation of colonic biopsies related to inflammatory conditions can be challenging because the colorectal mucosa has a limited repertoire of morphologic responses to various injurious agents. Only few processes have specific diagnostic features, and many of the various histological patterns reflect severity and duration of the disease. Importantly the correlation with endoscopic and clinical information is often cardinal to arrive at a specific diagnosis in many cases.

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.

Clinical Characteristics of Microscopic Colitis in Korea: Prospective Multicenter Study by KASID

BACKGROUND/AIMS

Microscopic colitis (MC) encompasses collagenous and lymphocytic colitis and is characterized by chronic diarrhea. In cases of MC, colonic mucosae are macroscopically normal, and diagnostic histopathological features are observed only upon microscopic examination. We designed a prospective multicenter study to determine the clinical features, pathological distribution in the colon and prevalence of MC in Korea.

METHODS

We prospectively enrolled patients having watery diarrhea no more than 3 times a day between March 2008 and February 2009. We obtained patient histories and performed colonoscopies with random biopsies at each colon segment.

RESULTS

A total of 100 patients with chronic diarrhea were enrolled for a normal colonoscopy and stool exam. MC was observed in 22 patients (22%) (M:F 1.2:1; mean age, 47.5 years). Of those 22 patients, 18 had lymphocytic colitis and 4 had collagenous colitis. The entire colon was affected in only 3 cases (13.6%), the ascending colon in 6 cases (27.2%), the transverse colon in 3 cases (13.6%), and the left colon in 3 cases (13.6%). More than 2 segments were affected in 7 cases (31.8%). Nonsteroidal anti-inflammatory drug-associated MCs were observed in 4 cases (18.2%), 3 of which showed improved diarrhea symptoms following discontinuation of the medication. Frequently associated symptoms were abdominal pain and weight loss. Autoimmune diseases were observed in 4 cases (18.2%). Half of the 22 patients with MC improved with conservative care by loperamide or probiotics.

CONCLUSIONS

In a prospective multicenter study of Korean patients with chronic diarrhea, the frequency of MC was found to be approximately 20%, similar to the percentage observed in Western countries. Therefore, the identification of MC is important for the adequate management of Korean patients with chronic diarrhea.

Microscopic colitis as a missed cause of chronic diarrhea

AIM: To determine the prevalence of increased intraepithelial lymphocytes, using immunohistochemistry in patients with normal colonoscopy and near normal biopsy.

METHODS: We retrospectively reviewed all non-malignant colon mucosal biopsies between 2005 and 2007, reported as normal, chronic inflammation or melanosis coli in patients who were undergoing routine colonoscopy. Immunohistochemistry using CD3 was performed on all mucosal biopsies and an intraepithelial lymphocyte count (IEL) was determined. Cases with an IEL count of ≥ 20 IELs per 100 surface epithelial cells were correlated with demographic, clinical and follow-up data. A further subgroup was evaluated for lymphocytic colitis.

RESULTS: Twenty (8.3%) of 241 cases revealed an IEL count ≥ 20. Six (2.5%) patients were identified as having lymphocytic colitis (P < 0.001), of whom, five were missed on initial evaluation (P = 0.01). Four of these five patients were labeled with diarrhea-predominant irritable bowel syndrome (IBS). On follow-up, three of the remaining 20 cases were diagnosed with malignancy (renal cell carcinoma and myelodysplastic syndrome) and one had an unknown primary tumor with multiple liver metastases. Two cases of collagenous colitis with an IEL count < 10 were included in this study. Increased IELs were not confined to patients with diarrhea as a primary presenting symptom, but were also present in patients with abdominal pain (n = 7), constipation (n = 3) and loss of weight (n = 1).

CONCLUSION: Immunohistochemistry using CD3 is of value in identifying and quantifying IELs for the presence of microscopic colitis in patients with diarrhea-predominant IBS.

An association between microscopic colitis and celiac disease

BACKGROUND & AIMS

Microscopic colitis has been associated with celiac disease. We aimed to determine the extent and significance of this relationship.

METHODS

A prospectively maintained database of celiac disease patients, seen between 1981 and 2006, was analyzed. Standardized morbidity ratios (SMR) were calculated using a general population study of microscopic colitis as the reference group. Statistical analysis was conducted using the Student t test, Pearson chi(2) test, or Fisher exact test.

RESULTS

Microscopic colitis was found in 44 of 1009 patients (4.3%); this represented a 70-fold increased risk for individuals with celiac disease to have microscopic colitis, compared with the general population (SMR, 72.39; 95% confidence interval [CI], 52.52-95.36). The celiac disease patients with microscopic colitis were older (P = .0001) and had more severe villous atrophy (P = .002) than the celiac disease patients without microscopic colitis. Microscopic colitis was diagnosed after celiac disease in 64% of the patients, simultaneously in 25%, and before celiac disease in 11% (P = .0001). Pancolitis predominated, though 16% had colitis limited to the right colon. Steroid or immunosuppressant therapies were required in 66% of the celiac disease patients with microscopic colitis and given as maintenance therapy to 50% of these patients. Follow-up biopsies revealed that the colitis persisted in 57% of the patients with celiac disease and microscopic colitis, despite improved diarrhea symptoms; the diarrhea resolved in most of the patients.

CONCLUSIONS

Microscopic colitis is more common in patients with celiac disease than in the general population. Patients with celiac disease and microscopic colitis have more severe villous atrophy and frequently require steroids or immunosuppressant therapies to control diarrhea.

Association of alpha 2A adrenergic receptor gene (ADRAlpha2A) polymorphism with irritable bowel syndrome, microscopic and ulcerative colitis

BACKGROUND

Alpha 2 adrenergic receptors (alpha2 ARs) play a central role in the regulation of systemic sympathetic activity. Prejunctional alpha 2A adrenoceptor regulates through negative feedback at presynaptic nerve ending. A-1291 C>G polymorphism located in alpha2-adrenergic receptor gene (ADRAlpha2A) has been identified. We investigated the possible association between 1291 C>G polymorphism in the promoter region of ADRAlpha2A in clinical subtypes of IBS, ulcerative and microscopic colitis patients.

METHODS

This prospective case control study included 92 patients with diarrhea predominant IBS (D-IBS), 44 with constipation predominant IBS (C-IBS), 15 with alternating diarrhea and constipation IBS (M-IBS), 75 ulcerative colitis (UC), 41 microscopic colitis (MC) and 100 healthy controls. The subjects were genotyped by using PCR amplification of the promoter region of ADRAlpha2A gene followed by digestion with the restriction enzyme MspI. The study was approved by the institute ethical committee.

RESULTS

A strong genotypic association was observed between alpha2A-1291 C>G polymorphism and D-IBS (chi2=6.38, df=2, p<0.05). There was no significant difference in alpha2A-1291 C>G genotype and allele frequency between C-IBS, M-IBS, UC, MC cases and control subjects.

CONCLUSIONS

A significant association was observed between alpha2A-1291C>G polymorphism and D-IBS. Thus, alpha2 AR gene may be a potential candidate involved in the pathophysiology of D-IBS.

Association of collagenous colitis with prurigo nodularis

The etiology and pathogenesis of collagenous colitis (CC) is poorly understood and probably multifactorial; many potential pathophysiological mechanisms have been described, although none have been conclusively proved. Circumstantial evidence suggests that CC appears as an autoimmune response to a luminal or epithelial antigen of unknown origin. Infections and certain drugs (e.g. NSAID, lansoprazole) may act as triggers for an immune-mediated process. CC is characterized clinically by chronic watery, nonbloody diarrhea with normal endoscopic appearance and without radiological abnormalities, but specific microscopic changes in the colon. Histopathology is featured by the presence of a thickened subepithelial collagen band adjacent to the basal membrane. Up to 40% of patients with CC have associated diseases of autoimmune or inflammatory origin, such as thyroid disease, coeliac disease, rheumatoid arthritis, diabetes mellitus, Sjögren's syndrome, CREST syndrome, scleroderma, pernicious anemia, and sarcoidosis. Prurigo nodularis is a chronic condition characterized by intensely pruritic, lichenified, or excoriated papules and nodules of unknown etiology. It is assumed to represent a cutaneous reaction pattern to repeated scrubbing or scratching caused by pruritus. We report a case of CC and prurigo nodularis. To our knowledge, this association has not been reported earlier.

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.

Microscopic colitis: a common and an easily overlooked cause of chronic diarrhoea

Microscopic colitis, comprising collagenous colitis and lymphocytic colitis, is characterised clinically by chronic watery diarrhoea, 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 in collagenous colitis. The aetiology is unknown. Abdominal pain, weight loss, fatigue, and faecal incontinence are common symptoms in addition to chronic diarrhoea that impair the health-related quality of life of the patient. There is an association to 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.

Microscopic colitides: a single center experience in Mexico

BACKGROUND/AIM

Microscopic colitis is characterized by chronic diarrhea and specific microscopic changes in a macroscopically normal colonic mucosa. In this paper, we report the clinical and histological features of a group of Mexican patients with microscopic colitis.

MATERIALS AND METHODS

Patients were identified from 10 years of data in the pathology database of our institution. A pathologist reassessed all biopsy material. We included only patients who met strict histopathological criteria. Clinical data were obtained from medical records.

RESULTS

Microscopic colitis was diagnosed in 26 cases. The female/male ratio was 1.8:1. The median age at diagnosis was 56.5 +/- 15.7 (range, 26-85) years. The most frequent symptoms were diarrhea in all, weight loss in 22 (84%), and abdominal pain in 18 (69%) patients. Sixteen (61%) patients reported associated diseases; autoimmune thyroid disorders were the most common. Drug-induced microscopic colitis was suspected in 12 (46%) patients. More than 80% of the treated patients improved or had clinical remission.

CONCLUSION

Microscopic colitis is an uncommon colonic disease at our institution, representing less than 1% of the final diagnoses in mucosal colonic biopsies. It is the largest case series of microscopic colitis in the Mexican population.

Mesalazine with or without cholestyramine in the treatment of microscopic colitis: randomized controlled trial

BACKGROUND

Collagenous colitis (CC) and lymphocytic colitis (LC) are chronic inflammatory diseases of the colon with a benign and sometimes relapsing course. Frequency among patients with chronic diarrhea and normal looking colonoscopy is around 10-15%. To date, treatment of CC and LC is not well defined. Data about these conditions are mostly derived from retrospective studies. The aim of the present study was to evaluate the response to treatment and the clinical course of CC and LC in a large group of patients prospectively diagnosed.

METHODS AND RESULTS

A total of 819 patients underwent a colonoscopy because of chronic watery diarrhea and among them we found 41 patients with LC and 23 with CC. These patients were later randomized and assigned to treatment with mesalazine or mesalazine + cholestyramine for 6 months. Fifty-four patients (84.37%) had resolved diarrhea in less than 2 weeks. After 6 months a colonoscopy with biopsies was repeated. Clinical and histological remission was achieved in 85.36% of patients with LC and in 91.3% with CC, with a better result in patients with CC treated with mesalazine + cholestyramine. During a mean period of 44.9 months, 13% of patients relapsed; four with LC and three with CC. They were retreated for another 6 months. At the end of this period one patient with CC was still symptomatic and persistence of CC was confirmed at histology.

CONCLUSIONS

Treatment with mesalazine seems to be an effective therapeutic option for LC to date, while mesalazine + cholestyramine seems to be more useful in the treatment of CC.

Pharmacotherapy for Microscopic Colitis

Microscopic colitis is a common cause of chronic watery diarrhea. Its etiology is unknown, but use of nonsteroidal antiinflammatory drugs, aspirin, and lansoprazole may be risk factors for developing the disorder. Therapy is directed primarily at resolving the symptoms of microscopic colitis; bismuth subsalicylate, aminosalicylates, traditional corticosteroids, and budesonide have been evaluated. Compared with other therapies, budesonide has the strongest evidence for effectiveness in decreasing the volume and frequency of stools and improving the quality of life; it is, however, a costly drug. We reviewed all available primary English-language literature accounts of treatment of microscopic colitis. We performed searches of MEDLINE and International Pharmaceutical Abstracts, as well as reviewing the bibliographies from key articles, to procure pertinent reports. Microscopic colitis can be successfully treated with pharmacotherapy. Based on cost and adverse-effect profiles, antidiarrheals and bismuth subsalicylate are reasonable first options, but many patients may require budesonide to achieve remission.

Steroids reduce local inflammatory mediator secretion and mucosal permeability in collagenous colitis patients

AIM: To study the effect of oral steroids upon clinical response and rectal mucosa secretion of eosinophil cationic protein (ECP), myeloperoxidase (MPO), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and albumin in patients with collagenous colitis (CC).

METHODS: A segmental perfusion technique was used to collect perfusates from rectum of CC patients once before and twice (one and four weeks) after the start of steroid treatment. Clinical data was monitored and ECP, MPO, bFGF, VEGF and albumin concentrations were analyzed by immunochemical methods in perfusates and in serum.

RESULTS: Steroids reduced the number of bowel movements by more than five times within one week and all patients reported improved subjective well-being at wk 1 and 4. At the same time, the median concentrations of ECP, bFGF, VEGF and albumin in rectal perfusates decreased significantly. MPO values were above the detection limit in only 3 patients before treatment and in none during treatment. VEGF, bFGF, ECP and albumin concentrations correlated with each other with the exception of ECP and albumin. A decrease of serum ECP and VEGF concentrations was also seen even if the overtime reduction was not significant.

CONCLUSION: Oral steroid treatment in CC patients induced a simultaneous reduction of bowel movements and rectal release of ECP, bFGF, VEGF and albumin, suggesting that these polypeptides and increased mucosal permeability are important components of the pathophysiology in collagenous colitis.

Collagenous pouchitis

Collagenous colitis is characterised by watery diarrhoea, normal colonic mucosa on endoscopy, diffuse colitis with surface epithelial injury, and a distinctive thickening of the subepithelial collagen table on histology. Some patients can develop medically refractory collagenous colitis, in which case they may require surgical intervention. This is the first report of collagenous pouchitis in a collagenous colitis patient with proctocolectomy and ileal pouch-anal anastomosis. A patient with medically refractory collagenous colitis who underwent a total proctocolectomy and ileal pouch-anal anastomosis was sequentially evaluated with an endoscopy and histology of the colon, distal small intestine, and ileal pouch. A 58-year-old female had a 10-year history of collagenous colitis before having a total proctocolectomy and ileal pouch-anal anastomosis for medically refractory disease. The histologic features of collagenous colitis were present in all colon and rectum biopsy or resection specimens, but were absent in the distal ileum specimen. The post-operative course was complicated by persistent increase of stool frequency, abdominal cramps, and incontinence. A pouch endoscopy was performed 3 years after ileal pouch-anal anastomosis which showed the histologic features of collagenous colitis in the ileal pouch, collagenous pouchitis, while the pre-pouch neo-terminal ileum had no pathologic changes. After antibiotic therapy, the histologic changes of collagenous pouchitis resolved. This is the first reported case of collagenous pouchitis. Since the abnormal collagen table and its associated features were only present in the pouch and absent in the neo-terminal ileum, and the patient had histologic improvement after antibiotic therapy, it would suggest that faecal stasis and bacterial load may play a role in the pathogenesis.

Microscopic colitis demonstrates a T helper cell type 1 mucosal cytokine profile

BACKGROUND

Microscopic colitis (MC) is an inflammatory disorder of unknown aetiology.

AIM

To characterise the mucosal cytokine profile of MC, with a view to understanding its potential pathogenic mechanisms.

METHODS

Cytokine profiles of mucosal biopse specimens taken at flexible sigmoidoscopy from 18 patients (8 with lymphocytic colitis and 10 with collagenous colitis) were analysed using real-time reverse transcriptase-PCR, in comparison with those from 13 aged-matched controls with diarrhoea-predominant irritable bowel syndrome. Biopsy specimens from six patients with histologically documented remission were available for comparative analysis. Biopsy specimens were also taken to determine the cellular expression of cytokine and cytokine-related proteins using immunohistochemistry.

RESULTS

Mucosal mRNA levels were 100 times greater for interferon (IFN)gamma and interleukin (IL) 15, 60 times greater for tumour necrosis factor alpha, and 35 times greater for inducible nitric oxide synthase in MC compared with controls. Apart from a trend for increased levels of IL10, levels of other T helper cell type 2 (T(H)2) cytokines including IL2 and IL4 were too low to be accurately quantified. Mucosal IFNgamma mRNA levels correlated with the degree of diarrhoea, and returned to normal in remission. The immunohistochemical expression of cell junction proteins E-cadherin and ZO-1 was reduced in active disease. No differences were noted between lymphocytic and collagenous colitis for any of the above parameters.

CONCLUSIONS

MC demonstrates a T(H)1 mucosal cytokine profile with IFNgamma as the predominantly upregulated cytokine, with concurrent induction of nitric oxide synthase and down regulation of IFNgamma-related cell junction proteins. This pattern is similar to that in coeliac disease and suggests that it might represent a response to a luminal antigen.

Systematic review: microscopic colitis

BACKGROUND

Collagenous and lymphocytic colitis are fairly common causes of chronic non-bloody diarrhoea, especially in elderly female.

AIM

To present a systematic review of microscopic colitis.

METHODS

A PubMed search using the MeSH terms microscopic colitis, collagenous colitis, lymphocytic colitis and chronic diarrhoea was performed.

RESULTS

Annual incidence of each disorder is 4-6/100,000 inhabitants. The aetiology is unknown. Clinical characteristics are well described and there is an association with autoimmune diseases. Budesonide is the best-documented short-term treatment of collagenous colitis. In meta-analysis pooled odds ratio for clinical response after 6-8 weeks of treatment was 12.3 (95% CI: 5.5-27.5) in comparison with placebo. The evidence for bismuth subsalicylate is weaker and the effectiveness of other alternatives such as loperamide, cholestyramine, aminosalicylates, probiotics, or Boswellia serrata extract is unknown. Although unproven, in unresponsive severe disease azathioprine or methotrexate may be tried. No controlled trials have been carried out in lymphocytic colitis. The long-term prognosis of microscopic colitis is good, serious complications are rare and there is no increased mortality.

CONCLUSIONS

Clinical and epidemiological aspects of microscopic colitis are well described. Budesonide is the best-documented short-term therapy in collagenous colitis, but the optimal long-term strategy needs further study. Controlled treatment data of lymphocytic colitis are awaited for.

Histopathological diagnosis of microscopic colitis

A typical symptom of microscopic colitis (MC) is chronic watery diarrhea with normal endoscopic findings and characteristic inflammatory changes in histopathology. Treatment of the disease is mainly empiric. MC has two main subtypes: lymphocytic colitis and collagenous colitis. There are also untypical histopathological forms of MC: MC with giant cells, MC not otherwise specified (NOS) and cryptal lymphocytic coloproctitis. Some other histopathological changes in MC have been observed, especially Paneth cell hyperplasia or epithelial degeneration. Eosinophilic colitis, acute colitis, amyloidosis, ulcerative colitis and Crohn's disease should be taken into consideration in differential diagnosis. The most reliable biopsy material for histopathological examination are samples obtained from transverse colon. Some studies proved that treatment of MC makes it possible to reduce not only clinical, but also histopathological, manifestations.

Overview of role of the immune system in the pathogenesis of inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are caused by the over-activity of the immune system. Current and novel therapies are designed to dampen these over-active responses. Analysis of the types of immune responses ongoing in diseased mucosa of inflammatory bowel disease patients has revealed that CD and UC are fundamentally different diseases. The former has the molecular imprints of a Th1 dominant cell-mediated hypersensitivity response whereas the latter appears to involve antibody-mediated hypersensitivity.

Mechanism of diarrhea in microscopic colitis

AIM: To search the pathophysiological mechanism of diarrhea based on daily stool weights, fecal electrolytes, osmotic gap and pH.

METHODS: Seventy-six patients were included: 51 with microscopic colitis (MC) [40 with lymphocytic colitis (LC); 11 with collagenous colitis (CC)]; 7 with MC without diarrhea and 18 as a control group (CG). They collected stool for 3 d. Sodium and potassium concentration were determined by flame photometry and chloride concentration by titration method of Schales. Fecal osmotic gap was calculated from the difference of osmolarity of fecal fluid and double sum of sodium and potassium concentration.

RESULTS: Fecal fluid sodium concentration was significantly increased in LC 58.11±5.38 mmol/L (P<0.01) and CC 54.14±8.42 mmol/L (P<0.05) than in CG 34.28±2.98 mmol/L. Potassium concentration in LC 74.65±5.29 mmol/L (P<0.01) and CC 75.53±8.78 mmol/L (P<0.05) was significantly less compared to CG 92.67±2.99 mmol/L. Chloride concentration in CC 36.07±7.29 mmol/L was significantly higher than in CG 24.11±2.05 mmol/L (P<0.05). Forty-four (86.7%) patients had a secretory diarrhea compared to fecal osmotic gap. Seven (13.3%) patients had osmotic diarrhea.

CONCLUSION: Diarrhea in MC mostly belongs to the secretory type. The major pathophysiological mechanism in LC could be explained by a decrease of active sodium absorption. In CC, decreased Cl/HCO₃ exchange rate and increased chloride secretion are coexistent pathways.

Microscopic colitis: pathologic considerations, changing dogma

Microscopic colitis as an entity was first recognized in 1976, and has become one of the most frequent diseases to exclude on colonic mucosal biopsies. In some pathology practices, up to 30% of colonic biopsies received are from patients in whom microscopic colitis is the clinical question. In this review, the evolution of the terminology and early studies describing the pathology of microscopic colitis are discussed. The pathology of lymphocytic and collagenous colitis is reviewed in detail, including common diagnostic pitfalls, and what is currently known about the pathogenesis of these diseases. The differential diagnosis of microscopic colitis includes other idiopathic inflammatory bowel diseases (Crohn's and ulcerative colitis), infections, and drug reactions. The distinction between these entities and microscopic colitis is discussed in detail. Finally, recent studies have revealed new histopathologic changes in microscopic colitis that challenge the currently held concepts of how microscopic colitis fits into the spectrum of inflammatory bowel diseases.

Microscopic colitis

Microscopic colitis is a condition that is clinically underrecognized as a cause of chronic or intermittent diarrhea and can be diagnosed only by mucosal biopsy. Microscopic colitis is more common in middle-age to elderly women, appears to be induced by some medications, particularly nonsteroidal antiinflammatory drugs, and has been associated with autoimmune conditions and sprue. Symptomatic treatment includes cholestyramine and antidiarrheal medications. Bismuth subsalicylate, and 5-amniosalicylates are therapeutic options; however, budesonide is more effective in achieving clinical and histologic improvement and/or remission and has been studied in more randomized trials. Use of immune modulators should be restricted to more severe cases that are steroid refractory or steroid dependent. Surgical intervention should be reserved for a very highly select group of refractory cases. Diverting ileostomy or colectomy appear to be equally effective surgical alternatives for microscopic colitis, which is not a risk factor for carcinoma.

Collagenous colitis and cutaneous polyarteritis nodosa in the same patient

Collagenous colitis is associated with chronic diarrhoea and inflammatory changes detected by colonic biopsy, but no endoscopic abnormalities. Cutaneous polyarteritis nodosa shows the same histopathology as systemic polyarteritis nodosa, but is limited to the skin. Both diseases are rare and of unknown aetiology. Collagenous colitis has been described in association with different autoimmune disorders. We report on a case of collagenous colitis and cutaneous polyarteritis nodosa. To our knowledge, this association has not been reported previously.