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

BACKGROUND: Microscopic colitis (MC) is considered a chronic disease associated with autoimmune disease, smoking, and drugs. The aim was to examine the association between MC and celiac disease, adjusted for smoking, considering subtypes and clinical course of the disease in a retrospectively collected female cohort. METHODS: Women (n = 240), ≤ 73 years, diagnosed as MC in medical records or pathological registers were invited. One hundred and fifty-eight women accepted to be included. Participants completed a study questionnaire about sociodemographic factors, lifestyle habits, and medical history; the Rome III questionnaire; and the visual analog scale for irritable bowel syndrome (VAS-IBS). Participants were categorized into collagenous colitis (CC) (n = 92) and lymphocytic colitis (LC) (n = 66) or MC with one episode of the disease (n = 70) and refractory MC (n = 88). Presence of IBS-like symptoms were noted. Blood samples were collected and analyzed for anti-transglutaminase antibodies. Differences between groups were calculated and logistic regression was adjusted for smoking habits. RESULTS: MC and celiac disease debuted simultaneously in half of the cases. Celiac disease was most prevalent in LC (12.1% vs. 3.3%; p = 0.05) and MC with one episode (12.9% vs. 2.3%; p = 0.01). Anti-transglutaminase antibodies were found in one patient with one episode of MC. Corticosteroid use was most often found in CC (37.0% vs. 21.2%; p = 0.037) and refractory MC (38.6% vs. 20.0%; p = 0.015). Past smokers were most prevalent in patients with one episode of MC (54.3 vs. 29.5%; p = 0.007). Current smoking was the smoking habit with highest prevalence of IBS-like symptoms. When adjusted for smoking habits, celiac disease was associated with LC (OR: 4.222; 95% CI: 1.020-17.469; p = 0.047) and tended to be inversely associated with refractory MC (OR: 0.210; 95% CI: 0.042-1.506; p = 0.058). CONCLUSION: Celiac disease is most common in patients with one episode of LC. The question remains whether LC in combination with celiac disease should be classified as celiac disease or two different entities.

Celiac disease and risk of microscopic colitis: A nationwide population-based matched cohort study.

BACKGROUND: An association has been reported between celiac disease (CD) and microscopic colitis (MC). However, large, population-based cohort studies are rare. OBJECTIVE: To systematically examine the association between CD and MC in a large, nationwide cohort. METHODS: We conducted a nationwide population-based matched cohort study in Sweden of 45,138 patients with biopsy-verified CD (diagnosed in 1990-2016), 223,149 reference individuals, and 51,449 siblings of CD patients. Data on CD and MC were obtained from all (n = 28) pathology departments in Sweden. Adjusted hazard ratios (aHRs) were calculated using Cox regression. RESULTS: During follow-up, 452 CD patients and 197 reference individuals received an MC diagnosis (86.1 vs. 7.5 per 100,000 person-years). This difference corresponded to an aHR of 11.6 (95% confidence interval [CI] = 9.8-13.8) or eight extra MC cases in 1000 CD patients followed up for 10 years. Although the risk of MC was highest during the first year of follow-up (aHR 35.2; 95% CI = 20.1-61.6), it remained elevated even after 10 years (aHR 8.1; 95% CI = 6.0-10.9). Examining MC subtypes lymphocytic colitis (LC) and collagenous colitis (CC) separately, the aHR was 12.4 (95% CI = 10.0-15.3) for LC and 10.2 (95% CI = 7.7-13.6) for CC. MC was also more common before CD (adjusted odds ratio [aOR] = 52.7; 95% CI = 31.4-88.4). Compared to siblings, risk estimates decreased but remained elevated (CD and later MC: HR = 6.2; CD and earlier MC: aOR = 7.9). CONCLUSION: Our study demonstrated a very strong association of MC with CD with an increased risk of future and previous MC in CD patients. The magnitude of the associations underscores the need to consider the concomitance of these diagnoses in cases in which gastrointestinal symptoms persist or recur despite a gluten-free diet or conventional MC treatment. The comparatively lower risk estimates in sibling comparisons suggest that shared genetic and early environmental factors may contribute to the association between CD and MC.

Frequency And Risk Factors Of Microscopic Colitis As A Cause Of Chronic Watery Diarrhoea.

BACKGROUND: Microscopic colitis (MC) is one of the most underdiagnosed conditions leading to chronic watery diarrhoea in patients worldwide. This is the first study of this kind in Pakistan and we aimed to calculate the frequency as well as study the risk factors behind the disease. METHODS: This was a prospective cross-sectional study in a tertiary care hospital in Pakistan. A total of 58 participants with chronic watery diarrhoea who had normal colonoscopy were recruited for the study and biopsies were obtained for diagnosing MC. RESULTS: 2 participants out of 58 (3.4%) had biopsy proven microscopic colitis; one patient had a lymphocytic colitis variant and the other had a collagenous colitis variant. The average score based on the MC scoring system was 7.53 in the entire study group. The patient with lymphocytic colitis had a score of 06 while the patient with collagenous colitis had a score of 8. CONCLUSIONS: The frequency of microscopic colitis was found to be 3.4% of all cases of chronic watery diarrhoea. A link between MC and autoimmune diseases was also observed. However, we had a limited sample size and encouraged future studies to employ a larger sample size to get a multifaceted look at the disease process.

Temporal changes in the histology of microscopic colitis.

BACKGROUND: In a subgroup of patients with microscopic colitis [MC], its histopathology changed from lymphocytic [LC] to collagenous colitis [CC] and vice versa. Previous studies have also observed histopathological transitions between MC and inflammatory bowel disease [IBD]. AIMS: The aim of the present study was to analyse the prevalence of such transitions in a large population of MC patients. METHODS: The Inform Diagnostics database is an electronic repository of histopathology records of patients distributed throughout the USA. In a cross-sectional study, we analysed the prevalence of changes in MC histology. Each prevalence was expressed as the rate per 100 MC patients with its 95% Poisson confidence interval. RESULTS: In a total population of 29 307 MC patients, our cross-sectional study focused on a subgroup of 4363 patients who underwent two or more consecutive colonoscopies between December 2008 and March 2020. Overall, 1.6% [95% CI 1.2-2.0%] of patients changed their MC phenotype from LC to CC, and 0.5% [0.3-0.7%] from CC to LC. Of 4363 MC patients, 414 [9.5%] were also diagnosed with IBD. In 2.9% [2.4-3.5%], MC and IBD were diagnosed as synchronous mucosal lesions. In 2.1% [1.7-2.6%], MC changed to IBD, and in 4.5% [3.9-5.2%] IBD changed to MC. CONCLUSIONS: The analysis confirmed the synchronous occurrence of MC and IBD and transitions between the two diagnoses. In patients who fail therapy for either one of the two diseases, the gastroenterologist should search for changes in the underlying phenotype as a possible explanation.

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

BACKGROUND: Collagenous colitis (CC) is an inflammatory bowel disease where chronic diarrhoea is the main symptom. Diagnostic markers distinguishing between CC and other causes of chronic diarrhoea remain elusive. This study explores neutrophil gelatinase-associated lipocalin (NGAL) and its mRNA lipocalin2 (LCN2) as histological and faecal disease markers in CC. METHODS: NGAL/LCN2 were studied in colonic biopsies from CC patients before and during budesonide treatment using RNA sequencing (n = 9/group), in situ hybridization (ISH) (n = 13-22/group) and immunohistochemistry (IHC) (n = 14-25/group). Faecal samples from CC (n = 3-28/group), irritable bowel syndrome diarrhoea (IBS-D) (n = 14) and healthy controls (HC) (n = 15) were assayed for NGAL and calprotectin. RESULTS: NGAL/LCN2 protein and mRNA expression were upregulated in active CC vs HC, and vs paired samples of treated CC in clinical remission. IHC and ISH localized increased NGAL/LCN2 mainly to epithelium of active CC, compared to almost absence in HC and treated CC. In contrast, calprotectin was solely expressed in immune cells. Despite great individual differences, faecal NGAL was significantly increased in active CC compared to HC, IBS-D and treated CC and had high test sensitivity. Faecal calprotectin levels were variably increased in active CC, but the values remained below usual clinical cut-offs. CONCLUSION: NGAL/LCN2 is upregulated in the epithelium of active CC and reduced during budesonide-induced clinical remission to the level of HC and IBD-S. This was reflected in NGAL faecal concentrations. We propose NGAL as an IHC marker for disease activity in CC and a potential faecal biomarker discriminating CC from HC and IBS-D.

Gastrointestinal Infection and Risk of Microscopic Colitis: A Nationwide Case-Control Study in Sweden.

BACKGROUND AND AIMS: Gastrointestinal infections have been linked to changes in the composition and function of gut microbiome and development of inflammatory bowel diseases. We therefore sought to examine the relationship between gastroenteritis and risk of microscopic colitis (MC). METHODS: We conducted a case-control study of all adult patients with MC diagnosed between 1990 and 2016 in Sweden matched to up to 5 general population controls according to age, sex, calendar year, and county. Cases of MC were identified using Systematized Nomenclature of Medicine codes from the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study, a cohort of gastrointestinal pathology reports from all 28 pathology centers in Sweden. We used logistic regression modeling to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). RESULTS: Through December of 2016, we matched 13,468 MC cases to 64,479 controls. The prevalence of previous diagnosed gastrointestinal infection was 7.5% among patients with MC, which was significantly higher than in controls (3.0%, Pcomparison < .001). After adjustment, gastroenteritis was associated with an increased risk of MC (aOR 2.63; 95% CI 2.42-2.85). Among specific pathogens, Clostridioides difficile (aOR 4.39; 95% CI 3.42-5.63), Norovirus (aOR 2.87; 95% CI 1.66-4.87), and Escherichia species (aOR 3.82; 95% CI 1.22-11.58), but not Salmonella species, were associated with an increased risk of MC. The association between gastrointestinal infections and risk of MC was stronger for collagenous subtype (aOR 3.23; 95% CI 2.81-3.70) as compared with lymphocytic colitis (aOR 2.51; 95% CI 2.28-2.76; Pheterogeneity = .005). The associations remained significant after adjustment for immune-mediated conditions and polypharmacy and when compared with unaffected siblings. CONCLUSION: In a nationwide study, we found that gastrointestinal infection, particularly Clostridioides difficile, is associated with an increased risk of subsequent MC. This study was approved by the Regional Ethics Committee, Stockholm, Sweden (Protocol no. 2014/1287-31/4).

Epidemiological and clinical characteristics, and response to treatment in 113 patients with microscopic colitis. / Características epidemiológicas, clínicas y respuesta al tratamiento en 113 pacientes con colitis microscópica.

OBJECTIVE: To study the epidemiological and clinical characteristics, and response to treatment in patients with microscopic colitis. PATIENTS AND METHOD: Epidemiological, clinical, blood test and endoscopic data were retrospectively collected from 113 patients with microscopic colitis. Response to treatment was analyzed in 104 of them. Efficacy and relapse after treatment with budesonide were assessed using survival curves (Kaplan-Meier). RESULTS: 78% of the patients were women, with a mean age of 65 ± 16 years. In smokers, the mean age was 10 years younger. 48% of them had some concomitant autoimmune disease; 60% suffered a single outbreak of the disease. The clinical presentation was similar in both subtypes, although patients with collagenous colitis had a chronic course more frequently (48% vs. 29%, p = 0.047). The remission rate with budesonide was 93% (95% CI 82-98). The cumulative incidence of relapse, after a median follow-up of 21 months, was 39% (95% CI 26-54%): 19% at one year, 32% at two years, and 46% at three years of follow-up. There were no differences in clinical response to budesonide based on smoking habit or microscopic colitis subtype. CONCLUSIONS: Microscopic colitis is more frequent in elderly women. Smoking was associated with earlier onset of the disease, although it did not influence the clinical course or response to treatment. The majority (> 90%) of patients treated with budesonide achieved remission, although nearly half subsequently relapsed.

Microscopic colitis and its associations with complications observed in classic inflammatory bowel disease: a systematic review.

Objectives: Crohn's disease and ulcerative colitis are associated with an increased risk to develop anemia, cutaneous diseases, liver diseases, malignancy, osteoporosis, rheumatic diseases, thromboembolism and uveitis. The association between these diseases and microscopic colitis (MC) is not known. The aim of the present systematic review was to examine associations between MC and diseases observed in association with Crohn's disease and ulcerative colitis.Material and methods: According to the review protocol, original articles which described the prevalence of abovementioned diseases in relation to MC, were searched for in PubMed, Embase and Web of Science.Results: After exclusion of duplicates, 928 articles remained. Based on relevancy of their title, abstract or type of article, 16 articles were ordered in full text and after assessment, nine articles could be included in the review. A second research strategy with individual diseases rendered further two articles. Seven articles covered malignancy/neoplasia, where four showed no association with malignancy and three a reduced association compared with controls. Four articles covering rheumatic diseases showed an association between these diseases and MC. One study showed an association between MC and osteoporosis, whereas one did not. One study showed an association between MC and cutaneous diseases, whereas anemia, eye diseases and thromboembolism showed no associations.Conclusions: Due to short follow-up time in small studies, with selection bias due to exclusion of former or prevalent malignancy in an older population, no conclusions can be drawn concerning the true association between MC and malignancy. Rheumatic diseases seem to be associated with MC.

A nationwide cohort study of the incidence of microscopic colitis in Sweden.

BACKGROUND: Epidemiological studies of microscopic colitis have shown varying but increasing incidence rates. AIM: To assess the incidence of microscopic colitis in Sweden. METHODS: Nationwide cohort study performed in 1995-2015 based on biopsy reports. Age-specific and age-standardised incidence rates were calculated. RESULTS: We identified 13 844 patients with an incident diagnosis of microscopic colitis. Lymphocytic colitis (n = 9238) constituted 67% and collagenous colitis (n = 4606) 33% of microscopic colitis. The mean age at time of diagnosis of microscopic colitis was 60.2 years (58.6 for lymphocytic colitis, 63.3 for collagenous colitis). The lifetime risk of developing microscopic colitis was 0.87% in women (95% confidence interval, CI: 0.85-0.88) and 0.35% in men (95% CI: 0.34-0.36). From 2006, the overall incidence of microscopic colitis was approximately 10.5 cases per 100 000 person-years (95% CI: 9.8-11.3) with higher rates in women (72% of cases, incidence rate ratio = 2.4 (95% CI: 2.3-2.5) and the elderly with increasing rates up to 75-79 years. From 2006-2015, there was a significant increase of 1% per year (P = 0.02) in the overall microscopic colitis incidence rate in women; the estimated annual percent change was similar, although not statistically significant, in men (P = 0.15). CONCLUSIONS: In Sweden, the incidence of microscopic colitis is still increasing in women, although the rate appears to be stabilising. The incidence is particularly high in women and the elderly up to age 75-79 years. Finally, across a lifetime, 1 in 115 females and 1 in 286 males are expected to be diagnosed with microscopic colitis and thus posing a considerable disease burden.

Microscopic colitis: a population-based case series over a 9-year period in Northern Ireland.

AIM: We report clinicopathological experience of microscopic colitis (MC) in a population-based case series in Northern Ireland over a 9-year period. METHOD: The pathology laboratory information system within a large teaching centre serving two healthcare trusts was interrogated for cases coded between 2008 and 2016 as collagenous colitis (CC) or lymphocytic colitis (LC). Demographic, clinical and follow-up information was collected from healthcare records. RESULTS: A total of 326 new diagnoses of MC were identified, an average annual incidence of 6.7 per 100 000 population. The average annual incidence of CC and LC was 5.0 and 1.7 per 100 000 population, respectively. For coding reasons it is likely that LC data are incomplete. Of 191 cases diagnosed by specialist gastrointestinal pathologists, 141 patients had CC and 50 patients had LC. Both CC and LC predominantly involved women aged 60-79. Some 15% demonstrated endoscopic abnormalities. Endoscopic sampling protocols varied widely: 30% of individuals with CC and 32% of those with LC had the right and left colon sampled separately, with histology concordant in 95% of cases. Of the 191 cases, only one case (of LC) was refractory to treatment; the rest exhibited a clinical response. Only 35 patients had follow-up endoscopy and biopsies, and three of each diagnosis showed persistent disease on histology. CONCLUSION: Overall, CC and LC are benign conditions with similar demographics, clinical associations, management and outcomes. Separate sampling of the right and left colon is advised at colonoscopy if this diagnosis is being considered, but left colonic sampling, which can be performed at flexible sigmoidoscopy, will diagnose the vast majority of cases.

Microscopic colitis in patients with ulcerative colitis or Crohn's disease: a retrospective observational study and review of the literature.

OBJECTIVES: Onset of microscopic colitis (MC) in patients with ulcerative colitis (UC) or Crohn's disease (CD), or vice versa, has been reported occasionally but the subject is not well described. We therefore report a retrospective observational study of such patients and review the literature. METHODS: Forty-six Swedish gastroenterology clinics were contacted about patients with diagnoses of both inflammatory bowel disease (IBD) and MC. Publications were searched on PubMed. RESULTS: We identified 31 patients with onset of MC after a median (range) of 20 (2-52) years after diagnosis of IBD, or vice versa; 21 UC patients developed collagenous colitis (CC) (n = 16) or lymphocytic colitis (LC) (n = 5); nine CD patients developed CC (n = 5) or LC (n = 4); one CC patient developed CD. Of the 21 UC patients, 18 had extensive disease, whereas no consistent phenotype occurred in CD. Literature review revealed 27 comprehensive case reports of patients with diagnoses of both IBD and MC. Thirteen MC patients developed IBD, of which four required colectomy. Fourteen IBD patients later developed MC. There were incomplete clinical data in 115 additional reported patients. CONCLUSIONS: Altogether 173 patients with occurrence of both IBD and MC were found. The most common finding in our patients was onset of CC in a patient with UC. Although these are likely random associations of two different disorders, MC should be considered in the patient with UC or CD if there is onset of chronic watery diarrhoea without endoscopic relapse of IBD.

Smoking is Associated with an Increased Risk of Microscopic Colitis: Results From Two Large Prospective Cohort Studies of US Women.

BACKGROUND: Long-term data on the influence of smoking on risk of microscopic colitis are limited. We therefore sought to examine and characterize the association between smoking and risk of incident microscopic colitis in two large prospective cohorts of women. METHODS: We conducted a prospective study of 231015 women enrolled in the Nurses' Health Study [NHS] and NHSII. Information regarding smoking, other lifestyle factors and medications were collected biennially from 1976 to 2012 in NHS and from 1989 to 2013 in NHSII. Incident cases of microscopic colitis were confirmed through physician medical record review. We used Cox proportional hazards modelling to examine the association between smoking and risk of microscopic colitis. RESULTS: We documented 166 incident cases of microscopic colitis over 6122779 person-years of follow up. Compared to non-smokers, the multivariable-adjusted hazard ratio [HR] for microscopic colitis was 2.52 (95% confidence interval [CI] 1.59-4.00) amongst current smokers and 1.54 [95% CI 1.09-2.17] amongst past smokers. The risk increased with higher pack-years of smoking [p trend = 0.001] and diminished following smoking cessation [p trend = 0.017]. Current smoking appeared to be more strongly associated with risk of collagenous colitis [HR 3.68; 95% CI 1.94-6.97] than lymphocytic colitis [HR 1.71; 95% CI 0.83-3.53]. CONCLUSION: In two large prospective cohort studies, we observed an association between current smoking and risk of microscopic colitis. Risk of microscopic colitis appeared to increase with higher pack-years and diminish following smoking cessation. Future studies focused on characterizing the biological mechanisms underlying these associations are warranted.

Macroscopic findings, incidence and characteristics of microscopic colitis in a large cohort of patients from the United Kingdom.

OBJECTIVE: Microscopic colitis (MC) is classically associated with normal or near-normal endoscopic appearances. However, non-specific macroscopic findings have been described, the importance of biopsy location for confirming a diagnosis of MC is unclear, and reported incidence data from the United Kingdom are limited. This study was designed to assess macroscopic features, incidence, demographics, and location and positivity of biopsy samples in MC. MATERIALS AND METHODS: Retrospective, cross-sectional study of individuals with newly diagnosed MC. RESULTS: From 2010 to 2015, 540 cases of MC were reported. Macroscopic findings occurred in 16.5% (n = 89) cases, with trends towards increased frequency of ulceration or linear scarring in collagenous colitis (CC). The mean incidence of MC was 11.3 per 100,000 population/year, including 291 (53.9%) with CC (incidence 6.1 per 100,000/year), 203 (37.6%) with lymphocytic colitis (incidence 4.2 per 100,000/year) and 46 (8.5%) with MC, not otherwise specified. Most individuals were female (70.2%). Common features in patients with MC included symptom duration <6 months, weight loss, abdominal pain and use of proton pump inhibitors, statins, or non-steroidal anti-inflammatory drugs. In individuals with right- and left-sided biopsies taken, 98.2% had diagnostic features in both. However, rectal biopsies were only positive in 88.7%. CONCLUSIONS: One in six patients with MC demonstrated distinct macroscopic findings at colonoscopy. Our data confirm a female preponderance in MC, a relatively short symptom duration and use of certain drugs as common features. Both right- and left-sided biopsies were frequently positive, suggesting flexible sigmoidoscopy and biopsy could confirm a diagnosis in certain individuals.

Family history, comorbidity, smoking and other risk factors in microscopic colitis: a case-control study.

OBJECTIVES: Data on heredity, risk factors and comorbidity in microscopic colitis, encompassing collagenous colitis (CC) and lymphocytic colitis (LC), are limited. AIM: The aim was to carry out a case-control study of family history, childhood circumstances, educational level, marital status, smoking and comorbidity in microscopic colitis. METHODS: A postal questionnaire was sent in 2008-2009 to microscopic colitis patients resident in Sweden and three population-based controls per patient, matched for age, sex and municipality. RESULTS: Some 212 patients and 627 controls participated in the study. There was an association with a family history of microscopic colitis in both CC [odds ratio (OR): 10.3; 95% confidence interval (CI): 2.1-50.4, P=0.004] and LC (OR not estimated, P=0.008). Current smoking was associated with CC [OR: 4.7; 95% CI: 2.4-9.2, P<0.001) and LC (OR: 3.2; 95% CI: 1.6-6.7, P=0.002). The median age at diagnosis was around 10 years earlier in ever-smokers compared with never-smokers.CC was associated with a history of ulcerative colitis (UC) (OR: 8.7, 95% CI: 2.2-33.7, P=0.002), thyroid disease (OR: 2.3; 95% CI: 1.1-4.5, P=0.02), coeliac disease (OR: 13.1; 95% CI: 2.7-62.7, P=0.001), rheumatic disease (OR 1.9; 95% CI: 1.0-3.5, P=0.042) and previous appendicectomy (OR: 2.2; 95% CI: 1.3-3.8, P=0.003), and LC with UC (OR: 6.8; 95% CI: 1.7-28.0, P=0.008), thyroid disease (OR: 2.4; 95% CI: 1.1-5.4, P=0.037) and coeliac disease (OR: 8.7; 95% CI: 2.8-26.7, P<0.001). CONCLUSION: Association with a family history of microscopic colitis indicates that familial factors may be important. The association with a history of UC should be studied further as it may present new insights into the pathogenesis of microscopic colitis and UC.

Incidence, Clinical Presentation, and Associated Factors of Microscopic Colitis in Northern France: A Population-Based Study.

OBJECTIVE: To date, there are no epidemiological data on microscopic colitis (MC) in France. The aim of this study was to determine the incidence of MC in the Somme department in Northern France, to evaluate clinical characteristics, and to search for risk factors for both collagenous colitis (CC) and lymphocytic colitis (LC). DESIGN: Between January 1, 2005, and December 31, 2007, four pathology units in the Somme department recorded all new cases of MC diagnosed in patients living in the area. Colonic biopsies were reviewed by 4 pathologists together. For each incident case, demographic, clinical, endoscopic, and biological data were collected according to methodology of the EPIMAD registry. RESULTS: One hundred and thirty cases of MC, including 87 CC and 43 LC, were recorded during the three-year study. The mean annual incidence for MC was 7.9/105 inhabitants, 5.3/105 inhabitants for CC, and 2.6/105 inhabitants for LC. Annual standardized incidence of Crohn's disease and ulcerative colitis in the EPIMAD registry during the same period (2005-2007) were 7.4/105 and 4.9/105, respectively. Median age at diagnosis was 63 years for MC, 70 for CC, and 48 for LC. The female-to-male gender ratio was 3.5 for MC, 4.1 for CC, and 2.6 for LC. Median time to diagnosis was 8 weeks. Chronic diarrhea and abdominal pain were, respectively, present in 93 and 47 % of the cases. An autoimmune disease was associated in 28 % of MC cases. At diagnosis, proton pump inhibitor treatment was more often reported in CC than in LC (46 vs 16 %; p = 0.003). Budesonide was effective on diarrhea in 77 % of patients, and thirteen percent of patients became steroid dependent. CONCLUSION: This population-based study shows that the incidence of MC in France is high and similar to Crohn's disease incidence and confirms that this condition is associated with female gender, autoimmune diseases, and medications.

Towards a new paradigm of microscopic colitis: Incomplete and variant forms.

Microscopic colitis (MC) is a chronic inflammatory bowel disease that has emerged in the last three decades as a leading cause of chronic watery diarrhoea. MC classically includes two main subtypes: lymphocytic colitis (LC) and collagenous colitis (CC). Other types of histopathological changes in the colonic mucosa have been described in patients with chronic diarrhoea, without fulfilling the conventional histopathological criteria for MC diagnosis. Whereas those unclassified alterations remained orphan for a long time, the use of the term incomplete MC (MCi) is nowadays universally accepted. However, it is still unresolved whether CC, LC and MCi should be considered as one clinical entity or if they represent three related conditions. In contrast to classical MC, the real epidemiological impact of MCi remains unknown, because only few epidemiological studies and case reports have been described. MCi presents clinical characteristics indistinguishable from complete MC with a good response to budesonide and cholestiramine. Although a number of medical treatments have been assayed in MC patients, currently, there is no causal treatment approach for MC and MCi, and only empirical strategies have been performed. Further studies are needed in order to identify their etiopathogenic mechanisms, and to better classify and treat MC.

Microscopic colitis: a descriptive clinical cohort study of 795 patients with collagenous and lymphocytic colitis.

OBJECTIVE: Microscopic colitis is a common cause of chronic diarrhoea in the Scandinavian countries. This report comprises demographic data, clinical and endoscopic features, and occurrence of coeliac and inflammatory bowel disease (IBD) in a large urban cohort of patients with lymphocytic colitis (LC) and collagenous colitis (CC). MATERIALS AND METHODS: A total of 795 patients with microscopic colitis from two hospitals in Stockholm were included. Medical records were reviewed and clinical data, including endoscopic and histological findings, were compiled. RESULTS: Forty-three percent had CC (female:male ratio 3.7:1) and 57% had LC (female:male ratio 2.7:1). The mean age at diagnosis of CC was 63 years and of LC was 59 years (p = 0.005). Clinical features were similar in both entities, but the intensity of symptoms differed. Watery diarrhoea was reported in 55% in CC patients versus in 43% in LC patients (p = 0.0014), and nocturnal diarrhoea in 28% versus 18% (p = 0.002). Subtle endoscopic mucosal findings were reported in 37% of the CC patients and in 25% of the LC patients (p = 0.0011). Colorectal adenomatous polyps were found in 5.3% of all patients. Coeliac disease occurred in 6% and IBD occurred in 2.1% of all patients. CONCLUSIONS: Clinical features of LC and CC are similar but not identical. CC seems to be a more severe type of bowel inflammation and LC tends to occur earlier in life. Both forms might indeed feature endoscopic findings despite the designation 'microscopic'. Our study confirms the strong association with coeliac disease.

The epidemiology of microscopic colitis: a 10-year pathology-based nationwide Danish cohort study.

OBJECTIVE: Microscopic colitis (MC) includes two main types: collagenous colitis (CC) and lymphocytic colitis (LC). Previous studies have indicated an increasing incidence, but these have mainly been based on regional databases. We found it important to study the epidemiology based on a comprehensive nationwide cohort. MATERIAL AND METHODS: We studied the epidemiological data of MC in Denmark from 2002 to 2011. The cohort consisted of all patients with a recorded diagnosis of either CC or LC in the Danish Pathology Register during the study period. Data on all patients with a registered colon biopsy were also included. RESULTS: A total of 7777 patients, 4749 (61%) with CC and 3028 (39%) with LC, were identified. Over the study period, the annual incidence of diagnosed cases of CC increased from 2.9/10(5) to 14.9/10(5) and of LC from 1.7/10(5) to 9.8/10(5). In 2011, the incidence of MC was 24.7/10(5) inhabitants. The age-specific incidence showed that the risk of both CC and LC increased with age. The female/male ratio, distribution of the type of colitis and mean age at diagnosis were relatively stable during the study period. The annual number of registered colon biopsies in the pathology register increased from 21.583 in 2002 to 39.733 in 2011, indicating an increased diagnostic activity. CONCLUSION: In a nationwide cohort study, the incidence of CC and LC continued to increase from 2002 to 2011. An increased diagnostic activity could in part explain the increase in the number of diagnosed cases.

Microscopic colitis or functional bowel disease with diarrhea: a French prospective multicenter study.

OBJECTIVES: To describe the characteristics of a cohort of patients with microscopic colitis (MC; lymphocytic (LC) or collagenous (CC) colitis) and to compare them with patients with functional bowel disorder with diarrhea (FBD-D). METHODS: Between September 2010 and June 2012, patients fulfilling the following inclusion criteria were prospectively included in 26 centers in France: (i) having at least three bowel movements daily with change in stool consistency; (ii) duration of abnormal bowel habit >4 weeks; and (iii) normal or near-normal colonoscopy. Each patient underwent a colonoscopy and colonic biopsies. We compared the demographic, clinical, biological, and etiological characteristic of patients with MC (CC and LC) with those of control patients with FBD-D. RESULTS: A total of 433 patients were included: 129 with MC (87 LC and 42 CC), 23 with another organic disease, and 278 with FDB-D, including patients with diarrhea and abdominal pain who met the criteria of Rome III (irritable bowel syndrome with diarrhea) and patients with functional diarrhea without abdominal pain. Logistic regression analysis identified the following independent predictors of MC: age >50 years (odds ratio (OR)=3.1, 95% confidence interval (CI)=1.6-5.9), presence of nocturnal stools (OR=2, 95% CI=1.1-3.9), weight loss (OR=2.5, 95% CI=1.3-4.7), duration of diarrhea <12 months (OR=2.0, 95% CI=1.1-3.5), recent introduction of new drugs (OR=3.7, 95% CI=2.1-6.6; P<0.0001), and the presence of a known autoimmune disorder (OR=5.5, 95% CI=2.5-12). CONCLUSIONS: Age >50 years, the presence of nocturnal stools, weight loss, the introduction of a new drug, and the presence of a known autoimmune disease increase the probability of MC and thus the indication for colonoscopy with biopsies.