Clinical features of microscopic colitis in a nation-wide follow-up study in Iceland

Follow-Up of Microscopic Colitis Patients and Diarrhea Controls at 1 Year

BACKGROUND AND AIMS

Microscopic colitis (MC) is a common cause of chronic diarrhea; however, the clinical course of this disease is poorly understood. We aimed to investigate how patients diagnosed with MC were treated in routine clinical practice and how their symptoms compared to patients with other causes of chronic diarrhea at one year follow-up.

METHODS

We conducted a case-control study of patients undergoing outpatient colonoscopy to evaluate diarrhea. The study pathologist determined whether patients were classified as MC cases or non-MC controls. One year after colonoscopy, we interviewed cases (n = 74) and controls (n = 162) about their diagnosis, medications for diarrhea, and symptom burden.

RESULTS

At 1-year follow-up after colonoscopy, 10% of MC cases were unaware of the diagnosis, 60% had been prescribed a medication for diarrhea, 40% had fecal urgency, 32% had weight loss, and 21% had fecal incontinence. Among cases, 46% were treated with budesonide. Compared to cases, controls had worse symptoms based on the Microscopic Colitis Disease Activity Index score with a median score of 3.0 (interquartile range 1.9-4.2) vs 2.3 (interquartile range 1.4-3.2) at 1-year follow-up. Controls had more frequent stools, urgency, fecal incontinence, and abdominal pain.

CONCLUSION

In a cohort of patients with biopsy-confirmed MC and diarrhea controls, we found that some cases remained unaware of their diagnosis, many cases had persistent symptoms, and controls had worse symptoms than cases. These findings suggest there are opportunities to improve management of this chronic disease.

Course of Disease in Patients with Microscopic Colitis: A European Prospective Incident Cohort Study

BACKGROUND AND AIMS

The disease course of microscopic colitis [MC] is considered chronic but benign. However, this assumption is based on mainly retrospective studies, reporting on incomplete follow-up of selective cohorts. Systematic, prospective and unbiased data to inform patients and healthcare professionals on the expected course of the disease and real-life response to therapy are warranted.

METHODS

A prospective, pan-European, multi-centre, web-based registry was established. Incident cases of MC were included. Data on patient characteristics, symptoms, treatment and quality of life were systematically registered at baseline and during real-time follow-up. Four disease course phenotypes were discriminated and described.

RESULTS

Among 381 cases with complete 1-year follow-up, 49% had a chronic active or relapsing disease course, 40% achieved sustained remission after treatment and 11% had a quiescent course. In general, symptoms and quality of life improved after 3 months of follow-up. A relapsing or chronic active disease course was associated with significantly more symptoms and impaired quality of life after 1 year.

CONCLUSIONS

A minority of MC patients follow a quiescent disease course with spontaneous clinical improvement, whereas the majority suffer a chronic active or relapsing disease course during the first year after diagnosis, with persisting symptoms accompanied by a significantly impaired quality of life.

Long-Term Natural History of Microscopic Colitis: A Population-Based Cohort

Data on long-term natural history of microscopic colitis (MC), including collagenous (CC) and lymphocytic colitis (LC), are lacking.

Prevalence and Natural History of Microscopic Colitis: A Population-Based Study With Long-term Clinical Follow-up in Terrassa, Spain

BACKGROUND AND AIMS

Few studies have assessed the prevalence of microscopic colitis (MC) and the natural history of this disease is not well known. The aim of this study was to evaluate the prevalence rate of MC, the burden of disease in terms of loss of health and the long-term natural history of MC in a population-based cohort study.

METHODS

Cases were obtained from the pathology department registry Hospital Universitari Mutua Terrassa. Belonging to the catchment area, maintaining residence in that area, and being alive on August 31, 2014 were confirmed for each case. Adjusted prevalence rates were calculated. Current active drugs for MC and diarrhoea persistence in every patient were recorded.

RESULTS

The prevalence rate of MC was 107 per 10(5) inhabitants. The rate of patients with active disease, i.e. those representing the true burden of the disease in terms of loss of health, was 31 per 10(5) inhabitants. After a follow-up of 7.8±0.38 years from diagnosis, 75% of the patients experienced prolonged disease remission, defined as clinical remission without requiring drugs for 1 year or more. The only variable associated with prolonged MC remission was how clinical remission was achieved (spontaneous 93.3%, drug-induced, 60.5%; odds ratio 8.4, 95% confidence interval 2.7-26).

CONCLUSIONS

The rate of patients with MC and active disease, which represents the true disease burden in terms of loss of health, is low. Most patients with MC experience prolonged disease remission, with key differences between spontaneous and drug-induced clinical remission.

Advances for improved diagnosis of microscopic colitis in patients with chronic diarrhoea

Microscopic colitis is a generic term that includes 2 main forms, collagenous colitis and lymphocytic colitis, and describes a form of inflammatory bowel disease with a chronic and relapsing course. The incidence of microscopic colitis is between 2 and 8 times higher in women than in men, although age, more than sex, increases the risk of collagenous colitis (odds ratio [OR] 8.3 for age ≥65 vs. <65 and OR 2.8 for women). The main symptom is chronic non-bloody watery diarrhoea. Other common symptoms include abdominal pain (50%-70%), with the result that many patients with microscopic colitis meet criteria for irritable bowel syndrome. Colonoscopy with multiple colonic biopsies is currently recommended, as histological changes are the main characteristic feature. The colonic mucosa is macroscopically normal, although certain minimal endoscopic abnormalities have been described.

The Temporal Evolution of Histological Abnormalities in Microscopic Colitis

BACKGROUND AND AIMS

Microscopic colitis (MC) is a common cause of chronic watery diarrhoea but long-term follow-up data are sparse.

METHODS

We performed a retrospective review of health records and all pathology reports in a regional cohort of patients with MC to describe the change in pre- and post-diagnostic colon biopsies.

RESULTS

MC was diagnosed in 468 patients with collagenous colitis (CC), 361 with lymphocytic colitis (LC) and 226 with incomplete MC (MCi). The 2014 incidence of CC, LC and MCi was 14.5, 14.9 and 5 per 10(5). Biopsies from both right and left colon were obtained in 237 (51%) patients with CC, 200 (55%) with LC and 107 (47%) with MCi. The diagnostic sensitivities of both left- and right-sided biopsies for MC were high and did not differ. Pre-diagnostic biopsies were obtained in 150 patients and lamina propria inflammation was described in 59, 47 and 43% of patients with a diagnosis of CC, LC and MCi respectively within 1 year, while histology was normal in 16, 13 and 21%. Post-diagnostic biopsies were obtained in 283 patients. MC persisted for up to one year in 77% with CC, 64% with LC and 45% with MCi, of whom 6, 9 and 18% respectively changed to a different MC subgroup.

CONCLUSIONS

Colonic biopsies obtained prior to the MC diagnosis often revealed increased lamina propria inflammation. The pathological changes of CC and LC are more persistent than those of MCi. Biopsies from the descending or sigmoid colon are sufficient to elucidate whether a patient with chronic watery diarrhoea has MC.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evolution of microscopic colitis to giant cell colitis without significant intraepithelial lymphocytosis or thickened collagen plate

Microscopic colitis (MC) is an umbrella term that encompasses lymphocytic colitis (LC) and collagenous colitis (CC). Several histological variants of these 2 entities exist; among them is the uncommon giant cell colitis (GCC), in which histiocytic giant cells (GCs) are present in background of CC or LC. We report the case of a 71-year-old woman complaining of watery diarrhea for several years that was diagnosed with CC. At follow-up, she developed giant cell colitis (GCC). Nine years later, a colectomy revealed a form of microscopic colitis in which significant intraepithelial lymphocytosis and collagen plate thickening have disappeared while GCs persisted with diffuse mononuclear cells inflammation of the lamina propria. Thinning of the collagen plate in association with GCs has been described previously. The case contributes the possibility of further evolution of MC into a pure giant cell colitis in which the prototypical manifestations of MC have all but disappeared.

Incidence of microscopic colitis in the Netherlands. A nationwide population-based study from 2000 to 2012

BACKGROUND

Incidence rates of microscopic colitis are mainly based on regional data from a limited number of countries. To evaluate geographical differences and changes over time, more nationwide incidence rates are needed.

AIMS

The aim of this retrospective study was to assess the incidence rate of microscopic colitis in the Netherlands in a nationwide cohort.

METHODS

A search was performed in the Dutch pathology registry, covering records of all approximately 16.5 million inhabitants. Incident cases were defined as a first diagnosis of microscopic colitis (collagenous or lymphocytic colitis) between 2000 and 2012.

RESULTS

In total, 7228 incident cases were identified with a mean annual incidence rate of 3.4 per 100,000 person years. Collagenous colitis was present in 3741 cases and lymphocytic colitis in 2718 cases, with a mean annual incidence rate of 1.8 and 1.3 per 100,000 person years, respectively. Remaining 769 cases were described as undefined microscopic colitis. Collagenous and lymphocytic colitis incidence rates increased significantly over time (p<0.001) with a male:female ratio of 1:3 and 1:2, respectively.

CONCLUSION

The Dutch mean annual incidence rates of collagenous and lymphocytic colitis were considerably lower than previously reported by other countries. However, incidence rates increased gradually over time, with a clear female predominance.

Long-term prognosis of clinical symptoms and health-related quality of life in microscopic colitis: a case-control study

BACKGROUND

Microscopic colitis, comprising collagenous colitis (CC) and lymphocytic colitis (LC), is a common cause of chronic diarrhoea. The long-term prognosis is not well described.

AIM

To study outcome of symptoms and health-related quality of life (HRQoL).

METHODS

A case-control study using a postal questionnaire with three population-based controls per patient matched for age, sex and municipality. HRQoL was assessed by the Short Health Scale (SHS). Patients in clinical remission, defined as a mean of <3 stools/day, were evaluated separately (CC; n = 72, LC; n = 60).

RESULTS

The study included 212 patients and 627 matched controls. Median disease duration was 5.9 (range 0.5-27) years and 6.4 (0.3-14.8) years for CC and LC respectively. Abdominal pain, fatigue, arthralgia, myalgia, faecal incontinence and nocturnal defecation were significantly more prevalent in CC patients compared with controls. These differences persisted in CC patients in clinical remission with respect to abdominal pain (36% vs. 21%), fatigue (54% vs. 34%), arthralgia (61% vs. 41%) and myalgia (53% vs. 37%). In LC patients, abdominal pain, fatigue, faecal incontinence and nocturnal defecation were more prevalent compared with controls. In LC patients in clinical remission, fatigue was more prevalent compared with controls (54% vs. 37%). These differences were statistically significant (P < 0.05). All four HRQoL dimensions (symptom burden, social function, disease-related worry, general well-being) were impaired in patients with active CC and LC.

CONCLUSIONS

Although considered to be in clinical remission, patients with microscopic colitis suffer from persisting symptoms such as abdominal pain, fatigue, arthralgia or myalgia several years after diagnosis.

Microscopic colitis in Uppsala health region, a population-based prospective study 2005-2009

OBJECTIVE

The aim of this study is to report on the incidence of microscopic colitis (MC), any possible relation with inflammatory bowel disease (IBD), concomitant drug consumption, related diseases and the clinical course of the diseases.

METHODS

Both new cases of IBD and MC were registered at the same time in the same geographical area. The study started in the county of Uppsala 2005-2006, and other parts of the surrounding health region were included 2007-2009. Established morphological criteria were used, i.e. a layer of subepithelial collagen band ≥ 10 μm in collagenous colitis (CC) with concomitant inflammation and at least 20 lymphocytes per 100 epithelial cells in lymphocytic colitis (LC).

RESULTS

The authors found 272 new cases of MC, 154 with CC and 118 with LC. The mean age-adjusted incidence was 7.0/1,000,000 for CC and 4.8/100,000 for LC. The clinical course was dominated by single episodes with diarrhea or intermittent symptoms, but 14% suffered from chronic diarrhea. In 10% of the cases, diagnosis was made in individuals without chronic watery diarrhea. Although not systematically tested, concomitant celiac disease was found in approximately 5% of the patients.

CONCLUSIONS

The incidence of MC in Uppsala health region is similar to other studied areas. The majority of patients had a self-limiting or easily treated condition, but 14% need a more or less continuous medication. Ten percent of the patients demonstrate other symptoms than chronic watery diarrhea. The possibility of concomitant celiac disease should be considered in new cases of MC.

Impact of current smoking on the clinical course of microscopic colitis

BACKGROUND

Whether current smoking worsens the clinical course of microscopic colitis (MC) is unknown. The aim was to evaluate the impact of smoking on the clinical course of MC.

METHODS

One hundred and eighty-four patients (72% women; age, 62.4 ± 1.1 years) with MC (118 collagenous colitis (CC) and 66 lymphocytic colitis (LC) were evaluated (39 of them were current smokers). In all the patients, smoking habits and clinical data at presentation, response to therapy, and clinical relapses during follow-up were prospectively recorded. Risk factors for clinical relapse were studied in 160 patients after a mean follow-up of 28 ± 1 months. Cox regression analysis was used to adjust for confounding variables.

RESULTS

Age at diarrhea onset was 63.0 ± 1.4 years in nonsmokers and 50.4 ± 2.1 years in current smokers (P < 0.001). There was no significant influence of smoking habit on either clinical symptoms at diagnosis or clinical remission rate. Clinical relapse rate was 25.5% for CC and 29.6% for LC, with the mean relapse-free time 28.8 months (95% confidence interval, 26.3-31.4) for CC and 26.9 months (95% confidence interval, 26-30.3) for LC (P = 0.5). Multivariate analysis showed that age at diagnosis (<50 years versus others; adjusted hazard ratio, 2.8; 95% confidence interval, 1.3-6; P = 0.01) was associated with risk of relapse of CC but not LC. Current smoking was not an independent risk factor for either CC or LC relapse.

CONCLUSIONS

Active smokers developed MC more than a decade before nonsmokers. Age at diagnosis, but not smoking, was an independent risk factor of relapse in patients with CC.

Clinical presentation, diagnosis, pathogenesis and treatment options for lymphocytic colitis (Review)

Lymphocytic colitis (LC) is characterized by chronic or relapsing non-bloody watery diarrhea and a macroscopically normal colon. However, histopathological examination of colonic biopsy samples reveals an increased intraepithelial infiltration of lymphocytes (≥20/100 enterocytes), and increased inflammatory cells within the lamina propria, but with a normal mucosal architecture. The reported prevalence of LC varies from 14.2 to 45 per 100,000 individuals, while its reported incidence is between 0.6 and 16 per 100,000 individuals. LC has a high rate of spontaneous symptomatic remission and is not associated with an increased risk of colon cancer or inflammatory bowel disease. The diagnosis is based on the histopathological findings. The density of colonic chromogranin A-positive cells provides an effective diagnostic tool with high sensitivity and specificity in both the right and left colon. Gastrointestinal infections, drugs, and/or autoimmunity may trigger chronic colonic low-grade inflammation. Colonic nitric oxide, serotonin and peptide YY (PYY) cell densities are markedly increased in patients with LC. It has been hypothesized that the low-grade inflammation in LC through the endocrine-immune axis causes this increase. It has been postulated further that these abnormalities in the neuroendocrine system of the colon are responsible for the diarrhea observed in patients with LC. The benign course and rate of spontaneous remission of LC denotes that drugs with severe side-effects should be avoided if possible. The drug cost and drug coverage may also be limiting factors for some patients. These aspects should be taken into account when making decisions regarding treatment options.

Is microscopic colitis a drug-induced disease?

Microscopic colitis (MC) is diagnosed in up to 13% of patients investigated for chronic diarrhea, particularly in middle-aged and elderly patients. Recent studies have suggested an etiological role for various drugs, including nonsteroidal anti-inflammatory drugs and proton pump inhibitors. To ascertain the potential role for drug exposure in the development of MC, we performed a systematic review based on a MEDLINE search and conducted a meta-analyses on the available data. We also give an overview of the case reports and studies illustrating the role of drugs in inducing MC. A number of hypotheses are formulated with regard to the potential pathophysiological mechanisms in drug-induced MC. However, confirmative evidence is still largely lacking. Considering the high number of drug users and the relatively low incidence of MC, it is more likely that drug-induced cases of MC are the result of an idiosyncratic reaction.

Non-IBD colitides (eosinophilic, microscopic)

Microscopic colitis includes the terms lymphocytic colitis and collagenous colitis, and is a common cause of chronic diarrhoea in older adults. The incidence of microscopic colitis has increased over time and has reached levels comparable to other forms of inflammatory bowel disease. In this chapter, an updated review on the epidemiology, diagnosis and treatment of microscopic colitis has been provided. There is limited data available about eosinophilic colitis, which is the least common of the eosinophilic GI disorders. It is important to rule out the secondary causes of colonic eosinophilia in patients with suspected eosinophilic colitis.

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.

Systematic review: are lymphocytic colitis and collagenous colitis two subtypes of the same disease - microscopic colitis?

BACKGROUND

Despite similar clinical symptoms, collagenous colitis (CC) and lymphocytic colitis (LC) are considered two distinct disease entities.

AIM

To compare pathoanatomical findings, clinical presentations, risk factors, course of diseases and response to treatment in CC and LC to establish whether they could be subtypes of the same disease, microscopic colitis (MC).

METHODS

The MEDLINE was searched for CC, LC and MC, and clinical studies of >20 patients were included. Pooled results with 95% confidence intervals were calculated based on the number of patients.

RESULTS

An abnormal number of intraepithelial lymphocytes are found in 45% (40-50%) with CC, and an abnormal subepithelial collagen band in 16% (13-20%) with LC suggesting a histological overlap. The incidence of CC and LC has increased in parallel. Mean age (CC 63 years; LC 60 years) and clinical presentation are indistinguishable, and females are predominant in CC (77%; 75-79%) as well as LC (68%; 66-70%). Risk factors such as nonsteroid anti-inflammatory drugs consumption CC 39% (36-42%); LC 32% (29-35%) are similar and prevalence of concomitant autoimmune diseases such as coeliac disease (CC 5%; CI: 4-6% and LC 7%; CI: 6-9%) do not differ. Bile acid diarrhoea is highly prevalent in CC (41%; 37-45%) and LC (29%; 24-34%). The effect of budesonide is identical.

CONCLUSIONS

CC and LC could be considered histological subtypes of the same disease, MC. To facilitate recruitment to clinical trials, all MC patients could be included in future trials and stratified for subtypes.

Decreased colorectal cancer and adenoma risk in patients with microscopic colitis

INTRODUCTION

Microscopic colitis is currently considered to harbor no increased risk for colorectal cancer, based on a few small studies with limited long-term follow-up. Our aim was to identify patients with microscopic colitis, and to compare long-term rates of colorectal cancer or adenoma to a control group of patients without microscopic colitis.

METHODS

We reviewed the records of patients diagnosed with microscopic colitis, as identified by a hospital-based pathology database from January 2000 to August 2008. Clinical factors, including history of adenoma or adenocarcinoma, and all colonoscopy findings, were recorded. Age and gender-matched patients without microscopic colitis served as the control in a 1:1 fashion.

RESULTS

A total of 647 patients (153 male: 494 female) were identified with microscopic colitis (MC). Any history of colorectal cancer was detected in 1.92, 1.81, and 4.17% of patients with collagenous colitis (CC), lymphocytic colitis (LC), and controls, respectively (P = 0.095, P = 0.040, P = 0.015 for CC, LC, and all MC, respectively, comparing to controls). Overall, covariate-adjusted risk (odds ratio) of any history of colorectal cancer and colorectal adenoma in MC patients was 0.34 (95% confidence interval [CI] 0.16-0.73, P = 0.006) and 0.52 (95% CI 0.50-0.76, P < 0.0001), respectively. The mean duration of follow-up was 4.63 years, with 147/647 (22.7%) of patients with clinical follow-up >7 years.

CONCLUSIONS

In this case-control study involving a large retrospective cohort, microscopic colitis is negatively associated with the risk for colorectal cancer and adenoma. Further studies are required to determine a temporal relationship between microscopic colitis and the future development of colorectal neoplasia.

Microscopic colitis: clinical findings, topography and persistence of histopathological subgroups

BACKGROUND

Uncertainty remains on topography and persistence of histological subgroups of microscopic colitis (MC).

AIM

To assess longitudinal clinical, endoscopic, histological, and therapeutic description of MC subgroups including patients with incomplete findings of MC (MCi).

METHODS

Retrospective review of a consecutive cohort with MC and histological reassessment of MCi.

RESULTS

Clinical characteristics of 168 patients with lymphocytic colitis (LC), 270 with collagenous colitis (CC) and 101 with MCi were similar. At colonoscopy 95% (95% CI: 91-98%) of CC and 98% (93-100%) of LC cases had diagnostic histopathology of MC in both left and right colon. Eight and three patients had characteristics of MC only in the left and right colon, respectively. Histology findings resembling coexistence of the other MC subtype was present in 48% (40-55%) with CC and 24% (18-31%) with LC. A first diagnosis of MC was made in 49 (30%) of 164 patients only at repeat endoscopy. Another 34 of 115 (30%) with MC in the first endoscopy did not fulfil the MC criteria at repeat endoscopy. Only seven cases had a primary endoscopy without histopathological abnormalities. Fifteen percentage of MCi were reclassified as MC. Ileal inflammation was present in 33 of 81 patients. Budesonide was efficacious in all MC subgroups irrespective of bile acid malabsorption.

CONCLUSIONS

Clinical characteristics of microscopic colitis subgroups are indistinguishable. Biopsies from the left colon suffice to exclude microscopic colitis, and the histological diagnosis of microscopic colitis is inconsistent over time. Ileal inflammation is common. The term microscopic colitis should perhaps be considered one clinical entity and include lymphocytic colitis, collagenous colitis, and incomplete findings of microscopic colitis.

Review article: Microscopic colitis--lymphocytic, collagenous and 'mast cell' colitis

BACKGROUND

Microscopic colitis is a relatively common cause of chronic diarrhoea in predominantly older adults, traditionally termed lymphocytic colitis and collagenous colitis. Increased mast cells found in the colonic biopsies of some patients with chronic diarrhoea may represent a distinct type of microscopic colitis.

AIM

To provide an updated review of the epidemiology, diagnosis and treatment of microscopic colitis, and to discuss the role of mast cells in the gastrointestinal tract and their potential role in cases of functional diarrhoea.

METHOD

A MEDLINE literature search was performed to identify pertinent articles. Relevant clinical abstracts were also reviewed.

RESULTS

Incidence rates of microscopic colitis (lymphocytic and collagenous colitis) have increased over time, to levels comparable with other forms of inflammatory bowel disease. The possibility of drug-induced microscopic colitis and concomitant coeliac sprue are important considerations when evaluating these patients. There are few controlled treatment trials in microscopic colitis, with much of the data on treatment coming from retrospective studies. Mast cells have been implicated in functional bowel disorders, with increased mast cells possibly contributing to cases of otherwise unexplained chronic diarrhoea, although this concept requires further investigation.

CONCLUSIONS

In patients with microscopic colitis, a systematic approach to therapy often leads to satisfactory control of symptoms. The role of mast cells in chronic diarrhoea represents an evolving field, with the potential to offer alternative treatment pathways in patients with otherwise unexplained functional diarrhoea.

Cytokine gene polymorphism in microscopic colitis association with the IL-6-174 GG genotype

OBJECTIVES

Microscopic colitis (MC) is a chronic inflammatory disease with unknown pathogenesis. Very little is known about polymorphisms in the cytokine genes in MC. We have investigated the occurrence of well-characterized polymorphisms of interleukins (IL-6, IL-1β, IL-1 receptor antagonist, IL-10) and CD14 in MC. We also determined the serum IL-6 levels.

METHODS

We genotyped 81 patients with MC and 178 controls for polymorphisms of IL-6-174, IL-1β-511, IL-1β-3953, IL-1 receptor antagonist, IL-10-1082 and CD14-159. Serum concentration of IL-6 was measured in 72 patients.

RESULTS

Genotype GG of IL-6-174 was more prevalent in MC compared with the controls (P=0.030; odds ratio: 1.941; confidence interval: 1.078-3.495), and the frequency of allele G of IL-6-174 was higher in MC (0.55 vs. 0.47; P=0.036; odds ratio: 1.514; confidence interval: 1.041-2.203). However, after correction for multiple comparisons, the difference became nonsignificant. IL-6 genotype and the serum IL-6 concentration showed no association. The concentration of IL-6 was higher in patients with collagenous colitis than in those with lymphocytic colitis (median 1.73 vs. 1.34 pg/ml, P=0.011). No association between polymorphisms of other cytokine genes and MC was seen.

CONCLUSION

The IL-6-174 gene polymorphism has a possible association with MC, as the IL-6 GG genotype was more frequent in patients with the disease. As this genotype may be linked with an enhanced IL-6 production, we speculate that this polymorphism can influence the pathogenesis of MC by evoking a proinflammatory bias in the mucosal cytokines. The enhanced concentration of IL-6 in collagenous colitis compared with lymphocytic colitis supports a difference in the pathogenetic mechanisms between the two subgroups of MC.

Lansoprazole-induced microscopic colitis: an increasing problem? Results of a prospecive case-series and systematic review of the literature

BACKGROUND

Microscopic colitis (MC), comprising lymphocytic and collagenous colitis (LC, CC), causes chronic diarrhoea. Lansoprazole can cause MC. Likelihood criteria defining the causative relationship between drugs and MC have not been applied to lansoprazole, nor has lansoprazole-related-MC been characterized.

AIM

To analyse a series of lansoprazole-related MC cases, and characterize lansoprazole-related CC and LC.

METHODS

Cases were diagnosed over 23 months and causal relationship evaluated by established likelihood criteria. A systematic Medline search was conducted and publications analysed.

RESULTS

Eight patients had lansoprazole-related MC. In all cases chronological and causality likelihood scores supported lansoprazole causative role. Discontinuation determined resolution without further treatment. Twenty-five cases of lansoprazole-related MC from 10 publications were grouped with the present series, and differences between CC and LC analysed. CC cases had more macroscopic alterations at colonoscopy (72.2 vs. 6.6%; p=0.0002). Time between lansoprazole start and symptoms onset was longer for CC (median 60 vs. 28 days; p=0.03).

CONCLUSIONS

Peculiar features of lansoprazole-related CC were described through the analysis of a newly diagnosed lansoprazole-related MC series in which the causative role of lansoprazole was for the first time defined by established likelihood criteria, and by pooled evaluation with other cases retrieved by a systematic literature review.