Collagenous and lymphocytic colitis: systematic review and update of the literature

[Clinical cases of microscopic colitis: Diagnosis and treatment issues. Case report]

Currently, there is an increase in the incidence of microscopic colitis. There are difficulties in diagnosing this disease due to the variability of histological signs, variability of morphological changes in the mucous membrane of the colon in different parts of the colon, and the combination in one patient of not only various forms of microscopic colitis, but also other intestinal diseases. The article describes the differential diagnosis, an example of its staging and successful treatment of various forms of microscopic colitis with budesonide (two clinical cases presented).

Low prevalence of colorectal neoplasia in microscopic colitis: A large prospective multi-center study

BACKGROUND AND AIMS

Microscopic colitis (MC) is the most frequent condition in subjects undergoing ileocolonoscopy for chronic non-bloody diarrhea (CNBD) in Western countries. Emerging evidence has shown a negative association between MC and colorectal cancer. Within this prospective multi-center study we have evaluated the risk of colorectal neoplasia in MC and non-MC patients with CNBD receiving ileocolonoscopy with high-definition plus virtual chromoendoscopic imaging and histopathological assessment.

METHODS

Patients with CNBD of unknown origin were prospectively enrolled in 5 referral centers in Northern Italy for ileocolonoscopy with high-definition and digital/optical chromoendoscopy plus multiple biopsies in each segment. The prevalence of colorectal neoplasia (cancer, adenoma, serrated lesion) in MC was compared to that observed in a control group including CNBD patients negative for MC, inflammatory bowel disease or eosinophilic colitis.

RESULTS

From 2014 and 2017, 546 consecutive CNBD patients were recruited. Among the 492 patients (mean age 53±18 years) fulfilling the inclusion criteria against the exclusion critieria, MC was the predominant diagnosis at histopathological assessment (8.7%: N=43, 28 CC, 15 LC). The regression model adjusted for age and gender showed a significant negative association between the diagnosis of CM and colorectal neoplasia (OR=0.39; 95% CI 0.22-0.67, p <0.001) with a 60% decreased risk of adenomatous and neoplastic serrated polyps as compared to the control group (n=412).

CONCLUSION

This multi-center study confirms MC as a low-risk condition for colorectal neoplasia. No surveillance colonoscopy program is to be performed for MC diagnosis.

Review of Drug-induced Injury in Mucosal Biopsies From the Tubular Gastrointestinal Tract

The use of prescription and over-the-counter medications is on the rise in the US population, especially among those aged 65 and over, with over 46% of the population taking at least 1 prescription medication. Given the frequency of medication use, and that the majority of these medications are taken orally, it has become increasingly relevant for pathologist examining endoscopically obtained gastrointestinal tract mucosal biopsies to consider and recognize patterns of mucosal injury associated with various drugs. Reports on injuries associated with certain classes of drugs can be scattered among different sources, making a comprehensive view of various injury patterns and the drugs known to cause them difficult to obtain. Herein, we provide a comprehensive overview of the drugs known to cause mucosal injuries in the tubular gastrointestinal tract organized by the organ involved and the prominent pattern of injury.

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.

显微镜结肠炎的诊疗进展

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

Lymphocytic colitis complicated by a mass in the terminal ileum

Lymphocytic colitis is a chronic inflammatory disease affecting the bowel. The clinical course of lymphocytic colitis is believed to be benign with watery diarrhoea. We report herein what is, to the best of our knowledge, the first case of lymphocytic colitis complicated by a terminal ileal mass. A 23-year-old man presented with diarrhoea. Blind biopsies of samples taken from the terminal ileum, caecum and ascending colon showed features of lymphocytic colitis. He declined treatment with budesonide or 5-aminosalicylates. He presented 14 months later with pain over the right lumbar region and nausea. Computed tomographic enteroclysis showed a focal soft tissue enhancing mass at the terminal ileum. Excision of the soft tissue mass revealed that it was reactive nodular lymphoid hyperplasia with fibrous granulation tissue. In conclusion, an untreated lymphocytic colitis may result in the formation of an inflammatory mass lesion.

New insights and challenges in microscopic colitis

Microscopic colitis (MC) is described as an inflammatory bowel disease characterized by chronic, bloodless diarrhea with normal or close to normal endoscopic findings. Histopathological examination reveals two subtypes: collagenous colitis (CC) and lymphocytic colitis (LC), which are indistinguishable clinically. The disease debuts typically in middle-aged patients, but can occur at all ages, including children. A female predominance is found in both CC and LC, but is not confirmed by others in LC. The etiology is unclear, but the disease has been assumed to be of autoimmune origin. However, several etiologies may render a microscopic inflammation in the mucosa; this is a common, universal reaction to a variety of irritants in contact with the intestinal lumen. Furthermore, some patients with a microscopic inflammation in their colonic mucosa have no symptoms, or are suffering from constipation or abdominal pain, rather than diarrhea. Recently, a discussion was initiated calling into question the overdiagnosing of symptoms and pointing out the danger of exacerbating people's perception of their ailments, of weakening their eligibility in health insurance, of overprescription of drugs, and thus the increasing cost to the society of health care. In the light of this discussion, this review will highlight histopathological and clinical features of MC, and discuss the diagnosis and management of this disease. Perhaps, the intestinal mucosa has no other mode by which to react than an inflammatory response, irrespective of the presence or absence of autoimmunity. Thus, to better identify and classify subgroups of MC, and to clarify and correctly handle the inflammatory changes, this field of research stands to benefit from a review of the results and experience gained to date.

Microscopic colitis: a review

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Clinical characteristics of collagenous colitis with linear ulcerations

BACKGROUND

The relationship between the thickness of subepithelial collagen bands (CB) and the development of linear ulcerations (LU) in collagenous colitis (CC) remains unclear. The aim of the present study was to compare the clinical and pathological features, including the thickness of CB, in CC patients with and without LU.

PATIENTS AND METHODS

Twenty-five patients with CC diagnosed by pathological examination of biopsy specimens were analyzed. Eleven patients with LU (LU group) and 14 patients without LU (non-LU group) were compared.

RESULTS

Ten patients in the LU group and seven in the non-LU group were taking lansoprazole (P = 0.038). Seven patients in the LU group and one in the non-LU group were taking non-steroidal anti-inflammatory drugs (NSAIDs) (P = 0.004). All LU were locatedin the transverse or left colon. Patients in the LU group were older than those in the non-LU group (P = 0.015). CB were significantly thicker in the LU group than in the non-LU group (mean ± SD, 40 ± 21 μm vs 20 ± 11 μm, P = 0.004). Multivariate analysis showed that NSAIDs use (odds ratio, 19.236; 95% confidence interval, 1.341-275.869) and CB thickness (odds ratio, 0.893; 95% confidence interval, 0.804-0.999) were independently associated with the development of LU.

CONCLUSION

Use of lansoprazole and NSAIDs, thick CB, and advanced age are associated with the development of LU in CC patients.

Lymphocytic and collagenous colitis: epidemiologic differences and similarities

BACKGROUND

It is unknown whether the subtypes of microscopic colitis (MC) represent distinct nosologic entities or related presentations of the same disease. Our aim was to search for epidemiologic differences among its various histopathologic subtypes.

METHODS

In a computerized database of 789,568 colon pathology reports, we compared the characteristics of 8,745 MC patients with those of the remaining population.

RESULTS

MC was diagnosed as three distinct histopathologic subtypes: lymphocytic colitis (LC) in 51 %, collagenous colitis (CC) in 43 %, and incomplete colitis (IC) in 6 % of patients. Only 0.65 % was simultaneously diagnosed with more than one subtype of MC. The prevalence of all three subtypes showed an age-dependent rise, with the average age (SD) being 63.3 (14.3) years in LC, 66.4 (12.1) years in CC, and 67.3 (12.7) years in IC (p < 0.0001). There was a striking female predominance in all three subtypes, the female fraction being 72 % in LC, 82 % in CC, and 79 % in IC (p < 0.0001). All three subtypes showed similar geographic distributions among different US states. They were similarly associated with diarrhea and weight loss, the odds ratios for all MC being 45.92 (43.35-48.63) and 5.12 (4.68-5.60), respectively, compared to control patients without MC. All three subtypes also harbored significantly less colonic adenomas, the overall odds ratio being 0.11 (0.10-0.12).

CONCLUSION

MC comes in three distinct histopathologic entities, which show striking similarities of their general epidemiologic features. The slight differences in their demographic characteristics could point at varying sets of environmental influences that affect the occurrence of subtypes.

Ascorbic acid and low-volume polyethylene glycol for bowel preparation prior to colonoscopy: A meta-analysis

AIM: To evaluate the benefits of low-volume polyethylene glycol (PEG) with ascorbic acid compared to full-dose PEG for colonoscopy preparation.

METHODS: MEDLINE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, CINAHL, PubMed, and recent abstracts from major conferences were searched (January 2012). Only randomized-controlled trials on adult subjects comparing low-volume PEG (2 L) with ascorbic acid vs full-dose PEG (3 or 4 L) were included. Meta-analysis for the efficacy of low-volume PEG with ascorbic acid and full-dose PEG were analyzed by calculating pooled estimates of number of satisfactory bowel preparations as well as adverse patient events (abdominal pain, nausea, vomiting). Separate analyses were performed for each main outcome by using OR with fixed and random effects models. Heterogeneity was assessed by calculating the I² measure of inconsistency. RevMan 5.1 was utilized for statistical analysis.

RESULTS: The initial search identified 242 articles and trials. Nine studies (n = 2911) met the inclusion criteria and were analyzed for this meta-analysis with mean age range from 53.0 to 59.6 years. All studies were randomized controlled trials on adult patients comparing large-volume PEG solutions (3 or 4 L) with low-volume PEG solutions and ascorbic acid. No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for number of satisfactory bowel preparations (OR 1.07, 95%CI: 0.86-1.33, P = 0.56). No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for abdominal pain (OR 1.09, 95%CI: 0.81-1.48, P = 0.56), nausea (OR 0.70, 95%CI: 0.49-1.00, P = 0.05), or vomiting (OR 0.99, 95%CI: 0.78-1.26, P = 0.95). No publication bias was noted.

CONCLUSION: Low-volume PEG with the addition of ascorbic acid demonstrates no statistically significant difference to full-dose PEG for satisfactory bowel preparation and side-effects.

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.

Colorectal normal histology and histopathologic findings in patients with chronic diarrhea

Collagenous and lymphocytic colitis are common causes of chronic watery diarrhea that are characterized by distinct histopathologic abnormalities without endoscopically visible lesions and are summarized as microscopic colitis. Several variants of microscopic colitis have been described, although their clinical significance still has to be defined. Preserved mucosal architecture is a histologic hallmark of microscopic colitis and distinguishes the disease from inflammatory bowel disease (IBD). In addition to architectural abnormalities, the diagnosis of IBD rests on characteristic inflammatory changes. Differential diagnosis of IBD mainly includes prolonged infection and diverticular disease-associated colitis, also known as segmental colitis associated with diverticulosis.

The Differential Diagnosis of Colitis in Endoscopic Biopsy Specimens: A Review Article

Context.—A variety of inflammatory disorders may affect the colon, with widely differing clinical outcomes and management. These conditions encompass a spectrum of acute and chronic conditions.

Objective.—Review the pathology of the major colitides and highlight the most diagnostically useful features.

Data Sources.—Review of recent literature supplemented with personal experience in the field of gastrointestinal pathology.

Conclusions.—The etiologies associated with the various types of colitis are diverse and the range of histologic changes is somewhat limited. Nevertheless, the combination of clinical and endoscopic data coupled with histopathology allows for accurate classification in the majority of cases.

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.

Foxp3 expression patterns in microscopic colitides: a clinicopathologic study of 69 patients

Microscopic colitides, including lymphocytic (LC) and collagenous colitis (CC), are well-described pathologic conditions. An altered immune response is implicated in the pathogenesis of both entities. CD8+ T lymphocytes (CTLs) secrete interleukin 2 which stimulates proliferation of regulatory T cells (Tregs), and Tregs, in turn, inhibit CTLs, inducing cytotoxic tissue damage. In Tregs, Foxp3 regulates T-cell-related immune responses. The distribution of Tregs and CTLs in microscopic colitides has remained underexplored. To characterize differences in the distribution pattern of Foxp3 in biopsy specimens from patients with LC and CC, 71 colonic biopsy specimens from 69 consecutive patients were categorized into 1 of 3 diagnoses: no significant histopathologic abnormality (NSHPA), LC, or CC. Further immunohistochemical evaluation of all biopsy specimens was conducted using a panel of markers including CD8 and Foxp3. Our study demonstrated that CTL distribution pattern differences exist among these 2 colitides and that differences in the immunologic recruitment of Foxp3+ Tregs in the colonic mucosa correlate with differences in the spectrum of morphologic changes seen in patients with either LC or CC.

Mucosa-associated bacteria in two middle-aged women diagnosed with collagenous colitis

AIM: To characterize the colon microbiota in two women histologically diagnosed with collagenous colitis using a culture-independent method.

METHODS: Biopsies were taken from the ascending colon and the total DNA was extracted. Universal bacterial primers were used to amplify the bacterial 16S rRNA genes. The amplicons were then cloned into competent Escherichia coli cells. The clones were sequenced and identified by comparison to known sequences.

RESULTS: The clones could be divided into 44 different phylotypes. The microbiota was dominated by Firmicutes and Bacteroidetes. Seven phylotypes were found in both patients and constituted 47.5% of the total number of clones. Of these, the most dominating were clones similar to Bacteroides cellulosilyticus, Bacteroides caccae, Bacteroides thetaiotaomicron, Bacteroides uniformis and Bacteroides dorei within Bacteroidetes. Sequences similar to Faecalibacterium prausnitzii and Clostridium citroniae were also found in both patients.

CONCLUSION: A predominance of potentially pathogenic Bacteroides spp., and the presence of clones showing similarity to Clostridium clostridioforme were found but the overall colon microbiota showed similarities to a healthy one. Etiologies for collagenous colitis other than an adverse bacterial flora must also be considered.

Cardiac arrest due to lymphocytic colitis: a case report

INTRODUCTION

We present a case of cardiac arrest due to hypokalemia caused by lymphocytic colitis.

CASE PRESENTATION

A 69-year-old Caucasian man presented four months prior to a cardiac arrest with watery diarrhea and was diagnosed with lymphocytic colitis. Our patient experienced a witnessed cardiac arrest at his general practitioner's surgery. Two physicians and the emergency medical services resuscitated our patient for one hour and four minutes before arriving at our university hospital. Our patient was defibrillated 16 times due to the recurrence of ventricular tachyarrhythmias. An arterial blood sample revealed a potassium level of 2.0 mmol/L (reference range: 3.5 to 4.6 mmol/L) and pH 6.86 (reference range: pH 7.37 to 7.45). As the potassium level was corrected, the propensity for ventricular tachyarrhythmias ceased. Our patient recovered from his cardiac arrest without any neurological deficit. Further tests and examinations revealed no other reason for the cardiac arrest.

CONCLUSION

Diarrhea can cause life-threatening situations due to the excretion of potassium, ultimately causing cardiac arrest due to hypokalemia. Physicians treating patients with severe diarrhea should consider monitoring their electrolyte levels.

The spectrum of drug-related colitides: important entities, though frequently overlooked

BACKGROUND

There is at present a relative lack of knowledge concerning drug-related colitides, although these may be not infrequent entities in clinical practice.

AIMS

To assess the frequency and the clinical-pathological subtypes of drug-related colitides in a gastrointestinal pathology referral centre.

METHODS

All charts of endoscopic biopsy samples referred for colitis in a eight-year period were reviewed. To be classified as drug related colitis, patients' charts should report the use of any drug in a two month period before colonoscopy and no other obvious cases of colitis be present. For analysis, we considered only patients taking one drug in this period.

RESULTS

We found 122 cases of drug-related colitis out of 3877 charts reviewed (3% of the overall colitis group). These cases were represented by microscopic colitis (50%), eosinophil rich infiltrate of the left colon (34%), ischemic colitis (11%), pseudomembranous colitis (3%), apoptotic colopathy (2%). The drugs most frequently associated with these colitides were represented by non-steroidal anti-inflammatory drugs.

CONCLUSION

It is important to raise awareness concerning drug-related colitides, to avoid diagnostic errors and provide a better therapeutic approach to patients with these conditions.