Review of the microscopic colitides

Histological disease activity in patients with microscopic colitis is not related to clinical disease activity or long-term prognosis

BACKGROUND

Microscopic colitis (MC) is a common cause of chronic watery diarrhea. Biopsies with characteristic histological features are crucial for establishing the diagnosis. The two main subtypes are collagenous colitis (CC) and lymphocytic colitis (LC) but incomplete forms exist. The disease course remains unpredictable varying from spontaneous remission to a relapsing course.

AIM

To identify possible histological predictors of course of disease.

METHODS

Sixty patients from the European prospective MC registry (PRO-MC Collaboration) were included. Digitised histological slides stained with CD3 and Van Gieson were available for all patients. Total cell density and proportion of CD3 positive lymphocytes in lamina propria and surface epithelium were estimated by automated image analysis, and measurement of the subepithelial collagenous band was performed. Histopathological features were correlated to the number of daily stools and daily watery stools at time of endoscopy and at baseline as well as the clinical disease course (quiescent, achieved remission after treatment, relapsing or chronic active) at 1-year follow-up.

RESULTS

Neither total cell density in lamina propria, proportion of CD3 positive lymphocytes in lamina propria or surface epithelium, or thickness of collagenous band showed significant correlation to the number of daily stools or daily watery stools at any point of time. None of the assessed histological parameters at initial diagnosis were able to predict clinical disease course at 1-year follow-up.

CONCLUSIONS

Our data indicate that the evaluated histological parameters were neither markers of disease activity at the time of diagnosis nor predictors of disease course.

Collagenous Colitis Is Associated With HLA Signature and Shares Genetic Risks With Other Immune-Mediated Diseases

BACKGROUND & AIMS

Collagenous colitis (CC) is an inflammatory bowel disorder with unknown etiopathogenesis involving HLA-related immune-mediated responses and environmental and genetic risk factors. We carried out an array-based genetic association study in a cohort of patients with CC and investigated the common genetic basis between CC and Crohn's disease (CD), ulcerative colitis (UC), and celiac disease.

METHODS

DNA from 804 CC formalin-fixed, paraffin-embedded tissue samples was genotyped with Illumina Immunochip. Matching genotype data on control samples and CD, UC, and celiac disease cases were provided by the respective consortia. A discovery association study followed by meta-analysis with an independent cohort, polygenic risk score calculation, and cross-phenotype analyses were performed. Enrichment of regulatory expression quantitative trait loci among the CC variants was assessed in hemopoietic and intestinal cells.

RESULTS

Three HLA alleles (HLA-B∗08:01, HLA-DRB1∗03:01, and HLA-DQB1∗02:01), related to the ancestral haplotype 8.1, were significantly associated with increased CC risk. We also identified an independent protective effect of HLA-DRB1∗04:01 on CC risk. Polygenic risk score quantifying the risk across multiple susceptibility loci was strongly associated with CC risk. An enrichment of expression quantitative trait loci was detected among the CC-susceptibility variants in various cell types. The cross-phenotype analysis identified a complex pattern of polygenic pleiotropy between CC and other immune-mediated diseases.

CONCLUSIONS

In this largest genetic study of CC to date with histologically confirmed diagnosis, we strongly implicated the HLA locus and proposed potential non-HLA mechanisms in disease pathogenesis. We also detected a shared genetic risk between CC, celiac disease, CD, and UC, which supports clinical observations of comorbidity.

Lymphocytic colitis pattern of injury presenting as endoscopic polyps: a case series

Lymphocytic colitis (LC) is characterized by chronic watery diarrhea and unremarkable endoscopic findings. Only one case of LC presenting as multiple colonic polyps has been reported. We report a case series of histologic LC pattern of injury (LCPI), presenting as endoscopic polyps, and compare them with typical LC cases. Eighteen archived (2009-2019) polypoid LCPI cases without an associated cause of polyp, such as adenoma, hyperplastic change, or lymphoid aggregate, were retrieved from 17 (12 female and 5 male) patients. The clinical history and endoscopic findings were noted. A total of 40 conventional LC cases were used as controls. Fisher's exact test was performed to evaluate associations between two variables. The mean age of the patients was 61.1 years. The indication for colonoscopy was chronic watery diarrhea (56%), screening/surveillance (33%), and rectal bleeding (11%). The mean number and size of the polyps was 1.6 and 2.9 mm, respectively. Seventy-six percent were located in the left colon, and 48% were sessile. When biopsied (14/18; 78%), the background colonic mucosa showed LCPI. There was no significant difference in age, gender, and the average number of lymphocytes in the two groups. Hypertension and history of malignancy was more common in the polypoid LCPI group than in the control LC group (P < 0.05). LCPI may present as endoscopic polyps, frequently in patients with hypertension and history of malignancy. Polypoid LCPI may be a harbinger of LCPI in the background nonpolypoid colonic mucosa. A subset of polypoid LCPI (56%) cases represents true LC.

Prevalence, Pathogenesis, Diagnosis, and Management of Microscopic Colitis

Microscopic colitis (MC), which is comprised of lymphocytic colitis and collagenous colitis, is a clinicopathological diagnosis that is commonly encountered in clinical practice during the evaluation and management of chronic diarrhea. With an incidence approaching the incidence of inflammatory bowel disease, physician awareness is necessary, as diagnostic delays result in a poor quality of life and increased health care costs. The physician faces multiple challenges in the diagnosis and management of MC, as these patients frequently relapse after successful treatment. This review article outlines the risk factors associated with MC, the clinical presentation, diagnosis and histologic findings, as well as a proposed treatment algorithm. Prospective studies are required to better understand the natural history and to develop validated histologic endpoints that may be used as end points in future clinical trials and serve to guide patient management.

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.

Review: chronic and persistent diarrhea with a focus in the returning traveler

Background

Travelers’ diarrhea is a common malady afflicting up to 50% of travelers after a 2-week travel period. An appreciable percentage of these cases will become persistent or chronic. We summarized the published literature reporting persistent/chronic diarrhea in travelers elucidating current understanding of disease incidence, etiology and regional variability.

Methods

We searched electronic databases (Medline, Embase, and Cochrane database of clinical trials) from 1990 to 2015 using the following terms: “chronic or persistent diarrh* and (returning) travel* or enteropathogen, GeoSentinel, and travel-associated infection. Included studies published in the English language on adult returning travelers (duration < 3-months) reporting denominator data. Point estimates and standard 95% confidence intervals were calculated for incidence using a random-effects model. Study incidence heterogeneity rates were assessed using x² heterogeneity statistics, graphically represented with Forest plots.

Results

We identified 19 studies meeting the inclusion criteria (all published after 1999). 18 studies reported upon the incidence of persistent/chronic diarrhea as a syndromic diagnosis in returning travelers; one study reported adequate denominator data from which to assess pathogen specific etiology. Giardiasis comprise an appreicaible percentage of infectious mediated persistent/chronic diarrhea in returning travelers. The overall estimate of persistent/chronic diarrhea incidence was 6% (0.05–0.07) in 321,454, travelers; with significant heterogeniety observed across regions. The total number of regional travelers, and point estimates for incidence (95% CI) for Latin American, African, and Asian travelers were [15816 (0.09 [0.07–0.11]), 42290 (0.06 [0.05–0.07]), and 27433 (0.07 [0.06–0.09])] respectively. We identified lower published rates of chronic diarrhea from Sub-Saharan Africa relative to [North Africa, South Central Asia, and Central America]. Persistent/chronic diarrhea ranked fourth as a syndromic diagnosis in all regions.

Conclusions

Persistent/Chronic diarrhea is a leading syndromic diagnosis in returning travelers across all regions. The 6% incidence [proportionate morbidity (PM) of 60] observed in over >300,000 global travelers is comparable to prior estimates. We identified lower published rates of chronic diarrhea from Sub-Saharan Africa relative to [North Africa, South Central Asia, and Central America]. Giardiasis comprises an appreciabile percentatge of travel-associated infectious mediated persistent/chronic diarrhea. There’s a dearth of published data characterizing the incidence of specific enteropathogenic etiologies for persistent/chronic diarrhea in returning travelers.

The association between the intake of specific dietary components and lifestyle factors and microscopic colitis

Background/Objectives:

The incidence of microscopic colitis (MC) has increased over the previous decades. In addition to smoking and drugs, currently unidentified environmental factors may have a role. The aim of this study was to determine whether specific dietary or other lifestyle factors were associated with the development of MC.

Subject/Methods:

The population-based cohort Malmö Diet and Cancer Study of 28 095 individuals was examined. Information about dietary habits was collected by a modified diet history method. Data on anthropometry were measured, and socio-economic and lifestyle factors were collected by questionnaires. Cases of MC were identified in medical registers. Associations were estimated using Cox regression analysis.

Results:

During a 22-year period, 135 patients were diagnosed with MC. Intakes of protein, carbohydrates, sucrose, saturated fat, monounsaturated fat, polyunsaturated fat, omega-3 or omega-6 fatty acids, fibre and zinc were not associated with MC. We could verify the previously reported association between MC and smoking (hazard ratio (HR): 2.29; 95% confidence interval (CI): 1.66–3.84) and the female gender (HR: 3.57; 95% CI: 2.22–5.74). High alcohol consumption was associated with an increased risk for MC (HR: 1.89 for the highest quartile; 95% CI: 0.82–4.33, P for trend=0.032). In a post hoc analysis, alcohol intake including all patients independently of consumption seemed to reduce the smoking-related risk.

Conclusions:

Despite a large cohort and a long follow-up period, we could not detect any dietary risk factors for MC. The aetiological mechanisms behind the positive impact of smoking and alcohol on MC risk should be investigated.

CD3 immunohistochemical staining in diagnosis of lymphocytic colitis

Microscopic colitis (MC) is a common cause of chronic watery diarrhea. Traditionally, MC encompasses the 2 subgroups lymphocytic colitis (LC) and collagenous colitis, but recently, an additional subgroup, MC incomplete, has been introduced. Distinguishing between the subgroups relies exclusively on histopathologic evaluation. In the present study, 4 pathologists evaluated 156 archived biopsies originally diagnosed as LC or LC incomplete (LCi). Each pathologist assigned a diagnosis of LC, LCi, or nonspecific inflammation to all cases at 2 independent assessments. At the first assessment, hematoxylin and eosin (HE) stainings were available. At the second assessment, a supplementary CD3 immunohistochemical staining was also available. The aim was to evaluate whether a supplementary CD3 would increase the diagnostic agreement among pathologists, and whether a CD3 stain would change the diagnosis based on HE staining only. After the complete assessment, the cases were divided into 3 groups, that is, full agreement, partial agreement, and disagreement. The CD3 staining increased the number of cases with full agreement from 60 to 78. One hundred thirty-one cases with agreement or partial diagnostic agreement based on HE + CD3 were compared with the HE diagnoses. In 44 (34%) of 131 cases, CD3 changed the diagnosis. Cases assigned to the LCi category based on HE were often changed by a supplementary CD3. Conclusively, it is recommended to use a CD3 before giving the histopathologic diagnosis of LCi.

Proximal collagenous gastroenteritides: clinical management. A systematic review

AIM

While collagenous colitis represents the most common form of the collagenous gastroenteritides, the collagenous entities affecting the proximal part of the gastrointestinal tract are much less recognized and possibly overlooked. The aim was to summarize the latest information through a systematic review of collagenous gastritis, collagenous sprue, and a combination thereof.

METHOD

The search yielded 117 studies which were suitable for inclusion in the systematic review. Excluding repeated cases, 89 case reports and 28 case series were reported, whereas no prospective studies with or without control groups were identified. Further, no randomized, controlled trials were identified. The total number of patients with proximal collagenous gastroenteritides reported was 330.

RESULTS

An overview of clinical presentations, prognosis, pathophysiology and histopathology, as well as management of these disorders is presented. The prognosis of both collagenous gastritis and sprue seems not to be as dismal as considered previously. Data point to involvement of immune or autoimmune mechanisms potentially driven by luminal antigens initiating the fibroinflammatory condition.

CONCLUSIONS

To reach the diagnosis it is recommended that biopsies are obtained during gastroduodenoscopies. Therapies with anti-secretory strategies, glucocorticoids, and in some cases iron supplementation are suggested, although rational treatment options from randomized, controlled trials do not exist for these rare or even overlooked disorders.

Clinical features and treatment responses in pediatric lymphocytic and collagenous colitis

OBJECTIVE

Microscopic colitis (MC) is prevalent in adults investigated for chronic watery diarrhea, yet characterization of pediatric MC is limited.

METHODS

Our pathology database was searched from 1995 to 2011 for pediatric cases of lymphocytic colitis (LC) or collagenous colitis (CC). Those with diarrhea persisting for >2 weeks and visually normal colonoscopy were accepted as cases. Demographics, laboratory results, medication use within 3 months of presentation, medical and family history of autoimmune disease, and response to treatment were abstracted.

RESULTS

A total of 27 cases were histologically consistent with MC on biopsy; 5 with concomitant enteric infection or isolated abdominal pain were excluded. Twenty-two cases of MC (female patients, 59%; median age at diagnosis, 15.3 years) were included (19 LC and 3 CC). Two had type 1 diabetes mellitus, 2 were anti-nuclear antibody positive, and 2 had common variable immunodeficiency. Of 20 patients who underwent an esophagogastroduodenoscopy, 1 had collagenous sprue and 4 had celiac disease. One presented after the clearance of recurrent Clostridium difficile infection. Previous drug exposures included nonsteroidal anti-inflammatory drugs (n = 7), proton pump inhibitors (n = 6), and selective serotonin reuptake inhibitors (n = 3). Common symptoms in addition to diarrhea included abdominal pain (77.3%) and weight loss (27.3%). Of 17 patients with follow-up, all of the 8 treated with steroids had some response: 57.1% (4/7) responded to mesalamine and 42.9% (3/7) responded to bismuth subsalicylate.

CONCLUSIONS

In this cohort of pediatric patients, LC was much more common than CC. As described in adults, we observed associations with celiac disease, type 1 diabetes mellitus, and medications; we additionally saw an association with immunodeficiency. Our patients showed greater response to steroids than mesalamine or bismuth.

Observer variability in the histopathologic diagnosis of microscopic colitis and subgroups

The diagnosis of microscopic colitis (MC) is based on histologic findings and includes collagenous colitis (CC) and lymphocytic colitis (LC). Incomplete MC (MCi) denotes patients with chronic diarrhea and a normal endoscopy and morphological changes that do not completely meet the histologic criteria of LC or CC. The aim of this study was to investigate the intraobserver and interobserver agreement on the MC subtypes of CC, LC, and MCi and the ability to discriminate MCi from normal and inflammatory bowel disease/nonspecific reactive changes. A single hematoxylin and eosin-stained specimen from biopsies of the following 5 groups were randomly selected and blinded: CC, LC, MCi, inflammatory bowel disease, and normal. Three pathologists independently reviewed the specimens. The specimens were relabeled and reinterpreted 4 months later. Intraobserver and interobserver agreement was evaluated by κ statistics. κ values for intraobserver agreement were good for 5 diagnostic groups varying from 0.70 to 0.83 and very good when simplifying to only 3 diagnostic groups varying from 0.88 to 0.96, separating MC/MCi from non-MC. κ values for interobserver agreement varied from 0.60 to 0.75 for 5 diagnostic groups and 0.81 to 0.89 for 3 diagnostic groups. The study shows that the intraobserver and interobserver agreement is high for discriminating between MC/MCi and non-MC, whereas the ability to discriminate MCi from CC and LC is lower. A revision and consensus on the histologic criteria of the MC subtypes seem warranted.

Microscopic colitis. A review

Microscopic colitis (MC) is characterized by a triad of watery diarrhea, usually normal colonoscopic findings and typical microscopic findings. Two distinct histological forms of MC have been defined: lymphocytic colitis and collagenous colitis, but overlapping features may be present. The incidence of MC appears to be rising and in some countries it may account for as many as 10-20% of patients with non-bloody watery diarrhea. The cause of MC remains unknown and is likely to be multifactorial. The pathogenesis is poorly defined, and numerous immunological abnormalities have been reported. MC is commonly associated with autoimmune diseases including celiac disease. Use of various medications, most notably non-steroidal anti-inflammatory agents and proton pump inhibitors, have been etiologically implicated but not firmly established as causative. In imperfect trials several agents have been reported to be effective in the treatment of MC; budesonide is the best studied and evidence supporting its effectiveness is the most persuasive. In cases of otherwise unexplained watery, non-bloody diarrhea, MC should be considered and colonic biopsied specimens should be taken of normal-appearing mucosa.

De novo inflammatory bowel disease and its mimics after organ transplantation

Diarrhea is a common symptom after solid organ transplantation or hematopoietic stem cell transplantation, with a reported prevalence up to 72%. One of the uncommon causes for diarrhea in the posttransplant setting is development of de novo inflammatory bowel disease (IBD). The incidence of posttransplantation de novo IBD was shown to be higher than that in the general population (206 versus 20 per 100,000 cases annually). The frequency seems to be much higher following orthotopic liver transplantation than the transplantation of other solid organs. De novo IBD has also been described in the setting of bone marrow transplantation though not as commonly as after SOT. While IBD is considered an immune-mediated disorder and responds favorably to immunosuppressive, de novo IBD or IBD-like conditions can occur in the posttransplant period despite antirejection immunosuppressive therapy. Damage or pathogen-associated molecular pattern molecules and their associated ongoing inflammation within the transplanted organ and the recipients' intestine have been implicated as possible etiologies. Various viral, bacterial, and protozoal infections can mimic IBD in postorgan transplantation. Common IBD mimickers in the postbone marrow transplant setting are graft-versus-host disease, infectious enteritis/colitis, and less commonly "cord colitis" that is described in detail below. In this article, we discuss the epidemiology, clinical features, and outcomes of de novo IBD after transplantation and highlight their differences in presentation, diagnosis, and management.

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.

Chromogranin A cell density as a diagnostic marker for lymphocytic colitis

BACKGROUND

Lymphocytic colitis (LC) can be mistakenly diagnosed as irritable bowel syndrome (IBS). In a previous study on IBS, some patients showed extremely high colonic chromogranin A cell density. Further examination of these patients showed that they suffered from LC.

AIMS

To investigate whether chromogranin A cell density is increased in LC patients and to examine the possibility of using this increase as a marker for the diagnosis of LC.

METHODS

Fifty-seven patients diagnosed with LC and 54 controls were included in the study. Biopsies from the right and left colon were obtained from both patients and controls, which were immunostained using the Avidin-biotin-complex method for chromogranin A, and cell density was quantified.

RESULTS

In both the right and left colon of patients with LC, the density of chromogranin A was significantly higher than in controls. This increase in chromogranin A cells occurs whether the number of these cells is expressed as number/mm(2) epithelium or as number/field. Chromogranin A cell density for the right and left colon expressed as number of cells/mm(2) epithelium or as cell number/field showed a high sensitivity and specificity as a diagnostic marker for LC.

CONCLUSIONS

Chromogranin A is a common marker for endocrine cells, and the present finding suggests that colonic hormones are involved in the pathophysiology of LC. The chromogranin cell density seems to be a good diagnostic marker with high sensitivity and specificity in both the right and left colon, thus sigmoidoscopy can be used in the diagnosis of LC using with this marker.

High densities of serotonin and peptide YY cells in the colon of patients with lymphocytic colitis

AIM: To investigate colonic endocrine cells in lymphocytic colitis (LC) patients.

METHODS: Fifty-seven patients with LC were included. These patients were 41 females and 16 males, with an average age of 49 years (range 19-84 years). Twenty-seven subjects that underwent colonoscopy with biopsies were used as controls. These subjects underwent colonoscopy because of gastrointestinal bleeding or health worries, where the source of bleeding was identified as haemorrhoids or angiodysplasia. They were 19 females and 8 males with an average age of 49 years (range 18-67 years). Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. Biopsies were fixed in 4% buffered paraformaldehyde, embedded in paraffin and cut into 5 μm-thick sections. The sections immunostained by the avidin-biotin-complex method for serotonin, peptide YY (PYY), pancreatic polypeptide (PP) enteroglucagon and somatostatin cells. The cell densities were quantified by computerised image analysis using Olympus software.

RESULTS: The colon of both the patient and the control subjects were macroscopically normal. Histopathological examination of colon biopsies from controls revealed normal histology. All patients fulfilled the diagnosis criteria required for of LC: an increase in intraepithelial lymphocytes (> 20 lymphocytes/100 epithelial cells) and surface epithelial damage with increased lamina propria plasma cells and absent or minimal crypt architectural distribution. In the colon of both patients and control subjects, serotonin-, PYY-, PP-, enteroglucagon- and somatostatin-immunoreactive cells were primarily located in the upper part of the crypts of Lieberkühn. These cells were basket- or flask-shaped. There was no statistically significant difference between the right and left colon in controls with regards to the densities of serotonin- and PYY-immunoreactive cells (P = 0.9 and 0.1, respectively). Serotonin cell density in the right colon in controls was 28.9 ± 1.8 and in LC patients 41.6 ± 2.6 (P = 0.008). In the left colon, the corresponding figures were 28.5 ± 1.9 and 42.4 ± 2.9, respectively (P = 0.009). PYY cell density in the right colon of the controls was 10.1 ± 1 and of LC patients 41 ± 4 (P = 0.00006). In the left colon, PYY cell density in controls was 6.6 ± 1.2 and in LC patients 53.3 ± 4.6 (P = 0.00007).

CONCLUSION: The change in serotonin cells could be caused by an interaction between immune cells and serotonin cells, and that of PYY density might be secondary.

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

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