Morphometric evaluation of duodenal biopsies in celiac disease

A thin cryobiopsy device compatible with transnasal endoscopy for the gastrointestinal tract

Luminal organ biopsies are critical for disease diagnosis and are obtained using single-bite forceps inserted through the working channel of large endoscopes. Procedures using these endoscopes frequently require patient sedation or anesthesia and may not be feasible for use in pediatric patients. Additionally, forceps-derived biopsies can suffer from difficulty maintaining tissue orientation, crush artifacts, and lack of precise control of biopsy depth. The high cost and risks of anesthesia and sedation have driven the development of smaller endoscopes for unsedated procedures. However, reduced endoscope size limits working-channel dimensions, restricting biopsy forceps to sizes that may yield insufficient or nondiagnostic samples. To address these limitations, we developed an image-guided, depth-controlled, ultrasmall-diameter (1.2-millimeters) cryobiopsy device (μCryoProbe). We optimized the coolant flow profile into the device to enhance tissue freezing, optimizing device-tissue contact time and freezing depth. We tested the device for gastrointestinal biopsy collection in ex vivo preclinical tissues, in an in vivo porcine model, and in sedated human participants. Dimensions and quality of mucosal cryobiopsies from esophagus, stomach, and duodenum were compared with those of forceps-derived biopsies, and it was found that the μCryoProbe device consistently produced high-quality biopsies with optimal tissue orientation and no evidence of crush artifacts. We also demonstrated the ability to capture gastrointestinal biopsies from sedated human participants. By capturing large, well-oriented samples using a small-diameter biopsy tool, this technology has the potential to shift procedures from large to small endoscopes, reducing the need for sedation and improving patient diagnosis through the acquisition of tissue samples with better quality.

A feasibility study using quantitative and interpretable histological analyses of celiac disease for automated cell type and tissue area classification

Histological assessment is essential for the diagnosis and management of celiac disease. Current scoring systems, including modified Marsh (Marsh-Oberhuber) score, lack inter-pathologist agreement. To address this unmet need, we aimed to develop a fully automated, quantitative approach for histology characterisation of celiac disease. Convolutional neural network models were trained using pathologist annotations of hematoxylin and eosin-stained biopsies of celiac disease mucosa and normal duodenum to identify cells, tissue and artifact regions. Biopsies of duodenal mucosa of varying celiac disease severity, and normal duodenum were collected from a large central laboratory. Celiac disease slides (N = 318) were split into training (n = 230; 72.3%), validation (n = 60; 18.9%) and test (n = 28; 8.8%) datasets. Normal duodenum slides (N = 58) were similarly divided into training (n = 40; 69.0%), validation (n = 12; 20.7%) and test (n = 6; 10.3%) datasets. Human interpretable features were extracted and the strength of their correlation with Marsh scores were calculated using Spearman rank correlations. Our model identified cells, tissue regions and artifacts, including distinguishing intraepithelial lymphocytes and differentiating villous epithelium from crypt epithelium. Proportional area measurements representing villous atrophy negatively correlated with Marsh scores (r =  - 0.79), while measurements indicative of crypt hyperplasia positively correlated (r = 0.71). Furthermore, features distinguishing celiac disease from normal duodenum were identified. Our novel model provides an explainable and fully automated approach for histology characterisation of celiac disease that correlates with modified Marsh scores, potentially facilitating diagnosis, prognosis, clinical trials and treatment response monitoring.

A Mouse Model of Celiac Disease

The design and use of mouse models that reproduce key features of human diseases are critical to advance our understanding of the pathogenesis of autoimmune diseases and to test new therapeutic strategies. Celiac disease is a unique organ-specific autoimmune-like disorder occurring in genetically susceptible individuals carrying HLA-DQ2 or HLA-DQ8 molecules who consume gluten. The key histological characteristic of the disease in humans is the destruction of the lining of the small intestine, a feature that has been difficult to reproduce in immunocompetent animal models. This unit describes the DQ8-Dd -villin-IL-15 transgenic mouse model of CeD, which was engineered based on the knowledge acquired from studying CeD patients' intestinal samples, and which represents the first animal model that develops villous atrophy in an HLA- and gluten-dependent manner without administration of any adjuvant. We provide detailed protocols for inducing and monitoring intestinal tissue damage, evaluating the cytotoxic properties of intraepithelial lymphocytes that mediate enterocyte lysis, and assessing the activation of the enzyme transglutaminase 2, which contributes to the generation of highly immunogenic gluten peptides. Detailed protocols to prepare pepsin-trypsin digested gliadin (PT-gliadin) or chymotrypsin-digested gliadin (CT-gliadin), which allow antibody detection against native or deamidated gluten peptides, are also provided in this unit. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Induction of celiac-like disease in DQ8-Dd -villin-IL-15tg mice Basic Protocol 2: Histological assessment of villous atrophy Support Protocol 1: Morphometric assessment of villous/crypt ratio Support Protocol 2: Evaluation of epithelial cells renewal Support Protocol 3: Evaluation of the density of intraepithelial lymphocytes Basic Protocol 3: Analysis of cytotoxic intraepithelial lymphocytes Basic Protocol 4: Transglutaminase 2 activation and measurement of antibodies against native and deamidated gluten peptides Support Protocol 4: Preparation of CT-gliadin Support Protocol 5: Preparation of PT-gliadin.

The global burden of coeliac disease: opportunities and challenges

Coeliac disease is a systemic disorder characterized by immune-mediated enteropathy, which is caused by gluten ingestion in genetically susceptible individuals. The clinical presentation of coeliac disease is highly variable and ranges from malabsorption through solely extra-intestinal manifestations to asymptomatic. As a result, the majority of patients with coeliac disease remain undiagnosed, misdiagnosed or experience a substantial delay in diagnosis. Coeliac disease is diagnosed by a combination of serological findings of disease-related antibodies and histological evidence of villous abnormalities in duodenal biopsy samples. However, variability in histological grading and in the diagnostic performance of some commercially available serological tests remains unacceptably high and confirmatory assays are not readily available in many parts of the world. Currently, the only effective treatment for coeliac disease is a lifelong, strict, gluten-free diet. However, many barriers impede patients' adherence to this diet, including lack of widespread availability, high cost, cross-contamination and its overall restrictive nature. Routine follow-up is necessary to ensure adherence to a gluten-free diet but considerable variation is evident in follow-up protocols and the optimal disease management strategy is not clear. However, these challenges in the diagnosis and management of coeliac disease suggest opportunities for future research.

Prospective study using villous length morphometry as an adjunctive tool to assess modified Marsh grade in patients with coeliac disease

Coeliac disease, an autoimmune disease, is caused by ingestion of gluten in genetically susceptible individuals. The currently used modified-Marsh grading, used to assess mucosal injury, is fraught with interobserver and intraobserver variability. The aim is to reduce this variability by villous length morphometry. Our prospective study was conducted on newly diagnosed cases of coeliac disease that were assessed by serohaematological profile, and duodenal biopsies were evaluated by modified Marsh grading. Villous length was measured in Grades 2, 3a and 3b using an eyepiece graticule lens calibrated with a stage micrometer. Severity of mucosal injury in different Marsh grades was significantly correlated to mean villous length, elevation of mean IgA tTG and drop in haemoglobin.

Intestinal stem cells promote crypt fission during postnatal growth of the small intestine

OBJECTIVE

Wnt-β-catenin signalling is essential for intestinal stem cells. Our aim was to investigate the relationship between intestinal stem cells and crypt fission which peaks during infancy.

DESIGN

Duodenal biopsies were obtained during endoscopy to assess the severity of reflux oesophagitis of 15 infants, children and teenagers, which would not affect the duodenum. Samples of small intestine were also obtained from rats 7-72 days of life. Crypt fission was assessed using microdissection of 100 whole crypts and recording the percentage of bifid crypts. Intestinal LGR5+ stem cells were identified by in situ hybridisation. Rats were treated with Dickkopf to block Wnt-β-catenin signalling.

RESULTS

Crypt fission peaked during infancy before declining after 3-4 years in humans and after 21 days of life in rats. Occasional mitotic figures were seen in bifid crypts during early fission. Stem cells were elevated for a greater period during infancy and childhood in humans. Clustering of Paneth cells was present around the stem cells at the crypt base. Dickkopf reduced the number of stem cells and crypt fission to 45% and 29%, respectively, of control values, showing dependence of both crypt fission and Lgr5+ stem cells on Wnt signalling. However, Dickkopf did not decrease mitotic count per crypt, indicating a difference in signalling between stem cells and their progeny in the transit amplifying zone.

CONCLUSION

Crypt fission peaks during infancy and is dependent on intestinal stem cells. This is relatively hidden by 'a cloak of invisibility' due to the low proliferation of stem cells.

Quantitative histology-based classification system for assessment of the intestinal mucosal histological changes in patients with celiac disease

BACKGROUND/AIMS

The existing histological classifications for the interpretation of small intestinal biopsies are based on qualitative parameters with high intraobserver and interobserver variations. We have developed and propose a quantitative histological classification system for the assessment of intestinal mucosal biopsies.

METHODS

We performed a computer-assisted quantitative histological assessment of digital images of duodenal biopsies from 137 controls and 124 patients with celiac disease (CeD) (derivation cohort). From the receiver-operating curve analysis, followed by multivariate and logistic regression analyses, we identified parameters for differentiating control biopsies from those of the patients with CeD. We repeated the quantitative histological analysis in a validation cohort (105 controls and 120 patients with CeD). On the basis of the results, we propose a quantitative histological classification system. The new classification was compared with the existing histological classifications for interobserver and intraobserver agreements by a group of qualified pathologists.

RESULTS

Among the histological parameters, intraepithelial lymphocyte count of ≥25/100 epithelial cells, adjusted villous height fold change of ≤0.7, and crypt depth-to-villous height ratio of ≥0.5 showed good discriminative power between the mucosal biopsies from the patients with CeD and those from the controls, with 90.3% sensitivity, 93.5% specificity, and 96.2% area under the curve. Among the existing histological classifications, our quantitative histological classification showed the highest intraobserver (69.7%-85.03%) and interobserver (24.6%-71.5%) agreements.

CONCLUSIONS

Quantitative assessment increases the reliability of the histological assessment of mucosal biopsies in patients with CeD. Such a classification system may be used for clinical trials in patients with CeD. (Intest Res, Published online).

Diagnosing celiac disease: A critical overview

The diagnosis of celiac disease (CD) no longer rests on a malabsorptive state or severe mucosal lesions. For the present, diagnosis will always require the gold-standard of a biopsy, interpreted through its progressive phases (Marsh classification). Marsh classification articulated the immunopathological spectrum of gluten-induced mucosal changes in association with the recognition of innate (Marsh I infiltration) and T cell-based adaptive (Marsh II, and the surface re-organisation typifying Marsh III lesions) responses. Through the Marsh classification the diagnostic goalposts were considerably widened thus, over its time-course, permitting countless patients to begin a gluten-free diet but who, on previous criteria, would have been denied such vital treatment. The revisions of this classification failed to provide additional insight in the interpretation of mucosal pathology. Morever, the subclassification of Marsh 3 imposed an enormous amount of extra work on pathologists with no aid in diagnosis, treatment, or prognosis. Therefore, it should now be apparent that if gastroenterologists ignore these sub-classifications in clinical decision-making, then on that basis alone, there is no need whatsoever for pathologists to persist in reporting them. Since new treatments are under critical assessment, we might have to consider use of some other higher level histological techniques sensitive enough to detect the changes sought. A promising alternative would be to hear more voices from imaginative histopathologists or morphologists together with some more insightful approaches, involving molecular-based techniques and stem cell research may be to evaluate mucosal pathology in CD.

Active β-Catenin Signaling in the Small Intestine of Humans During Infancy

BACKGROUND

Wnt-β-catenin signaling is essential for homeostasis of intestinal stem cells in mice and is thought to promote intestinal crypt fission.

AIMS

The aim of this study was to investigate Wnt-β-catenin signaling in intestinal crypts of human infants.

METHODS

Duodenal biopsies from nine infants (mean, range 0.9 years, 0.3-2 years) and 11 adults (mean, range 43 years, 34-71 years) were collected endoscopically. Active β-catenin signaling was assessed by cytoplasmic and nuclear β-catenin, nuclear c-Myc, and cytoplasmic Axin-2 expression in the base of crypts. Tissues were stained by an immunoperoxidase staining technique and quantified as pixel energy using cumulative signal analysis. Data were expressed as mean ± SD and significance assessed by Student's t test.

RESULTS

Crypt fission was significantly higher in infants compared to adults (16 ± 8.6% versus 0.7 ± 0.6%, respectively, p < 0.0001). Expression of cytoplasmic and nuclear β-catenin was 1.8-fold (p < 0.0001) and 2.9-fold (p < 0.0001) higher in infants, respectively, while cytoplasmic Axin-2 was 3.1-fold (p < 0.0001) increased in infants. c-Myc expression was not significantly different between infants and adults. Expression was absent in Paneth cells but present in the transit amplifying zone of crypts. Crypt base columnar cells, which were intercalated between Paneth cells, expressed c-Myc.

CONCLUSIONS

Wnt-β-catenin signaling was active in crypt base columnar cells (i.e., intestinal stem cells) in human infants. This signaling could promote crypt fission during infancy. Wnt-β-catenin signaling likely acts in concert with other pathways to promote postnatal growth.

Efficacy of duodenal bulb biopsy for diagnosis of celiac disease: a systematic review and meta-analysis

Background and study aims  Although duodenal biopsy is considered the "gold standard" for diagnosis of celiac disease, the optimal location of biopsy within the small bowel for diagnosis remains unclear. The primary aim of this study was to perform a structured systematic review and meta-analysis to evaluate the diagnostic utility of endoscopic duodenal bulb biopsy for celiac disease. Patients and methods  Searches of PubMed, EMBASE, Web of Science, and Cochrane Library databases were performed from 2000 through December 2017. Review of titles/abstracts, full review of potentially relevant studies, and data abstraction was performed. Measured outcomes of adult and pediatric patients included location of biopsy, mean number of biopsies performed, and diagnosis of celiac disease as defined by the modified Marsh-Oberhuber classification. Results  A total of 17 studies (n = 4050) were included. Seven studies evaluated adults and 11 studies assessed pediatric populations. Mean age of adults and pediatric patients was 46.70 ± 2.69 and 6.33 ± 1.26 years, respectively. Overall, sampling from the duodenal bulb demonstrated a 5 % (95 % CI 3 - 9; P  < 0.001) increase in the diagnostic yield of celiac disease. When stratified by pediatric and adult populations, duodenal bulb biopsy demonstrated a 4 % (95 % CI: 1 to 9; P  < 0.001) and 8 % (95 % CI: 6 to 10; P  < 0.001) increase in the diagnostic yield of celiac disease. Non-celiac histologic diagnoses including Brunner gland hyperplasia and peptic duodenitis were reported more commonly in the duodenal bulb as compared to the distal duodenum with an increase in diagnostic yield of 4 % (95 % CI 3 - 5; P  < 0.001) and 1 % (95 % CI 1 - 2; P  < 0.001), respectively. Conclusions  Based upon our results, biopsy and histologic examination of duodenal bulb during routine upper endoscopy increases the diagnostic yield of celiac disease.

No Difference Between Latiglutenase and Placebo in Reducing Villous Atrophy or Improving Symptoms in Patients With Symptomatic Celiac Disease

BACKGROUND & AIMS

Gluten ingestion leads to symptoms and small intestinal mucosal injury in patients with celiac disease. The only option is the strict lifelong exclusion of dietary gluten, which is difficult to accomplish. Many patients following a gluten-free diet continue to have symptoms and have small intestinal mucosal injury. Nondietary therapies are needed. We performed a phase 2 study of the ability of latiglutenase, an orally administered mixture of 2 recombinant gluten-targeting proteases, to reduce mucosal morphometric measures in biopsy specimens from patients with celiac disease.

METHODS

We performed a double-blind, placebo-controlled, dose-ranging study to assess the efficacy and safety of latiglutenase in 494 patients with celiac disease (with moderate or severe symptoms) in North America and Europe, from August 2013 until December 2014. Participants reported following a gluten-free diet for at least 1 year before the study began. Patients with documented moderate or severe symptoms and villous atrophy (villous height:crypt depth ratio of ≤2.0) were assigned randomly to groups given placebo or 100, 300, 450, 600, or 900 mg latiglutenase daily for 12 or 24 weeks. Subjects completed the Celiac Disease Symptom Diary each day for 28 days and underwent an upper gastrointestinal endoscopy with duodenal biopsy of the distal duodenum at baseline and at weeks 12 and 24. The primary end point was a change in the villous height:crypt depth ratio. Secondary end points included numbers of intraepithelial lymphocytes, serology test results (for levels of antibodies against tissue transglutaminase-2 and deamidated gliadin peptide), symptom frequencies, and safety.

RESULTS

In a modified intent-to-treat population, there were no differences between latiglutenase and placebo groups in change from baseline in villous height:crypt depth ratio, numbers of intraepithelial lymphocytes, or serologic markers of celiac disease. All groups had significant improvements in histologic and symptom scores.

CONCLUSIONS

In a phase 2 study of patients with symptomatic celiac disease and histologic evidence of significant duodenal mucosal injury, latiglutenase did not improve histologic and symptom scores when compared with placebo. There were no significant differences in change from baseline between groups. ClinicalTrials.gov no: NCT01917630.

Small bowel villous atrophy: celiac disease and beyond

Small bowel villous atrophy can represent a diagnostic challenge for gastroenterologists and pathologists. In Western countries small bowel atrophy and mild non-atrophic alterations are frequently caused by celiac disease. However, other pathology can mimic celiac disease microscopically, widening the differential diagnosis. The several novelties on this topic and the introduction of the device-assisted enteroscopy in the diagnostic flowchart make an update of the literature necessary. Areas covered: In this review, a description of the different clinical scenarios when facing with small bowel mucosal damage, particularly small bowel atrophy, is described. The published literature on this subject has been summarized and reviewed. Expert commentary: When an intestinal mucosal alteration is histologically demonstrated, the pathology report forms part of a more complex workup including serological data, clinical presentation and clinical history. A multidisciplinary team, including pathologists and enteroscopy-devoted endoscopists, is frequently required to manage patients with small bowel alterations, especially in cases of severe malabsorption syndrome.

Classification chaos in coeliac disease: Does it really matter?

The spectrum of mucosal pathology in coeliac disease (CD), initially defined by Marsh in 1992 has been subjected to several modifications in the following years by Oberhuber, then by Corazza and Villanaci, and finally by Ensari. The present study, aimed to end the ongoing confusion regarding the classification of mucosal pathology in CD by applying all the classifications proposed so far on a large series of cases. A total of 270 duodenal biopsies taken from the distal duodenum of patients with a diagnosis of CD were included in the study. All biopsies were classified according to Marsh, Oberhuber, Corazza Villanaci, and Ensari classification schemes. For statistical analyses cases were divided into three groups: Group 1 included type 1 lesions in Marsh, Ensari, and Oberhuber and grade A in Corazza Villanaci classifications. Group 2 comprised of type 2 lesions in Marsh and Ensari classifications together with type2, type 3a and 3b lesions in Oberhuber classification and grade B1 lesions in Corazza Villanaci classification. Group 3 included type 3 lesions in Marsh and Ensari classifications, and type 3c lesions in Oberhuber, and grade B2 lesions in Corazza Villanaci classifications. The kappa value was 1.00 (excellent) for group 1, 0.53 (fair) for group 2 and 0.78 (excellent) for group 3 (p<0.0001). These results suggest that any of the above classification system would serve similar purposes in the diagnosis of CD. Therefore, it is advisable that the pathologist should use the simplest reliable scheme.

Histological evaluation of duodenal biopsies from coeliac patients: the need for different grading criteria during follow-up

Background

Coeliac disease is characterised by villous atrophy, which usually normalises after gluten withdrawal. Sometimes the revaluation of duodenal histology is required during follow-up, even if the methodology for comparing duodenal histology before and after introducing a gluten-free diet is not yet established. Our aim was to evaluate a novel criterion to compare duodenal histology in coeliac disease before and after gluten withdrawal.

Methods

Duodenal biopsies from coeliac patients were retrospectively reviewed to compare duodenal histology at diagnosis and after at least one year on a gluten-free diet. Two different methods were used: the first was represented by the classical Marsh-Oberhuber score, the second compared the areas covered by each Marsh-Oberhuber grade and expressed as percentages, the final grade being calculated from the analysis of ten power fields per duodenal biopsy.

Results

Sixty-nine patients (17 males 52 females, age at diagnosis 36 ± 15 years) who underwent duodenal biopsies, were considered. According to the classical Marsh-Oberhuber scale, 32 patients did not present atrophy during follow-up while 37 showed duodenal atrophy, among whom 26 improved the grade of severity and 11 retained the same one. Of these latter, according to the second method, eight patients were considered improved, two showed a worsened duodenal damage and only one remained unchanged; the evaluation changed in 91 % of cases.

Conclusions

The proposed semi-quantitative approach (i.e. the second method) for the evaluation of histology at follow-up provides additional information about the progression/regression of the mucosal damage.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0361-8) contains supplementary material, which is available to authorized users.

Cancer etiology. Variation in cancer risk among tissues can be explained by the number of stem cell divisions

Some tissue types give rise to human cancers millions of times more often than other tissue types. Although this has been recognized for more than a century, it has never been explained. Here, we show that the lifetime risk of cancers of many different types is strongly correlated (0.81) with the total number of divisions of the normal self-renewing cells maintaining that tissue's homeostasis. These results suggest that only a third of the variation in cancer risk among tissues is attributable to environmental factors or inherited predispositions. The majority is due to "bad luck," that is, random mutations arising during DNA replication in normal, noncancerous stem cells. This is important not only for understanding the disease but also for designing strategies to limit the mortality it causes.

Mucosal healing in children with treated celiac disease

OBJECTIVES

Limited data suggest complete mucosal healing in treated children with celiac disease (CD), but recent data from adult endoscopic biopsies have shown substantial numbers with persistent mucosal injury. We aimed to assess the rate of mucosal healing and indications for repeat small bowel (SB) biopsy in children with CD.

METHODS

We retrospectively reviewed records of children (ages 1-18 years) with CD who underwent a second SB biopsy. All of the children were seen at Mayo Clinic (Rochester, MN) from January 1997 through June 2013.

RESULTS

Forty children were identified (14 boys); average age at diagnosis was 8.5 years. Indications for second SB biopsy were abdominal pain (n = 20), diarrhea (n = 7), constipation (n = 5), non-celiac-related concern (n = 2), follow-up (n = 5), and persistent serology (n = 1). Average time between biopsies was 24 months (range 4-120 months). Histology on the second biopsy showed complete healing (n = 25), intraepithelial lymphocytes (n = 9), and persistent villous atrophy (n = 6). Of these, 3 patients had partial villous atrophy and 3 had with complete villous atrophy. Persistent villous atrophy was observed in 2 of 20 patients with abdominal pain and 1 of 7 with diarrhea. All of the patients with persistent constipation (n = 5) had complete resolution.

CONCLUSIONS

Mucosal healing in children with CD may not be complete as previously assumed. Abdominal pain was the most common indication for repeating the SB biopsy. Persistence of abdominal pain, diarrhea, and constipation was poorly associated with persistence of mucosal injury.

Assessment of the response to gluten-free diet in an Iraqi population with coeliac disease. A histological and serological follow-up study

INTRODUCTION

Coeliac disease (CD) is a common diagnosis among children and adults in Iraq; however, removal of gluten from the diet is essential for patients with CD. The aim of this study, the first such study in Iraq, was to assess the serological and histological recovery profiles of coeliac patients, in both children and adults groups after commencing a gluten-free diet (GFD) for at least 1 year ± 1 month.

MATERIAL AND METHODS

The study group comprised 78 proved coeliac patients (46 children and 32 adults, median age: 15 years, range: 1-66 years) who all agreed to undergo endoscopy in addition to serological assessment before and after treatment. The duodenal biopsies were interpreted histologically according to modified Marsh criteria and the sera were tested for anti-gliadin antibody (AGA), endomysium antibody (EMA) and anti-tissue transglutaminase antibody (tTG).

RESULTS

Complete histological remission was seen in 29 (63.1%) of 46 treated children CD patients, while only 5 (10.9%) showed Marsh IIIa changes compared with 11 (24%) before GFD. Similarly none of the 32 adults after GFD showed Marsh IIIb and Marsh IIIc compared with 46.9% and 28.1% before treatment respectively (p = 001). Meanwhile, there was strongly significant reduction in AGA, EMA, and tTG antibodies levels (p = 0.00001) following GFD.

CONCLUSIONS

Repeating the duodenal biopsy 1 year ±1 month after diagnosis and starting a GFD supports the routine measurement of using histological findings as a gold standard test to confirm recovery of Iraqi CD patients along with using known coeliac serology antibodies.

Celiac disease: a disease with varied manifestations in adults and adolescents

OBJECTIVE

We aimed to determine the characteristics of patients with celiac disease and differences between those who presented during adolescence or adulthood.

METHODS

We retrospectively reviewed the case records of 233 consecutive patients with celiac disease who were diagnosed at 12-18 years or >18 years of age. The diagnosis of celiac disease was made on the basis of the modified European Society of Pediatric Gastroenterology, Hepatology and Nutrition criteria.

RESULTS

The diagnosis of celiac disease was made after 18 years of age in 153 (65.7%) patients. Median duration of symptoms at the diagnosis was 54 months (range 1 month to 29 years). In all, 103 (44.2%) patients with atypical manifestations were referred by other departments for evaluation. Chronic diarrhea (48.5%), short stature (27.0%) and chronic anemia (9.0%) were the common modes of presentation. Elevated level of aminotransaminase were present in 50 (24.3%) patients. Chronic diarrhea, hypocalcemia and hypoalbuminemia were present in significantly higher number of adult than adolescent patients. In all, 227 (97.4%) patients responded to a 6-month gluten-free diet and six non-responders were non-compliant.

CONCLUSIONS

More than 40% of the patients with celiac disease present to clinicians other than gastroenterologists or internists with atypical manifestations. A high index of suspicion is required for diagnosing its variant forms.

Notch signaling promotes intestinal crypt fission in the infant rat

BACKGROUND

Growth of the small intestine in the infant rat is promoted by crypt fission and later by increased crypt cell proliferation. Notch signaling could promote crypt fission. Hes-1 is a Notch target gene.

AIM

We assessed the effect of Notch signaling on intestinal crypt fission and on growth of the intestine in the infant rat.

METHODS

Hes-1 expression was determined in the small intestine of litters of Hooded Wistar rats aged between 3 and 72 days. Hes-1 RNA expression was measured by quantitative RT-PCR. Four groups of rats (n = 8 or 9) were injected daily, ip, either with vehicle or with the Notch inhibitor DAPT at doses of 3, 10, and 30 mg/kg, from days 9 to 13 of life, and killed on day 14. A microdissection technique was used to measure crypt fission, mitotic count, and apoptotic count. Data were analyzed by ANOVA and by use of Dunnett's F test.

RESULTS

Hes-1 expression and crypt fission peaked on day 14. DAPT reduced Hes-1 immunostaining in proportion to dose. DAPT reduced villous area to 72 % (p < 0.01), 53 % (p < 0.001), and 38 % (p < 0.001) of control values for 3, 10 and 30 mg/kg doses, respectively, and reduced crypt fission to 53 % (p < 0.001) and 38 % (p < 0.001) of control values, respectively, for 10 and 30 mg/kg doses. Crypt mitotic count was not affected by any DAPT dose. DAPT at 10 and 30 mg/kg significantly increased apoptosis in crypts, by 6.5 and 4.8-fold, respectively.

CONCLUSIONS

We conclude that Notch signaling promotes crypt fission and growth of the intestine by maintaining low apoptosis of crypt cells.

Serum I-FABP as marker for enterocyte damage in coeliac disease and its relation to villous atrophy and circulating autoantibodies

BACKGROUND

Enterocyte damage is the hallmark of coeliac disease (CD) resulting in malabsorption. Little is known about the recovery of enterocyte damage and its clinical consequences. Serum intestinal fatty acid binding protein (I-FABP) is a sensitive marker to study enterocyte damage.

AIMS

To evaluate the severity of enterocyte damage in adult-onset CD and its course upon a gluten-free diet (GFD). Furthermore, the correlation among enterocyte damage, CD autoantibodies and histological abnormalities during the course of disease is studied.

METHODS

Serum I-FABP levels were determined in 96 biopsy-proven adult CD patients and in 69 patients repeatedly upon a GFD. A total of 141 individuals with normal antitissue transglutaminase antibody (IgA-tTG) levels served as controls. I-FABP levels were related to the degree of villous atrophy (Marsh grade) and IgA-tTG.

RESULTS

I-FABP levels were elevated in untreated CD (median 691 pg/mL) compared with controls (median 178 pg/mL, P < 0.001) and correlated with Marsh grade (r = 0.265, P < 0.05) and IgA-tTG (r = 0.403, P < 0.01). Upon a GFD serum levels decreased significantly, however, not within the range observed in controls, despite the common observed normalisation of IgA-tTG levels and Marsh grade. CD patients with elevated I-FABP levels nonresponding to GFD showed persistent histological abnormalities.

CONCLUSIONS

Enterocyte damage assessed by serum I-FABP correlates with the severity of villous atrophy in coeliac disease at the time of diagnosis. Although enterocyte damage improves upon treatment, substantial enterocyte damage persists despite absence of villous atrophy and low IgA-tTG levels in the majority of cases. Elevated I-FABP levels nonresponding to gluten-free diet are indicative of histological abnormalities and warrant further evaluation.

Celiac disease: prevalence, diagnosis, pathogenesis and treatment

Celiac disease (CD) is one of the most common diseases, resulting from both environmental (gluten) and genetic factors [human leukocyte antigen (HLA) and non-HLA genes]. The prevalence of CD has been estimated to approximate 0.5%-1% in different parts of the world. However, the population with diabetes, autoimmune disorder or relatives of CD individuals have even higher risk for the development of CD, at least in part, because of shared HLA typing. Gliadin gains access to the basal surface of the epithelium, and interact directly with the immune system, via both trans- and para-cellular routes. From a diagnostic perspective, symptoms may be viewed as either "typical" or "atypical". In both positive serological screening results suggestive of CD, should lead to small bowel biopsy followed by a favourable clinical and serological response to the gluten-free diet (GFD) to confirm the diagnosis. Positive anti-tissue transglutaminase antibody or anti-endomysial antibody during the clinical course helps to confirm the diagnosis of CD because of their over 99% specificities when small bowel villous atrophy is present on biopsy. Currently, the only treatment available for CD individuals is a strict life-long GFD. A greater understanding of the pathogenesis of CD allows alternative future CD treatments to hydrolyse toxic gliadin peptide, prevent toxic gliadin peptide absorption, blockage of selective deamidation of specific glutamine residues by tissue, restore immune tolerance towards gluten, modulation of immune response to dietary gliadin, and restoration of intestinal architecture.

Wnt blockade with dickkopf reduces intestinal crypt fission and intestinal growth in infant rats

OBJECTIVES

Intestinal crypt fission peaks during infancy. In human and experimental familial polyposis coli, increased crypt fission is due to activation of Wnt/β-catenin signalling, but the molecular basis of crypt fission during intestinal growth has not been examined. The aim of this project was to investigate whether crypt fission and intestinal growth are affected by experimental blockade of the Wnt/β-catenin signalling pathway.

METHODS

Hooded Wistar rats were given either the Wnt inhibitor, dickkopf (30 and 100 ng), daily or vehicle control intraperitoneally from days 11 to 15 and were killed at day 16. Intestinal morphometry was used to measure villous area, crypt area, percentage of crypt fission, and crypt mitotic count. Intestinal stem cells were assessed by expression of real time-polymerase chain reaction for Lgr5 (a stem cell marker), and the number of β-catenin-expressing crypts by immunostaining was determined after 100-ng dickkopf treatment.

RESULTS

Dickkopf at 30 and 100 ng/day reduced villous area to 71% (P = 0.013) and 29% (P < 0.0001), crypt area to 42% (P = 0.0026) and 30% (P = 0.0067), and crypt fission to 51% (P = 0.006) and 29% (P < 0.0001), respectively, of control values. Mitotic count per crypt did not change. Lgr5 RNA expression and the number of β-catenin-expressing crypts decreased in dickkopf-treated animals.

CONCLUSIONS

We conclude that intestinal crypt fission during infancy is mediated by Wnt signalling. It is possible that local treatment with Wnt agonists could be used to increase intestinal growth.

No evidence of circulating autoantibodies against osteoprotegerin in patients with celiac disease

AIM: To investigate risk factors for low bone mineral density (BMD) in celiac disease (CD) patients, focusing on circulating autoantibodies against osteoprotegerin (OPG).

METHODS: Seventy asymptomatic CD adult patients on gluten-free diet (GFD) and harbouring persistent negative CD-related serology were recruited. Conventional risk factors for osteoporosis (e.g., age, sex, menopausal status, history of fractures, smoke, and body mass index) were checked and BMD was assessed by dual energy X ray absorptiometry. Serum calcium and parathyroid hormone (PTH) levels were evaluated. Thirty-eight patients underwent repeat duodenal biopsy. Serum samples from a selected sub-group of 30 patients, who were also typed for human leukocyte antigen (HLA) DQ2 and DQ8 haplotype, were incubated with homodimeric recombinant human OPG and tested by western blotting with an anti-OPG antibody after immunoprecipitation.

RESULTS: Despite persistent negative CD-related serology and strict adherence to GFD, 49 out of the 70 (74%) patients displayed low BMD. Among these patients, 13 (24%) showed osteoporosis and 36 (76%) osteopenia. With the exception of age, conventional risk factors for osteoporosis did not differ between patients with normal and low BMD. Circulating serum calcium and PTH levels were normal in all patients. Duodenal mucosa healing was found in 31 (82%) out of 38 patients who underwent repeat duodenal biopsy with 20 (64%) still displaying low BMD. The remaining 7 patients had an incomplete normalization of duodenal mucosa with 6 (84%) showing low BMD. No evidence of circulating antibodies against OPG was found in the serum of 30 celiac patients who were tested for, independent of BMD, duodenal histology, and HLA status.

CONCLUSION: If any, the role of circulating autoantibodies against OPG in the pathogenesis of bone derangement in patients with CD is not a major one.

Advances in coeliac disease

PURPOSE OF REVIEW

This article critically summarizes the recent scientific and clinical advances in coeliac disease.

RECENT FINDINGS

Epidemiological studies have shown that coeliac disease is as common in parts of Asia, Africa and Eastern Europe as in the western world. Genome-wide association studies continue to identify genetic susceptibilities that are both unique to coeliac disease and overlap with other autoimmune diseases. Human leukocyte antigen genotyping offers additional sensitivity in detecting coeliac disease in individuals who have self-prescribed gluten-free diets (GFD) or have atypical presentations. Immunological advances have highlighted the potential proinflammatory pitfalls of vitamin A supplementation in active coeliac disease and have enabled identification of oat and barley subsets that may be safely incorporated into coeliac diets. Large population-based studies have expanded our knowledge of the long-term risks of coeliac disease, in addition to excluding infertility as a cause for concern once a GFD has been established.

SUMMARY

The long-term implications of active coeliac disease emphasize the need for early detection and strict adherence to GFD, which remains the cornerstone of management. Technological advances in food modulation and immuno-therapies offer promise, but remain in the translational phases of clinical trials at present.

Update on celiac disease - etiology, differential diagnosis, drug targets, and management advances

Celiac disease (CD) is an immune-mediated enteropathy triggered by exposure to wheat gluten and similar proteins found in rye and barley that affects genetically susceptible persons. This immune-mediated enteropathy is characterized by villous atrophy, intraepithelial lymphocytosis, and crypt hyperplasia. Once thought a disease that largely presented with malnourished children, the wide spectrum of disease activity is now better recognized and this has resulted in a shift in the presenting symptoms of most patients with CD. New advances in testing, both serologic and endoscopic, have dramatically increased the detection and diagnosis of CD. While the gluten-free diet is still the only treatment for CD, recent investigations have explored alternative approaches, including the use of altered nonimmunogenic wheat variants, enzymatic degradation of gluten, tissue transglutaminase inhibitors, induction of tolerance, and peptides to restore integrity to intestinal tight junctions.

Capsule endoscopy: a valuable tool in the follow-up of people with celiac disease on a gluten-free diet

OBJECTIVES:

Traditional celiac disease guidelines recommend follow-up endoscopy and duodenal biopsies at 6–12 months after commencing a gluten-free diet (GFD). However, histology may remain abnormal even 1–2 years later. We evaluated the role of capsule endoscopy in patients with celiac disease after treatment with a GFD.

METHODS:

Twelve adult patients with newly diagnosed celiac disease were prospectively enrolled. All patients had baseline symptom assessment, celiac serology (tissue transglutaminase antibody, tTG), and capsule endoscopy. Twelve months after commencing a GFD, patients underwent repeat symptom assessment, celiac serology, upper gastrointestinal endoscopy, and capsule endoscopy.

RESULTS:

At baseline, capsule endoscopy detected endoscopic markers of villous atrophy in the duodenum and extending to a variable distance along the small intestine. On the basis of small bowel transit time, the mean±s.e.m. percentage of small intestine with villous atrophy was 18.2±3.7%. After 12 months on a GFD, repeat capsule endoscopy demonstrated mucosal healing from a distal to proximal direction, and the percentage of small intestine with villous atrophy was significantly reduced to 3.4±1.2% (P=0.0014) and this correlated with improvement in the symptom score (correlation 0.69, P=0.01). There was a significant improvement in symptom score (5.2±1.0 vs. 1.7±0.4, P=0.0012) and reduction in immunoglobulin A–tTG levels (81.5±10.6 vs. 17.5±8.2, P=0.0005). However, 42% of subjects demonstrated persistent villous abnormality as assessed by duodenal histology.

CONCLUSIONS:

After 12 months on a GFD, patients with celiac disease demonstrate an improvement in symptoms, celiac serology, and the extent of disease as measured by capsule endoscopy. Mucosal healing occurs in a distal to proximal direction. The extent of mucosal healing correlates with improvement in symptoms. Duodenal histology does not reflect the healing that has occurred more distally.