Analysis of Biopsies From Duodenal Bulbs of All Endoscopy Patients Increases Detection of Abnormalities but has a Minimal Effect on Diagnosis of Celiac Disease

Role of Duodenal Bulb Biopsy in Diagnosing Suspected Celiac Disease in Adult Patients: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Current guidelines recommend multiple biopsies from the first (D1) and second (D2) part of duodenum to establish a diagnosis of celiac disease. In this meta-analysis we aimed to find whether D1 biopsy can increase the diagnostic yield of adult celiac disease.

METHODS

Literature databases were searched until January 2023 for studies reporting diagnosis of celiac disease in the adult population using D1 biopsy. Meta-analysis was done using a random-effects model. Heterogeneity was assessed by I 2 % and 95% prediction interval statistics. Measured outcomes were diagnostic yield with D1 and D2 biopsies and from 4 versus 2 biopsy samples.

RESULTS

A total of 16 studies were included in the final analysis. The pooled diagnostic rate of celiac disease from D1 biopsy was 77.4% [95% CI (64.7-86.5, I 2 94%)] and from D2 biopsy was 75.3% [60.8-85.7, I 2 96%]. The pooled rate of increase in diagnostic yield with D1 biopsy was 6.9% I [4.6-10.2, I 2 66%]. The pooled diagnosis rate with 2 biopsy samples were 77.3% [50-92, I 2 93%] and 86.4% I [58.4-96.7, I 2 87%] from D1 and D2 respectively, whereas that with 4 biopsy samples were 83.3% [49.8-96.2, I 2 76%] and 70.5% I [51-84.6, I 2 96%] from D1 and D2, respectively, the difference being non-significant.

CONCLUSION

Our study demonstrates that taking 4 biopsy samples does not incur any additional diagnostic value over taking 2 biopsy samples from each duodenum segment. Although biopsy from the D1 and D2 has similar diagnostic yield in the adult population, there was an overall increase in diagnostic yield with D1 biopsy, especially in those with a patchy disease distribution.

Budesonide Induces Favourable Histologic and Symptomatic Recovery in Patients with Non-responsive and Refractory Coeliac Disease When Given in an Open Capsule Format

INTRODUCTION

Non-responsive coeliac disease (NRCD), where symptoms and enteropathy persist despite a prolonged gluten-free diet (GFD), is common. Refractory coeliac disease (RCD), characterised by malabsorption and extensive enteropathy, is rare but serious. In both, treatment options are limited. Topical budesonide may help and an open capsule format promoting proximal small intestinal delivery may be advantageous.

AIM

To describe the effect of budesonide and its presentation on mucosal healing, symptoms, and tolerability in NRCD and RCD.

METHODS

A retrospective cohort study of NRCD and RCD patients who received budesonide for enteropathy despite a strict GFD for over 12 months. Primary outcome was improvement in histology. Symptoms and adverse treatment effects were recorded.

RESULTS

50 patients with NRCD (n = 14; 86% F), RCD type 1 (n = 30; 60% F), and RCD type 2 (n = 6 based on aberrant duodenal T cells; 33% F) were identified. Common RCD symptoms were diarrhoea (68%), fatigue (40%), and weight loss (34%). 16 received closed capsule budesonide (CCB) 9 mg OD and 35 open capsule budesonide (OCB) 3 mg 3 times a day. Complete and partial mucosal healing was significantly higher after OCB compared to CCB (p < 0.001, Mann-Whitney U test). Symptom improvement was also significantly higher after OCB compared to CCB (p = 0.002, Mann-Whitney U test). Side effects were mild and self-limiting and were reported in 25% of both cohorts.

CONCLUSION

OCB was well tolerated and associated with improvements in enteropathy (83%) and symptoms (90%) in NRCD and RCD. Our findings support OCB as the preferred 1st-line therapy for NRCD and RCD type 1.

Diagnosis of Seronegative and Ultrashort Celiac Disease

In its conventional form, celiac disease (CeD) is characterized by both positive serology and flat villi in the duodenum, and is well known by gastroenterologists and general practitioners. The aim of this review was to shed light on 2 neglected and not yet well-defined celiac phenotypes, that is, seronegative and ultrashort CeD. Seronegative CeD can be suspected in the presence of flat villi, positive HLA-DQ2 and/or HLA-DQ8, and the absence of CeD antibodies. After ruling out other seronegative enteropathies, the diagnosis can be confirmed by both clinical and histologic improvements after 1 year of a gluten-free diet. Ultrashort CeD is characterized by the finding of flat villi in the duodenal bulb in the absence of mucosal damage in the distal duodenum and with serologic positivity. Data on the prevalence, clinical manifestations, histologic lesions, genetic features, and outcome of seronegative and ultrashort CeD are inconclusive due to the few studies available and the small number of patients diagnosed. Some additional diagnostic tools have been developed recently, such as assessing intestinal transglutaminase 2 deposits, flow cytometry technique, microRNA detection, or proteomic analysis, and they seem to be useful in the identification of complex cases. Further cooperative studies are highly desirable to improve the knowledge of these 2 still-obscure variants of CeD.

Histologic evaluation in the diagnosis and management of celiac disease: practical challenges, current best practice recommendations and beyond

Celiac disease (CD) is an immunoallergic enteropathy affecting genetically susceptible individuals upon dietary exposure to gluten. In current clinical practice, the diagnosis of CD is based on a combination of clinical, serologic, and histologic factors with the possible exception of pediatric patients. Histopathologic evaluation of small intestinal tissue plays a critical role in the disease diagnosis and management, despite many practical challenges. Recently published best practice guidelines help to standardize biopsy sample procurement, tissue preparation, histology interpretation, and reporting, to optimize patient care. In addition, an increasing demand for monitoring the disease course, particularly demonstrating the efficacy of dietary and nondietary interventions for disease management, calls for the use of quantitative histology. With the advent of a gradual transition toward digital pathology in routine diagnostic practice, quantitative histopathologic evaluation in CD shows a promising future.

Clinical utility of GI pathology data: implications for practising pathologists

Gastrointestinal (GI) tract pathology represents one of the largest individual specialties within cellular pathology departments globally. As with other specialties, clear communication with clinicians providing primary care for the patient is of utmost importance for optimal management and for appropriate use of resources such as endoscopy. A wide breadth of neoplastic and inflammatory conditions afflicts the GI tract. Here, we aim to illustrate how pathology reporting of GI tract specimens influences patient management and specifically how precise reporting of key parameters in different specimen types and different disease processes can directly impact patient care. We describe the potential clinical relevance of selected pathology data items pertinent to specific conditions and highlight areas of contention with respect to the significance of some pathology features. Recent guidelines are described where a change, for example, in diagnostic criteria for a condition is described, or criteria influencing further management such as endoscopic surveillance. The aim of this review is to focus on the clinical importance of careful written communication between the pathologist and primary clinician, illustrated by selective clinical scenarios involving the upper and lower GI tracts.

Ultra-short celiac disease exhibits differential genetic and immunophenotypic features compared to conventional celiac disease

BACKGROUND

Ultra-short coeliac disease (USCD) is a novel celiac disease (CD) subtype limited to the duodenal bulb (D1). HLA haplotypes and flow cytometry have not been assessed yet.

AIMS

To compare genetic, clinical, serologic, histopathologic and inmmunophenotypic parameters between USCD and conventional celiac disease (CCD) patients.

METHODS

Prospective single-center study in children and adult patients undergoing duodenal biopsies on a gluten-containing diet. Biopsies for histology and flow cytometry were taken separately from D1 and distal duodenum. Biopsies in seronegative patients with celiac lymphogram were repeated after 2 years on a gluten-free diet.

RESULTS

Among 505 included patients, 127 were diagnosed with CD, of whom 7 (5.5%) showed USCD. HLADQ2 was significantly less common in USCD compared to CCD (71% vs. 95%, p 0.003). Likewise, USCD patients showed more frequent non-significant seronegativity (28% vs. 8%, p 0.07) and significantly lower titrations (7-15 IU/ml) of tissue transglutaminase antibodies (tTG-IgA) (60% vs. 13%, p<0.001). Biopsies from D1 revealed significant less NK cells down-expression in USCD patients (1.4 vs. 5, p 0.04).

CONCLUSIONS

Up to 5.5% of CD patients showed USCD. A lower frequency of HLADQ2, along with less serum tTG-IgA titration and duodenal NK cell suppression, were differential features of USCD.

The Role of the Gluten-Free Diet in the Management of Seronegative Enteropathy

The differential diagnosis and treatment of seronegative enteropathy, also termed seronegative villous atrophy (SNVA), is a clinical challenge. Although seronegative coeliac disease (CD) is a frequent cause of SNVA, the aetiology can include immune-mediated, inflammatory, infectious, and drug-related forms. As a misdiagnosis of SNVA can result in patients being unnecessarily placed on a lifelong strict gluten-free diet or even given incorrect immunosuppressive therapy, the aim of this paper is to provide an evidence-based and practical approach for the workup and management of SNVA.

Endoscopic tissue sampling - Part 1: Upper gastrointestinal and hepatopancreatobiliary tracts. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that, where there is a suspicion of eosinophilic esophagitis, at least six biopsies should be taken, two to four biopsies from the distal esophagus and two to four biopsies from the proximal esophagus, targeting areas with endoscopic mucosal abnormalities. Distal and proximal biopsies should be placed in separate containers.Strong recommendation, low quality of evidence. 2: ESGE recommends obtaining six biopsies, including from the base and edge of the esophageal ulcers, for histologic analysis in patients with suspected viral esophagitis.Strong recommendation, low quality of evidence. 3: ESGE recommends at least six biopsies are taken in cases of suspected advanced esophageal cancer and suspected advanced gastric cancer.Strong recommendation, moderate quality of evidence. 4: ESGE recommends taking only one to two targeted biopsies for lesions in the esophagus or stomach that are potentially amenable to endoscopic resection (Paris classification 0-I, 0-II) in order to confirm the diagnosis and not compromise subsequent endoscopic resection.Strong recommendation, low quality of evidence. 5: ESGE recommends obtaining two biopsies from the antrum and two from the corpus in patients with suspected Helicobacter pylori infection and for gastritis staging.Strong recommendation, low quality of evidence. 6: ESGE recommends biopsies from or, if endoscopically resectable, resection of gastric adenomas.Strong recommendation, moderate quality of evidence. 7: ESGE recommends fine-needle aspiration (FNA) and fine-needle biopsy (FNB) needles equally for sampling of solid pancreatic masses.Strong recommendation, high quality evidence. 8: ESGE suggests performing peroral cholangioscopy (POC) and/or endoscopic ultrasound (EUS)-guided tissue acquisition in indeterminate biliary strictures. For proximal and intrinsic strictures, POC is preferred. For distal and extrinsic strictures, EUS-guided sampling is preferred, with POC where this is not diagnostic.Weak recommendation, low quality evidence. 9: ESGE suggests obtaining possible non-neoplastic biopsies before sampling suspected malignant lesions to prevent intraluminal spread of malignant disease.Weak recommendation, low quality of evidence. 10: ESGE suggests dividing EUS-FNA material into smears (two per pass) and liquid-based cytology (LBC), or the whole of the EUS-FNA material can be processed as LBC, depending on local experience.Weak recommendation, low quality evidence.

Epidemiology, Presentation, and Diagnosis of Celiac Disease

The incidence of celiac disease is increasing, partly because of improved recognition of, and testing for, the disease. The rise in incidence is also due to a real increase of this immune-based disorder, independent of disease detection. The reasons for this true rise in recent decades are unknown but may be related to environmental factors that may promote loss of tolerance to dietary gluten. Strategies to reduce the development of celiac disease have not been proven successful in randomized trials, but the quantity of early-life gluten exposure has been a major focus of prevention efforts. The criteria for the diagnosis of celiac disease are changing, but in adults, diagnosis still depends on the presence of duodenal villous atrophy while the patient is on a gluten-containing diet, along with findings from serology analysis. Although guidelines in the United States continue to mandate a biopsy at all ages, some children receive a diagnosis of celiac disease without a biopsy. If proven accurate and scalable, assays that detect gluten-HLA tetramer complexes might be used in diagnosis to be made in the context of a gluten-free diet without intestinal biopsy.

The indications for biopsy in routine upper gastrointestinal endoscopy

This review describes the indications and contraindications for endoscopic biopsy, in routine practice, of the upper gastrointestinal (GI) tract. We accept that this review provides grounds for controversy, as our stance in certain situations is counter to some national guidelines. Nevertheless, we provide evidence to support our viewpoints, especially on efficiency and economic grounds. We describe the particular controversies concerning the biopsy assessment of Barrett's oesophagus, chronic gastritis and the duodenum in the investigation of coeliac disease. We accept that there are indications for more extensive upper GI biopsy protocols in children than in adults; the latter constitute our main focus in this article. We would encourage detailed discussion between pathologists and their endoscopy colleagues about the indications, or lack of them, for routine upper GI endoscopic biopsy, as studies have shown that adherence to agreed guidelines has resulted in a very considerable diminution in the biopsy workload without compromising patient management. Furthermore, where biopsy is indicated, we emphasise the importance of accompanying clinical information provided to the pathologist, in particular regarding biopsy site(s), and regular feedback to endoscopists to improve and maintain the quality of such information. Finally, local dialogue is also advised, when necessary, to indicate to endoscopists the need to appropriately segregate biopsies into separate, individually labelled specimens, to maximise the information that can be derived by pathological evaluation and thereby improve the quality of the final pathology report.

The role of histopathology in the diagnosis and management of coeliac disease and other malabsorptive conditions

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

Effect of a Gluten-free Diet on Quality of Life in Patients With Nonclassical Versus Classical Presentations of Celiac Disease

BACKGROUND

Celiac disease (CD) often presents with symptoms of diarrhea and malabsorption, termed classical CD. However, it can also present as nonclassical CD, which is commonly associated with nongastrointestinal symptoms. Studies suggest that nonclassical CD tends to have less severe symptoms than classical CD, which may affect both adherence to a gluten-free diet (GFD) and psychological stress. Therefore, we compared adherence to a GFD and psychological measures, including quality of life (QOL) and somatization, between patients with nonclassical and classical presentations of CD.

METHODS

Patients at a tertiary care center with biopsy-proven CD, who completed a Talley Bowel Disease Questionnaire and the Short Form-36 at diagnosis and who had been on a GFD for at least 1 year, were included in this study. Patients were further surveyed to assess gastrointestinal symptoms, QOL, Somatization Symptom Checklist (SSC), and adherence to a GFD. Results were compared between patients with classical versus nonclassical CD presentation.

RESULTS

Among 122 patients included in this study, 62 had classical CD and 60 had nonclassical CD. At diagnosis, health-related QOL was lower in the classical CD group than in the nonclassical CD group. After following a GFD, both groups had improved QOL after following a GFD, and body mass index significantly increased in both groups. Most subscales of QOL, SSC scores, and adherence to the GFD were similar between the groups, except the Short Form-36 Mental Component summary scores that were still lower in the classical CD (48.4 vs. 52.6 nonclassical CD group; P=0.03).

CONCLUSIONS

Despite QOL at diagnosis being higher in those with nonclassical CD versus lower in those with classical CD, both groups had improved QOL and achieved a similar QOL after following a GFD.

Duodenal bulb biopsy in the diagnostic work-up of coeliac disease

Coeliac disease (CD) is an autoimmune enteropathy which can present with patchy mucosal lesions. The aim of the present study is to investigate the significance of duodenal bulb biopsy in the diagnostic work-up of CD in both pediatric and adult patients, and to highlight the key points for pathologists. D1 (duodenal bulb) and D2 (distal duodenum) biopsies of 153 newly diagnosed serology-positive CD patients were evaluated for villous/crypt ratio and intraepithelial lymphocyte (IEL) counts on CD3-stained slides and were classified according to Marsh. Mucosal pathology was patchy in 15% (13% only D1 and 2% only D2) of patients, and 85% of patients had diffuse mucosal pathology involving both D1 and D2 biopsies which showed concordant histology in 60% and discordant in 25% of the cases. Though majority of the patients (75%) with only D1 involvement were pediatric cases, no significant difference was found between pediatric and adult patients when all cases were considered (17 vs 14%). Our results clearly indicate that without D1 sampling, diagnosis of CD would have been missed in a significant number of cases (13%), thereby highlighting the importance of taking duodenal biopsies from multiple sites in the diagnostic work-up of CD. We, therefore, conclude that every biopsy piece from both D1 and D2 should be carefully evaluated for the whole spectrum of mucosal changes caused by gluten ingestion and classified using a scheme based on Marsh to allow recognition of mild lesions.

Statement on Best Practices in the Use of Pathology as a Diagnostic Tool for Celiac Disease: A Guide for Clinicians and Pathologists

Small intestinal biopsy interpretation has been the cornerstone for the diagnosis of celiac disease for over 50 years. Despite the existence of sensitive and specific serological tests, duodenal mucosal biopsies continue to be obtained in the vast majority of patients in whom a diagnosis of celiac disease is being considered. The accurate evaluation of these biopsies requires coordination and information sharing between the gastroenterologist, laboratory, and pathologist in order to optimize tissue sampling, preparation and interpretation. This document, a collaboration between the Rodger C. Haggitt Gastrointestinal Pathology Society and the North American Association for the Study of Celiac Disease, is intended to provide clinicians and pathologists with a summary of best practices in the use of endoscopy and biopsy for patients with suspected celiac disease. The authors present a comprehensive and critical appraisal of the literature with respect to the topics of endoscopic findings, best methods for the obtaining biopsies, completing the pathology form and pathologic assessment, including evaluating intraepithelial lymphocytes and villous architecture. A discussion of conditions with overlapping pathologic findings in duodenal mucosal biopsies is presented. In order to provide additional guidance for challenging situations, the authors include an appendix containing practical suggestions. This review may be utilized in interdisciplinary discussions to optimize care for patients with possible celiac disease.

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.

Diagnosis of Celiac Disease: Taking a Bite Out of the Controversy

Celiac disease is a common autoimmune disorder of the small intestine, triggered by an immunological response to the gluten present in wheat, barley, and rye in individuals who are genetically at risk. A key to reducing the complications of this disease is early diagnosis, preferably in childhood, and consuming a lifelong gluten-free diet once diagnosis is confirmed. Yet, the diagnosis of celiac disease is often considerably delayed, exposing patients to needless suffering and morbidity. It is also difficult to confirm histologically if dietary gluten has been restricted prior to obtaining a diagnostic biopsy, a significant problem given the current growing popularity of gluten-free diets. Furthermore, failure to understand or follow current guidelines means physicians may recommend patients commence the gluten-free diet before initiating referral to a gastroenterologist. Finally, adding further confusion, pediatric guidelines in Europe support a diagnosis based on serology rather than on histology, whereas those based in North America do not. The purpose of this review is to discuss these issues and other controversies in the diagnosis of celiac disease and to consider ways to optimize diagnosis across the lifespan.

Measuring Change In Small Intestinal Histology In Patients With Celiac Disease

Small intestinal histologic abnormalities in celiac disease include atrophy of the intestinal villi, hypertrophy of the crypts and lymphocytic infiltration of intraepithelial spaces and lamina propria. These findings are central to diagnosis and their severity and change over time are valuable to monitor disease course and response to therapy. Subjective methods to grade celiac disease histological severity include the Marsh-Oberhuber and Corazza-Villanacci systems. Quantitative histology uses villus height (Vh), crypt depth (Cd), and intra-epithelial lymphocyte count (per 100 enterocytes) to provide objective measures of histologic changes including Vh:Cd ratio. Here we examine the available literature regarding these methodologies and support the use of quantitative histology as the preferred method for accurately and reproducibly demonstrating change of relevant histologic end points over time. We also propose a Quantitative-Mucosal Algorithmic Rules for Scoring Histology (Q-MARSH) system to partially align quantitative histology results with the traditional Marsh, Marsh-Oberhuber, and Corazza-Villanacci systems. Q-MARSH can provide a standardized, objective, and quantitative histology scoring system for use as a clinical or research application.

Coeliac disease

Coeliac disease occurs in about 1% of people in most populations. Diagnosis rates are increasing, and this seems to be due to a true rise in incidence rather than increased awareness and detection. Coeliac disease develops in genetically susceptible individuals who, in response to unknown environmental factors, develop an immune response that is subsequently triggered by the ingestion of gluten. The disease has many clinical manifestations, ranging from severe malabsorption to minimally symptomatic or non-symptomatic presentations. Diagnosis requires the presence of duodenal villous atrophy, and most patients have circulating antibodies against tissue transglutaminase; in children, European guidelines allow a diagnosis without a duodenal biopsy provided that strict symptomatic and serological criteria are met. Although a gluten-free diet is an effective treatment in most individuals, a substantial minority develop persistent or recurrent symptoms. Difficulties adhering to a gluten-free diet have led to the development of non-dietary therapies, several of which are undergoing trials in human beings.

Optimizing the diagnosis of celiac disease

PURPOSE OF REVIEW

The diagnostic approach in celiac disease is continuously evolving as our understanding of its pathophysiology improves. This review aims to provide a summary of contemporary work that supports optimization of the diagnosis of this common yet underdiagnosed condition.

RECENT FINDINGS

The recently updated National Institute of Clinical Excellence and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines and the contentious biopsy-free diagnostic approach will be discussed. We will review the evidence advocating optimal biopsy techniques such as single bite biopsy and controversial bulb biopsy sampling to increase diagnostic yield. Recent data providing phenotypical characterization and clinical outcomes of celiac subtypes such as potential celiac disease, seronegative celiac disease and ultrashort celiac disease will be covered. We will present emerging evidence on novel case finding strategies with point of care tests. Promising novel markers for celiac disease such as serum intestinal fatty acid binding protein and in-vitro gluten challenge will be included.

SUMMARY

Recent work has demonstrated the clinical significance of the celiac disease subtypes, emphasizing the importance of careful diagnosis and recognition. There is a move toward a less invasive and perhaps more cost-effective diagnostic approach in celiac disease, but duodenal biopsy remains the gold standard at present for all adults and the majority of pediatric patients.