ACG clinical guidelines: diagnosis and management of celiac disease

Gluten and wheat intolerance today: are modern wheat strains involved?

Celiac disease is a food-induced enteropathy resulting from exposure to gluten in genetically predisposed individuals. The non-celiac gluten sensitivity (NCGS) is a less known syndrome whose prevalence is under-estimated. The last decades have seen changes in the clinical presentation of both diseases. One possible explanation is that changes in the gluten-rich cereals themselves were the principal causes. Celiac-triggering gluten proteins are indeed expressed to higher levels in modern cereals while non-triggering proteins are expressed less. Sophisticated hybridization techniques have been used to produce new strains of modern wheat, the most high-yielding of which have since made their way into human foods in the absence of animal or human safety testing. The dramatic changes in the clinical presentation of celiac disease and NCGS have taken place when new cereal hybrids were introduced into human foods. This is a critical medical and environmental issue which needs to be investigated by appropriate studies.

Accurate and robust genomic prediction of celiac disease using statistical learning

Practical application of genomic-based risk stratification to clinical diagnosis is appealing yet performance varies widely depending on the disease and genomic risk score (GRS) method. Celiac disease (CD), a common immune-mediated illness, is strongly genetically determined and requires specific HLA haplotypes. HLA testing can exclude diagnosis but has low specificity, providing little information suitable for clinical risk stratification. Using six European cohorts, we provide a proof-of-concept that statistical learning approaches which simultaneously model all SNPs can generate robust and highly accurate predictive models of CD based on genome-wide SNP profiles. The high predictive capacity replicated both in cross-validation within each cohort (AUC of 0.87–0.89) and in independent replication across cohorts (AUC of 0.86–0.9), despite differences in ethnicity. The models explained 30–35% of disease variance and up to ∼43% of heritability. The GRS's utility was assessed in different clinically relevant settings. Comparable to HLA typing, the GRS can be used to identify individuals without CD with ≥99.6% negative predictive value however, unlike HLA typing, fine-scale stratification of individuals into categories of higher-risk for CD can identify those that would benefit from more invasive and costly definitive testing. The GRS is flexible and its performance can be adapted to the clinical situation by adjusting the threshold cut-off. Despite explaining a minority of disease heritability, our findings indicate a genomic risk score provides clinically relevant information to improve upon current diagnostic pathways for CD and support further studies evaluating the clinical utility of this approach in CD and other complex diseases.

Celiac disease (CD) is a common immune-mediated illness, affecting approximately 1% of the population in Western countries but the diagnostic process remains sub-optimal. The development of CD is strongly dependent on specific human leukocyte antigen (HLA) genes, and HLA testing to identify CD susceptibility is now commonly undertaken in clinical practice. The clinical utility of HLA typing is to exclude CD when the CD susceptibility HLA types are absent, but notably, most people who possess HLA types imparting susceptibility for CD never develop CD. Therefore, while genetic testing in CD can overcome several limitations of the current diagnostic tools, the utility of HLA typing to identify those individuals at increased-risk of CD is limited. Using large datasets assaying single nucleotide polymorphisms (SNPs), we have developed genomic risk scores (GRS) based on multiple SNPs that can more accurately predict CD risk across several populations in “real world” clinical settings. The GRS can generate predictions that optimize CD risk stratification and diagnosis, potentially reducing the number of unnecessary follow-up investigations. The medical and economic impact of improving CD diagnosis is likely to be significant, and our findings support further studies into the role of personalized GRS's for other strongly heritable human diseases.

All that glitters is not always gold

Biopsies from the second part of the duodenum are routinely performed in patients with unintentional weight loss. When villous atrophy and an increased intraepithelial lymphocytosis are detected, the commonest cause of it is coeliac disease. Severe villous atrophy with increased intraepithelial lymphocytosis (Marsh IIIc) is highly specific for coeliac disease. However, coeliac disease with this presentation is very rare. Milder abnormalities such as Marsh I-II (microscopic enteritis) and Marsh IIIa are not specific for coeliac disease and could occur in other conditions like those listed in the discussion. We present the case of a 74-year-old woman who, after being diagnosed with seronegative coeliac disease, failed to improve on a gluten-free diet. We discuss the differential diagnosis of coeliac disease and the possible alternative causes for villous blunting, paying particular attention to the diagnosis of small intestinal bacterial overgrowth.

Nutritional consequences of celiac disease and the gluten-free diet

Celiac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals and represents a major health issue. The immune mediated response results in villous atrophy of the small intestine with subsequent malabsorption. The classic mode of presentation is that of a malabsorption syndrome resulting in deficiencies of macro and micronutrients. The gluten-free diet is the only treatment currently available for this disorder. The aim of this special report is to elucidate and explain the various nutritional deficiencies seen in newly diagnosed patients with celiac disease and while on the gluten-free diet. Though initiation of the gluten-free diet results in improvement of symptoms and most deficiencies, certain nutritional limitations are associated with the gluten-free diet.

PROgnosticating COeliac patieNts SUrvivaL: the PROCONSUL score

Introduction

It has been shown that mortality rates of coeliac patients correlate with age at diagnosis of coeliac disease, diagnostic delay for coeliac disease, pattern of clinical presentation and HLA typing. Our aim was to create a tool that identifies coeliac patients at higher risk of developing complications.

Methods

To identify predictors of complications in patients with coeliac disease, we organised an observational multicenter case-control study based on a retrospective collection of clinical data. Clinical data from 116 cases (patients with complicated coeliac disease) and 181 controls (coeliac patients without any complications) were collected from seven European centres. For each case, one or two controls, matched to cases according to the year of assessment, gender and age, were selected. Diagnostic delay, pattern of clinical presentation, HLA typing and age at diagnosis were used as predictors.

Results

Differences between cases and controls were detected for diagnostic delay and classical presentation. Conditional logistic models based on these statistically different predictors allowed the development of a score system. Tertiles analysis showed a relationship between score and risk of developing complications.

Discussion

A score that shows the risk of a newly diagnosed coeliac patient developing complications was devised for the first time. This will make it possible to set up the follow-up of coeliac patients with great benefits not only for their health but also for management of economic resources.

Conclusions

We think that our results are very encouraging and represent the first attempt to build a prognostic score for coeliac patients.

Gastro 2013 APDW/WCOG Shanghai working party report: chronic diarrhea: definition, classification, diagnosis

Diarrhea is best defined as passage of loose stools often with more frequent bowel movements. For clinical purposes, the Bristol Stool Form Scale works well to distinguish stool form and to identify loose stools. Laboratory testing of stool consistency has lagged behind. Acute diarrhea is likely to be due to infection and to be self-limited. As diarrhea becomes chronic, it is less likely to be due to infection; duration of 1 month seems to work well as a cut-off for chronic diarrhea, but detailed scientific knowledge is missing about the utility of this definition. In addition to duration of diarrhea, classifications by presenting scenario, by pathophysiology, and by stool characteristics (e.g. watery, fatty, or inflammatory) may help the canny clinician refine the differential diagnosis of chronic diarrhea. In this regard, a careful history remains the essential part of the evaluation of a patient with diarrhea. Imaging the intestine with endoscopy and radiographic techniques is useful, and biopsy of the small intestine and colon for histological assessment provides key diagnostic information. Endomicroscopy and molecular pathology are only now being explored for the diagnosis of chronic diarrhea. Interest in the microbiome of the gut is increasing; aside from a handful of well-described infections because of pathogens, little is known about alterations in the microbiome in chronic diarrhea. Serological tests have well-defined roles in the diagnosis of celiac disease but have less clearly defined application in autoimmune enteropathies and inflammatory bowel disease. Measurement of peptide hormones is of value in the diagnosis and management of endocrine tumors causing diarrhea, but these are so rare that these tests are of little value in screening because there will be many more false-positives than true-positive results. Chemical analysis of stools is of use in classifying chronic diarrhea and may limit the differential diagnosis that must be considered, but interpretation of the results is still evolving. Breath tests for assessment of carbohydrate malabsorption, small bowel bacterial overgrowth, and intestinal transit are fraught with technical limitations that decrease sensitivity and specificity. Likewise, tests of bile acid malabsorption have had limited utility beyond empirical trials of bile acid sequestrants.

Appropriate nutrient supplementation in celiac disease

Reduced levels of iron, folate, vitamin B12, vitamin D, zinc, and magnesium are common in untreated celiac disease (CD) patients probably due to loss of brush border proteins and enzymes needed for the absorption of these nutrients. In the majority of patients, removal of gluten from the diet leads to histological recovery and normalization of iron, vitamin, and mineral levels. Iron deficiency anemia is the most common extra-intestinal sign of CD and usually resolves with adherence to a gluten-free diet. However, deficiencies of both folate and vitamin B12 may persist in some patients on a gluten-free diet, thus requiring vitamin supplementation to improve subjective health status. Similarly, exclusion of gluten from the diet does not always normalize bone mineral density; in these cases, supplementation of vitamin D and calcium is recommended. Resolution of mucosal inflammation may not be sufficient to abrogate magnesium deficiency. Since gluten-free cereal products have a lower magnesium content as compared with gluten-containing counterparts, a magnesium-enriched diet should be encouraged in CD patients. In this article we discuss the frequency and clinical relevance of nutrient deficiency in CD and whether and when nutrient supplementation is needed.

Analysis of the cytokine profile in the duodenal mucosa of refractory coeliac disease patients

This study shows that refractory coeliac disease-associated immune response is marked by a profile of cytokines, which differs from that in active coeliac disease. Moreover, it documents the clinical benefit of a neutralizing anti-TNF-α antibody in a patient with refractory coeliac disease.

The clinical response to gluten challenge: a review of the literature

The aim of this review was to identify, evaluate and summarize all relevant studies reporting on the clinical response to gluten challenge by adult or pediatric patients with suspected or diagnosed coeliac disease (CD) on a gluten-free diet. We evaluated the effect of gluten challenge on changes in symptoms, intestinal mucosa histology, and serum antibodies. A systematic electronic search was performed for studies published as of 1966 using PubMed and Scopus databases. In the reviewed studies, doses ranged from 0.2 to 30 g/day of wheat gluten or comprised a gluten-containing diet. The onset of symptoms upon gluten intake varied largely from days to months and did not parallel serum antibody or histological changes. Within 3 months of gluten challenge, 70%-100% of pediatric CD patients became positive for AGA-IgA and EMA-IgA antibodies and 50%-70% for AGA-IgG. A limited number of trials suggest that no more than half of adult patients developed positive AGA-IgA, EMA-IgA, tTG-IgA or DGP-IgA/IgG titers. Approximately 50%-100% of pediatric and adult patients experienced mucosal relapse of gluten provocation within 3 months, which was preceded by increased mucosal intra-epithelial lymphocytes within several days of challenge. A 3-month high-dose gluten challenge should be suitable to diagnose the majority of CD patients. In some cases prolonged challenge may be needed to verify diagnosis. Combination testing for antibodies and mucosal histology may fasten the diagnosis.

How I treat unexplained refractory iron deficiency anemia

Endoscopic gastrointestinal workup fails to establish the cause of iron deficiency anemia (IDA) in a substantial proportion of patients. In patients referred for hematologic evaluation with unexplained or refractory IDA, screening for celiac disease, autoimmune gastritis, Helicobacter pylori, and hereditary forms of IDA is recommended. About 4% to 6% of patients with obscure refractory IDA have celiac disease, and autoimmune gastritis is encountered in 20% to 27% of patients. Stratification by age cohorts in autoimmune gastritis implies a disease presenting as IDA many years before the establishment of clinical cobalamin deficiency. Over 50% of patients with unexplained refractory IDA have active H pylori infection and, after excluding all other causes of IDA, 64% to 75% of such patients are permanently cured by H pylori eradication. In young patients with a history suggestive of hereditary iron deficiency with serum ferritin higher than expected for IDA, mutations involving iron trafficking and regulation should be considered. Recognition of the respective roles of H pylori, autoimmune gastritis, celiac disease, and genetic defects in the pathogenesis of iron deficiency should have a strong impact on the current diagnostic workup and management of unexplained, or refractory, IDA.

Optimising delivery of care in coeliac disease - comparison of the benefits of repeat biopsy and serological follow-up

BACKGROUND

The majority of deleterious health consequences of coeliac disease (CD) are most likely to be secondary to intestinal inflammation; hence, mucosal recovery is a desirable goal of therapy. Follow-up in CD is controversial and serological response is often used as a surrogate for histological recovery.

AIMS

To inform the clinical management of CD using comparative serological and histological data from a biopsy-driven pathway of care.

METHODS

A retrospective analysis of the Cambridge Coeliac Clinic database of 595 patients routinely followed up by biopsy and serology.

RESULTS

Paired biopsy results were available for 391 patients (15% seronegative). Persisting villous atrophy (VA) occurred in 182 patients (47%). The sensitivity of anti-tissue transglutaminase (TTG) antibody for ongoing VA was only 43.6%. Information on dietetic management and further biopsy to assess response was available for 94 initially unresponsive patients, in whom targeted dietetic intervention by removal of identified gluten sources or avoidance of trace amounts of gluten led to resolution of persistent VA in 50%. The effects of institution of a formal care pathway are analysed in 298 patients. Discharge to primary care and clinical management was facilitated by the information derived from repeat biopsy.

CONCLUSIONS

Serology appears to be a poor surrogate marker for mucosal recovery on a gluten-free diet; dietary assessment fails to identify a potential gluten source in many patients with ongoing villous atrophy. The benefits of re-biopsy on diet include stratification of patients with coeliac disease suitable for early discharge from secondary care or those requiring more intensive clinical management.

Interprovider variation of celiac disease testing in childhood chronic abdominal pain

Background

To determine within one tertiary care center: 1) the variation between providers in testing for celiac disease in children with chronic abdominal pain; 2) the characteristics of those children who were more likely to be tested, and 3) the prevalence of celiac disease in those evaluated.

Methods

Retrospective review of children with a primary complaint of chronic abdominal pain referred to a tertiary care children’s hospital for pediatric gastroenterology evaluation over a 2-year period was conducted. Children with at least two visits and without an identified organic etiology for the pain were included.

Results

160 children were evaluated by 16 pediatric gastroenterologists and one nurse practitioner. Celiac serologic testing was completed in 63 (39.4%) children. There was no significant variance in the frequency of celiac serologic testing between providers. Child age, gender, body mass index, and baseline gastrointestinal symptoms did not predict whether celiac serologic testing occurred, though Caucasians (P < 0.01) were more likely to be tested. Eighty-two (51.3%) children underwent either serologic testing and/or esophagogastroduodenoscopy. Four (4.9%, 95% CI: 1.6-11.3%) of the 82 tested were diagnosed with celiac disease.

Conclusions

Though interprovider variation for celiac disease testing in children with chronic abdominal pain did not occur, a large number of these children were not evaluated for celiac disease. Children’s race/ethnicity but not their associated gastrointestinal symptoms predicted whether celiac testing was undertaken. In those tested, celiac disease was identified in a higher percentage than that expected in the general population.

IL-17 producing T cells in celiac disease: angels or devils?

Celiac disease (CD) is a very common chronic condition in human beings, affecting approximately one in 100 individuals. It is an autoimmune disease with a defined environmental trigger, the gluten contained in dietary cereals, occurring in genetically susceptible individuals. The disease has a very strong HLA association. More than 90% of CD patients have HLA-DQ2, and almost all of the remaining celiac population possesses HLA-DQ8 molecules. Th17 cells seem to participate in the disease pathogenesis producing and secreting either proinflammatory or anti-inflammatory cytokines.

Diagnostic dilemmas in celiac disease

Celiac disease (CD) is an immune-mediated systemic condition triggered by dietary gluten occurring in genetically susceptible individuals. Our understanding of its numerous and varied clinical presentations has evolved over time, which has contributed to the incidence of CD increasing. In most cases, the diagnosis is readily established and patients promptly improve after commencing a gluten-free diet (GFD). However, in some, the diagnosis is not straightforward and presents a challenge to clinicians. Potential dilemmas include those with positive serology but normal histology, negative serology but abnormal duodenal mucosal histology, failure to respond to a GFD or response to a GFD without evidence of CD. In recent years, development of new assays and modifications to existing diagnostic algorithms for CD has also challenged the traditional role of small-bowel histology as critical in CD diagnosis.

Oral food challenge to wheat: a near-fatal anaphylaxis and review of 93 food challenges in children

Background

Wheat allergy is among the most common food allergy in children, but few publications are available assessing the risk of anaphylaxis due to wheat.

Methods

In this study, we report the case of near-fatal anaphylaxis to wheat in a patient undergoing an oral food challenge (OFC) after the ingestion of a low dose (256 mg) of wheat. Moreover, for the first time, we analyzed the risk of anaphylaxis during an OFC to wheat in 93 children, compared to other more commonly challenged foods such as milk, egg, peanuts, and soy in more than 1000 patients.

Results

This study, which includes a large number of OFCs to wheat, shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration (Odds Ratio [OR] = 2.4) and anaphylaxis requiring epinephrine administration to low dose antigen (OR = 8.02). Other risk factors for anaphylaxis, anaphylaxis requiring epinephrine administration, and anaphylaxis to low dose antigen was a history of a prior reaction not involving only the skin (OR = 1.8, 1.9 and 1.8 respectively). None of the clinical variables available prior to performing the OFC could predict which children among those undergoing OFCs to wheat would develop anaphylaxis or anaphylaxis for low dose antigen.

Conclusion

This study shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration and anaphylaxis requiring epinephrine administration to low dose antigen.

[Immunological screening and follow-up of celiac disease: experience of the University Hospital of Marseille]

PURPOSE

Anti-tissue transglutaminase antibodies (ATTG) have helped to distinguish atypical and silent clinical forms of celiac disease (CD). Immunological diagnosis or follow-up of the disease is now based in France in first line upon IgA ATTG serum evaluation. In the University Hospital of Marseille, the serological diagnosis of CD had consisted during several years in simultaneous determination of both IgA anti-endomysial antibodies (AEA) and IgA ATTG. In literature, few studies focused on the concordance between the two tests and a very few epidemiological data about CD in France are available.

METHODS

Five thousand nine hundred and eighty-one patients for whom both AEA and ATTG testing were available were retrospectively included. Characteristics of this cohort were detailed. We numbered and analyzed especially bioclinical charts from patients with AAE/AATG discordance.

RESULTS

Among our patients, all ages and all medical subspecialties were represented. Eighty-five new cases of CD were identified. Among the 6516 serum evaluations performed, only 31 tests were discordant.

CONCLUSIONS

Our data give information about CD epidemiology in France. They support the contention that ATTG have to be evaluated in first line for CD diagnosis.

Liver abnormalities in bowel diseases

Liver abnormalities are often seen in bowel diseases. Whether these represent aspects of two separate diseases, or if one is causing the other, is not always easy to decide. Extraintestinal manifestations of inflammatory bowel disease (IBD) or coeliac disease are frequently observed. Of these extraintestinal manifestations, hepatic disorders are among the most common. Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis are the most frequent hepatic disorders in IBD and coeliac disease, respectively. Genetic studies have lately elucidated the associations between IBD and PSC, but there is still a long way until we have complete understanding of the molecular aetiology and pathophysiology of these conditions. There is no curative treatment available for PSC, besides liver transplantation. Steatosis and cholelithiasis are also common in IBD, as are signs of hepatic injury due to IBD treatment. Less common liver abnormalities include liver abscesses, hepatic thromboembolic events, granulomatous liver disease and hepatic amyloidosis.

Personalized lifestyle medicine: relevance for nutrition and lifestyle recommendations

Public health recommendations for lifestyle modification, including diet and physical activity, have been widely disseminated for the prevention and treatment of disease. These guidelines are intended for the overall population without significant consideration for the individual with respect to one's genes and environment. Personalized lifestyle medicine is a newly developed term that refers to an approach to medicine in which an individual's health metrics from point-of-care diagnostics are used to develop lifestyle medicine-oriented therapeutic strategies for improving individual health outcomes in managing chronic disease. Examples of the application of personalized lifestyle medicine to patient care include the identification of genetic variants through laboratory tests and/or functional biomarkers for the purpose of designing patient-specific prescriptions for diet, exercise, stress, and environment. Personalized lifestyle medicine can provide solutions to chronic health problems by harnessing innovative and evolving technologies based on recent discoveries in genomics, epigenetics, systems biology, life and behavioral sciences, and diagnostics and clinical medicine. A comprehensive, personalized approach to medicine is required to promote the safety of therapeutics and reduce the cost of chronic disease. Personalized lifestyle medicine may provide a novel means of addressing a patient's health by empowering them with information they need to regain control of their health.