ACG clinical guidelines: diagnosis and management of celiac disease

Celiac disease and non-celiac gluten sensitivity

Celiac disease is a multisystem immune based disorder that is triggered by the ingestion of gluten in genetically susceptible individuals. The prevalence of celiac disease has risen in recent decades and is currently about 1% in most Western populations. The reason for this rise is unknown, although environmental factors related to the hygiene hypothesis are suspected. The pathophysiology of celiac disease involves both the innate and adaptive immune response to dietary gluten. Clinical features are diverse and include gastrointestinal symptoms, metabolic bone disease, infertility, and many other manifestations. Although a gluten-free diet is effective in most patients, this diet can be burdensome and can limit quality of life; consequently, non-dietary therapies are at various stages of development. This review also covers non-celiac gluten sensitivity. The pathophysiology of this clinical phenotype is poorly understood, but it is a cause of increasing interest in gluten-free diets in the general population.

Adherence to Endoscopy Biopsy Guidelines for Celiac Disease

OBJECTIVE

Histologic changes in celiac disease (CD) may be patchy or confined to the bulb. Present guidelines recommend obtaining multiple biopsies from the bulb and distal duodenum when evaluating for CD. Adherence to these recommendations among adult gastroenterologists is low. There are no such data for pediatric gastroenterologists. This study compared endoscopic biopsy practices among pediatric gastroenterologists in histologically confirmed patients with CD to those without histologically confirmed CD.

METHODS

Retrospective review of esophagogastroduodenoscopies (EGDs) during a 13-month period was performed. Children with histologically confirmed CD and a random sample of age-matched children without CD were identified. Endoscopy and histology reports were reviewed. The site and number of biopsy samples obtained was recorded. The groups were compared for number of biopsies.

RESULTS

A total of 98 children with CD were compared with 103 controls without CD. The number of biopsies obtained in the group with CD was higher than the group without CD (5.9 ± 1.6 vs 3.6 ± 1.2) (P < 0.0001). In children with CD, 80.5% had ≥5 biopsies compared with 11.7% in the group without CD (P < 0.0001). Only 10% of the children in the group with CD had bulb biopsies documented compared with none in the group without CD.

CONCLUSIONS

Pediatric gastroenterologists at our center generally obtain the recommended number of biopsies in children with histologically confirmed CD but seldom document biopsies from the bulb. In those without histologic evidence of CD, fewer biopsies are obtained with none documented from the bulb. Failure to take the recommended number of biopsies could result in some missed cases of CD.

Extraintestinal manifestations of coeliac disease

Coeliac disease is a common disorder that can arise at any age and typically presents with a broad spectrum of symptoms. The disease is thought to be underdiagnosed, in part owing to the fact that coeliac disease is often characterized by associated conditions and extraintestinal manifestations that can misdirect and impede diagnosis. Some of these manifestations are direct consequences of autoimmunity, such as dermatitis herpetiformis or gluten ataxia, whereas others are indirectly related to inflammation and/or malabsorption including anaemia, osteoporosis, short stature and delayed puberty. Any organ from the central nervous system to joints, liver or teeth can be affected. In some cases, extraintestinal symptoms are the only clinical manifestations of coeliac disease or occur in conjunction with diarrhoea and malabsorptive symptoms. An increased awareness among medical practitioners of the variety of extraintestinal manifestations of coeliac disease is essential to improve diagnosis and treatment.

Practical insights into gluten-free diets

Coeliac disease is a global disease, and the only currently available treatment is a gluten-free diet (GFD). Although conceptually simple, the diet changes are substantial and have a profound effect on a patient's life. Untreated coeliac disease is associated with complications, including excess mortality, most of which can be avoided with a strict GFD. However, there are many barriers, including availability, cost and safety of gluten-free foods, and gluten cross-contamination. The GFD can be restrictive in social situations, leading to poor quality of life and, ultimately, nonadherence. As the number of patients with coeliac disease increases worldwide, clinicians need to be aware of the challenges patients face. Heightened awareness by physicians, dietitians and other providers can help maximize successful treatment, improve outcomes, and reduce health-care costs and disease burden. Routine follow-up is necessary to reinforce the need for a GFD, provide social and emotional support, and achieve mucosal healing, leading to reduced risk of complications. Unfortunately, there is wide variation in follow-up practices. The objective of this Review is to increase awareness of the challenges, management and follow-up of patients with coeliac disease to help them achieve GFD adherence and prevent complications whilst preserving their quality of life.

Are ESPGHAN "biopsy-sparing" guidelines for celiac disease also suitable for asymptomatic patients?

OBJECTIVES

In 2012, European Society of Pediatric Gastroenterology, Hepatology, and Nutrition published novel guidelines on celiac disease (CD) diagnosis. Symptomatic children with serum anti-transglutaminase (anti-tTG) antibody levels ≥10 times upper limit of normal (ULN) could avoid duodenal biopsies after positive HLA test and serum anti-endomysial antibodies (EMAs). So far, both asymptomatic and symptomatic patients with anti-tTG titer <10 times ULN should undergo upper endoscopy with duodenal biopsies to confirm diagnosis. The aim of this study was to assess the accuracy of serological tests to diagnose CD in asymptomatic patients.

METHODS

We retrospectively reviewed data of 286 patients (age range: 10 months to 17 years) with CD diagnosis based on elevated titer of anti-tTG, EMA positivity, and histology. All patients were distinguished between symptomatic and asymptomatic; histological lesions were graded according to the Marsh-Oberhuber (MO) criteria. Fisher exact test was applied to analyze both groups in terms of diagnostic reliability of serological markers.

RESULTS

A total of 196 patients (68.53%) had anti-tTG titers ≥10 times ULN. Among them, a group of 156 patients (79.59%) also had symptoms suggestive of CD ("high-titer" symptomatic); of these, 142 patients (91.02%) showed severe lesion degree (3a, 3b, 3c MO). Conversely, 40 out of 196 patients (20.40%) were asymptomatic ("high-titer" asymptomatic) and 37 patients (92.5%) of them showed severe lesion degree (3a, 3b, 3c MO). No difference in histological damage was found between "high-titer" symptomatic and "high-titer" asymptomatic children (Fisher exact test, P=1.000).

CONCLUSIONS

If confirmed in large multicenter prospective studies, the "biopsy-sparing" protocol seems to be applicable to both symptomatic and asymptomatic patients with anti-tTG titer ≥10 times ULN, positive EMA, and HLA-DQ2/DQ8.

Diagnostic yield of endoscopic markers for celiac disease

RATIONALE

In the setting of open access endoscopy, the recognition of suggestive endoscopic features in the duodenum can select patients with probability of celiac disease (CD). This could add to the current efforts to increase the diagnostic rate of this disease.

AIM

The aim of this study was to evaluate the diagnostic accuracy of these markers for CD in an adult population undergoing endoscopy, without a prior serological testing.

METHODS AND RESULTS

Over a period of 3 years, between June 2012 and 2015, all the patients who underwent upper gastrointestinal endoscopy and presented one or more of the endoscopic markers consistent with CD, or those suspected for CD, irrespective of the presence of these markers, were included. Sensitivity, specificity, positive and negative predictive values were calculated for these markers in CD diagnosis. Among the 182 patients, 56.04% were females, with a mean age of 47.6 ± 13.9 years. 20/182 (10.99%) had a final diagnosis of CD. The presence of any endoscopic marker had a high sensitivity (95%) and a negative predictive value (98.41%). Bulb atrophy and reduced folds in the descending duodenum had a low diagnostic accuracy, while scalloping, mosaic pattern and fissures were highly specific for CD (98.77%, 99.38% and 98.77%) and their presence greatly increased the probability of CD, with a positive likelihood ratio of 24.3, 24.3 and 12.15, respectively.

DISCUSSIONS

A wide set of endoscopic markers, including the duodenal bulb, were evaluated in this study. Our results showed that the endoscopy with a careful examination of the duodenum is a sensitive indicator for CD.

ABBREVIATIONS

CD = celiac disease, GI = gastrointestinal, VA = villous atrophy, NSAID = nonsteroidal anti-inflammatory drug, Sn = sensitivity, Sp = specificity, PPV = positive predictive value, NPV = negative predictive value, AUC = area under the curve, ROC = receiver operating characteristics, WLE = white light endoscopy, NBI = narrow band imaging, tTG = tissue transglutaminase, EMA = anti-endomysial antibodies.

Polymeric drugs: Advances in the development of pharmacologically active polymers

Synthetic polymers play a critical role in pharmaceutical discovery and development. Current research and applications of pharmaceutical polymers are mainly focused on their functions as excipients and inert carriers of other pharmacologically active agents. This review article surveys recent advances in alternative pharmaceutical use of polymers as pharmacologically active agents known as polymeric drugs. Emphasis is placed on the benefits of polymeric drugs that are associated with their macromolecular character and their ability to explore biologically relevant multivalency processes. We discuss the main therapeutic uses of polymeric drugs as sequestrants, antimicrobials, antivirals, and anticancer and anti-inflammatory agents.

Refractory Celiac Disease Type II: A Case Report that Demonstrates the Diagnostic and Therapeutic Challenges

Refractory celiac disease is an uncommon but serious complication of celiac disease. We describe a case of a severe refractory celiac disease type II, complicated with ulcerative jejunoileitis, in a 68 years old female, unresponsive to consecutive treatments with budesonide, prednisolone, cladribine and autologous stem cell transplantation. The patient maintained severe malnutrition, advanced osteoporosis, anaemia, vitamin deficiencies and hydro-electrolytic imbalances, necessitating consecutive hospitalizations for total parenteral nutrition. The patient also developed life-threatening complications, namely respiratory and urinary septic shock and also episodes of haemorrhagic shock secondary to ulcerative jejunoileitis. The progression to enteropathy associated T-cell lymphoma was never demonstrated, but the patient died 7 years after the diagnosis due to a septic shock secondary to a nosocomial pneumonia and osteomyelitis related to a spontaneous hip fracture. This case highlights the difficulties in the diagnostic process, therapeutic management and surveillance of this rare condition associated with very poor prognosis.

Celiac disease: a disorder emerging from antiquity, its evolving classification and risk, and potential new treatment paradigms

Celiac disease is a chronic genetically based gluten-sensitive immune-mediated enteropathic process primarily affecting the small intestinal mucosa. The disorder classically presents with diarrhea and weight loss; however, more recently, it has been characterized by subclinical occult or latent disease associated with few or no intestinal symptoms. Diagnosis depends on the detection of typical histopathological biopsy changes followed by a gluten-free diet response. A broad range of clinical disorders may mimic celiac disease, along with a wide range of drugs and other therapeutic agents. Recent and intriguing archeological data, largely from the Gobleki Tepe region of the Fertile Crescent, indicate that celiac disease probably emerged as humans transitioned from hunter-gatherer groups to societies dependent on agriculture to secure a stable food supply. Longitudinal studies performed over several decades have suggested that changes in the prevalence of the disease, even apparent epidemic disease, may be due to superimposed or novel environmental factors that may precipitate its appearance. Recent therapeutic approaches are being explored that may supplement, rather than replace, gluten-free diet therapy and permit more nutritional options for future management.

Seronegative Celiac Disease and Immunoglobulin Deficiency: Where to Look in the Submerged Iceberg?

In the present narrative review, we analyzed the relationship between seronegative celiac disease (SNCD) and immunoglobulin deficiencies. For this purpose, we conducted a literature search on the main medical databases. SNCD poses a diagnostic dilemma. Villous blunting, intraepithelial lymphocytes (IELs) count and gluten "challenge" are the most reliable markers. Immunohistochemistry/immunofluorescence tissue transglutaminase (tTG)-targeted mucosal immunoglobulin A (IgA) immune complexes in the intestinal mucosa of SNCD patients may be useful. In our experience, tTG-mRNA was similarly increased in seropositive celiac disease (CD) and suspected SNCD, and strongly correlated with the IELs count. This increase is found even in the IELs' range of 15-25/100 enterocytes, suggesting that there may be a "grey zone" of gluten-related disorders. An immune deregulation (severely lacking B-cell differentiation) underlies the association of SNCD with immunoglobulin deficiencies. Therefore, CD may be linked to autoimmune disorders and immune deficits (common variable immunodeficiency (CVID)/IgA selective deficiency). CVID is a heterogeneous group of antibodies dysfunction, whose association with CD is demonstrated only by the response to a gluten-free diet (GFD). We hypothesized a familial inheritance between CD and CVID. Selective IgA deficiency, commonly associated with CD, accounts for IgA-tTG seronegativity. Selective IgM deficiency (sIgMD) is rare (<300 cases) and associated to CD in 5% of cases. We diagnosed SNCD in a patient affected by sIgMD using the tTG-mRNA assay. One-year GFD induced IgM restoration. This evidence, supporting a link between SNCD and immunoglobulin deficiencies, suggests that we should take a closer look at this association.

Noncoeliac gluten sensitivity: a diagnostic dilemma

PURPOSE OF REVIEW

Noncoeliac gluten sensitivity (NCGS) has gained attention as an emerging clinical entity. Data regarding the epidemiology, pathogenesis, and management of NCGS are scattered in view of the diagnostic uncertainty surrounding the disorder. We aim to provide a current perspective of NCGS and its associated controversies.

RECENT FINDINGS

NCGS consists of a spectrum of intestinal and extraintestinal symptoms related to the ingestion of gluten-containing food, yet in the absence of coeliac disease or wheat allergy. To date, no specific biomarker exists for NCGS, thereby leaving the diagnosis to be confirmed by dietary elimination followed by double-blind placebo-controlled gluten-based rechallenges. Unfortunately, this technique is cumbersome, not readily-available in routine clinical practise, and can still leave the diagnosis of NCGS open to debate as to whether the effects demonstrated can be specifically attributed to the gluten-protein per se or rather coexisting nongluten components, such as fermentable carbohydrates and amylase-trypsin inhibitors.

SUMMARY

Physicians are increasingly being posed with the dilemma of patients presenting with self-reported NCGS. However, this appears to be the tip of the iceberg and future studies are in need of delineating which gluten-based component is responsible for each individual patient's complaint.

High Proportions of People With Nonceliac Wheat Sensitivity Have Autoimmune Disease or Antinuclear Antibodies

BACKGROUND & AIMS

There is much interest in wheat sensitivity among people without celiac disease (CD), but little is known about any risks associated with the condition. We evaluated the prevalence of autoimmune diseases (ADs) among patients with nonceliac wheat sensitivity (NCWS), and investigated whether they carry antinuclear antibodies (ANA).

METHODS

We performed a retrospective study of 131 patients diagnosed with NCWS (121 female; mean age, 29.1 years) at 2 hospitals in Italy from January 2001 through June 2011. Data were also collected from 151 patients with CD or irritable bowel syndrome (IBS) (controls). Patient medical records were reviewed to identify those with ADs. We also performed a prospective study of 42 patients (38 female; mean age, 34 years) diagnosed with NCWS from July 2011 through March 2014 at 3 hospitals in Italy. One hundred age- and sex-matched subjects with CD or IBS served as controls. Serum samples were collected from all subjects and ANA levels were measured by immunofluorescence analysis. Participants completed a questionnaire and their medical records were reviewed to identify those with ADs.

RESULTS

In the retrospective analysis, similar portions of subjects with NCWS (29%) and CD (29%) developed ADs (mainly Hashimoto's thyroiditis, 29 cases), compared with a smaller proportion of subjects with IBS (4%) (P < .001). In the prospective study, 24% of subjects with NCWS, 20% of subjects with CD, and 2% of subjects with IBS developed ADs (P < .001). In the retrospective study, serum samples tested positive for ANA in 46% of subjects with NCWS (median titer, 1:80), 24% of subjects with CD (P < .001), and 2% of subjects IBS (P < .001); in the prospective study, serum samples were positive for ANA in 28% of subjects with NCWS, 7.5% of subjects with CD (P = .02), and 6% of subjects with IBS (P = .005 vs patients with NCWS). ANA positivity was associated with the presence of the HLA DQ2/DQ8 haplotypes (P < .001).

CONCLUSIONS

Higher proportions of patients with NCWS or CD develop autoimmune disorders, are ANA positive, and showed DQ2/DQ8 haplotypes compared with patients with IBS.

The spectrum of noncoeliac gluten sensitivity

The past 5 years have seen an increase in the use of a gluten-free diet outside a diagnosis of coeliac disease or IgE-mediated wheat allergy. This trend has led to the identification of a new clinical entity termed noncoeliac gluten sensitivity (NCGS). In this Review, we discuss the evidence for NCGS as demonstrated by the results of double-blind, placebo-controlled dietary rechallenge studies. Furthermore, the characteristic phenotype of individuals with NCGS is described as well as the symptom manifestations commonly reported after gluten exposure, which include intestinal symptoms consistent with IBS, and extraintestinal symptoms such as neurological dysfunction, psychological disturbances, fibromyalgia and skin rash. Moreover, emerging evidence suggests that NCGS can be associated with organic gastrointestinal pathologies, such as IBD, in which its presence might be a reflection of severe or stricturing disease. However, NCGS is not without its controversies and uncertainties, in particular pertaining to whether it is gluten or nongluten components of the grain evoking symptoms; evidence suggests that fermentable carbohydrates, amylase trypsin inhibitors and wheat-germ agglutinin can also be responsible culprits. Finally, we discuss the novel techniques that might help diagnose NCGS in the future.

Nonceliac Gluten Sensitivity

Nonceliac gluten sensitivity (NCGS) is the clinical term used to describe gastrointestinal (GI) and/or extraintestinal symptoms associated with gluten ingestion. The prevalence of NCGS is unknown. The condition has clinical features that overlap with those of celiac disease (CD) and wheat allergy (WA). The pathophysiologic process in NCGS is thought to be through an innate immune mechanism, whereas CD and WA are autoimmune- and allergen-mediated, respectively. However, dietary triggers other than gluten, such as the fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, have been implicated. Currently, no clinical biomarker is available to diagnose NCGS. Exclusion of CD and WA is necessary in the evaluation of a patient suspected to have NCGS. The onset of symptoms in patients with NCGS can occur within hours or days of gluten ingestion. Patients with NCGS have GI and extraintestinal symptoms that typically disappear when gluten-containing grains are eliminated from their diets. However, most patients suspected to have NCGS have already initiated a gluten-free diet at the time of an evaluation. A gluten elimination diet followed by a monitored open challenge of gluten intake to document recurrence of GI and/or extraintestinal symptoms can sometimes be helpful. If NCGS is strongly suggested, then a skilled dietitian with experience in counseling on gluten-free diets can provide proper patient education. Additional research studies are warranted to further our understanding of NCGS, including its pathogenesis and epidemiology, and to identify a biomarker to facilitate diagnosis and patient selection for proper management.

Adherence to gluten-free diet and barriers to adherence in patients with celiac disease

BACKGROUND

While adherence to gluten-free diet (GFD) is essential for effective control of celiac disease, the level of adherence to GFD may vary. We assessed the level of adherence to GFD and identified barriers to adherence in patients with celiac disease.

METHODS

Both treatment-naive and follow up patients with celiac disease were recruited from a celiac disease clinic. All the patients were assessed for symptom improvement using celiac symptom index (CSI), weight, and hemoglobin; adherence to GFD using detailed dietary history and food-labeled quiz questionnaire; identification of barriers to GFD using a self-administered 36-point questionnaire; and quality of life using a standard 36-item short form (SF36) questionnaire.

RESULTS

Among the patients who were already on GFD, only 53.3% maintained an excellent or good level of adherence, which increased to 92.4% at 6 months with repeated counseling. Among the treatment-naive patients, 64.8% maintained either excellent or good compliance at 1 month after first counseling, which increased to 96.3% at 6 months with repeated counseling. The most common barrier to adherence was non-availability of GFD. Certain barriers could be modified with repeated counseling and education. Response to GFD, as measured by CSI, gain in weight, and improvement in hemoglobin, was better in those having either excellent or good compliance to GFD compared to those who remained poorly adherent.

CONCLUSIONS

Repeated counseling increased the level of adherence to GFD.

Profound Reversible Hypogammaglobulinemia Caused by Celiac Disease in the Absence of Protein Losing Enteropathy

When patients with hypogammaglobulinemia are encountered, a vigorous search should be undertaken for secondary treatable causes. Here we describe the first case of a patient with severe asymptomatic hypogammaglobulinemia where the underlying cause was undiagnosed celiac disease. A strict gluten free diet resulted in resolution of her mild long-standing abdominal symptoms and correction of her hypogammaglobulinemia. There was corresponding improvement in her duodenal histology and normalisation of her celiac serology. Protein losing enteropathy was unlikely to have been the mechanism of her profound hypogammaglobulinemia, as her albumin was within the normal range and she had a normal fecal alpha 1 antitrypsin level. Application of the Ameratunga et al. (2013) diagnostic criteria was helpful in confirming this patient did not have Common Variable Immunodeficiency Disorder (CVID). Celiac disease must now be considered in the differential diagnosis of severe hypogammaglobulinemia. There should be a low threshold for undertaking celiac serology in patients with hypogammaglobulinemia, even if they have minimal symptoms attributable to gut disease.

Interaction study between wheat-derived peptides and procyanidin B3 by mass spectrometry

Tannins have the ability to complex and precipitate proteins, being particularly reactive towards the proline-rich ones. The main structural feature of the wheat peptides responsible for the onset of Celiac Disease (CD) is their high content in proline residues. The aim of this work was to characterize the binding between a common food tannin (procyanidin B3) and different wheat-derived peptidic fractions. For this, seven peptide mixtures were obtained after in vitro digestion of a wheat gliadins crude extract and further characterized by LC-ESI-MS/MS. Several soluble B3-peptide complexes were identified by ESI-MS. The peptides involved in complex formation varied in terms of their size and diversity in CD epitopes. Although binding selectivity of procyanidin B3 towards peptides containing CD epitopes was not found, the major complexes contained or could contain immunoreactive peptides. This study highlights the potential beneficial effects of food polyphenols as a nutritional approach in the modulation of CD.

Celiac Disease and Type 1 Diabetes in Adults: Is This a High-Risk Group for Screening?

The association between celiac disease (CD), an autoimmune condition involving intestinal inflammation related to gluten ingestion, and type 1 diabetes has long been recognized. CD prevalence rates 4 to 6 times greater in adults with type 1 diabetes than in the general population. Much of the existing literature focuses on important implications related to the impact of a gluten-free diet on short-term outcomes in metabolic control and quality of life. Canadian Diabetes Association guidelines recommend targeted CD screening in patients with type 1 diabetes who have classic symptoms, such as abdominal pain, bloating, diarrhea, unexplained weight loss or labile metabolic control; however, a significant proportion (40% to 60%) of patients may have mild or absent symptoms. Recent evidence suggests that adult patients with both conditions are at higher risk for diabetes microvascular comorbidities, increased mortality and impaired bone health if the CD is untreated. The purpose of this review is to describe the association between CD and type 1 diabetes and to summarize recent literature that evaluates risks in patients with both conditions.

Enhanced B-Cell Receptor Recognition of the Autoantigen Transglutaminase 2 by Efficient Catalytic Self-Multimerization

A hallmark of the gluten-driven enteropathy celiac disease is autoantibody production towards the enzyme transglutaminase 2 (TG2) that catalyzes the formation of covalent protein-protein cross-links. Activation of TG2-specific B cells likely involves gluten-specific CD4 T cells as production of the antibodies is dependent on disease-associated HLA-DQ allotypes and dietary intake of gluten. IgA plasma cells producing TG2 antibodies with few mutations are abundant in the celiac gut lesion. These plasma cells and serum antibodies to TG2 drop rapidly after initiation of a gluten-free diet, suggestive of extrafollicular responses or germinal center reactions of short duration. High antigen avidity is known to promote such responses, and is also important for breakage of self-tolerance. We here inquired whether TG2 avidity could be a feature relevant to celiac disease. Using recombinant enzyme we show by dynamic light scattering and gel electrophoresis that TG2 efficiently utilizes itself as a substrate due to conformation-dependent homotypic association, which involves the C-terminal domains of the enzyme. This leads to the formation of covalently linked TG2 multimers. The presence of exogenous substrate such as gluten peptide does not inhibit TG2 self-cross-linking, but rather results in formation of TG2-TG2-gluten complexes. The celiac disease autoantibody epitopes, clustered in the N-terminal part of TG2, are conserved in the TG2-multimers as determined by mass spectrometry and immunoprecipitation analysis. TG2 multimers are superior to TG2 monomer in activating A20 B cells transduced with TG2-specific B-cell receptor, and uptake of TG2-TG2-gluten multimers leads to efficient activation of gluten-specific T cells. Efficient catalytic self-multimerization of TG2 and generation of multivalent TG2 antigen decorated with gluten peptides suggest a mechanism by which self-reactive B cells are activated to give abundant numbers of plasma cells in celiac disease. Importantly, high avidity of the antigen could explain why TG2-specific plasma cells show signs of an extrafollicular generation pathway.

Attitudes Toward Genetic Testing for Celiac Disease

HLA molecular typing for celiac disease (CD) is a genetic test with a high negative predictive value. The aim of this study is to explore knowledge of and attitudes towards genetic testing (GT). A 25-item questionnaire was developed by a multidisciplinary team and distributed to members of CD support groups across the United States. Respondents (n = 1835) were mainly female (88 %), married (76 %), and college-educated (55 %), with a median age range of 31-50 years. Those who were married (82 vs 75 %, p = 0.002), had children (82 vs 74 %, p < 0.001), and had pursued education beyond high school (81 vs 68 %, p = 0.004) were more likely to be aware of the availability of GT. On multivariable analysis, adjusting for age, sex, education, marital status, region of residence, and having children, college-education (OR 2.05, 95 % CI: 1.33-3.16) and having children (OR 1.56, 95 % CI: 1.15-2.11) remained significant predictors of GT awareness. A majority of patients with a personal or family history of CD planned GT for their children, and the most common concerns regarding GT were cost and impact on health care and/or insurance. In conclusion, awareness of GT is high among CD support group members. Efforts should be made to increase knowledge of GT in those with a lower educational level, and healthcare professionals should attempt to address concerns regarding GT cost and the impact of results on health care and insurance status.

Cost Effectiveness of Routine Duodenal Biopsy Analysis for Celiac Disease During Endoscopy for Gastroesophageal Reflux

BACKGROUND & AIMS

Some patients with refractory gastroesophageal reflux disease (GERD) actually have undiagnosed celiac disease. These patients often undergo an esophagogastroduodenoscopy (EGD) to determine the etiology and severity of GERD. Performing routine duodenal biopsy analysis during an EGD could identify patients with celiac disease. We evaluated the cost effectiveness of this approach.

METHODS

We performed a systematic search of the MEDLINE database to identify publications through March 2014 on patients who underwent a duodenal biopsy analysis during an EGD for GERD. Data collected were used to construct a decision tree to calculate the cost effectiveness of an EGD with and without celiac disease tests.

RESULTS

Among 10,000 patients with refractory GERD who underwent an EGD, we predicted a biopsy strategy would detect 70% of patients with celiac disease if the prevalence of celiac disease was 1% in this cohort. Biopsy analysis at the start of the EGD procedure would increase the remaining quality-adjusted life years (QALYs) by 0.0032, and increase the lifetime cost by $389/patient. Compared with no biopsy, the biopsy strategy cost $55,692.86/case of celiac disease detected, and $121,875/QALY gained. The incremental cost-effectiveness ratio for the biopsy strategy met the threshold of less than $50,000/QALY when 1 of the following parameters was met: when the utility of living with GERD was less than 0.88, when the prevalence of celiac disease in patients with refractory GERD was greater than 1.8%, when biopsy analysis detected celiac disease with more than 98.1% specificity, when the cost of a gluten-free diet was less than $645.85/y, or if the cost of proton pump inhibitor therapy was more than $5874.01/y.

CONCLUSIONS

Based on base-case values, it is not cost effective to perform a biopsy analysis to detect celiac disease in patients undergoing an EGD for refractory GERD. However, the approach becomes cost effective when the prevalence of celiac disease in this population is 1.8% or greater.

Celiac Disease: Ten Things That Every Gastroenterologist Should Know

There are 10 things that all gastroenterologists should know about celiac disease (CD). (1) The immunoglobulin A tissue transglutaminase is the single best serologic test to use for the detection of CD. (2) CD can be recognized endoscopically, and water immersion enhances villi detection, although a normal endoscopic appearance does not preclude the diagnosis. (3) It is recommended that 4 biopsies be taken from the second part of the duodenum and 2 bulb biopsies be taken at the 9 o'clock and 12 o'clock positions to maximize the sensitivity for histologic confirmation of CD. (4) Consider serologic testing of first-degree relatives, patients with type 1 diabetes mellitus, Down's, Turner's, and Williams' syndromes, as well as those with premature osteoporosis, iron deficiency, abnormal liver biochemistries, and other manifestations of CD. (5) Patients already on a prolonged gluten-free diet (GFD) should be tested for the presence of HLA DQ2 or DQ8, thereby avoiding the need for further evaluation of CD in non-allelic carriers. (6) The basic treatment of CD is a strict, lifelong GFD, enabled by an expert dietitian. (7) Newly diagnosed adults with CD should be assessed for micronutrient deficiencies (iron, B12, folate, zinc, copper), fat soluble vitamin deficiencies (vitamin D), and bone densitometry. (8) All patients diagnosed with CD should have clinical follow-up to ensure response and adherence to a GFD. (9) In those with persistent or relapsing symptoms, the robustness of the original diagnosis should be reviewed, gluten exposure sought, and a systematic evaluation for alternative and associated diseases performed. (10) Evaluate those with refractory disease for malignant transformation.

Prevalence of abnormal liver function tests in celiac disease and the effect of a gluten-free diet in the US population

OBJECTIVES

Guidelines recommend routine screening of liver function tests (LFTs) in patients diagnosed with celiac disease (CD). However, little is known about the prevalence of liver disorders in CD outside of Europe. Our aims were to estimate the prevalence of LFT abnormalities in CD and to evaluate the effect of a gluten-free diet (GFD) on LFTs.

METHODS

Adult patients with biopsy-proven CD were identified from a prospectively maintained database and matched with healthy controls. LFT levels for women and men were defined as abnormal based on the Third National Health and Nutrition Examination Survey (NHANES III) criteria. Data on demographics, coexisting liver diseases, and laboratory work-ups including aspartate transaminase (AST) and alanine transaminase (ALT) values at the time of diagnosis and on a GFD were recorded. Subsequently, data from this cohort were compared with data from 7,789 individuals participating in the National Health and Nutrition Examination Survey, 2009-2010. Univariate logistic regression, Wilcoxon signed-ranks, Student's t-test, χ(2), and Fischer's exact test were used for statistical analysis.

RESULTS

In 463 CD patients with ALT or AST levels at the time of CD diagnosis, 40.6% had elevated LFTs compared with 24.2% of treated CD patients (P<0.001) and 16.6% of matched controls (P<0.001). Similarly, 36.7% of CD patients on the NHANES database had abnormal ALT values compared with 19.3% of non-celiac patients (P=0.03). Approximately, 78.6% of CD patients with elevated LFTs at diagnosis normalized LFTs on a GFD after a mean duration of 1.5±1.5 years.

CONCLUSIONS

Forty percent of individuals will have elevated LFTs at CD diagnosis; however, the majority will normalize with standard CD therapy. LFTs should be checked in all patients with CD and coexisting liver disorder should be considered in patients whose LFTs have not improved within a year on a GFD.

Computer versus physician identification of gastrointestinal alarm features

OBJECTIVE

It is important for clinicians to inquire about "alarm features" as it may identify those at risk for organic disease and who require additional diagnostic workup. We developed a computer algorithm called Automated Evaluation of Gastrointestinal Symptoms (AEGIS) that systematically collects patient gastrointestinal (GI) symptoms and alarm features, and then "translates" the information into a history of present illness (HPI). Our study's objective was to compare the number of alarms documented by physicians during usual care vs. that collected by AEGIS.

METHODS

We performed a cross-sectional study with a paired sample design among patients visiting adult GI clinics. Participants first received usual care by their physicians and then completed AEGIS. Each individual thus contributed both a physician-documented and computer-generated HPI. Blinded physician reviewers enumerated the positive alarm features (hematochezia, melena, hematemesis, unintentional weight loss, decreased appetite, and fevers) mentioned in each HPI. We compared the number of documented alarms within patient using the Wilcoxon signed-rank test.

RESULTS

Seventy-five patients had both physician and AEGIS HPIs. AEGIS identified more patients with positive alarm features compared to physicians (53% vs. 27%; p<.001). AEGIS also documented more positive alarms (median 1, interquartile range [IQR] 0-2) vs. physicians (median 0, IQR 0-1; p<.001). Moreover, clinicians documented only 30% of the positive alarms self-reported by patients through AEGIS.

CONCLUSIONS

Physicians documented less than one-third of red flags reported by patients through a computer algorithm. These data indicate that physicians may under report alarm features and that computerized "checklists" could complement standard HPIs to bolster clinical care.

Self-Reported Prevalence of Symptomatic Adverse Reactions to Gluten and Adherence to Gluten-Free Diet in an Adult Mexican Population

The prevalence of symptomatic adverse reactions to gluten and adherence to gluten-free diet in Latin American countries is unknown. These measurements are strongly linked to gluten-related disorders. This work aimed to estimate the prevalence of adverse reactions to oral gluten and the adherence to gluten-free diet in the adult Mexican population. To reach this aim, a self-administered questionnaire was designed and tested for clarity/comprehension and reproducibility. Then, a self-administered questionnaire-based cross-sectional study was conducted in the Mexican population. The estimated prevalence rates were (95% CI): 11.9% (9.9–13.5) and 7.8 (6.4–9.4) for adverse and recurrent adverse reactions to gluten respectively; adherence to gluten-free diet 3.7% (2.7–4.8), wheat allergy 0.72% (0.38–1.37); celiac disease 0.08% (0.01–0.45), and NCGS 0.97% (0.55–1.68). Estimated pooled prevalence of self-reported physician-diagnosis of gluten-related disorders was 0.88% (0.49–1.5), and 93.3% respondents reported adherence to gluten-free diet without a physician-diagnosis of gluten-related disorders. Symptom comparisons between those who reported recurrent adverse reactions to gluten and other foods showed statistically significant differences for bloating, constipation, and tiredness (p < 0.05). Gluten-related disorders may be underdiagnosed in the Mexican population and most people adhering to a gluten-free diet are doing it without proper diagnostic work-up of these disorders, and probably without medical/dietician advice.

The Gluten-Free Diet in the 3rd Millennium: Rules, Risks and Opportunities

The gluten-free diet has long been considered the standard treatment for celiac disease. However, a significant number of patients continue to experience persistent symptoms despite following a gluten-free diet. Inadvertent gluten ingestion, fermentable carbohydrates, cross-contamination, and social or financial burdens present obstacles to maintaining a gluten-free diet. Proper diet education and follow-up by an expert Registered Dietitian (RD) is essential to ensure adequate nutrition on the gluten-free diet. Patients may experience unintended weight gain or elevated cholesterol levels after initiating the gluten-free diet due to adequate absorption and healing of the intestines. This review deals with the evolving gluten-free diet, optimal recommendations while considering the overall health of patients, and multi-factorial aspects of the permanent lifestyle change.

Increased Detection of Celiac Disease With Measurement of Deamidated Gliadin Peptide Antibody Before Endoscopy

BACKGROUND & AIMS

Celiac disease is underdiagnosed. Many patients are examined by endoscopy, but celiac disease is missed or not detected. We evaluated the accuracy of finger prick-based point-of-care tests in the detection of celiac disease and developed an algorithm for diagnosis.

METHODS

We performed a prospective study of 2 groups of patients with celiac disease evaluated at the Royal Hallamshire Hospital in Sheffield (United Kingdom) from March 2013 through February 2014. In group 1, patients at high risk of celiac disease who tested positive for endomysial antibody (n = 55) were evaluated using the Biocard test (BHR Pharmaceuticals, Nuneaton, UK) and the Celiac Quick Test (Biohit Healthcare UK, Ellesmere Port, UK), which measure antibodies to tissue transglutaminase (anti-tTG), and the Simtomax test (Tillotts Pharma, Rheinfelden, Switzerland), which measures deamidated gliadin peptide antibodies (DGP). Patients in group 2 (508 consecutive patients who underwent an endoscopy examination for any indication) received the DGP test, and also were evaluated using a diagnostic algorithm that incorporated results from the DGP test and data on symptoms. In both groups, point-of-care tests were taken at the time of endoscopy and results were compared with results from histologic analyses of duodenal biopsy specimens from all patients.

RESULTS

In group 1, the DGP test identified patients with celiac disease with 94.4% sensitivity, the Celiac Quick Test identified patients with 77.8% sensitivity (P = .03 vs the DGP test), and the Biocard test identified patients with 72.2% sensitivity (P = .008 vs the DGP test). In group 2, the DGP test identified patients with celiac disease with 92.7% sensitivity (95% confidence interval, 83.0-97.3), 85.2% specificity (95% confidence interval, 81.5-88.3), a positive predictive value of 49.2% (95% confidence interval, 40.3-58.2), and a negative predictive value of 98.7% (95% confidence interval, 96.8-99.5). Measurement of serum anti-tTG identified patients with celiac disease with 91.2% sensitivity (95% confidence interval, 81.1-96.4), 87.5% specificity (95% confidence interval, 84.0-90.4), a positive predictive value of 53.0% (95% confidence interval, 43.6-62.2), and a negative predictive value of 98.5% (95% confidence interval, 96.5-99.4). The algorithm identified patients with celiac disease with 98.5% sensitivity; its use could reduce duodenal biopsies by 35%.

CONCLUSIONS

In a prospective study, a test for DGP identified patients with celiac disease with similar levels of sensitivity and specificity as standard serologic analysis of anti-tTG. Use of the DGP test before endoscopy could increase the accuracy of the diagnosis of celiac disease. Further studies, in lower-prevalence populations, are required to assess the impact of the test in clinical practice.

Unrecognized Celiac Disease in Children Presenting for Rheumatology Evaluation

BACKGROUND AND OBJECTIVES

Current clinical guidelines do not consider patients with rheumatic conditions to be at high risk for celiac disease (CD) despite numerous reported associations between the two in adults and children. The objective of this study was to evaluate the prevalence of CD among patients presenting for pediatric rheumatology evaluation.

METHODS

A total of 2125 patients presenting for initial evaluation by the Division of Pediatric Rheumatology at the Hospital for Special Surgery between June 2006 and December 2013 were screened for CD as a part of the standard initial serologic evaluation. The charts of these patients were evaluated retrospectively at the end of this period.

RESULTS

36 patients (30 girls, 6 boys, mean age 9.4 ± 4.3 years, range 2-16 years) received a diagnosis of CD after serologic testing and evaluation by pediatric gastroenterology. Eight additional patients with known diagnoses of CD presented during this time period. The total prevalence of CD over this 6.5-year period was 2.0%. The most common presenting complaints among patients diagnosed with CD were myalgias, arthralgias, and rash. Less frequently, patients reported gastrointestinal complaints including abdominal pain, nausea, and diarrhea. All patients reported improvement or complete resolution of their musculoskeletal symptoms after initiation of a gluten-free diet.

CONCLUSIONS

This study identified 36 new cases of CD among children presenting for rheumatology evaluation, for an overall prevalence rate of 2.0%. The majority of patients who ultimately received a diagnosis of CD presented with extraintestinal manifestations. These results underscore the importance of screening children presenting for rheumatology evaluation for CD.

Frequency of Celiac Disease In Children With Chronic Functional Constipation in Shiraz-Iran

BACKGROUND Celiac disease is an autoimmune mediated small intestine inflammation which occurs due to hypersensitivity reaction to gluten and related proteins in diet in genetically predisposed individuals. Prevalence of celiac among the population is about 0.5 - 1 % in most countries. Frequency of celiac disease in children is the subject of a few research. In this study, we aim to determine the frequency of celiac disease in patients presenting with functional constipation. METHODS This cross-sectional study was conducted on children referring to Imam Reza Clinic, affiliated to Shiraz University of Medical Sciences during one year starting from 2011, March 20. One hundred and one children 2-18 years of age with constipation for more than 2 months according to ROME III criteria. The entire participants underwent serologic studies of Total IgA and IgA TTG. Serum IgG TTG was measured in cases with reported values of Total IgA below the lowest normal limits. Moreover, endoscopic biopsy of the small intestine was also performed for patients with positive serology. RESULTS Of all the 101 studied participants, only four individuals (3.96 %) had positive test results for IgA TTG ( potential celiac disease). one of these patients refused to do endoscopy and endoscopic small intestine biopsy was performed for 3 patients. Two of them had normal pathology and one of them(0.99 %) was confirmed for celiac disease. CONCLUSION The frequency of celiac disease in children with chronic constipation is slightly higher than general population but without significant difference( 0.99% VS 0.6% ; p=0.64). So the screening serologic test for celiac disease is not recommended in children with chronic constipation.

Pondering the potential of quantitative analysis of video capsule endoscopy images in the management of children with celiac disease

Celiac disease is common throughout the world, affecting approximately 1% of patients of all age groups. In this review, the role of video capsule endoscopy in characterizing the small intestinal lumen of pediatric patients with celiac disease is discussed in detail. Quantitative aspects of video capsule endoscopy which may be helpful in diagnosing pediatric patients are highlighted.

Low yield of routine duodenal biopsies for evaluation of abdominal pain

AIM

To determine the yield of biopsying normal duodenal mucosa for investigation of abdominal pain.

METHODS

This is a retrospective chart review of consecutive patients who underwent esophagogastroduodenoscopy (EGD) with duodenal biopsies of normal appearing duodenal mucosa for an indication that included abdominal pain. All the patients in this study were identified from an electronic endoscopy database at a single academic medical center and had an EGD with duodenal biopsies performed over a 4-year period. New diagnoses that were made as a direct result of duodenal biopsies were identified. All duodenal pathology reports and endoscopy records were reviewed for indications to perform the examination as well as the findings; all the medical records were reviewed. Exclusion criteria included age less than 18 years, duodenal mass, nodule, or polyp, endoscopic duodenitis, duodenal scalloping, known celiac disease, positive celiac serology, Crohns disease, or history of bone marrow transplant. Information was collected in a de-identified database with pertinent demographic information including human immunodeficiency virus (HIV) status, and descriptive statistics were performed.

RESULTS

About 300 patients underwent EGD with biopsies of benign appearing or normal appearing duodenal mucosa. The mean age of patients was 44.1 ± 16.8 years; 189 of 300 (63%) were female. A mean of 4.3 duodenal biopsies were performed in each patient. In the subgroup of patients with abdominal pain without anemia, diarrhea, or weight loss the mean age was 43.4 ± 16.3 years. Duodenal biopsies performed for an indication that included abdominal pain resulting in 4 new diagnoses (3 celiac disease and 1 giardiasis) for an overall yield of 1.3%. 183 patients with abdominal pain without anemia, diarrhea, or weight loss (out of the total 300 patients) underwent duodenal biopsy of duodenal mucosa resulting in three new diagnoses (two cases of celiac disease and one giardiasis) for a yield of 1.6%. Duodenal biopsies of 19 HIV patients presenting for evaluation of abdominal pain did not reveal any new diagnoses. Information pertaining to new diagnoses is provided.

CONCLUSION

Routine biopsy of normal appearing duodena in patients with abdominal pain should be reserved for those with a high pre-test probability given its low diagnostic yield.

Non-celiac gluten hypersensitivity: What is all the fuss about?

Non-celiac gluten sensitivity (NCGS) has been introduced recently as a potentially common disease on the basis of studies of patients with claimed reactivity to gluten but without the characteristics of celiac disease (CD). CD is characterized by antibody reactivity toward the autoantigen transglutaminase 2, characteristic histological abnormalities of the small intestine, and an almost obligatory genetic haplotype (HLA-DQ2 or DQ8). The diagnosis of NCGS is based largely on the clinical suspicion of hyper-reactivity to gluten and the absence of the characteristics of CD. Few published studies have used double-blind placebo-controlled food challenges (DBPCFCs) for the diagnosis of NCGS, and none in children. Innate immune reactivity to amylase trypsin inhibitors has been suggested as the pathogenic principle in NCGS, but confirmatory evidence is lacking. Also, further clinical studies including DBPCFCs are needed.

Diagnosis of gluten related disorders: Celiac disease, wheat allergy and non-celiac gluten sensitivity

Cereal crops and cereal consumption have had a vital role in Mankind’s history. In the recent years gluten ingestion has been linked with a range of clinical disorders. Gluten-related disorders have gradually emerged as an epidemiologically relevant phenomenon with an estimated global prevalence around 5%. Celiac disease, wheat allergy and non-celiac gluten sensitivity represent different gluten-related disorders. Similar clinical manifestations can be observed in these disorders, yet there are peculiar pathogenetic pathways involved in their development. Celiac disease and wheat allergy have been extensively studied, while non-celiac gluten sensitivity is a relatively novel clinical entity, believed to be closely related to other gastrointestinal functional syndromes. The diagnosis of celiac disease and wheat allergy is based on a combination of findings from the patient’s clinical history and specific tests, including serology and duodenal biopsies in case of celiac disease, or laboratory and functional assays for wheat allergy. On the other hand, non-celiac gluten sensitivity is still mainly a diagnosis of exclusion, in the absence of clear-cut diagnostic criteria. A multimodal pragmatic approach combining findings from the clinical history, symptoms, serological and histological tests is required in order to reach an accurate diagnosis. A thorough knowledge of the differences and overlap in clinical presentation among gluten-related disorders, and between them and other gastrointestinal disorders, will help clinicians in the process of differential diagnosis.

DQ2, DQ7 and DQ8 Distribution and Clinical Manifestations in Celiac Cases and Their First-Degree Relatives

HLA-linked genes are relevant to celiac disease (CD); the potential genetic differences present worldwide are not fully understood. Previous results suggest that the distribution of HLA-DQ2/DQ7/DQ8 in Chile may differ from that in Europe and North America. In celiac patients and their first-degree relatives (FDRS), we assessed their clinical, serological and histological characteristics, determined HLA-DQ2, HLA-DQ7 and HLA-DQ8 alleles and genotypes, and evaluated the relations between them. A total of 222 individuals were assessed (56 cases, 166 FDRs). 16.9% of FDRs were tTG positive; 53.6% of them showed overweight/obesity and 3% undernourishment; they spontaneously declared being asymptomatic, but detailed questioning revealed that 60.7% experienced symptoms, which had not been investigated. DQ2 was present in 53.9% and 43.9.0% of cases and FDRs (p < 0.05). The most frequent genotype distribution was DQ2/DQ7 (fr 0.392 (cases) and 0.248 (FDRs), respectively, p < 0.02). The next most common genotypes were HLA-DQ2/DQ8 (fr 0.236 in FDRs and 0.176 in cases, p < 0.05). 3.92% cases were not HLA-DQ2/DQ8 carriers. Among tTG positive FDRs, 57.4%, 22.3% and 20.2% carried DQ2, DQ7 and DQ8, respectively. In cases, 72.7% of the biopsies classified Marsh ≥ 3 carried at least one DQ2; 91.7% of DQ2/DQ2 and 88.3% of DQ2/DQ7 were Marsh ≥ 3. Thus, DQ2 frequency is lower than reported; the higher frequency found for DQ8 and DQ7 concur with recent publications from Argentine and Brazil. These results suggest that although CD may manifest clinically in ways similar to those described in other populations, some genetic peculiarities in this region deserve further study.

Eosinophils in Gastrointestinal Disorders: Eosinophilic Gastrointestinal Diseases, Celiac Disease, Inflammatory Bowel Diseases, and Parasitic Infections

The gastrointestinal (GI) tract provides an intriguing organ for considering the eosinophil's role in health and disease. The normal GI tract, except for the esophagus, is populated by eosinophils that are present throughout the mucosa, raising the possibility that eosinophils participate in innate mechanisms of defense. However, data from clinical studies associates increased numbers of eosinophils with inflammatory GI diseases, prompting concerns that eosinophils may have a deleterious effect on the gut. We present clinical features of 4 disease processes that have been associated with eosinophilia and suggest areas requiring investigation as to their clinical significance and scientific relevance.

Celiac Disease: Diagnostic Standards and Dilemmas

Celiac Disease (CD) affects at least 1% of the population and evidence suggests that prevalence is increasing. The diagnosis of CD depends on providers being alert to both typical and atypical presentations and those situations in which patients are at high risk for the disease. Because of variable presentation, physicians need to have a low threshold for celiac testing. Robust knowledge of the pathogenesis of this autoimmune disease has served as a catalyst for the development of novel diagnostic tools. Highly sensitive and specific serological assays including Endomysial Antibody (EMA), tissue transglutaminase (tTG), and Deamidated Gliadin Peptide (DGP) have greatly simplified testing for CD and serve as the foundation for celiac diagnosis. In addition, genetic testing for HLA DQ2 and DQ8 has become more widely available and there has been refinement of the gluten challenge for use in diagnostic algorithms. While diagnosis is usually straightforward, in special conditions including IgA deficiency, very young children, discrepant histology and serology, and adoption of a gluten free diet prior to testing, CD can be difficult to diagnose. In this review, we provide an overview of the history and current state of celiac disease diagnosis and provide guidance for evaluation of CD in difficult diagnostic circumstances.

HLA-DQ genetic risk gradient for type 1 diabetes and celiac disease in northwestern Mexico

BACKGROUND

Type 1 diabetes (T1D) and celiac disease (CD) are the 2 most common autoimmune childhood diseases that share their HLA-DQ2 and DQ8 genetic origin. There has currently been an increase in both diseases worldwide. In children from the low-population State of Sonora (15 inhabitants/km(2)) in north-western Mexico, there is no information on their genetic risk or the distribution of the related alleles in the general population.

AIMS

To compare the HLA-DQ allele frequency in a representative sample of newborns from Sonora with that of T1D and CD patients to determine the risk gradient, and to identify the presence of celiac autoimmunity in the T1D group.

METHODS

The study included 397 Sonoran newborns, with 44 cases of T1D, and 25 CD cases. The CD and T1D cases were clinically diagnosed by specialists at the Hospital Infantil del Estado de Sonora, and the autoantibodies were determined by ELISA. Whole blood was collected, gDNA was extracted, and HLA-DQ2 and DQ8 were typed by PCR-SSP. The risk gradient was calculated by comparing the allele frequencies of the cases with those of the newborns.

RESULTS

The Sonoran HLA-DQ risk heterodimer proportion was 16.1% for HLA-DQ2 and 13.6% for HLA-DQ8, with an HLA-DQ2:HLA-DQ8 ratio of 1.2:1. The DQ8/DQ2 genotype represented a 1:14 risk for T1D, whereas the DQ8/DQB1*0201 combination showed a 1:6 risk for CD. The prevalence of CD autoimmunity in T1D children was 7%.

CONCLUSION

The Sonoran population has a distinctive HLA-DQ allele distribution due to its ancestry. The HLA-DQ8 combinations with DQ2 or one of its alleles conferred the highest risk for both diseases, and T1D and CD frequently appear together.

Effect of a Gluten-Free Diet on Cortical Excitability in Adults with Celiac Disease

INTRODUCTION

An imbalance between excitatory and inhibitory synaptic excitability was observed in de novo patients with celiac disease (CD) in a previous study with Transcranial Magnetic Stimulation (TMS), suggesting a subclinical involvement of GABAergic and glutamatergic neurotransmission in asymptomatic patients. The aim of this investigation was to monitor the eventual changes in the same cohort of patients, evaluated after a period of gluten-free diet.

METHODS

Patients were re-evaluated after a median period of 16 months during which an adequate gluten-free diet was maintained. Clinical, cognitive and neuropsychiatric assessment was repeated, as well as cortical excitability by means of single- and paired-pulse TMS from the first dorsal interosseous muscle of the dominant hand.

RESULTS

Compared to baseline, patients showed a significant decrease of the median resting motor threshold (from 35% to 33%, p<0.01). The other single-pulse (cortical silent period, motor evoked potentials latency and amplitude, central motor conduction time) and paired-pulse TMS measures (intracortical inhibition and intracortical facilitation) did not change significantly after the follow-up period. Antibodies were still present in 7 subjects.

DISCUSSION

In patients under a gluten-free diet, a global increase of cortical excitability was observed, suggesting a glutamate-mediated functional reorganization compensating for disease progression. We hypothesize that glutamate receptor activation, probably triggered by CD-related immune system dysregulation, might result in a long-lasting motor cortex hyperexcitability with increased excitatory post-synaptic potentials, probably related to phenomena of long-term plasticity. The impact of the gluten-free diet on subclinical neurological abnormalities needs to be further explored.

Microscopic colitis (lymphocytic and collagenous), eosinophilic colitis, and celiac disease

Multiple tests are needed to diagnose a patient with noninfectious diarrhea. Some patients will be mistakenly labeled as diarrhea-predominant irritable bowel syndrome (IBS-D) because of nonspecific computed tomographic scans and grossly normal endoscopic findings. It is crucial to understand other less common pathologies to avoid these instances of misdiagnosis. This article focuses on microscopic colitis (MC), eosinophilic colitis (EC), and celiac disease. MC is an inflammatory condition of the colon that presents with two subtypes, only to be differentiated by histology. EC is a rare chronic inflammatory process. Depending on the extent of the disease, it can present with mild diarrhea, malabsorption, or at its worst, cause obstruction and perforation. Celiac disease affects the small bowel, but interestingly can present similarly to colitis. Both MC and EC respond to oral budesonide. Patients with celiac disease improve on gluten-free diets. These treatments are distinctly different from typical IBS-D care plans.

The prevention of coeliac disease

Primary prevention of coeliac disease is currently not possible. Previously, a 'window of opportunity' was suggested for primary prevention, by introducing gluten between four and six months of age. However, results from recent prospective studies establish that the timing of gluten introduction and the duration or maintenance of breastfeeding do not influence the development of the disease. Secondary prevention is possible through early diagnosis and treatment. Since coeliac disease is severely underdiagnosed, the only way to achieve large-scale secondary prevention is by mass screening. Prospective studies indicate that important health problems, such as reduced foetal growth and birth weight, delayed growth in height and weight in children, and reduced bone mineral density in both children and adults can be prevented by mass screening. Adherence to a strict gluten-free diet may be considered as tertiary prevention.

Racial Differences in the Prevalence of Celiac Disease in the US Population: National Health and Nutrition Examination Survey (NHANES) 2009-2012

AIM

To provide an estimate of the prevalence of celiac disease by race/ethnic origin in large sample of US population.

METHODS

Data from the 2009-2010 and 2011-2012 NHANES were combined and analyzed. The NHANES is a nationally representative survey with oversampling of certain minorities. Sample-based frequencies were reported and weighted frequencies were used to estimate prevalence.

RESULTS

A total of 14,701 participants were checked for tissue transglutaminase (tTG) and endomysial (EMA) IgA antibodies. Seventy-four participants had positive tTG and/or EMA corresponding to prevalence of 0.79 % (95 % CI 0.54-1.04 %). Non-Hispanic white were more likely to be positive for both compared with other races (72.0 vs 31.7 %; p = 0.010) and less likely to be weakly positive for tTG but positive for EMA (3.6 vs 26.4 %; p = 0.03). The prevalence of positive serology according to race was as follows: 1.08 % (95 % CI 0.70-1.45 %) in non-Hispanic white, 0.23 % (95 % CI 0.03-0.43 %) in Mexican, 0.22 % (95 % CI 0.01-0.44 %) in non-Hispanic black, 0.38 % (95 % CI 0.00-0.89 %) in "other Hispanic," and 0.15 % (95 % CI 0.00-0.34 %) in other races including multiracial and undeterminable in non-Hispanic Asian due to the presence of only one positive EMA test. 0.9 % of the NHANES sample participants followed gluten-free diet. Of this group of participants, 85 % were never diagnosed with celiac disease and 99 % of them had negative celiac disease serology.

CONCLUSIONS

Potentially 0.79 % of the general US population demonstrate serologic evidence of celiac disease autoimmunity. The prevalence is 4-8 times higher among non-Hispanic white compared with other races. Close to 1 % of the population is electively following gluten-free diet despite having little evidence of the disease.

Coeliac disease - from genetic and immunological studies to clinical applications

Coeliac disease is a common and important gastrointestinal disease. It affects at least 1%, most Western European populations and in Nordic countries it is even more frequent. It is strongly associated with certain Human Leukocyte Antigen-DQ genes and triggered by ingestion of wheat gluten and related cereals from rye and barley. The diagnosis relies on a combination of clinical signs, serology and small intestinal biopsy. Work during the last couple of decades has shown that gluten-specific, Human Leukocyte Antigen-DQ-restricted T-cells in the intestinal mucosa are of paramount importance in the disease process. The gluten peptides are chemically modified by the endogenous enzyme transglutaminase 2, the same enzyme that serves as target in today's sensitive serological tests for coeliac disease. The increasing knowledge on the disease process allows for development of improved diagnosis, patient care and new treatment modalities.

Wheat-related disorders reviewed: making a grain of sense

Wheat-related disorders have become a growing area of clinical and scientific interest and can be categorized broadly as: autoimmune-mediated; allergic; and non-autoimmune/non-allergic conditions. Non-celiac gluten sensitivity (NCGS) and non-celiac wheat sensitivity (NCWS) present on this spectrum as disorders associated with adverse gastrointestinal and extra-intestinal manifestations following exposure to gluten and/or other wheat-related constituents. NCGS/NCWS is increasingly considered in patients with unexplained symptoms after the exclusions of celiac disease and wheat allergy. As objective diagnostic data and specific biomarkers are lacking, response to a gluten-free/wheat-free diet can confirm the presence of NCGS/NCWS. An association with irritable bowel syndrome has been detected, and the effects of other food components, such as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, may contribute. Our organization and synthesis of extant knowledge pertaining to wheat-related disorders may advance current practice and research efforts toward an improved understanding of NCGS/NCWS as an evolving clinical entity.