Accuracy of diagnostic antibody tests for coeliac disease in children: summary of an evidence report

Pancreatic Comorbidities in Pediatric Celiac Disease: Exocrine Pancreatic Insufficiency, Pancreatitis, and Diabetes Mellitus

Celiac disease (CD) is a chronic and immune-mediated disorder triggered by the ingestion of gluten in some genetically predisposed individuals. CD can be associated with extra-gastrointestinal manifestations and diseases affecting several organs. In this review, the aim is to analyze and discuss the pancreatic alterations and/or comorbidities that could arise in the context of pediatric CD. Exocrine pancreatic insufficiency (EPI) can be observed in a variable fraction (up to 30%) of children diagnosed with CD at the diagnosis; indeed, it usually resolves after the implementation of a gluten-free diet (GFD). The main pathophysiological mechanisms of EPI could be represented by the impaired pattern of gastrointestinal hormones in CD patients. Conversely, pancreatitis seems to be a very rare comorbidity in CD children, since very few cases have been described in children. Therefore, there is no evidence that pancreatitis (including autoimmune forms) represents a relevant comorbidity in pediatric CD. Type 1 diabetes mellitus (T1DM) is a well-known and frequent comorbidity in CD children. The main determinant of this epidemiological association is the common HLA-related predisposing background, even if other (non-HLA-related) genetic and environmental factors (viruses, gut microbiome, and others) are likely to be also implicated in the development of both these autoimmune diseases. T1DM children with concomitant CD may experience specific challenges in the adherence to GFD, which has no negative impact on the glycemic and, in general, metabolic control of diabetes, if it is properly implemented and followed up.

Celiac Disease-Narrative Review on Progress in Celiac Disease

Celiac disease is defined as a systemic immunological disorder caused by gluten (gliadin and other prolamin) in genetically predisposed individuals, who present with a variety of gluten-dependent symptoms, specific antibodies, the presence of the HLA DQ2 and DQ8 histocompatibility antigen, and enteropathy. Its prevalence, depending on the studied population and methodology, is estimated at 0.75-1.6% of the general population. During the complex immune reaction it induces, most cells involved in inflammatory processes are activated, which leads to the gradual atrophy of intestinal villi and the proliferation of enterocytes within intestinal crypts. The pathogenesis of celiac disease is extremely complicated and is still the subject of research. According to the current diagnostic guidelines, the following criteria should be taken into account: clinical symptoms (intestinal and extraintestinal), the presence of antibodies against tissue transglutaminase in the IgA class, the level of total IgA, and the presence of typical histological changes in duodenal biopsies. Diet-resistant celiac disease is one of the most important clinical challenges, causing serious complications. Currently, the basic method for treating celiac disease is an elimination diet (i.e., the exclusion of products that may contain gluten from the diet), however, new therapeutic strategies are still being sought, mainly based on supplementation with exogenous endopeptidases, modification of the immune response, and the use of zonulin inhibitors and transglutaminase 2 inhibitors. Clinical trials of new drugs are ongoing. The gradually expanding knowledge about the pathogenesis of celiac disease may allow for the development of new therapeutic strategies for both patients with a mild disease course, as well as those that are diet-resistant.

Development of Cell-Assembled Human Endomysial-Type Biomatrix Substrate for the Detection of Celiac Disease Autoantibodies

The endomysial antibody (EMA) immunofluorescent test is a highly specific method to detect disease-specific autoantibodies in celiac disease (CD) by their binding to natural transglutaminase-2 autoantigen in tissue sections, and it is used as a compulsory confirmatory test in the non-invasive diagnosis of CD. The classical EMA substrates are the monkey esophagus and the human umbilical cord. It is increasingly difficult to use these tissues due to ethical concerns and animal welfare regulations. In this study, we developed, in cell culture, an endomysium-type extracellular biomatrix assembled by human umbilical cord vein-derived endothelial cells which binds CD antibodies in a similar pattern as monkey esophagus and has similar macromolecular composition. Evaluating retrospectively and prospectively tested patient cohorts, including 130 CD cases and 105 non-celiac controls, IgA-class celiac antibody detection on the biomatrix was equally specific (100%) as EMA testing on tissues, and had higher sensitivity (95.6% versus 91.2%). Both EMA tests were less sensitive, but more specific than transglutaminase-based ELISA measurements. The decellularization of the biomatrix improved sensitivity, enabled the detection of IgG-class celiac antibodies, and allowed for simple reading without previous training. This easily available cell-assembled biomatrix substrate may replace substrate tissues in diagnostic EMA testing in the future.

Diagnostic Accuracy of IgA Anti-Transglutaminase Assessed by Chemiluminescence: A Systematic Review and Meta-Analysis

A new chemiluminescence immunoassay method (CLIA) for detecting IgA anti-transglutaminase (atTG IgA) in celiac disease (CD) has prompted inquiries into its diagnostic performance. We conducted a systematic review and meta-analysis comparing CLIA with traditional enzyme-linked immunosorbent assay (ELISA) and fluorescence enzyme immunoassay (FEIA). We searched PubMed, Medline, and Embase databases up to March 2024. The diagnostic references were intestinal biopsy and ESPGHAN guidelines. We calculated the sensitivity and specificity of atTG IgA assessed by CLIA and the odds ratio (OR) between the assays. Eleven articles were eligible for the systematic review and seven for the meta-analysis. Sensitivity and specificity of atTG IgA CLIA-assay were 0.98 (95% CI, 0.95-0.99) and 0.97 (95% CI, 0.94-0.99), respectively. The sensitivity of atTG IgA antibody detection did not significantly vary across the three assay modalities examined (CLIA vs. ELISA OR: 1.08 (95% CI, 0.56-2.11; p = 0.8); CLIA vs. FEIA OR: 6.97 (95% CI, 0.60-81.03; p = 0.1). The specificity of atTG IgA assessed by FEIA was higher than for CLIA (OR 0.17 (95% CI, 0.05-0.62); p < 0.007). According to the systematic review, normalization of atTG IgA levels in CD patients following a gluten-free diet was delayed when using CLIA compared to ELISA and FEIA methods. Conflicting findings were reported on the antibody threshold to use in order to avoid biopsy confirmation.

New and old criteria for diagnosing celiac disease: do they really differ? A retrospective observational study

BACKGROUND

The aim of this study is to compare two groups of celiac patients: the first one, in which diagnosis was based on a "biopsy sparing" approach according to the 2012 ESPGHAN criteria, and the second one, based on the biopsy approach like the one of the 1991 Revised Criteria, in order to find relevant difference for sex, M/F ratio, age at diagnosis, clinical features at the onset, presence and prevalence of concomitant autoimmune disorders.

METHODS

Our study involves 61 patients having the Celiac Disease (CD) onset from February 2013 to February 2020. The 32 patients who received diagnosis according "biopsy sparing" criteria were enrolled in group (1) The 29 patients who received diagnosis by duodenal biopsy were enrolled in group (2) Prevalence of comorbidities was analysed through chi-square test.

RESULTS

In group 1 the prevalence of comorbidities such as Insulin-Dependent Diabetes Mellitus (IDDM) and thyroiditis was of 53%, while in group 2 it was only of 24%. Analysing the IDDM prevalence between the two groups we found a relevant difference. At the same time, the prevalence of thyroiditis was also significantly different. In group 1, male patients, in particular, would seem to have a higher incidence of CD related autoimmune disorders.

CONCLUSIONS

An increased prevalence of IDDM, thyroiditis and juvenile idiopathic arthritis (JIA) in the first group would show that the "biopsy sparing" approach could expose patients to a greater length of disease activity that might be responsible for the onset of such comorbidities. Further studies should be carried out on more numerous samples of patients in order to confirm or not these data.

Identifying the Optimum Strategy for Identifying Adults and Children With Celiac Disease: A Cost-Effectiveness and Value of Information Analysis

OBJECTIVES

Celiac disease (CD) is thought to affect around 1% of people in the United Kingdom, but only approximately 30% are diagnosed. The aim of this work was to assess the cost-effectiveness of strategies for identifying adults and children with CD in terms of who to test and which tests to use.

METHODS

A decision tree and Markov model were used to describe testing strategies and model long-term consequences of CD. The analysis compared a selection of pre-test probabilities of CD above which patients should be screened, as well as the use of different serological tests, with or without genetic testing. Value of information analysis was used to prioritize parameters for future research.

RESULTS

Using serological testing alone in adults, immunoglobulin A (IgA) tissue transglutaminase (tTG) at a 1% pre-test probability (equivalent to population screening) was most cost-effective. If combining serological testing with genetic testing, human leukocyte antigen combined with IgA tTG at a 5% pre-test probability was most cost-effective. In children, the most cost-effective strategy was a 10% pre-test probability with human leukocyte antigen plus IgA tTG. Value of information analysis highlighted the probability of late diagnosis of CD and the accuracy of serological tests as important parameters. The analysis also suggested prioritizing research in adult women over adult men or children.

CONCLUSIONS

For adults, these cost-effectiveness results suggest UK National Screening Committee Criteria for population-based screening for CD should be explored. Substantial uncertainty in the results indicate a high value in conducting further research.

Performance of deamidated gliadin peptide antibodies as first screening for celiac disease in the general pediatric population

BACKGROUND

Celiac serology has evolved, with the identification of newer antibodies against deamidated gliadin peptides (DGP) [e.g., anti-DGP, immunoglobulin A (IgA), and immunoglobulin G (IgG) types] with sensitivity and specificity in detecting celiac disease (CeD) that are equivalent to anti-tissue transglutaminase [anti-tissue transglutaminase (TTG) IgA]-based tests, particularly in populations with high pretest probability of CeD (prevalence of CeD > 50% of the population under study). This opens the possibility that anti-DGP assays can be used to identify CeD in the general population where the prevalence of CeD is very low (≈1%).

OBJECTIVE

This study aimed (1) to determine the diagnostic performance of DGP antibodies-based serologic assays in identifying CeD during the screening of the general population and (2) to compare the levels of anti-DGP antibodies among CeD patients with mild and severe degrees of enteropathy.

METHODS

Serology tests for DGP antibodies (DGP-IgA, DGP-IgG, and conjugate TTG/DGP antibodies) were performed on 104 serum samples of positive TTG-IgA (100 confirmed and four potential celiac patients) and a randomly selected 1,000 negative TTG-IgA serum samples collected during mass screening of children (aged 6-15 years) in 2014-2015.

RESULTS

Sera from 32 of the 1,000 TTG-IgA negative serum specimens (3.2%) tested positive for one or more of the three anti-DGP serology tests. A total of 13 of the 32 anti-DGP seropositive patients had persistent positive results on follow-up samples in 2020 (1.3%). Eight of the 13 underwent endoscopy with biopsies, and only two had confirmed CeD (both DGP-IgG positive) (0.2%). The sensitivity and specificity of the serology assays were as follows: DGP-IgA (62.7%, 40%), DGP-IgG (80.4%, 100%), and conjugate TTG/DGP (96%, 10%). Based on receiver operating characteristic curves, the area under the curve for DGP-IgG (0.919; 95% CI -0.00406 to 0.114) was comparable to TTG-IgA (0.974; 95% CI 0.924-0.995) (P = 0.0679). Titers of antibodies to DGPs were significantly higher in children with severe intestinal damage than in those in children with mild lesions (P < 0.001).

CONCLUSION

The TTG-IgA assay remains the most reliable screening serology test for CeD in mass screening studies. The performance of TTG-IgA has improved marginally by adding DGP-IgG to the mass screening protocol. In CeD patients detected by mass screening, the anti-DGP antibody titer was significantly higher among patients with a severe degree of enteropathy as compared to the group with mild enteropathy.

The Gluten-Free Diet for Celiac Disease: Critical Insights to Better Understand Clinical Outcomes

The gluten-free diet (GFD) remains a complex paradigm in managing celiac disease (CeD) in children and adults, and there are many reasons why GFD adherence should be strict to improve outcomes. However, this is a challenging task for patients, since they need to have access to quality healthcare resources that facilitate optimal GFD adherence. Understanding the strengths and weaknesses of the GFD, tackling coexisting nutritional deficiencies, and dealing with complex situations, such as seronegative CeD or non-responsive CeD, all require the involvement of a multidisciplinary team. The short- and long-term follow-up of CeD patients should preferably be performed by a combined Gastroenterology and Nutrition service with well-defined quality standards and the multidisciplinary involvement of physicians, nurses, dietitians, and psychologists. Nutritional advice and counseling by an experienced dietitian can reduce the costs associated with long-term follow-up of CeD patients. Likewise, psychological interventions may be essential in specific scenarios where implementing and sustaining a lifelong GFD can cause a significant psychological burden for patients. This manuscript aims to provide guidelines to improve clinical practice in the follow-up and monitoring of CeD patients and provide information on the nutritional risks of an ill-advised GFD. Clinicians, biochemists, food technologists, dietitians, and psychologists with a global view of the disease have been involved in its writing.

Separate Gut Plasma Cell Populations Produce Auto-Antibodies against Transglutaminase 2 and Transglutaminase 3 in Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is an inflammatory skin disorder often considered as an extra intestinal manifestation of celiac disease (CeD). Hallmarks of CeD and DH are auto-antibodies to transglutaminase 2 (TG2) and transglutaminase 3 (TG3), respectively. DH patients have auto-antibodies reactive with both transglutaminase enzymes. Here it is reported that in DH both gut plasma cells and serum auto-antibodies are specific for either TG2 or TG3 with no TG2-TG3 cross reactivity. By generating monoclonal antibodies from TG3-specific duodenal plasma cells of DH patients, three conformational epitope groups are defined. Both TG2-specific and TG3-specific gut plasma cells have few immunoglobulin (Ig) mutations, and the two transglutaminase-reactive populations show distinct selection of certain heavy and light chain V-genes. Mass spectrometry analysis of TG3-specific serum IgA corroborates preferential usage of IGHV2-5 in combination with IGKV4-1. Collectively, these results demonstrate parallel induction of anti-TG2 and anti-TG3 auto-antibody responses involving separate B-cell populations in DH patients.

Nutrient deficiencies in children with celiac disease during long term follow-up

BACKGROUND

Celiac disease (CD) is associated with malabsorption and consequential nutritional deficiencies. Patients with CD must follow a gluten-free diet (GFD), which is also associated with nutrient deficiencies. Despite the clinical significance, consensus is lacking on the pattern and frequency of nutrient deficiencies in CD and the usefulness of assessment during follow-up. The aim was to investigate the presence of micronutrient and protein deficiencies in pediatric patients with CD after starting a GFD and receiving standard clinical care, taking disease activity into account.

METHODS

This single center retrospective chart review aimed to map the occurrence of nutrient deficiencies, determined in serum samples derived during follow-up in an expertise center for pediatric CD. Serological micronutrient levels were determined during routine clinical visits up until 10 years in children with CD on a GFD.

RESULTS

The data of 130 children with CD was included. When pooling the measurements between 3 months and 10 years after GFD initiation, a deficiency in iron, ferritin, vitamin D, vitamin B12, folate and zinc was present in 33%, 21,9%, 21,1%, 2,4%, 4,3% and 8,1% of measurements, respectively. No hypocalcemia or vitamin B6 deficiency was found.

CONCLUSION

The prevalence of deficiency varies amongst nutrients in children following a GFD, a high prevalence of some nutrient deficiencies is noteworthy. This study highlights the necessity to structurally investigate the risk of developing nutrient deficiencies while following a GFD. Knowledge of the risk to develop deficiencies can contribute to achieving a more evidence based approach in the management and follow-up of CD in children.

Anti-tissue transglutaminase antibodies (TG2A) positivity and the risk of vitamin D deficiency among children - a cross-sectional study in the generation R cohort

BACKGROUND

Suboptimal vitamin D status is common in people with celiac disease (CeD), a disease that can be characterized by the presence of serum anti-tissue transglutaminase antibodies (TG2A) (i.e., TG2A positivity). To date, it remains unclear whether childhood TG2A positivity is associated with vitamin D status and how this potential association can be explained by other factors than malabsorption only, since vitamin D is mainly derived from exposure to sunlight. The aim of our study was therefore to assess whether childhood TG2A positivity is associated with vitamin D concentrations, and if so, to what extent this association can be explained by sociodemographic and lifestyle factors.

METHODS

This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort. We measured serum anti-tissue transglutaminase antibodies (TG2A) concentrations and serum 25-hydroxyvitamin D (25(OH)D) concentrations of 3994 children (median age of 5.9 years). Children with serum TG2A concentrations ≥ 7 U/mL were considered TG2A positive. To examine associations between TG2A positivity and 25(OH)D concentrations, we performed multivariable linear regression, adjusted for sociodemographic and lifestyle factors.

RESULTS

Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) was found in 17 out of 54 TG2A positive children (31.5%), as compared to 1182 out of 3940 TG2A negative children (30.0%). Furthermore, TG2A positivity was not associated with 25(OH)D concentrations (β -2.20; 95% CI -9.72;5.33 for TG2A positive vs. TG2A negative children), and this did not change after adjustment for confounders (β -1.73, 95% CI -8.31;4.85).

CONCLUSIONS

Our findings suggest there is no association between TG2A positivity and suboptimal vitamin D status in the general pediatric population. However, the overall prevalence of vitamin D deficiency in both populations was high, suggesting that screening for vitamin D deficiency among children, regardless of TG2A positivity, would be beneficial to ensure early dietary intervention if needed.

Correlation of Anti-Tissue Transglutaminase Antibodies With the Mucosal Changes and IgA Status of Children With Celiac Disease

OBJECTIVES

The objective of this study was to assess the association between serological markers and changes of the intestinal mucosa in children with celiac disease (CD).

METHODS

Clinical data from CD patients under 15 years old were collected from the participating centers in an on-line multicenter nationwide observational Spanish registry called REPAC-2 (2011-2017). Correlation between anti-tissue transglutaminase antibodies (t-TGA) levels and other variables, including mucosal damage and clinical findings (symptoms, age, and gender), was assessed.

RESULTS

A total of 2955 of 4838 patients had t-TGA and a small bowel biopsy (SBB) performed for CD diagnosis. A total of 1931 (66.2%) patients with normal IgA values had a Marsh 3b-c lesion and 1892 (64.9%) had t-TGA Immunoglobulin A (IgA) ≥ 10 times upper limit of normal (ULN). There is a statistically significant association between t-TGA IgA levels and the degree of mucosal damage ( P < 0.001), the higher the t-TGA IgA levels the more severe the mucosal damage. Those patients who reported symptoms had more severe mucosal damage ( P = 0.001). On the contrary, there was a negative association between age and changes of the intestinal mucosa ( P < 0.001). No association was found with gender. Regarding the IgA-deficient patients, 47.4% (18 cases) had t-TGA Immunoglobulin A (IgA) ≥ 10 times ULN and a Marsh 3b-c lesion was observed in 68.4% (26 patients). No statistical relation was found between t-TGA IgG levels and the changes of the intestinal mucosa, neither a relation with age, gender, or symptoms.

CONCLUSIONS

There is a positive correlation between t-TGA IgA levels and the severity of changes of the intestinal mucosa. Such correlation was not found in IgA-deficient patients who had positive t-TGA IgG serology. The results in this group of patients support the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition recommendations about the need of performing a SBB in IgA-deficient individuals despite high t-TGA IgG levels.

Defining the optimum strategy for identifying adults and children with coeliac disease: systematic review and economic modelling

BACKGROUND

Coeliac disease is an autoimmune disorder triggered by ingesting gluten. It affects approximately 1% of the UK population, but only one in three people is thought to have a diagnosis. Untreated coeliac disease may lead to malnutrition, anaemia, osteoporosis and lymphoma.

OBJECTIVES

The objectives were to define at-risk groups and determine the cost-effectiveness of active case-finding strategies in primary care.

DESIGN

(1) Systematic review of the accuracy of potential diagnostic indicators for coeliac disease. (2) Routine data analysis to develop prediction models for identification of people who may benefit from testing for coeliac disease. (3) Systematic review of the accuracy of diagnostic tests for coeliac disease. (4) Systematic review of the accuracy of genetic tests for coeliac disease (literature search conducted in April 2021). (5) Online survey to identify diagnostic thresholds for testing, starting treatment and referral for biopsy. (6) Economic modelling to identify the cost-effectiveness of different active case-finding strategies, informed by the findings from previous objectives.

DATA SOURCES

For the first systematic review, the following databases were searched from 1997 to April 2021: MEDLINE® (National Library of Medicine, Bethesda, MD, USA), Embase® (Elsevier, Amsterdam, the Netherlands), Cochrane Library, Web of Science™ (Clarivate™, Philadelphia, PA, USA), the World Health Organization International Clinical Trials Registry Platform ( WHO ICTRP ) and the National Institutes of Health Clinical Trials database. For the second systematic review, the following databases were searched from January 1990 to August 2020: MEDLINE, Embase, Cochrane Library, Web of Science, Kleijnen Systematic Reviews ( KSR ) Evidence, WHO ICTRP and the National Institutes of Health Clinical Trials database. For prediction model development, Clinical Practice Research Datalink GOLD, Clinical Practice Research Datalink Aurum and a subcohort of the Avon Longitudinal Study of Parents and Children were used; for estimates for the economic models, Clinical Practice Research Datalink Aurum was used.

REVIEW METHODS

For review 1, cohort and case-control studies reporting on a diagnostic indicator in a population with and a population without coeliac disease were eligible. For review 2, diagnostic cohort studies including patients presenting with coeliac disease symptoms who were tested with serological tests for coeliac disease and underwent a duodenal biopsy as reference standard were eligible. In both reviews, risk of bias was assessed using the quality assessment of diagnostic accuracy studies 2 tool. Bivariate random-effects meta-analyses were fitted, in which binomial likelihoods for the numbers of true positives and true negatives were assumed.

RESULTS

People with dermatitis herpetiformis, a family history of coeliac disease, migraine, anaemia, type 1 diabetes, osteoporosis or chronic liver disease are 1.5-2 times more likely than the general population to have coeliac disease; individual gastrointestinal symptoms were not useful for identifying coeliac disease. For children, women and men, prediction models included 24, 24 and 21 indicators of coeliac disease, respectively. The models showed good discrimination between patients with and patients without coeliac disease, but performed less well when externally validated. Serological tests were found to have good diagnostic accuracy for coeliac disease. Immunoglobulin A tissue transglutaminase had the highest sensitivity and endomysial antibody the highest specificity. There was little improvement when tests were used in combination. Survey respondents (n = 472) wanted to be 66% certain of the diagnosis from a blood test before starting a gluten-free diet if symptomatic, and 90% certain if asymptomatic. Cost-effectiveness analyses found that, among adults, and using serological testing alone, immunoglobulin A tissue transglutaminase was most cost-effective at a 1% pre-test probability (equivalent to population screening). Strategies using immunoglobulin A endomysial antibody plus human leucocyte antigen or human leucocyte antigen plus immunoglobulin A tissue transglutaminase with any pre-test probability had similar cost-effectiveness results, which were also similar to the cost-effectiveness results of immunoglobulin A tissue transglutaminase at a 1% pre-test probability. The most practical alternative for implementation within the NHS is likely to be a combination of human leucocyte antigen and immunoglobulin A tissue transglutaminase testing among those with a pre-test probability above 1.5%. Among children, the most cost-effective strategy was a 10% pre-test probability with human leucocyte antigen plus immunoglobulin A tissue transglutaminase, but there was uncertainty around the most cost-effective pre-test probability. There was substantial uncertainty in economic model results, which means that there would be great value in conducting further research.

LIMITATIONS

The interpretation of meta-analyses was limited by the substantial heterogeneity between the included studies, and most included studies were judged to be at high risk of bias. The main limitations of the prediction models were that we were restricted to diagnostic indicators that were recorded by general practitioners and that, because coeliac disease is underdiagnosed, it is also under-reported in health-care data. The cost-effectiveness model is a simplification of coeliac disease and modelled an average cohort rather than individuals. Evidence was weak on the probability of routine coeliac disease diagnosis, the accuracy of serological and genetic tests and the utility of a gluten-free diet.

CONCLUSIONS

Population screening with immunoglobulin A tissue transglutaminase (1% pre-test probability) and of immunoglobulin A endomysial antibody followed by human leucocyte antigen testing or human leucocyte antigen testing followed by immunoglobulin A tissue transglutaminase with any pre-test probability appear to have similar cost-effectiveness results. As decisions to implement population screening cannot be made based on our economic analysis alone, and given the practical challenges of identifying patients with higher pre-test probabilities, we recommend that human leucocyte antigen combined with immunoglobulin A tissue transglutaminase testing should be considered for adults with at least a 1.5% pre-test probability of coeliac disease, equivalent to having at least one predictor. A more targeted strategy of 10% pre-test probability is recommended for children (e.g. children with anaemia).

FUTURE WORK

Future work should consider whether or not population-based screening for coeliac disease could meet the UK National Screening Committee criteria and whether or not it necessitates a long-term randomised controlled trial of screening strategies. Large prospective cohort studies in which all participants receive accurate tests for coeliac disease are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019115506 and CRD42020170766.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 44. See the NIHR Journals Library website for further project information.

Pediatric Celiac Disease and Selective IgA Deficiency: Unexpected Sequence of Events

PURPOSE

Selective IgA deficiency (IgAD) is the most common primary immunodeficiency, frequently leading to only minor clinical complaints. IgAD may be associated with autoimmune diseases such as celiac disease (CeD). Although IgAD is thought to precede CeD and autoimmunity, the association between the two conditions has not been clarified.

METHODS

Routine techniques were used to measure serum IgA and celiac diagnostic markers as transglutaminase 2 IgA (TG2-IgA) and deamidated gliadin IgG and for immunohistochemistry for IgG, IgM, and IgA.

RESULTS

We report two childhood cases of complete IgA deficiency that evolved after the diagnosis of CeD and the start of a gluten-free diet. Histology showed persistence of IgA in the intestinal mucosa.

CONCLUSION

Both children with CeD showed IgA deficiency that unexpectedly developed after the initiation of a gluten-free diet. This supports IgA deficiency as a process that develops gradually and occurs due to specific defects in immunoregulation.

Usefulness of deamidated gliadin peptide antibodies in diagnosing coeliac disease in children younger than 3 years old

AIM

The standard serological test to screen for coeliac disease (CD) is tissue transglutaminase (tTG) but some experts recommend including deamidated gliadin peptide (DGP) antibodies for children younger than 3 years old. This study evaluated the utility of DGP-immunoglobulin A (IgA) and DGP-immunoglobulin G (IgG) serologies when screening children younger than 3 years old for CD.

METHODS

A retrospective chart review was conducted including children 3 years old and under, who had DGP and/or tTG serologies along with duodenal biopsies during their initial diagnostic evaluation. Serology results were compared to the gold-standard histopathology by χ² to determine the significance of including DGP-IgG/IgA serologies when screening for CD in this age group.

RESULTS

We identified 478 patients, 52 who were younger than 3 years old, 43 of whom met inclusion criteria. The positive predictive value (PPV) of the DGP-IgA test was 91.7% whereas, DGP-IgG was 77.8%. When DGP serology was examined in conjunction with tTG-IgA, the PPV with DGP-IgA was 90.9% and with DGP-IgG was 87.5%.

CONCLUSIONS

In isolation, DGP-IgA provides a high PPV and specificity for CD in children younger than 3 years old, whereas DGP-IgG had a much lower PPV in this age group. When used alone or in conjunction with tTG-IgA, the DGP-IgA test results in a high PPV of 91.7 and 90.9%, respectively. Based on our study, we recommend obtaining both the DGP-IgA and the tTG-IgA serology when screening infants and children younger than 3 years old for coeliac disease.

Evaluation of Celiac Disease by Minimally Invasive Biomarkers in a Spanish Pediatric Population

Background: The diagnosis of celiac disease (CD) has been substantially improved with the availability of highly sensitive CD-specific IgA-TG2, Ig-GDP, and IgA-EMA. The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) published (2012) and updated (2020) diagnostic criteria for CD in order to simplify CD diagnosis and to avoid biopsies in selected patients. Methods: A prospective study including 5641 pediatric patients (0–16 years old) from January 2012 to January 2019 was performed. CD diagnosis was made according to the ESPGHAN algorithm. The objective of this study was to evaluate the utility of biomarkers and the relationship between TGA-IgA and EMA titers. Results: CD diagnoses were confirmed in 113 patients, 110 were IgA-TG2-positive and 3 (2.7%) had IgA deficiency. The diagnosis was made by serologic tests in 95 (84.1%) patients. Only 18 (15.9%) patients underwent intestinal biopsy. We obtained 100% concordance between IgA-EMA and positive results for IgA-TG2 ≥ 10 ULN with IgA-EMA antibody titer ≥ 1:80. Conclusions: This study provides evidence of a positive correlation between IgA-TG2 antibody serum levels and IgA-EMA. The diagnosis could be guaranteed with strict application of IgA-TG2 values ≥ 10 ULN (confirmed by subsequent testing) plus the serological response to the gluten-free diet (GFD).

Real-life Performance of Multiplex Celiac Antibody Test in the Diagnosis of Pediatric Celiac Disease

OBJECTIVE

Tissue-transglutaminase antibodies (TGA) may be used to diagnose celiac disease (CD) without biopsy in selected cases. We aimed to investigate real-life performance of a CD serology automated analyzer (Bioplex2200), and to explore the correlation between TGA levels and intestinal biopsies in children.

METHODS

A retrospective review was performed in 2 pediatric gastroenterological centers, between November 1, 2018 and April 1, 2020 and included patients with both TGA serology testing and duodenal biopsies. Retrieved data included patients' demographics, medical background, TGA levels, and biopsy results.

RESULTS

Overall, 538 children were evaluated, 256 with positive TGA (68.4% girls, median age 6.4 years), and 282 with negative TGA (53.9% girls, median age 13.4 years). Among patients with positive TGA, intestinal biopsies confirmed CD in 219 (85.5%). Overall, positive serology with normal histology was found in 14.5% of the cohort, with 52%; 21.6%; 21.1%; and 4.2% in TGA ranges of 1 to 3 times upper limit of normal (ULN); 3 to 5 ULN; 5 to 10 ULN; and above 10 times ULN, respectively, P < 0.001. Area under the receiver-operating characteristic curve (AUC) was 0.963 (95% CI 0.947-0.980). Among patients with positive TGA, 216 (84.4%) had positive anti-endomysial antibodies. In this sub-group, the overall diagnostic performance was inferior, with AUC of 0.737 (95% CI 0.834-0.839).

CONCLUSIONS

The Multiplex TGA assay had a very high diagnostic accuracy in real-life. Among patients with positive TGA, adding EMA did not improve the diagnostic performance of the test. False-positive rates differed between different ranges of TGA and were low with TGA above 10 times ULN.

Systematic review with meta-analysis: the accuracy of serological tests to support the diagnosis of coeliac disease

BACKGROUND

There is growing support for a biopsy avoidant approach to diagnose coeliac disease in both children and adults, using a serological diagnosis instead.

AIMS

To assess the diagnostic accuracy of serological tests for coeliac disease in adults and children.

METHODS

Seven electronic databases were searched between January 1990 and August 2020. Eligible diagnostic studies evaluated the accuracy of serological tests for coeliac disease against duodenal biopsy. Risk of bias assessment was performed using QUADAS-2. Bivariate random-effects meta-analyses were used to estimate serology sensitivity and specificity at the most commonly reported thresholds.

RESULTS

113 studies (n = 28,338) were included, all in secondary care populations. A subset of studies were included in meta-analyses due to variations in diagnostic thresholds. Summary sensitivity and specificity of immunoglobulin A (IgA) anti-tissue transglutaminase were 90.7% (95% confidence interval: 87.3%, 93.2%) and 87.4% (84.4%, 90.0%) in adults (5 studies) and 97.7% (91.0%, 99.4%) and 70.2% (39.3%, 89.6%) in children (6 studies); and of IgA endomysial antibodies were 88.0% (75.2%, 94.7%) and 99.6% (92.3%, 100%) in adults (5 studies) and 94.5% (88.9%, 97.3%) and 93.8% (85.2%, 97.5%) in children (5 studies).

CONCLUSIONS

Anti-tissue transglutaminase sensitivity appears to be sufficient to rule out coeliac disease in children. The high specificity of endomysial antibody in adults supports its use to rule in coeliac disease. This evidence underpins the current development of clinical guidelines for a serological diagnosis of coeliac disease. Studies in primary care are needed to evaluate serological testing strategies in this setting.

Pediatric Celiac Disease: A Review of Diagnostic Testing and Guideline Recommendations

BACKGROUND

The history of how our knowledge of celiac disease (CD) evolved points to its importance in children. Although it is now appreciated that CD can present at any age, it was originally thought to occur only in children and, if untreated, led to serious consequences.

CONTENT

This review includes a brief discussion of small bowel physiology and the pathogenesis of CD. Next, the varied clinical presentations of CD in children are reviewed, including both gastrointestinal and nongastrointestinal manifestations and how these contribute to the difficulty in diagnosis. In addition, information on specific conditions that are associated with CD is presented, particularly as it applies to diagnostic testing of apparently asymptomatic children. The review will also focus on diagnostic testing available for CD and their general performance characteristics. The review will end with a comparison between published guidelines from the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition for diagnosis of pediatric CD. In particular, this review will focus on differences in the incorporation of serologic and genetic testing, and the role of biopsies in the pediatric population.

SUMMARY

It is important for laboratorians to understand the evolution of diagnostic guidelines for pediatric CD and how serologic and genetic testing are being applied to and interpreted in this particular patient group.

Incidence of celiac disease autoimmunity and associations with maternal tuberculosis and pediatric Helicobacter pylori infections in 4-year-old Ethiopian children followed up in an HLA genotyped birth cohort

BACKGROUND

The prevalence of celiac disease in the general population is mainly unknown in most of sub-Saharan African countries. The aim of this study was to determine the incidence of celiac disease autoimmunity (CDA) and its associations with latent Mycobacterium tuberculosis (LMTB) and Helicobacter pylori (HP) infections in Ethiopian children aged 4 years in an HLA genotyped cohort study.

METHODS

Of 1,389 recruited children between 2018 and 2022, 1,046 (75.3%) had been screened at least twice for celiac disease between the ages of 2 and 4 years using a tissue transglutaminase autoantibody (tTGA) ELISA kit. Tissue TGA-positive children were retested using radio-binding assays. CDA was defined as persistent-confirmed tTGA positivity in two consecutive samples. Associations of CDA with LMTB and HP were tested in a subpopulation of 752 children born to mothers who were previously tested for LMTB with IFN-γ and anti-HP antibodies in samples collected at a mean age of 49.3 ± 5.3 months.

RESULTS

Screening detected 38 out of 1,046 (3.6%) IgA-tTGA-positive children. Ten (1.0%) were confirmed to be positive, with six (0.6%) children diagnosed with CDA. The incidence of CDA at 4 years of age was 1.2 per 1,000 person-years. LMTB was found in 4 of 6 (66.7%) mothers with CDA children compared with 340 of 734 (46.3%) mothers of children without CDA (p = 0.424), while HP was found in 3 of 6 (50.0%) CDA children compared with 315 of 746 (42.2%) children without CDA (p = 0.702).

CONCLUSION

The incidence of CDA in Ethiopian children is lower than the pooled global incidence. Neither LMTB nor HP infections are associated with CD in Ethiopian children.

Association between celiac disease and vitiligo: A review of the literature

Celiac disease (CD) is an autoimmune intestinal disease caused by the intake of gluten-containing cereals and their products by individuals with genetic susceptibility genes. Vitiligo is a commonly acquired depigmentation of the skin; its clinical manifestation are skin patches caused by localized or generalized melanin deficiency. Both diseases have similar global incidence rates (approximately 1%) and are associated to similar diseases, including autoimmune bullous disease, inflammatory bowel disease, autoimmune thyroiditis, autoimmune gastritis, and type 1 diabetes. The relationship between CD and vitiligo has been reported in several studies, but their conclusions are inconsistent. Further, it has also been reported that a gluten-free diet (GFD) can improve the symptoms of immune-related skin diseases such as vitiligo. In this mini-review, we summarize and review the literature on the relationship between CD and vitiligo, assess the therapeutic significance of GFD for patients with vitiligo, and explore their possible physiopathology. We are hopeful that the information summarized here will assist physicians who treat patients with CD or vitiligo, thereby improving the prognosis.

Wheat Breeding, Fertilizers, and Pesticides: Do They Contribute to the Increasing Immunogenic Properties of Modern Wheat?

Celiac disease (CD) is a small intestinal inflammatory condition where consumption of gluten induces a T-cell mediated immune response that damages the intestinal mucosa in susceptible individuals. CD affects at least 1% of the world’s population. The increasing prevalence of CD has been reported over the last few decades. However, the reason for this increase is not known so far. Certain factors such as increase in awareness and the development of advanced and highly sensitive diagnostic screening markers are considered significant factors for this increase. Wheat breeding strategies, fertilizers, and pesticides, particularly herbicides, are also thought to have a role in the increasing prevalence. However, less is known about this issue. In this review, we investigated the role of these agronomic practices in depth. Our literature-based results showed that wheat breeding, use of nitrogen-based fertilizers, and herbicides cannot be solely responsible for the increase in celiac prevalence. However, applying nitrogen fertilizers is associated with an increase in gluten in wheat, which increases the risk of developing celiac-specific symptoms in gluten-sensitive individuals. Additionally, clustered regularly interspaced short palindromic repeats (CRISPR) techniques can edit multiple gliadin genes, resulting in a low-immunogenic wheat variety that is safe for such individuals.

Celiac Disease in Children

Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. In patients with suspected celiac disease, measurement of serum IgA antibodies to tissue transglutaminase-2 has a high sensitivity and specificity and is the first screening test that should be ordered. The diagnosis of celiac disease is based on the presence of mucosal damage in small intestinal biopsies in patients having circulating celiac disease-specific antibodies. Celiac disease management includes lifelong adherence to a gluten-free diet and continuous long-term follow-up.

Clinical Presentation of Celiac Disease and Diagnosis Accuracy in a Single-Center European Pediatric Cohort over 10 Years

(1) Background: Changes in the clinical presentation of celiac disease (CD) in children have been reported. The guidelines of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) allow esophagogastroduodenoscopy (EGD) with biopsies to be avoided under specific circumstances. We aimed to assess the clinical picture of pediatric CD patients at diagnosis and to validate ESPGHAN non-biopsy criteria. (2) Methods: Patients with suspected CD or undergoing screening from 2004 to 2014 at the University Hospital in Modena, Italy were enrolled. The accuracy of ESPGHAN non-biopsy criteria and modified versions were assessed. (3) Results: In total, 410 patients were enrolled, of whom 403 were considered for analysis. Of the patients considered, 45 were asymptomatic and diagnosed with CD (11.2%) while 358 patients (88.2%) were symptomatic, of whom 295 were diagnosed with CD. Among symptomatic CD patients, 57 (19.3%) had gastrointestinal symptoms, 98 (33%) had atypical symptoms and 140 (47.4%) had both. No difference was found for the presence of gastrointestinal symptoms at different ages. The non-biopsy ESPGHAN criteria yielded an accuracy of 59.4% with a positive predictive value (PPV) of 100%; 173 out of 308 EGD (56.2%) could have been avoided. The modified 7× and 5× upper limit of normal cut-offs for IgA anti tissue-transglutaminase reached 60.7% and 64.3% of EGD avoided, respectively. (4) Conclusions: Over 10 years, late age at diagnosis and increased rates of atypical CD presentation were found. ESPGHAN non-biopsy criteria are accurate for CD diagnosis and allow half of unneeded EGD to be avoided. Modified versions allowed sparing a greater number of EGD.

Diagnosing coeliac disease: A literature review

Coeliac disease (CD) is an autoimmune gastroenteropathy triggered by gliadin and gliadin-tissue transglutaminase (tTG) complexes. CD is one of the few autoimmune diseases with an accurate, non-invasive serological test. Anti-endomysial, anti-tTG and anti-deaminated gliadin peptides (DGP) antibodies are currently used for serological tests with tTG ELISAs being the superior test. Duodenal biopsy, although invasive, is the gold standard for CD diagnosis. HLA genotyping and flow cytometry can also be used as supplementary tests. The incidence of CD is rising globally although the reasons for this remain unclear. In addition, the true incidence of coeliac disease in African populations remains unknown although recent work suggests that South African populations express the alleles associated with this disease. This review examines the pathogenesis and diagnosis of coeliac disease and considers novel and innovative biomarkers in its diagnosis specifically in an African population.

Association of Celiac Disease With Pembrolizumab

Immune checkpoint inhibitors (ICIs) in the recent times have transformed the landscape of the management of many solid tumors. Unfortunately, many immune-related adverse effects are associated with ICIs, which lead to a negative outcome in cancer treatment. We present a case of a 63-year-old female with metastatic adenocarcinoma of unknown origin, who developed celiac disease during the course of treatment with pembrolizumab. Association of celiac disease with this form of immunotherapy has never been documented before.

Celiac disease: Understandings in diagnostic, nutritional, and medicinal aspects

Celiac disease (CD) is characterized by clinical polymorphism, with classic, asymptomatic or oligosymptomatic, and extra-intestinal forms, which may lead to diagnostic delay and exposure to serious complications. CD is a multidisciplinary health concern involving general medicine, pediatric, and adult gastroenterology, among other disciplines. Immunology and pathology laboratories have a fundamental role in diagnosing and monitoring CD. The diagnosis consists of serological testing based on IgA anti-transglutaminase (TG2) antibodies combined with IgA quantification to rule out IgA deficiency, a potential misleading factor of CD diagnosis. Positive TG2 serology should be corroborated by anti-endomysium antibody testing before considering an intestinal biopsy. Owing to multiple differential diagnoses, celiac disease cannot be confirmed based on serological positivity alone, nor on isolated villous atrophy. In children with classical signs or even when asymptomatic, with high levels of CD-linked markers and positive HLA DQ2 and/or DQ8 molecules, the current trend is to confirm the diagnosis on basis of the non-systematic use of the biopsy, which remains obligatory in adults. The main challenge in managing CD is the implementation and compliance with a gluten-free diet (GFD). This explains the key role of the dietitian and the active participation of patients and their families throughout the disease-management process. The presence of the gluten in several forms of medicine requires the sensitization of physicians when prescribing, and particularly when dispensing gluten-containing formulations by pharmacists. This underlines the importance of the contribution of the pharmacist in the care of patients with CD within the framework of close collaboration with physicians and nutritionists.

Anti-tissue transglutaminase titers are associated with endoscopic findings and severity of mucosal damage in children with celiac disease

We aimed to assess the correlation between clinical findings, serology, endoscopic findings, and histology in children diagnosed with celiac disease. Medical records of children diagnosed with celiac disease (2010-2017) at the Schneider Children's Hospital were reviewed retrospectively. Correlation between serologic measures anti-tissue transglutaminase (anti-tTG)/anti-endomysial antibodies (EMA) and other variables including mucosal damage, endoscopic findings (scalloping of duodenal folds), and clinical findings (abdominal pain, diarrhea, and anemia) was assessed. Out of 686 patients, 432 patients fulfilled the inclusion criteria (females 262, 61%; median age 6.0; interquartile range 4.0-9.0 years). Distribution of histopathology findings was Marsh IIIa 4%, Marsh IIIb 25%, and Marsh IIIc 71% with 313 (73%) patients having anti-tTG titer of ≥ 10 times the upper normal limit. Anti-tTG titer (but not EMA) positively correlated with Marsh grades, scalloping of duodenal folds and anemia. Anti-tTG ≥ 10 times the upper normal limit was associated with Marsh IIIc changes with an adjusted odds ratio of 4.5 (95% confidence interval, 1.7-12.1). Diarrhea and abdominal pain were not associated with serologic, endoscopic, or histologic markers of disease severity.Conclusion: Anti-tTG titers correlated with macroscopic and microscopic mucosal damage, with anemia but not with diarrhea or abdominal pain in children with celiac disease. What is Known: • Tissue transglutaminase antibody titers were shown to correlate with the degree of mucosal damage in patients with celiac disease. • There is a limited evidence regarding the association of celiac serologies with endoscopic and clinical measures. What is New: • Higher titers of tissue transglutaminase but not anti-endomysial antibodies are associated with more severe histologic and endoscopic damage and with the presence of anemia. • Symptoms do not correlate with the severity of mucosal damage such as scalloping of duodenal folds and histopathology changes according to Marsh classification or with serologic markers.

Efficient implementation of the 'non-biopsy approach' for the diagnosis of childhood celiac disease in the Netherlands: a national prospective evaluation 2010-2013

The aim of this study was (1) to prospectively evaluate the nationwide implementation of the ESPGHAN-guidelines for the diagnosis of celiac disease (CD), (2) to investigate the incidence and clinical presentation of diagnosed childhood CD (0-14 years) in the Netherlands, and (3) to compare the findings with national survey data from 1975 to 1990 and 1993 to 2000 using the same approach. From 2010 to 2013, all practicing paediatricians were invited to report new celiac diagnoses to the Dutch Pediatric Surveillance Unit. Data were collected via questionnaires. A total of 1107 children with newly diagnosed CD were reported (mean age, 5.8 years; range, 10 months-14.9 years; 60.5% female). After the introduction of the non-biopsy approach in 2012, 75% of the diagnoses were made according to the guideline with a significant decrease of 46.3% in biopsies. The use of EMA and HLA-typing significantly increased with 25.8% and 62.1%, respectively. The overall incidence rate of childhood CD was 8.8-fold higher than in 1975-1990 and 2.0-fold higher than in 1993-2000. During the study period, the prevalence of diagnosed CD was 0.14%, far below 0.7% of CD identified via screening in the general Dutch paediatric population. Clinical presentation has shifted towards less severe and extra-intestinal symptoms.Conclusion: ESPGHAN guidelines for CD diagnosis in children were effectively and rapidly implemented in the Netherlands. Incidence of diagnosed CD among children is still significantly rising with a continuous changing clinical presentation. Despite the increasing incidence of diagnoses, significant underdiagnosis still remains. What is Known: • Since 2000 the incidence of diagnosed childhood CD in the Netherlands has shown a steady rise. • The rise in incidence has been accompanied by a changing clinical presentation at diagnosis. What is New: • The ESPGHAN guidelines 2012 for CD diagnosis were effectively and rapidly implemented in the Netherlands. • The incidence of diagnosed childhood CD in the Netherlands has continued to rise significantly during the reported period.

ESPGHAN 'biopsy-sparing' guidelines for celiac disease in children with low antitransglutaminase during COVID-19

OBJECTIVES

Recent guidelines for celiac disease have allowed a biopsy-free approach in endomysial antibodies (EMAs) positive children with high antitransglutaminase (TGA-IgA) titer [>10 time upper limit of normal (ULN)]. Esophagogastroduodenoscopy is still necessary for diagnosis in children with lower title. Because elective pediatric endoscopy has been substantially shouted down during coronavirus disease (COVID-19) pandemic, many children remained undiagnosed - and therefore untreated - for a long time. We aimed to analyze the feasibility and accuracy of a biopsy-free approach in suspected celiac disease children with TGA-IgA values <10 ULN to facilitate the diagnostic process by avoiding endoscopy.

METHODS

In this study cohort, we retrospectively analyzed all biopsy-confirmed diagnosis of celiac disease in our center (between 2014 and 2019). The positive predictive value (PPV) of TGA-IgA titers between 5 and 10 ULN and positive EMA in diagnosing celiac disease were determined. Mucosal atrophy and resolution of symptoms after gluten-free diet (GFD) were considered to confirm initial diagnosis.

RESULTS

Of 430 celiac disease patients (F: 274; mean age 7.54 years) diagnosed by endoscopy, 84 (F: 46; mean age 8 years) with TGA-IgA between 5 and 10 ULN and positive EMA were identified. The PPV of TGA-IgA between 5 and 10 ULN and positive EMA was 0.93 (95% confidence interval 0.90-0.96). All these children had a symptom resolution and antibodies normalization after GFD.

CONCLUSION

During the COVID-19 outbreak, a temporarily reduction of the TGA-IgA threshold for biopsy-sparing approach seems feasible in EMA positive children with TGA-IgA between 5 and 10 ULN.

Coeliac disease in childhood: An overview

Coeliac disease (CD) is an autoimmune condition, characterised by an immunological response to ingestion of gluten in genetically susceptible individuals, affecting about 1% of the population in many regions of the world. Increased knowledge regarding the pathogenesis, improved diagnostic techniques and increased awareness over the years have transformed our understanding of CD such that it is no longer a rare enteropathy, but rather a common multisystem disorder which affects individuals of all ages and results in wide-ranging clinical manifestations. Only a minority of children now present with the classical clinical picture of profound diarrhoea and malnutrition. An increasing number of children with CD present with either mild, non-specific gastrointestinal symptoms or extra-intestinal manifestations or even be asymptomatic, as in many screening-detected children. Knowledge about these diverse manifestations and a high index of suspicion is essential so that appropriate investigations can be undertaken, diagnosis established and treatment initiated. Although traditionally small bowel biopsy is considered essential for the diagnosis, recent guidelines from various professional bodies have paved the way to a biopsy-free diagnosis in a subset of symptomatic children. Life long, strict gluten-free diet still remains the only effective treatment at present, although several novel therapeutic agents are in various phases of clinical trials.

Value of biopsy in a cohort of children with high-titer celiac serologies: observation of dynamic policy differences between Europe and North America

Background

Healthcare systems implement change at different rates because of differences in incentives, organizational processes, key influencers, and management styles. A comparable set of forces may play out at the national and international levels as demonstrated in significant differences in the diagnostic management of pediatric Celiac Disease (CD) between European and North American practitioners.

Methods

We use retrospective clinical cohorts of 27,868 serum tissue transglutaminase (tTG) immunoglobulin A levels and 7907 upper gastrointestinal endoscopy pathology reports to create a dataset of 793 pathology reports with matching tTG results between July 1 of 2014 and July 1 of 2018. We use this dataset to characterize histopathological findings in the duodenum, stomach and esophagus of patients as a function of serum tTG levels. In addition, we use the dataset to estimate the local and national cost of endoscopies performed in patients with serum tTG levels greater than 10 times the upper limit of normal.

Results

Using evidence from a US tertiary care center, we show that in the cohort of pediatric patients with high pre-test probability of CD as determined by serum tTG levels, biopsy provides no additional diagnostic value for CD, and that it counter-intuitively introduces diagnostic uncertainty in a number of patients. We estimate that using the European diagnostic algorithms could avoid between 4891 and 7738 pediatric endoscopies per year in the US for evaluation of CD.

Conclusions

This study considers the North American and European management guidelines for the diagnosis of pediatric CD and highlights the slow adoption in North America of evidence-based algorithms developed and applied in Europe for triage of endoscopy and biopsy. We suggest that system dynamics influences that help maintain the status quo in North America include a variety of social and economic factors in addition to medical evidence. This work contributes to the growing body of evidence that the dynamics that largely favor maintaining status quo management policies in a variety of systems extend to clinical medicine and potentially influence clinical decisions at the level of individual patients and the population.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12913-020-05815-0.

Raising the Cut-Off Level of Anti-Tissue Transglutaminase Antibodies to Detect Celiac Disease Reduces the Number of Small Bowel Biopsies in Children with Type 1 Diabetes: A Retrospective Study

OBJECTIVE

To study the optimal cut-off value for anti-tissue transglutaminase type 2 IgA antibodies (TG2A) in serum to select for diagnostic small bowel biopsies for celiac disease in children with type 1 diabetes mellitus.

STUDY DESIGN

Children with type 1 diabetes mellitus with elevated TG2A titers and duodenal biopsies performed during the course of their diabetes treatment were included. Anti-endomysial antibodies were recorded if present. The optimal TG2A cut-off value, expressed as the ratio between obtained value and upper limit of normal (ULN), was determined using receiver operating characteristic curve analysis and compared with the cut-off value used in the European Society for Pediatric Gastroenterology, Hepatology and Nutrition guidelines in terms of sensitivity, specificity, positive and negative predictive value.

RESULTS

We included 63 children. The optimal cut-off value for performing biopsies is demonstrated to be 11 times the ULN. Raising the cut-off value from 3 times the ULN to 11 times the ULN changed sensitivity from 96% to 87% and increased specificity from 36% to 73%, increased the positive predictive value from 88% to 94% and lowered negative predictive value from 67% to 53%. The percentage of normal histology was decreased from 12% to 6%.

CONCLUSIONS

Increasing the TG2A cut-off value for performing duodenal biopsies in children with type 1 diabetes mellitus and suspected celiac disease leads to a substantial reduction of unnecessary biopsies. We advocate to adapt the European Society for Pediatric Gastroenterology, Hepatology and Nutrition 2012 guidelines for this group of children, including monitoring patients with TG2A levels of less than 11 times the ULN over time.

Williams-Beuren Syndrome and celiac disease: A real association?

Celiac disease (CD) screening in patients with Williams-Beuren Syndrome (WBS) is suggested, although data described in literature are discordant regarding CD prevalence in WBS. We retrospectively collected data from 101 WBS Italian patients [mean age: 13.5 years], to clarify the CD prevalence in a large cohort. All patients underwent a CD biochemical screening: IgA and anti-transglutaminase reflex antibodies (tTGA). CD-specific HLA typing was available for 42 patients. Small intestinal biopsy was performed in patients according to ESPGHAN guidelines. In 7 WBS patients an overt celiac disease was diagnosed. In 3 patients CD was confirmed by symptoms, HLA-DQ heterodimers and CD specific antibodies title, whereas in 4 patients, it was confirmed by a small intestinal biopsy. CD prevalence in our cohort is 6.9% (7/101). In 42/101 patients the CD-specific HLA typing was available, detecting 29/42 (69%) patients genetically predisposed to CD. The CD prevalence and CD-specific HLA prevalence are both higher than in the general population (p < 0.001; p < 0.001). Our cohort is the most numerous described confirming that the CD risk in WBS patients is significantly greater than in general population. Moreover, our HLA typing results, as well as scientific literature, suggest that the higher CD prevalence in WBS patients might not be intrinsically related to the genetic disease itself but with the higher HLA prevalence. However, HLA typing should be performed in bigger WBS cohorts to confirm this hypothesis. Our data confirms that HLA typing is mandatory in WBS patients and that CD screening should be performed only if genetically predisposed.

Automated Analyzers Are Suited for Diagnosing Celiac Disease Without a Biopsy

OBJECTIVES

The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) 2012 guidelines, enabled for the first time, a nonbiopsy approach in the diagnosis of celiac disease (CD). We aimed to prospectively assess 4 tissue-transglutaminase (tTg) IgA assays of 4 random-access analyzers and examine their accuracy in diagnosing CD without a biopsy.

METHODS

We enrolled 186 consecutive children referred to upper endoscopy and intestinal biopsy. One group included 109 patients with positive tTg that was referred for suspected CD. Another group included 77 patients with negative tTg referred because of other indications. All participants had a blood sample taken at the time of endoscopy. Samples were tested with 4 tTg IgA assays on automated analyzers and 1 Elisa kit. All intestinal biopsies were evaluated by a local pathologist, a central pathologist, and a CD expert blinded to each other. CD was diagnosed when full agreement was reached. Analytical performance of the assays included precision with controls and samples, lot to lot variation, and carryover.

RESULTS

In our cohort, all tested tTg IgA-automated assays showed sensitivities above 98% and specificities above 99%. ROC analysis demonstrated AUC (area under the curve) >0.99 for all 4 analyzers. The positive-predictive values (PPV) were all >0.99 and negative-predictive values (NPV) were >0.97. The Elisa kit had sensitivity of 95%, specificity of 96%, AUC of 0.96, PPV of 0.98 and NPV of 0.93.

CONCLUSION

CD can be accurately diagnosed without biopsy based on tTg IgA levels at least 10 times the ULN using the 4 high-volume random-access analyzers used in our study.

Intestinal Anti-tissue Transglutaminase2 Autoantibodies: Pathogenic and Clinical Implications for Celiac Disease

Celiac disease (CD) is a systemic disease that primarily affects the small intestine. The presence of anti-tissue transglutaminase 2 (anti-TG2) antibodies in the serum, as well as the presence of autoimmune phenomena, account for the inclusion of CD among autoimmune diseases. Anti-TG2 autoantibodies are produced at intestinal level, where they are deposited even before they appear in circulation. The pathogenic events that lead to their production are still not completely defined, but a central role seems to be played by gliadin-specific T cells. Interestingly, limited somatic mutations have been observed in VH and VL genes in TG2-specific plasma cells, another important aspect being the biased use of a heavy chain encoded by the VH5 gene. Conflicting data have been produced over the years on the effect of anti-TG2 antibodies on TG2 function. Although the presence of anti-TG2 antibodies in serum is considered a hallmark of CD and relevant from a clinical viewpoint, the role of these autoantibodies in the development of the celiac lesion remains to be defined. In the years, different technical approaches have been implemented to detect and measure intestinal CD-associated autoantibody production. Two aspects can make intestinal anti-TG2 antibodies relevant: from a clinical viewpoint: the first is their proposed ability in potential coeliac patients to predict the development of a full-blown enteropathy; the second is their possible role in revealing a condition of reactivity to gluten in patients with no circulating CD-associated autoantibodies. In fact, the detection of CD-specific autoantibodies production in the intestine, in the absence of serum positivity for the same antibodies, could be suggestive of a very early condition of gluten reactivity; alternatively, it could be not specific for CD and merely attributable to intestinal inflammation. In conclusion, the role of mucosal anti-TG2 antibodies in pathogenesis of CD is unknown. Their presence, the modalities of their production, their gluten dependence render them a unique model to study autoimmunity.

Interplay between Type 2 Transglutaminase (TG2), Gliadin Peptide 31-43 and Anti-TG2 Antibodies in Celiac Disease

Celiac disease (CD) is a common intestinal inflammatory disease involving both a genetic background and environmental triggers. The ingestion of gluten, a proteic component of several cereals, represents the main hexogen factor implied in CD onset that involves concomitant innate and adaptive immune responses to gluten. Immunogenicity of some gluten sequences are strongly enhanced as the consequence of the deamidation of specific glutamine residues by type 2 transglutaminase (TG2), a ubiquitous enzyme whose expression is up-regulated in the intestine of CD patients. A short gluten sequence resistant to intestinal proteases, the α-gliadin peptide 31-43, seems to modulate TG2 function in the gut; on the other hand, the enzyme can affect the biological activity of this peptide. In addition, an intense auto-immune response towards TG2 is a hallmark of CD. Auto-antibodies exert a range of biological effects on several cells, effects that in part overlap with those induced by peptide 31-43. In this review, we delineate a scenario in which TG2, anti-TG2 antibodies and peptide 31-43 closely relate to each other, thus synergistically participating in CD starting and progression.

European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for Diagnosing Coeliac Disease 2020

OBJECTIVES

The ESPGHAN 2012 coeliac disease (CD) diagnostic guidelines aimed to guide physicians in accurately diagnosing CD and permit omission of duodenal biopsies in selected cases. Here, an updated and expanded evidence-based guideline is presented.

METHODS

Literature databases and other sources of information were searched for studies that could inform on 10 formulated questions on symptoms, serology, HLA genetics, and histopathology. Eligible articles were assessed using QUADAS2. GRADE provided a basis for statements and recommendations.

RESULTS

Various symptoms are suggested for case finding, with limited contribution to diagnostic accuracy. If CD is suspected, measurement of total serum IgA and IgA-antibodies against transglutaminase 2 (TGA-IgA) is superior to other combinations. We recommend against deamidated gliadin peptide antibodies (DGP-IgG/IgA) for initial testing. Only if total IgA is low/undetectable, an IgG-based test is indicated. Patients with positive results should be referred to a paediatric gastroenterologist/specialist. If TGA-IgA is ≥10 times the upper limit of normal (10× ULN) and the family agrees, the no-biopsy diagnosis may be applied, provided endomysial antibodies (EMA-IgA) will test positive in a second blood sample. HLA DQ2-/DQ8 determination and symptoms are not obligatory criteria. In children with positive TGA-IgA <10× ULN at least 4 biopsies from the distal duodenum and at least 1 from the bulb should be taken. Discordant results between TGA-IgA and histopathology may require re-evaluation of biopsies. Patients with no/mild histological changes (Marsh 0/I) but confirmed autoimmunity (TGA-IgA/EMA-IgA+) should be followed closely.

CONCLUSIONS

CD diagnosis can be accurately established with or without duodenal biopsies if given recommendations are followed.

Efficacy Study of Anti-Endomysium Antibodies for Celiac Disease Diagnosis: A Retrospective Study in a Spanish Pediatric Population

The aim of this study was to assess the efficacy of anti-endomysium antibodies (EMA) as a serological marker for celiac disease (CD) diagnosis in a pediatric population. A retrospective study of pediatric patients who underwent a CD serological markers study: EMA and anti-tissue transglutaminase antibodies (anti-TG2). Clinical symptomatology, degree of histological lesion, human leukocyte antigen (HLA) haplotype compatible with CD (HLA DQ2 and/or DQ8), and final diagnosis were taken into account. We included 445 patients who were classified in two groups according to the final diagnosis. Group 1: 232 children with CD, 91.4% of whom exhibited small intestinal villous atrophy, 228 being EMA-positive and four EMA-negative. Group 2: 213 children with a non-CD diagnosis, 212 EMA negative and one EMA positive. Both antibodies, EMA and anti-TG2, reached similar sensitivities, 98% and 99% respectively, while EMA had a higher specificity (99%) than anti-TG2 (93%). By using both markers combined, compared to using anti-TG2 alone, 5.7% of patients are better diagnosed. However, when we compare the efficacy of EMA and anti-TG2 in asymptomatic and symptomatic patients, the sensitivity of EMA is 98% irrespective of symptoms, thus higher than for anti-TG2 ≥10 × upper limit of normal (ULN) (respectively 77% and 84%). Our results support the use of EMA to increase CD diagnostic accuracy in a non-biopsy approach, especially in asymptomatic children.

Misuse of serological screening tests for celiac disease in children: A prospective study in Italy

BACKGROUND

Despite a well-established diagnostic algorithm for celiac disease, it remains unclear whether prescriptions for celiac serological tests comply with the current pediatric guidelines.

AIM

To analyze the appropriateness of test prescription in children investigated for celiac disease in Italy, compared to the current European pediatric guidelines.

METHODS

All children who had performed a first evaluation for celiac disease were prospectively enrolled. Prescribed tests and related indications for testing were recorded, and compared to the European pediatric guidelines.

RESULTS

Overall, 202 children were enrolled (females 59%, mean age 7.1 years ±4.1) in two centers. The reasons for celiac disease testing were typical, atypical symptoms or celiac disease-associated conditions in 46.5%, 49%, and 4.5% of cases, respectively. First-line tests were IgA and IgG anti-transglutaminase antibodies in 88.1% and 29.7% of children, IgA and IgG anti-deamidated gliadin peptide antibodies in 43% and 47%, IgA and IgG anti native gliadin in 15.8%, IgA anti-endomysium antibodies in 44.5%, HLA predisposing genes in 10% of patients. Test redundancy was very common, and the current diagnostic guidelines were correctly followed only in 23/202 patients (11.4%).

CONCLUSIONS

Diagnostic European guidelines for celiac disease screening are often disregarded in Italy. Intervention to implement adherence to these guidelines is needed, with the aim of improving resource utilization, and quality of patient care.

Serological screening for coeliac disease in patients with juvenile idiopathic arthritis

BACKGROUND AND STUDY AIMS

Juvenile idiopathic arthritis (JIA) is characterized by autoimmune aetiology. A gene locus 4q27 related to rheumatoid arthritis, psoriatic arthritis, and coeliac disease is associated with susceptibility to JIA. There are reports indicating several patients with JIA had been diagnosed with CD. We aimed to assess the frequency of coeliac disease (CD) in patients with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

This prospective study was carried out from October 2015 to August 2016 and included 96 patients with JIA. All patients were evaluated in terms of clinical and laboratory findings of CD. Levels of total IgA and tissue transglutaminase antibody (tTG) IgA were measured in all patients. Those with increased level of tTG IgA were further tested for anti-endomysium IgA antibodies (EMA). Gastroduodenoscopy were planned for a definite diagnosis of CD in patients with positive EMA.

RESULTS

Of the 96 patients in our study, 34 (35.4%) had oligoarticular form of JIA, 29 (30.2%) had polyarticular form, 12 (12.5%) had ERA form, 11 (11.5%) had systemic form, and 10 (10.4%) had psoriatic form. Sixteen of our patients (16.6%) were not using any drugs during the study. Neither EMA IgA antibodies were analysed nor gastro-duodenoscopy was performed because no patients were positive for tTG IgA. There was no difference in terms of tTG levels between the patients using NSAIDs or other drugs.

CONCLUSION

We did not find CD in children with JIA. Long term studies with more JIA patients are needed to provide more precise interpretation.

Serologic Diagnosis of Celiac Disease: New Biomarkers

Most patients affected by celiac disease (CD) are asymptomatic or hyposymptomatic and undiagnosed, and are at risk of preventable complications. Therefore, early diagnosis is highly recommended. Multiple diagnostic antibodies are available; the most frequently used is IgA to tissue transglutaminase (IgA-tTg). It may yield false results and, alone, does not address IgA deficiency. Recently, a new generation of anti-neo-epitope tTg check (IgG + IgA) has become available. It is highly sensitive and specific, covers IgA-deficient patients with CD, reflects intestinal damage, and has predictive potential in the diagnosis of CD.

Celiac Disease in Children, Particularly with Accompanying Type 1 Diabetes, Is Characterized by Substantial Changes in the Blood Cytokine Balance, Which May Reflect Inflammatory Processes in the Small Intestinal Mucosa

Cytokines play a pivotal role in the maintenance of intestinal homeostasis inducing pro- or anti-inflammatory response and mucosal barrier function in celiac disease (CD) and type 1 diabetes (T1D). We aimed to compare the levels of pro- and anti-inflammatory cytokines in CD patients without and with coexisting T1D, as well as to evaluate its association with the presence of enteroviruses (EV), regulatory T cells (Tregs), and dendritic cells (DCs) in small bowel mucosa. Altogether, 72 patients (median age 10.1 years) who had undergone small bowel biopsy were studied. The study group consisted of 24 patients with CD (median age 6.5 years), 9 patients with CD and concomitant T1D (median age 7.0 years), two patients with T1D (median age 8.5 years), and 37 patients (median age 14.0 years) with functional gastrointestinal disorders (FGD) and a normal small bowel mucosa as controls. The levels of 33 cytokines in serum were measured by multiple analysis using the Milliplex® MAP Magnetic Bead assay. The densities of FOXP3+ Tregs, CD11c+ DC, indoleamine 2,3-dioxygenase+ (IDO+) DC, langerin+ (CD207+) DCs, and EV were evaluated by immunohistochemistry as described in our previous studies. Circulating anti-EV IgA and IgG were evaluated using ELISA. The most important finding of the study is the significant increase of the serum levels of IL-5, IL-8, IL-13, IL-15, IL-17F, IL-22, IL-27, IP-10, MIP-1β, sIL-2Rα, sTNFRII, and TNFα in CD patients compared to controls and its correlation with the degree of small bowel mucosa damage graded according to the Marsh classification. The leptin level was higher in females in all study groups. The levels of IL-2, IL-6, IL-12 (P70), IL-15, IP-10, and IFNγ correlated significantly with the density of FOXP3+ Tregs in lamina propria of the small bowel mucosa, which supports the evidence about the signaling role of these cytokines in the peripheral maintenance of FOXP3+ Tregs. At the same time, a significant negative correlation occurred between the level of IL-4 and density of FOXP3+ Tregs in controls. Another important finding of our study was the correlation of IL-17F, IP-10, sTNFRII, MCP-1, and GM-CSF with the density of EV-positive cells in the lamina propria of the small bowel mucosa. Correlation of MIP-1 (CCL-4) with CD103+ DC and langerin+ DC densities may point to their significance in the recruitment of immune cells into the lamina propria and in driving the inflammatory response in CD patients. Our results suggest the predominance of Th1 and Th17 immune responses over EV VP1 protein in CD and T1D patients. The significant elevation of Th2 cytokines, like IL-5 and IL-13, but not IL-4, in CD patients and its correlation with the degree of small bowel mucosa damage could reflect the role of these cytokines in gut defense and inflammation.

Celiac Disease: Clinical Features and Diagnosis

The presentation in celiac disease is shifting from the classical malabsorptive presentation to more nonclassical presentations, requiring clinicians to maintain a high level of suspicion for the disease and to be aware of the possible extraintestinal manifestations. The diagnosis of celiac disease is guided by initial screening with serology, followed by confirmation with an upper endoscopy and small intestinal biopsy. In some pediatric cases, biopsy may be avoided.