Population screening for coeliac disease in primary care by district nurses using a rapid antibody test: diagnostic accuracy and feasibility study

Universal screening for early detection of chronic autoimmune, metabolic and cardiovascular diseases in the general population using capillary blood (UNISCREEN): low-risk interventional, single-centre, pilot study protocol

INTRODUCTION

Chronic autoimmune (type 1 diabetes and coeliac disease) and metabolic/cardiovascular (type 2 diabetes, dyslipidaemia, hypertension) diseases are highly prevalent across all age ranges representing a major public health burden. Universal screening for prediction/early identification of these conditions is a potential tool for reducing their impact on the general population. The aim of this study is to assess whether universal screening using capillary blood sampling is feasible at a population-based level.

METHODS AND ANALYSIS

This is a low-risk interventional, single-centre, pilot study for a population-based screening programme denominated UNISCREEN. Participants are volunteers aged 1-100 who reside in the town of Cantalupo (Milan, Italy) undergoing: (1) interview collecting demographics, anthropometrics and medical history; (2) capillary blood collection for measurement of type 1 diabetes and coeliac disease-specific autoantibodies and immediate measurement of glucose, glycated haemoglobin and lipid panel by point-of-care devices; (3) venous blood sampling to confirm autoantibody-positivity; (4) blood pressure measurement; (5) fulfilment of a feasibility and acceptability questionnaire. The outcomes are the assessment of feasibility and acceptability of capillary blood screening, the prevalence of presymptomatic type 1 diabetes and undiagnosed coeliac disease, distribution of glucose categories, lipid panel and estimate of cardiovascular risk in the study population. With approximately 3000 inhabitants, the screened population is expected to encompass at least half of its size, approaching nearly 1500 individuals.

ETHICS AND DISSEMINATION

This protocol and the informed consent forms have been reviewed and approved by the San Raffaele Hospital Ethics Committee (approval number: 131/INT/2022). Written informed consent is obtained from all study participants or their parents if aged <18. Results will be published in scientific journals and presented at meetings.

CONCLUSIONS

If proven feasible and acceptable, this universal screening model would pave the way for larger-scale programmes, providing an opportunity for the implementation of innovative public health programmes in the general population.

TRIAL REGISTRATION NUMBER

NCT05841719.

Rapid Anti-tTG-IgA Screening Test for Early Diagnosis of Celiac Disease in Pediatric Populations

A large number of patients with celiac disease (CD) remain undiagnosed because they do not fulfill the criteria for entry into the conventional diagnostic workflow. This study evaluated the clinical utility of anti-tissue transglutaminase IgA antibody lateral flow immunoassays (anti-tTG-IgA LFIA) in the undiagnosed-CD-based pediatric population and the impact of a gluten-free diet (GFD) on screening-detected CD. A total of 576 volunteers were tested for anti-tTG-IgA. Gluten consumption habits, CD related symptoms, and risk factors for CD development were evaluated. Volunteers testing positive for anti-tTG-IgA were referred to the conventional CD diagnostic workflow, and the impact of the GFD on health-related quality of life (HR-QoL) was measured. Among them, 13 had a positive anti-tTG-IgA LFIA test result: 11 had confirmed CD (1.91%), one refused confirmatory tests, and another is undergoing diagnosis. Regarding the CD prevalence, no significant differences were observed among risk (1.89%) and symptomatic (2.65%) groups and the entire tested population (1.55%). Rapid anti-tTG-IgA LFIAs could be of clinical utility in primary care for the early identification of children with CD unidentified by the conventional diagnostic workflow. It could potentially reduce the costs of undiagnosed CD, avoiding unnecessary referrals to gastroenterologists, reducing diagnosis delays and long-term problems, and improving patients' HR-QoL.

Population level screening for celiac disease: is now the time?

PURPOSE OF REVIEW

As incidence and prevalence of celiac disease is increasing, subclinical and asymptomatic presentations are more commonly identified through celiac disease screening. However, the United States Preventive Services Task Force released a statement in 2017 maintaining that there is insufficient evidence to recommend general population screening for celiac disease for asymptomatic individuals. This review summarizes the current available evidence on celiac disease screening.

RECENT FINDINGS

Literature demonstrates that by limiting screening to individuals with recognized symptoms, celiac disease diagnosis is frequently delayed or missed entirely. Most individuals with screening-identified celiac disease have previously unrecognized symptoms that improve through treatment with a gluten-free diet. Screening-identified individuals also demonstrate signs of impaired nutrition, growth, bone health, and quality of life which improve with treatment. Overall, celiac disease screening is viewed favorably by those identified through celiac disease screening programs.

SUMMARY

Individuals with screening-identified celiac disease may still incur complications from untreated disease and receive benefit from treatment with a gluten-free diet. More data is needed to determine the cost effectiveness of different mass screening approaches that incorporate the societal perspective towards screening.

Relationship between gluten availability and celiac disease prevalence: A geo-epidemiologic systematic review

Celiac disease is a global disease requiring genetic susceptibility and gluten exposure to trigger immune-mediated enteropathy. The effect of the degree of gluten-containing grain availability on celiac disease prevalence is unknown. Our objective was to compare country-based gluten availability to celiac prevalence using a systematic literature review. We searched MEDLINE, Embase, Cochrane, and Scopus until May 2021. We included population-based serum screening with confirmatory testing (second serological study or small intestine biopsy) and excluded specific, high-risk, or referral populations. We determined country-specific gluten availability using the United Nations food balance for wheat, barley, and rye. Human leukocyte antigen (HLA) frequencies were obtained from allelefrequencies.net. The primary outcome was association between gluten-containing grain availability and celiac disease prevalence. Generalized linear mixed models method with Poisson's link was used for analysis. We identified 5641 articles and included 120 studies on 427 146 subjects from 41 countries. Celiac disease prevalence was 0-3.1%, median 0.75% (interquartile range 0.35, 1.22). Median wheat supply was 246 g/capita/day (interquartile range 214.8, 360.7). The risk ratio (RR) for wheat availability on celiac disease was 1.002 (95% confidence interval [CI]: 1.0001, 1.004, P = 0.036). A protective association was seen with barley, RR 0.973 (95% CI: 0.956, 0.99, P = 0.003), and rye, RR 0.989 (95% CI: 0.982, 0.997, P = 0.006). The RR for gross domestic product on celiac disease prevalence was 1.009 (95% CI: 1.005, 1.014, P < 0.001). The RR for HLA-DQ2 was 0.982 (95% CI: 0.979, 0.986, P < 0.001), and that for HLA-DQ8 was 0.957 (95% CI: 0.950, 0.964, P < 0.001). In this geo-epidemiologic study, gluten-containing grain availability showed mixed associations with celiac disease prevalence.

Population-Based Screening for Coeliac Disease in Lithuanian Children from 2009 to 2014

Background and Objectives. Coeliac disease is an autoimmune disorder provoked by a dietary group of proteins called gluten in genetically predisposed individuals. Over the past several decades, the prevalence of coeliac disease has been steadily growing and it is now recognized to be occurring worldwide. The prevalence varies greatly between ethnic, racial groups and regionally. Such variability makes local epidemiological studies important for spreading awareness and setting a threshold for suspicion of coeliac disease. We explored the potential application of a quick point-of-care test for the purpose of detecting a presence of IgA class TG2 antibodies for coeliac disease and screening in a Lithuanian pediatric population. Previously, there were no data regarding coeliac disease prevalence in Lithuania. Materials and Methods. Overall, we included 1458 children 11-13 years of age from several Lithuanian schools selected randomly in this study. Utilizing one point-of-care test using a single blood sample taken from a fingertip, we identified the existence of IgA class TG2 antibodies. Only children whose parents gave consent were enrolled in the study. Those with positive IgA class TG2-ab were directed to a tertiary hospital for additional clinical assessment and confirmation of suspected coeliac disease. Results. A total of two (0.14%) of the 1458 enrolled children were detected with the presence of TG2 antibodies and the coeliac disease diagnosis was further confirmed with histological examination of duodenal biopsy samples. Additionally, we checked that patients had not previously reported any clinical symptoms and signs that could suggest coeliac disease or any other disease of the gastrointestinal tract. Conclusions. The detected prevalence of coeliac disease in the Lithuanian pediatric population is 1:729. The rapid finger prick test for the presence of IgA class TG2 antibodies is a reasonable and accurate method to screen for celiac disease in children.

Point-of-Care Screening for Coeliac Disease in Schoolchildren Reveals Higher Disease Prevalence in Croatia

Coeliac disease (CD) is an immune-mediated inflammatory disease triggered by dietary gluten and related proteins in genetically predisposed individuals. Point-of-care (POC) methods are non-invasive and easily performed tests, which could help to reduce the diagnostic delay of CD. The aim of our study was to determine the prevalence of CD using rapid POC test in first-grade schoolchildren in Zagreb, Croatia. A rapid qualitative immunoassay POC test designed for detection of immunoglobulin (Ig) A and IgG deamidated gliadin antibodies (DGP), as well as total IgA (to identify IgA deficient patients) in whole blood, was used to test healthy children on gluten containing diet. Out of 1404 tested children (51% female), 85 (6.05%) had a positive rapid POC test result and were referred to paediatric gastroenterologist. Finally, 7 children were diagnosed with CD (0.5%). There was no significant difference in children with CD and children with positive POC but negative serology in sex, BMI, or symptoms. However, children diagnosed with CD complained of abdominal pain significantly more often. The prevalence of CD in first-grade schoolchildren was 1:200 (0.5%), higher than in previous studies performed in Croatia. The results imply the possible benefit of IgA and IgG DGP-based POC tests in population screening.

Recognizing the Emergent and Submerged Iceberg of the Celiac Disease: ITAMA Project-Global Strategy Protocol

Coeliac disease (CD) is frequently underdiagnosed with a consequent heavy burden in terms of morbidity and health care costs. Diagnosis of CD is based on the evaluation of symptoms and anti-transglutaminase antibodies IgA (TGA-IgA) levels, with values above a tenfold increase being the basis of the biopsy-free diagnostic approach suggested by present guidelines. This study showcased the largest screening project for CD carried out to date in school children (n=20,000) aimed at assessing the diagnostic accuracy of minimally invasive finger prick point-of-care tests (POCT) which, combined with conventional celiac serology and the aid of an artificial intelligence-based system, may eliminate the need for intestinal biopsy. Moreover, this study delves deeper into the "coeliac iceberg" in an attempt to identify people with disorders who may benefit from a gluten-free diet, even in the absence of gastrointestinal symptoms, abnormal serology and histology. This was achieved by looking for TGA-IgA mucosal deposits in duodenal biopsy. This large European multidisciplinary health project paves the way to an improved quality of life for patients by reducing the costs for diagnosis due to delayed findings of CD and to offer business opportunities in terms of diagnostic tools and support.

Insight in the diagnosis and treatment of coeliac disease in general practice: A survey and case vignette study among 106 general practitioners

Background

Coeliac disease (CD) is a highly prevalent (∼1%) disease that allegedly remains undiagnosed in over 80% of the cases because of atypical symptoms or silent disease. Currently, it is unknown how GPs deal with (suspected) CD.

Objectives

This study aimed to better understand the diagnostic approach and the clinical reasoning process of GPs concerning CD and concurrently address diagnostic pitfalls.

Methods

A questionnaire with case vignettes to assess the knowledge, diagnostic reasoning pattern and practice for CD by GPs was developed. It was sent through academic GP research networks (encompassing over 1500 GPs) in two large cities and to smaller practices in rural areas. The questionnaire was composed of seven background questions, 13 questions related to four case vignettes and six additional CD-related questions

Results

Responses were received from 106 GPs. Knowledge on risk factors for CD and appropriate testing of at-risk populations was limited. Twenty-two percent would diagnose CD in adults exclusively based on serology, without histopathological confirmation. In total, 99% would refer a newly diagnosed patient to a dietitian to initiate a gluten-free diet (GFD). In the absence of symptoms, only 33% would initiate a GFD.

Conclusion

The results of this study have given us insight into the diagnostic process of GPs encountering patient with gluten-related complaints. Multiple serology test is available and used, while a positive serology test is not always followed up by a gastroduodenal biopsy to confirm the diagnosis. Most GPs would refer a symptomatic CD patient to a dietician for a GFD.

Testing for coeliac disease rarely leads to a diagnosis: a population-based study

BACKGROUND

Coeliac disease (CD) has an estimated prevalence of ∼1% in Europe with a significant gap between undiagnosed and diagnosed CD. Active case finding may help to bridge this gap yet the diagnostic yield of such active case finding in general practice by serological testing is unknown.

OBJECTIVE

The aim of this study was to determine (1) the frequency of diagnosed CD in the general population, and (2) to investigate the yield of active case finding by general practitioners.

METHODS

Electronic medical records of 207.200 patients registered in 49 general practices in The Netherlands in 2016 were analysed. An extensive search strategy, based on International Classification of Primary Care codes, free text and diagnostic test codes was performed to search CD- or gluten-related contacts.

RESULTS

The incidence of CD diagnosis in general practice in 2016 was 0.01%. The prevalence of diagnosed CD reported in the general practice in the Netherlands was 0.19%, and considerably higher than previously reported in the general population. During the one year course of the study 0.95% of the population had a gluten-related contact with their GP; most of them (72%) were prompted by gastrointestinal complaints. Serological testing was performed in 66% (n = 1296) of these patients and positive in only 1.6% (n = 21).

CONCLUSION

The number of diagnosed CD patients in the Netherlands is substantially higher than previously reported. This suggests that the gap between diagnosed and undiagnosed patients is lower than generally assumed. This may explain that despite a high frequency of gluten-related consultations in general practice the diagnostic yield of case finding by serological testing is low.Key pointsThe diagnostic approach of GPs regarding CD and the diagnostic yield is largely unknownCase finding in a primary health care practice has a low yield of 1.6%CD testing was mostly prompted by consultation for gastrointestinal symptomsThere is a heterogeneity in types of serological test performed in primary care.

Early diagnosis of coeliac disease in the Preventive Youth Health Care Centres in the Netherlands: study protocol of a case finding study (GLUTENSCREEN)

Introduction

Coeliac disease (CD) occurs in 1% of the population, develops early in life and is severely underdiagnosed. Undiagnosed and untreated disease is associated with short-term and long-term complications. The current healthcare approach is unable to solve the underdiagnosis of CD and timely diagnosis and treatment is only achieved by active case finding. Aim: to perform a case finding project to detect CD children who visit the Youth Health Care Centres (YHCCs) in a well-described region in the Netherlands to evaluate whether it is feasible, cost-effective and well accepted by the population.

Methods/analysis

Prospective intervention cohort study. Parents of all children aged 12 months and 4 years attending the YHCCs for a regular visit are asked whether their child has one or more CD-related symptoms from a standardised list. If so, they will be invited to participate in the case finding study. After informed consent, a point of care test (POCT) to assess CD-specific antibodies against tissue transglutaminase (TG2A) is performed onsite the YHCCs. If the POCT is positive, CD is highly suspected and the child will be referred to hospital for definitive diagnosis according to the Guideline Coeliac Disease of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition guideline.

Main outcomes

Incidence rate of new CD diagnoses in the study region in comparison to the one in the same age diagnosed by standard of care in the rest of the Netherlands.Feasibility and cost-effectiveness of active CD case finding at the YHCCs. All costs of active case finding, diagnostics and treatment of CD and the potential short-term and long-term consequences of the disease will be calculated for the setting with and without case finding.Ethical acceptability: by questionnaires on parental and healthcare professionals' satisfaction.A statistical analysis plan was prepared and is published on the GLUTENSCREEN website (Statistical-Analysis-Plan-11-5-2021_def.pdf (glutenscreen.nl) and added as annex 1).

Ethics and dissemination

The Medical Ethics Committee Leiden approved this study. If we prove that case finding at the YHCC is feasible, cost-effective and well accepted by the population, implementation is recommended.

Trial registration number

NL63291.058.17.

Systematic review and meta-analysis: the incidence and prevalence of paediatric coeliac disease across Europe

BACKGROUND

Coeliac disease is one of the most prevalent immune-mediated gastrointestinal disorders in children.

AIM

To review the incidence and prevalence of paediatric coeliac disease, and their trends, regionally across Europe, overall and according to age at diagnosis.

METHODS

Systematic review and meta-analysis from January 1, 1950 to December 31, 2019, based on PubMed, CINAHL and the Cochrane Library, searches of grey literature and websites and hand searching of reference lists. A total of 127 eligible studies were included.

RESULTS

The prevalence of previously undiagnosed coeliac disease from screening surveys (histology based) ranged from 0.10% to 3.03% (median = 0.70%), with a significantly increasing annual trend (P = 0.029). Prevalence since 2000 was significantly higher in northern Europe (1.60%) than in eastern (0.98%), southern (0.69%) and western (0.60%) Europe. Large increases in the incidence of diagnosed coeliac disease across Europe have reached 50 per 100 000 person-years in Scandinavia, Finland and Spain. The median age at diagnosis increased from 1.9 years before 1990 to 7.6 since 2000. Larger increases in incidence were found in older age groups than in infants and ages <5 years.

CONCLUSIONS

Paediatric coeliac disease incidence and prevalence have risen across Europe and appear highest in Scandinavia, Finland and Spain. The most recent evidence shows large increases in incidence in most regions, but stabilisation in some (notably Sweden and Finland). Sharp increases in the age at diagnosis may reflect increases in milder and asymptomatic cases diagnosed since reliable serology testing became widely used, through endomysial antibodies after 1990 and tissue transglutaminase antibodies around 2000.

Mass Screening for Celiac Disease: The Autoimmunity Screening for Kids Study

INTRODUCTION

The Autoimmunity Screening for Kids (ASK) study is a large scale pediatric screening study in Colorado for celiac disease (CD) and type 1 diabetes. This is a report of the CD outcomes for the first 9,973 children screened through ASK.

METHODS

ASK screens children aged 1-17 years for CD using 2 highly sensitive assays for tissue transglutaminase autoantibodies (TGA): a radiobinding (RBA) assay for IgA TGA and an electrochemiluminescence (ECL) assay that detects all TGA isotypes. Children who test positive on either assay are asked to return for confirmatory testing. Those with a confirmed RBA TGA level ≥ 0.1 (twice the upper limit of normal) are referred to the Colorado Center for Celiac Disease for further evaluation; all others are referred to primary care.

RESULTS

Of the initial 9,973 children screened, 242 children were TGA+ by any assay. Of those initially positive, 185 children (76.4%) have completed a confirmation blood draw with 149 children (80.5%) confirming positive by RBA TGA. Confirmed RBA TGA+ was associated with a family history of CD (odds ratio [OR] = 1.83; 95% confidence interval 1.06-3.16), non-Hispanic white ethnicity (OR = 3.34; 2.32-4.79), and female sex (OR = 1.43; 1.03-1.98). Gastrointestinal symptoms of CD, assessed at the initial screening, were reported equally often among the RBA TGA+ vs TGA- children (32.1% vs 30.5%, P = 0.65).

DISCUSSION

The initial results of this ongoing mass-screening program confirm a high prevalence of undiagnosed CD autoimmunity in a screened US population. Symptoms at initial screening were not associated with TGA status (see Visual abstract, Supplementary Digital Content 5, http://links.lww.com/AJG/B587).

Molecular Biomarkers for Celiac Disease: Past, Present and Future

Celiac disease (CeD) is a complex immune-mediated disorder that is triggered by dietary gluten in genetically predisposed individuals. CeD is characterized by inflammation and villous atrophy of the small intestine, which can lead to gastrointestinal complaints, malnutrition, and malignancies. Currently, diagnosis of CeD relies on serology (antibodies against transglutaminase and endomysium) and small-intestinal biopsies. Since small-intestinal biopsies require invasive upper-endoscopy, and serology cannot predict CeD in an early stage or be used for monitoring disease after initiation of a gluten-free diet, the search for non-invasive biomarkers is ongoing. Here, we summarize current and up-and-coming non-invasive biomarkers that may be able to predict, diagnose, and monitor the progression of CeD. We further discuss how current and emerging techniques, such as (single-cell) transcriptomics and genomics, can be used to uncover the pathophysiology of CeD and identify non-invasive biomarkers.

Childhood growth prior to screen-detected celiac disease: prospective follow-up of an at-risk birth cohort

OBJECTIVES

To determine the association between childhood growth prior to the development of celiac disease (CD) and CD autoimmunity (CDA) identified by periodic serological screening.

STUDY DESIGN

The Diabetes Autoimmunity Study in the Young cohort includes 1979 genetically at-risk children from Denver, Colorado, with annual growth measurements from age nine months until ten years. Between 1993 and February 2019, 120 children developed CDA defined by persistent positive tissue transglutaminase autoantibodies (TGA); among these, 71 met our criteria for CD based on histopathological findings or high TGA levels. Age- and sex-specific z-scores of weight, body mass index (BMI), and height prior to seroconversion were derived using US reference charts as standards. Joint modeling of serial growth measurements was used to estimate adjusted hazard ratios (aHRs) accounting for celiac-associated human leukocyte antigens, early-life feeding practices, and socio-demographics.

RESULTS

In the first 10 years of life, there were no significant associations between the child's current weight, BMI and height and the risk of screening-detected CDA or CD, neither was the weight nor BMI velocity associated with CDA or CD as identified by screening (all aHRs approximated 1). Increased height velocity was associated with later CD, but not CDA, development (aHR per 0.01-z score/year, 1.28; 95% confidence interval [CI] 1.18-1.38 and 1.03; 0.97-1.09, respectively).

CONCLUSIONS

In the first 10 years of life, from prospectively collected serial growth measurements, we found no evidence of impaired childhood growth before CD and CDA development as identified through early and periodic screening.

Is There a Role of Using a Rapid Finger Prick Antibody Test in Screening for Celiac Disease in Children?

Introduction

Celiac disease (CD) is an autoimmune disease triggered by gluten in genetically predisposed individuals. Despite the increasing prevalence of CD, many patients remain undiagnosed. Standard serology tests are expensive and invasive, so several point-of-care tests (POC) for CD have been developed. We aimed to determine the prevalence of CD in first-grade pupils in Primorje-Gorski Kotar County, Croatia, using a POC test.

Methods

A Biocard celiac test that detects IgA antibodies to tissue transglutaminase in whole blood was used to screen for celiac disease in healthy first-grade children born in 2011 and 2012 who consumed gluten without restrictions.

Results

1478 children were tested, and none of them were tested positive with a rapid test. In 10 children (0,6%), IgA deficiency has been suspected; only 4 of them agreed to be tested further for total IgA, anti-tTG, and anti-DGP antibodies. IgA deficiency was confirmed in 3 patients, and in all 4 children, CD has been excluded.

Conclusion

Our results have not confirmed the usefulness of the POC test in screening the general population of first-grade schoolchildren. Further research is needed to establish the true epidemiology of CD in Primorje-Gorski Kotar County and to confirm the value of the rapid test in comparison with standard antibody CD testing.

Changing Pattern of Childhood Celiac Disease Epidemiology: Contributing Factors

Up until the 1960s and 1970s, diarrhea, malabsorption syndrome, and failure to thrive were the presenting symptoms and signs of celiac disease (CD) in young infants; however this disease was also at the same time reported to be disappearing. Indeed, clinical childhood CD was seen to transform into a milder form, resulting in an upward shift in age at diagnosis during the 1970s (and years later for many countries). This changing pattern of CD presentation then altered the epidemiology of the disease, with major differences between and within countries observed. An awareness of the changing clinical nature of CD and use of case-finding tools to detect even clinically silent CD became an important factor in this changing epidemiology. Countries report both low and high prevalence but it seems to be on the increase resulting in a population-based level of 1-2%. This paper discusses the potential causes and environmental factors behind these observed clinical changes, identifying new clues from different studies published at the time this transformation took place. For instance, it was found that breastfeeding postponed the diagnosis of the disease but did not altogether prevent it. Moreover, gluten introduction at a young age, specifically at the mean age of 2 months, seemed to also have a clear impact in inducing malabsorption syndrome and failure to thrive in young infants in addition to other factors such as gluten intake volume and type of cereal present in the weaning food. Further, the impact of cow's milk and its high osmolarity might have played an important role; humanized milk formulas were not yet invented. Future epidemiological studies on the contributing environmental factors to the shift in CD presentation are thus recommended for countries in which these changing clinical features are still being observed.

Diagnosing Celiac Disease: Towards Wide-Scale Screening and Serology-Based Criteria?

Celiac disease is one of the most common food-related chronic disorders in children. Unfortunately, this multifaceted disease is challenging to recognize and remains markedly underdiagnosed. Screening of either known at-risk groups or even the whole population could increase the suboptimal diagnostic yield substantially. Many recent guidelines recommend screening of at least selected risk groups, but more wide-scale screening remains controversial. The increasing prevalence of celiac disease and the development of autoantibody assays have also led to a gradual shift in the diagnostics towards less invasive serology-based criteria in a subgroup of symptomatic children. The main open questions concern whether these criteria are applicable to all countries and clinical settings, as well as to adult patients. On the other hand, widening screening and the mistaken practice of initiating a gluten-free diet before the appropriate exclusion of celiac disease increase the number of borderline seropositive cases, which may also challenge the classical histopathological diagnostics. Sophisticated diagnostic methods and a deeper understanding of the natural history of early developing celiac disease may prove useful in these circumstances.

Diagnostic Accuracy of Point of Care Tests for Diagnosing Celiac Disease: A Systematic Review and Meta-Analysis

GOALS

To perform a systematic review and meta-analysis to estimate the overall diagnostic accuracy of point of care tests (POCTs) for diagnosing celiac disease (CD).

BACKGROUND

Recently, POCTs for CD have been developed and are commercially available. Studies have reported significant variability in their sensitivity (70% to 100%) and specificity (85% to 100%).

STUDY

We searched MEDLINE, EMBASE databases, and the Cochrane library through June 2017. Positive reference test was defined as villous atrophy along with positive celiac-specific serology and/or clinical improvement after gluten-free diet. Normal duodenal biopsy was defined as negative reference test. Bivariate random-effect model was used to present the summary estimates of sensitivities and specificities along with 95% confidence regions We assessed methodologic quality using the quality assessment of diagnostic accuracy studies-2 tool.

RESULTS

The pooled sensitivity and specificity of all POCTs (based on tTG or DGP or tTG+Anti-gliadin antibodies) for diagnosing CD were 94.0% [95% confidence interval (CI), 89.9-96.5] and 94.4% (95% CI, 90.9-96.5), respectively. The pooled positive and negative likelihood ratios for POCTs were 16.7 and 0.06, respectively. The pooled sensitivity and specificity for IgA-tTG-based POCTs were 90.5% (95% CI, 82.3-95.1) and 94.8% (95% CI, 92.5-96.4), respectively.

CONCLUSIONS

The pooled sensitivity and specificity of POCTs in diagnosing CD are high. POCTs may be used to screen for CD, especially in areas with limited access to laboratory-based testing. Further research assessing the diagnostic accuracy of individual POCTs and comparing it with other available POCTs is needed.

Low Sensitivity of Simtomax Point of Care Test in Detection of Celiac Disease in a Prospective Multicenter Study

BACKGROUND & AIMS

Point of care tests (POCTs) might be used to identify patients with undiagnosed celiac disease who require further evaluation. We performed a large multicenter study to determine the performance of a POCT for celiac disease and assessed celiac disease prevalence in endoscopy centers.

METHODS

We performed a prospective study of 1055 patients (888 adults; median age, 48 yrs and 167 children; median age, 10 yrs) referred to 8 endoscopy centers in Germany, for various indications, from January 2016 through June 2017. Patients were tested for celiac disease using Simtomax, which detects immunoglobulin (Ig)A and IgG antibodies against deamidated gliadin peptides (DGP). Results were compared with findings from histologic analyses of duodenal biopsies (reference standard). The primary aim was to determine the accuracy of this POCT for the detection of celiac disease, to identify candidates for duodenal biopsy. A secondary aim was to determine the prevalence of celiac disease in adult and pediatric populations referred for outpatient endoscopic evaluation.

RESULTS

The overall prevalence of celiac disease was 4.1%. The POCT identified individuals with celiac disease with 79% sensitivity (95% CI, 64%-89%) and 94% specificity (95% CI, 93%-96%). Positive and negative predictive values were 37% and 99%. When we analyzed the adult and pediatric populations separately, we found the test to identify adults with celiac disease (prevalence 1.2%) with 100% sensitivity and 95% specificity. In the pediatric population (celiac disease prevalence 19.6%), the test produced false-negative results for 9 cases; the test therefore identified children with celiac disease with 72% sensitivity (95% CI 53%-86%). Analyses of serologic data revealed significantly lower DGP titers in the false-negative vs the true-positive group.

CONCLUSIONS

In a study of more than 1000 adults and children, we found the Simtomax POCT to detect celiac disease with lower overall levels of sensitivity than expected. Although the test identifies adults with celiac disease with high levels of sensitivity and specificity, the prevalence of celiac disease was as low as 1.2% among adults. The test's lack of sensitivity might be due to the low intensity of the POCT bands and was associated with low serum DGP titers. Study ID no: DRKS00012499.

Diagnostic accuracy of a fully automated multiplex celiac disease antibody panel for serum and plasma

Background

An automated multiplex platform using capillary blood can promote greater throughput and more comprehensive studies in celiac disease (CD). Diagnostic accuracy should be improved using likelihood ratios for the post-test probability of ruling-in disease.

Methods

The Ig_plex™ Celiac Disease Panel on the sqidlite™ automated platform measured IgA and IgG antibodies to tTG and DGP in n = 224 CD serum or plasma samples. Diagnostic accuracy metrics were applied to the combined multiplex test results for several CD populations and compared to conventional single antibody ELISA tests.

Results

With multiple positive antibody results, the post-test probability for ruling-in untreated and treated CD increased to over 90%. The number of samples positive for more than one antibody also increased in untreated CD to ≥90%. Measurement of all four CD antibodies generate cut-off dependent accuracy profiles that can monitor response to treatment with the gluten-free diet (GFD). Higher positive tTG and DGP antibodies are seen more frequently in confirmed CD without (81%–94%) than with GFD treatment (44%–64%). In CD lacking biopsy confirmation, overall agreement of plasma to serum was ≥98% for all antibodies, and 100% for venous to capillary plasma.

Conclusions

The Ig_plex Celiac Disease Panel increases the likelihood of confirming CD based on the post-test probability of disease results for multi-reactive markers. Specific positivity profiles and cut-off intervals can be used to monitor GFD treatment and likely disease progression. Using serum, venous and capillary plasma yield comparable and accurate results.

Faecal Scent as a Novel Non-Invasive Biomarker to Discriminate between Coeliac Disease and Refractory Coeliac Disease: A Proof of Principle Study

Currently, the gold standard for diagnosis of coeliac disease (CD) is based on serology and gastroduodenoscopy with histology of duodenal mucosal biopsies. The aim of this study was to evaluate the potential of faecal volatile organic compounds (VOCs) analysis as a novel, non-invasive tool to discriminate between CD in remission in patients on a gluten-free diet (GFD), refractory coeliac disease (RCD) and controls without CD. Patients with an established diagnosis of CD on a GFD, RCD and healthy controls (HC) were instructed to collect a faecal sample. All subjects completed questionnaires on clinical symptoms, lifestyle and dietary information. Faecal VOCs were measured using gas chromatography-ion mobility spectrometry. A total of 13 CD, 7 RCD and 10 HC were included. A significant difference in VOC profiles between CD and RCD patients (area under the curve (AUC) ± 95% CI: 0.91 (0.79–1) p = 0.000) and between CD and HC (AUC ± 95% CI: 0.71 (0.51–0.91) p = 0.0254) was observed. We found no significant differences between faecal VOC patterns of HC and RCD. Based on faecal VOCs, CD could be discriminated from RCD and HC. This implies that faecal VOC analysis may hold potential as a novel non-invasive biomarker for RCD. Future studies should encompass a larger cohort to further investigate and validate this prior to application in clinical practice.

Epidemiology of Celiac Disease

Celiac disease is a common, chronic inflammatory disorder of the small intestine triggered by exposure to gluten in individuals with certain genetic types. This disorder affects people of any age or gender. Although often thought to be European in origin, it is now global in extent. Presentations are variable, from asymptomatic patients to severe malnutrition. Initial detection usually relies on celiac-specific serology, and confirmation often requires intestinal biopsy. There have been substantial increases in prevalence and incidence over the last 2 decades for reasons that are almost certainly environmental but for which there is no clarity as to cause.

AGA Clinical Practice Update on Diagnosis and Monitoring of Celiac Disease-Changing Utility of Serology and Histologic Measures: Expert Review

PURPOSE

The purpose of this clinical practice update is to define key modalities in the diagnosis and monitoring of celiac disease (CD) in adults as well as in children and adolescents.

METHODS

The recommendations outlined in this expert review are based on available published evidence, including cohort and case-control studies of the diagnostic process as well as controlled and descriptive studies of disease management. Best Practice Advice 1: Serology is a crucial component of the detection and diagnosis of CD, particularly tissue transglutaminase-immunoglobulin A (TG2-IgA), IgA testing, and less frequently, endomysial IgA testing. Best Practice Advice 2: Thorough histological analysis of duodenal biopsies with Marsh classification, counting of lymphocytes per high-power field, and morphometry is important for diagnosis as well as for differential diagnosis. Best Practice Advice 2a: TG2-IgA, at high levels (> ×10 upper normal limit) is a reliable and accurate test for diagnosing active CD. When such a strongly positive TG2-IgA is combined with a positive endomysial antibody in a second blood sample, the positive predictive value for CD is virtually 100%. In adults, esophagogastroduodenoscopy (EGD) and duodenal biopsies may then be performed for purposes of differential diagnosis. Best Practice Advice 3: IgA deficiency is an infrequent but important explanation for why patients with CD may be negative on IgA isotype testing despite strong suspicion. Measuring total IgA levels, IgG deamidated gliadin antibody tests, and TG2-IgG testing in that circumstance is recommended. Best Practice Advice 4: IgG isotype testing for TG2 antibody is not specific in the absence of IgA deficiency. Best Practice Advice 5: In patients found to have CD first by intestinal biopsies, celiac-specific serology should be undertaken as a confirmatory test before initiation of a gluten-free diet (GFD). Best Practice Advice 6: In patients in whom CD is strongly suspected in the face of negative biopsies, TG2-IgA should still be performed and, if positive, repeat biopsies might be considered either at that time or sometime in the future. Best Practice Advice 7: Reduction or avoidance of gluten before diagnostic testing is discouraged, as it may reduce the sensitivity of both serology and biopsy testing. Best Practice Advice 8: When patients have already started on a GFD before diagnosis, we suggest that the patient go back on a normal diet with 3 slices of wheat bread daily preferably for 1 to 3 months before repeat determination of TG2-IgA. Best Practice Advice 9: Determination of HLA-DQ2/DQ8 has a limited role in the diagnosis of CD. Its value is largely related to its negative predictive value to rule out CD in patients who are seronegative in the face of histologic changes, in patients who did not have serologic confirmation at the time of diagnosis, and in those patients with a historic diagnosis of CD; especially as very young children before the introduction of celiac-specific serology.

MANAGEMENT

Best Practice Advice 10: Celiac serology has a guarded role in the detection of continued intestinal injury, in particular as to sensitivity, as negative serology in a treated patient does not guarantee that the intestinal mucosa has healed. Persistently positive serology usually indicates ongoing intestinal damage and gluten exposure. Follow-up serology should be performed 6 and 12 months after diagnosis, and yearly thereafter. Best Practice Advice 11: Patients with persistent or relapsing symptoms, without other obvious explanations for those symptoms, should undergo endoscopic biopsies to determine healing even in the presence of negative TG2-IgA.

Coeliac disease

Coeliac disease is an immune-mediated enteropathy against dietary gluten present in wheat, rye and barley and is one of the most common lifelong food-related disorders worldwide. Coeliac disease is also considered to be a systemic disorder characterized by a variable combination of gluten-related signs and symptoms and disease-specific antibodies in addition to enteropathy. The ingestion of gluten leads to the generation of harmful gluten peptides, which, in predisposed individuals, can induce adaptive and innate immune responses. The clinical presentation is extremely variable; patients may have severe gastrointestinal symptoms and malabsorption, extraintestinal symptoms or have no symptoms at all. Owing to the multifaceted clinical presentation, diagnosis remains a challenge and coeliac disease is heavily underdiagnosed. The diagnosis of coeliac disease is achieved by combining coeliac disease serology and small intestinal mucosal histology during a gluten-containing diet. Currently, the only effective treatment for coeliac disease is a lifelong strict gluten-free diet; however, the diet is restrictive and gluten is difficult to avoid. Optimizing diagnosis and care in coeliac disease requires continuous research and education of both patients and health-care professionals.

Systematic Literature Review of the Economic Burden of Celiac Disease

BACKGROUND

The prevalence of celiac disease (CD) has rapidly increased over recent decades, but costs related to CD remain poorly quantified.

OBJECTIVE

This systematic review assessed the economic burden of CD in North America and Europe.

METHODS

MEDLINE, EMBASE, EconLit, and the Cochrane Library databases were systematically searched to identify English-language literature from 2007 to 2018 that assessed costs, cost effectiveness, and health resource utilization for CD.

RESULTS

Forty-nine studies met the inclusion criteria, of which 28 (57.1%) addressed costs of testing and diagnosis; 33 (67.3%) were from Europe. The cost per positive CD diagnosis of testing patients already undergoing esophagogastroduodenoscopy for other indications ranged from 1300 Canadian dollars ($Can) in Canada (2016 value) to €44,712 in the Netherlands (2013 value). Adding the CD test was cost effective when it combined diagnostic modalities (e.g., serology and biopsy). Direct annual excess costs to a US payer per diagnosed CD patient totaled $US6000 (2013 value) more than for a person without CD, chiefly due to outpatient care. Hospitalizations, emergency visits, and medication use were more common with CD. After initiating a gluten-free diet (GFD), patients visited primary care providers less often, used more medications, and missed fewer days from school and work.

CONCLUSIONS

Most of the few available economic studies of CD assess testing and diagnosis costs, especially in Europe. Methods of testing generally are considered cost effective when they combine diagnostic modalities in symptomatic patients. Most costs to a payer of managing CD derive from outpatient care. Following GFD initiation, patients lose fewer days from work and school than pretreatment.

Diagnostic Yield of 2 Strategies for Adult Celiac Disease Identification in Primary Care

GOALS

To compare the diagnostic yield and cost-consequences of 2 strategies, screening regardless of symptoms versus case finding (CF), using a point-of-care test (POCT), for the detection of celiac disease (CD) in primary care, to bridge the diagnostic gap of CD in adults.

MATERIALS AND METHODS

All subjects under 75 years of age who consecutively went to their general practitioners' offices were offered POCT for anti-transglutaminase immunoglobulin A antibodies. The POCT was performed on all subjects who agreed, and then a systematic search for symptoms or conditions associated with higher risk for CD was performed, immediately after the test but before knowing the test results. The 2 resulting groups were: (a) POCT positive and (b) symptomatic subject at CF. Subjects were defined as symptomatic at CF in the presence of 1 or more symptoms. All POCT-positive or symptomatic subjects at CF were referred to the CD Centers for confirmation of CD. Data on resource consumption were gathered from patients' charts. Cost of examinations, and diagnostic and laboratory tests were estimated with regional outpatient tariffs (Sicily), and a price of &OV0556;2.5 was used for each POCT.

RESULTS

Of a total of 2197 subjects who agreed to participate in the study, 36 (1.6%) and 671 (30.5%) were POCT positive and symptomatic at CF, respectively. The yield from the screening and CF was 5 new celiac patients. The total cost and mean cost for each new CD case were &OV0556;7497.35 and &OV0556;1499.47 for the POCT screening strategy, and &OV0556;9855.14 and &OV0556;1971.03 for the CF strategy, respectively. Assuming consecutive use of both strategies, performing POCT only in symptomatic subjects at CF, the calculated yield would be 4 new diagnoses with a total cost of &OV0556;2345.84 and a mean cost of &OV0556;586.46 for each newly diagnosed patient. Only 1 patient was celiac despite a negative POCT.

CONCLUSIONS

Testing symptomatic subjects at CF only by POCT seems the most cost-effective strategy to bridge the diagnostic gap of adult CD in primary care.

Versatility of fuzzy logic in chronic diseases: A review

The review aims at providing current state of evidence in the field of medicine with fuzzy logic for diagnosing diseases. Literature reveals that fuzzy logic has been used effectively in medicine. Different types of methodologies have been applied to diagnose the diseases based on symptoms, historical and clinical data of an individual. Increase in the number of recent applications of medicine with fuzzy-logic is an indication of growing popularity of fuzzy systems. Fuzzy intelligent systems developed during 2007-2018 have been studied to explore various techniques applied for disease prediction. In the traditional approach, a physician is required to diagnose disease based on historical and clinical data but the intelligent system will help physicians as well as individuals to detect disease at any location of the world. The studies of various fuzzy logic systems and classified fuzzy logic applications in the field of diabetes, iris, heart, breast cancer, dental, cholera, brain tumor, liver, asthma, viral, parkinson, lung, kidney, huntington and chest diseases have been included in the review. This study indicates all the benefits of the fuzzy logic to the society and direction to tackle the diseases that still need software for their accurate detection. Further, different case studies for celiac disease have been reported earlier. The current review aims at exploring the future direction for fuzzy methodologies and domain on celiac disease.

Screening for coeliac disease in children

AIM

Coeliac disease is a common but markedly under-diagnosed condition, which may lead to serious long-term complications if untreated. Both the diagnostic yield and true incidence have significantly increased during the last few decades and it is now one of the most common chronic gastrointestinal conditions in children. The aim of this review was to summarise the current concepts on screening for coeliac disease in children and adolescents.

METHOD

We conducted a non-systematic literature review of papers published about coeliac disease screening since the year 2000.

RESULTS

Our review showed that the diagnostic yield could be significantly improved by screening for at-risk groups, or even the whole population, but these approaches remain controversial. Evidence suggests that screening for certain high-risk groups could be beneficial, but untargeted mass screening is not currently recommended. However, whether the benefits of an early diagnosis would overcome the challenges of lifelong dietary treatment, especially in asymptomatic individuals who consider themselves healthy, are unclear.

CONCLUSION

There is moderate evidence that screening certain at-risk groups for coeliac disease could be beneficial, but more studies in different settings are needed before large-scale population screening can be recommended.

Office-Based Point of Care Testing (IgA/IgG-Deamidated Gliadin Peptide) for Celiac Disease

OBJECTIVES

Celiac disease (CD) is common yet under-detected. A point of care test (POCT) may improve CD detection. We aimed to assess the diagnostic performance of an IgA/IgG-deamidated gliadin peptide (DGP)-based POCT for CD detection, patient acceptability, and inter-observer variability of the POCT results.

METHODS

From 2013-2017, we prospectively recruited patients referred to secondary care with gastrointestinal symptoms, anemia and/or weight loss (group 1); and patients with self-reported gluten sensitivity with unknown CD status (group 2). All patients had concurrent POCT, IgA-tissue transglutaminase (IgA-TTG), IgA-endomysial antibodies (IgA-EMA), total IgA levels, and duodenal biopsies. Five hundred patients completed acceptability questionnaires, and inter-observer variability of the POCT results was compared among five clinical staff for 400 cases.

RESULTS

Group 1: 1000 patients, 58.5% female, age 16-91, median age 57. Forty-one patients (4.1%) were diagnosed with CD. The sensitivities of the POCT, IgA-TTG, and IgA-EMA were 82.9, 78.1, and 70.7%; the specificities were 85.4, 96.3, and 99.8%. Group 2: 61 patients, 83% female; age 17-73, median age 35. The POCT had 100% sensitivity and negative predictive value in detecting CD in group 2. Most patients preferred the POCT to venepuncture (90.4% vs. 2.8%). There was good inter-observer agreement on the POCT results with a Fleiss Kappa coefficient of 0.895.

CONCLUSIONS

The POCT had comparable sensitivities to serology, and correctly identified all CD cases in a gluten sensitive cohort. However, its low specificity may increase unnecessary investigations. Despite its advantage of convenience and rapid results, it may not add significant value to case finding in an office-based setting.

Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Celiac disease is a major public health problem worldwide. Although initially it was reported from countries with predominant Caucasian populations, it now has been reported from other parts of the world. The exact global prevalence of celiac disease is not known. We conducted a systematic review and meta-analysis to estimate the global prevalence of celiac disease.

METHODS

We searched Medline, PubMed, and EMBASE for the keywords celiac disease, celiac, celiac disease, tissue transglutaminase antibody, anti-endomysium antibody, endomysial antibody, and prevalence for studies published from January 1991 through March 2016. Each article was cross-referenced with the words Asia, Europe, Africa, South America, North America, and Australia. The diagnosis of celiac disease was based on European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of 3843 articles, 96 articles were included in the final analysis.

RESULTS

The pooled global prevalence of celiac disease was 1.4% (95% confidence interval, 1.1%-1.7%) in 275,818 individuals, based on positive results from tests for anti-tissue transglutaminase and/or anti-endomysial antibodies (called seroprevalence). The pooled global prevalence of biopsy-confirmed celiac disease was 0.7% (95% confidence interval, 0.5%-0.9%) in 138,792 individuals. The prevalence values for celiac disease were 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania; the prevalence was higher in female vs male individuals (0.6% vs 0.4%; P < .001). The prevalence of celiac disease was significantly greater in children than adults (0.9% vs 0.5%; P < .001).

CONCLUSIONS

In a systematic review and meta-analysis, we found celiac disease to be reported worldwide. The prevalence of celiac disease based on serologic test results is 1.4% and based on biopsy results is 0.7%. The prevalence of celiac disease varies with sex, age, and location. There is a need for population-based prevalence studies in many countries.

Rapid, Loop-Mediated Isothermal Amplification Detection of Celiac Disease Risk Alleles

Human leukocyte antigen (HLA) genotyping has become a useful investigation in the diagnostic work-up of celiac disease (CD), with utility in risk stratification and screening. However, broad application of this technology has been hindered by the cost and time burden of conventional laboratory-based assays. We have developed and validated CD-loop-mediated isothermal amplification (CD-LAMP), a LAMP assay, which enables rapid identification of the signature CD risk genotypes, HLA-DQ2.5, HLA-DQ8, HLA-DQ2.2, and HLA-DQA1*05. Sample-to-answer is achieved in approximately 65 minutes without DNA purification, thermal cycling, or specialized analytical equipment. CD-LAMP genotyping of samples was 100% concordant with accredited pathology genotyping on a panel of 40 blood and 20 saliva samples. In a panel of 100 purified DNA samples, genotyping of the high-risk DQ2.5 genotype was 100% concordant with accredited pathology genotyping, with slightly reduced sensitivity for the DQ8 genotype (97.1%) and reduced specificity for the DQ8 (93.9%) and DQ2.2 (95.1%) genotypes. CD-LAMP results are easily visualized and instrument free through the addition of a DNA intercalating dye after amplification. Combined with point-of-care antibody testing, CD-LAMP may enable immediate, confident CD diagnosis at a low cost in the clinical setting.

The Relationship Between Child Mortality Rates and Prevalence of Celiac Disease

OBJECTIVES

Some evidence suggests that prevalence of celiac disease in the general population is increasing over time. Because the prognosis of celiac disease was a dismal one before discovering the role of gluten, our aim was to investigate a possible relationship between children under-5 mortality rates and prevalence rates of celiac disease.

METHODS

Thanks to a literature review, we found 27 studies performed in 17 different countries describing the prevalence of celiac disease in schoolchildren; between 1995 and 2011, 4 studies were performed in Italy. A meta-analysis of prevalence rates was performed. Prevalence was compared between specific country under-5 mortality groups, publication year, and age.

RESULTS

In the last decades, under-5 mortality rates have been decreasing all over the world. This reduction is paralleled by an increase of the prevalence of celiac disease. The Spearman correlation coefficient was -63%, 95% confidence interval -82% to -33% (P < 0.001). So, the higher the mortality rate, the lower the prevalence of CD. This finding is confirmed by the meta-analysis of the 4 studies conducted in Italy over time.

CONCLUSIONS

The under-5 mortality rate seems to influence the prevalence of celiac disease in the general population. In the near future, the number of patients with celiac disease will increase, thanks to the better environmental conditions that nowadays allow a better survival of children with celiac disease.

Celiac disease in non-clinical populations of Japan

BACKGROUND

Celiac disease is a chronic autoimmune enteropathy caused by gluten ingestion. While its prevalence in Western countries is reported to be as high as 1%, the prevalence has not been evaluated in a large-scale study of a Japanese population. The aim of our study was to clarify the possible presence of celiac disease in a Japanese non-clinical population as well as in patients showing symptoms suggestive of the disease.

METHODS

Serum samples were collected from 2008 non-clinical adults and 47 patients with chronic unexplained abdominal symptoms between April 2014 and June 2016. The anti-tissue transglutaminase (TTG) immunoglobulin A antibody titer was determined as a screening test for celiac disease in all subjects, and individuals with a value of >2 U/mL subsequently underwent testing for the presence of serum endomysial IgA antibody (EMA) as confirmation. Those testing positive for EMA or with a high concentration (>10 U/mL) of TTG were further investigated by histopathological examinations of duodenal mucosal biopsy specimens and HLA typing tests.

RESULTS

Of the 2008 non-clinical adults from whom serum samples were collected, 161 tested positive for TTG, and all tested negative for EMA. Four subjects who had a high TTG titer were invited to undergo confirmatory testing, and the histopathological results confirmed the presence of celiac disease in only a single case (0.05%). Of the 47 symptomatic patients, one (2.1%) was found to have a high TTG titer and was diagnosed with celiac disease based on duodenal histopathological findings.

CONCLUSION

The presence of celiac disease in a non-clinical Japanese population was low at 0.05% and was rarely found in patients with unexplained chronic abdominal symptoms.

Coeliac disease: to biopsy or not?

Coeliac disease is increasingly recognized as a global problem in both children and adults. Traditionally, the findings of characteristic changes of villous atrophy and increased intraepithelial lymphocytosis identified in duodenal biopsy samples taken during upper gastrointestinal endoscopy have been required for diagnosis. Although biopsies remain advised as necessary for the diagnosis of coeliac disease in adults, European guidelines for children provide a biopsy-sparing diagnostic pathway. This approach has been enabled by the high specificity and sensitivity of serological testing. However, these guidelines are not universally accepted. In this Perspective, we discuss the pros and cons of a biopsy-avoiding pathway for the diagnosis of coeliac disease, especially in this current era of the call for more biopsies, even from the duodenal bulb, in the diagnosis of coeliac disease. In addition, a contrast between paediatric and adult guidelines is presented.

The identification of celiac disease in asymptomatic children: the Generation R Study

BACKGROUND

The objective of our study was to assess whether TG2A levels in the healthy childhood population can be predictive of subclinical CD.

METHODS

A total of 4442 children (median age, 6.0 years) participating in a population-based prospective cohort study were screened on serum TG2A. Those with positive TG2A (≥7 U/ml; n = 60, 1.4%) were invited for clinical evaluation (median age, 9.0 years). Medical history, physical examination, serum TG2A, and IgA-endomysium (EMA) were assessed, as well as HLA DQ 2.2/2.5/8 typing. Patients with positive serologies and genetic risk types underwent duodenal biopsies. TG2A levels at the time of biopsy were compared with the degree of enteropathy.

RESULTS

Fifty-one TG2A-positive children were included in the follow-up: 31 (60.8%) children had CD, ten (19.6%) did not have CD, and ten (19.6%) were considered potential CD cases because of inconclusive serologies. Duodenal biopsies were performed in 26/31 children. CD with Marsh 3a/b enteropathy was observed in 75% (15/20) of children having TG2A levels ≥10ULN at 6 years of age, as well as in 75% (6/8) of children having a positive TG2A <10 ULN (OR 1.00; 95% CI 0.15-6.64). CD cases had a lower BMI SDS (mean -0.49, SD 0.92) than children without CD (mean 0.47, SD 1.37; p = 0.02). No differences were observed in gastrointestinal symptoms.

CONCLUSIONS

Serum TG2A screening at 6 years of age in the healthy childhood population has a positive predictive value of 61% to detect subclinical CD. We did not find a positive correlation between serum TG2A levels and the degree of enteropathy.

The Role of an IgA/IgG-Deamidated Gliadin Peptide Point-of-Care Test in Predicting Persistent Villous Atrophy in Patients With Celiac Disease on a Gluten-Free Diet

OBJECTIVES

Mucosal healing is important in celiac disease (CD) for the prevention of complications. However, obtaining duodenal biopsies is invasive, and there is currently no reliable surrogate marker for histological remission in clinical practice. We aimed to assess the role of a point-of-care test (POCT) based on IgA/IgG-deamidated gliadin peptide, in detecting persistent villous atrophy (VA) in CD.

METHODS

We prospectively recruited patients with CD attending endoscopy for the assessment of histological remission. All patients had IgA-endomysial (EMA) antibodies, IgA-tissue transglutaminase (TTG) antibodies, and the POCT performed, and completed a validated dietary adherence questionnaire. A gastroscopy was performed in all patients, with four biopsies taken from the second part of the duodenum and one from the duodenal bulb. We compared the diagnostic performance of the surrogate markers against duodenal histology as the reference standard.

RESULTS

A total of 217 patients with CD (70% female, age range 16-83 years, median age 53 years) on a gluten-free diet (median duration 6 years) were recruited from 2013 to 2017. Eighty-five (39.2%) patients had persistent VA. The sensitivities of the POCT, TTG, EMA, and the adherence score in detecting VA were 67.1%, 44.7%, 37.7%, and 24.7% respectively (P=0.0005). The combination of the POCT and adherence score only marginally increased the sensitivity to 70.6% (59.7-80.0%).

CONCLUSIONS

The sensitivity of the POCT was higher than the other surrogate markers in predicting VA. A POCT may provide the additional advantage of an immediate objective assessment of mucosal healing at the time of an office-based follow-up consultation.

Transglutaminase 2 in human diseases

Transglutaminase 2 (TG2) is an inducible transamidating acyltransferase that catalyzes Ca(2+)-dependent protein modifications. In addition to being an enzyme, TG2 also serves as a G protein for several seven transmembrane receptors and acts as a co-receptor for integrin β1 and β3 integrins distinguishing it from other members of the transglutaminase family. TG2 is ubiquitously expressed in almost all cell types and all cell compartments, and is also present on the cell surface and gets secreted to the extracellular matrix via non-classical mechanisms. TG2 has been associated with various human diseases including inflammation, cancer, fibrosis, cardiovascular disease, neurodegenerative diseases, celiac disease in which it plays either a protective role, or contributes to the pathogenesis. Thus modulating the biological activities of TG2 in these diseases will have a therapeutic value.

At-Risk Screened Children with Celiac Disease are Comparable in Disease Severity and Dietary Adherence to Those Found because of Clinical Suspicion: A Large Cohort Study

OBJECTIVE

To assess whether children at risk for celiac disease should be screened systematically by comparing their baseline and follow-up characteristics to patients detected because of clinical suspicion.

STUDY DESIGN

Five hundred four children with celiac disease were divided into screen-detected (n = 145) and clinically detected cohorts (n = 359). The groups were compared for clinical, serologic, and histologic characteristics and laboratory values. Follow-up data regarding adherence and response to gluten-free diet were compared. Subgroup analyses were made between asymptomatic and symptomatic screen-detected patients.

RESULTS

Of screen-detected patients, 51.8% had symptoms at diagnosis, although these were milder than in clinically detected children (P < .001). Anemia (7.1% vs 22.9%, P < .001) and poor growth (15.7% vs 36.9%, P < .001) were more common, and hemoglobin (126 g/l vs 124 g/l, P = .008) and albumin (41.0 g/l vs 38.0 g/l, P = .016) were lower in clinically detected patients. There were no differences in serology or histology between the groups. Screen-detected children had better dietary adherence (91.2% vs 83.2%, P = .047). The groups showed equal clinical response (97.5% vs 96.2%, P = .766) to the gluten-free diet. In subgroup analysis among screen-detected children, asymptomatic patients were older than symptomatic (9.0  vs 5.8 years of age, P = .007), but the groups were comparable in other variables.

CONCLUSIONS

More than one-half of the screen-detected patients with celiac disease had symptoms unrecognized at diagnosis. The severity of histologic damage, antibody levels, dietary adherence, and response to treatment in screen-detected cases is comparable with those detected on a clinical basis. The results support active screening for celiac disease among at-risk children.

Population-Based Screening for Selective Immunoglobulin A (IgA) Deficiency in Lithuanian Children Using a Rapid Antibody-Based Fingertip Test

BACKGROUND Selective immunoglobulin A (IgA) deficiency is the most common inherited immunodeficiency disorder worldwide. An early diagnosis is advocated because of the increased risk of infections, autoimmune diseases, and allergic reactions. We investigated the usefulness of a rapid point-of-care test in detecting for IgA deficiency in a population with a previously unknown prevalence. MATERIAL AND METHODS Altogether, 1000 children aged 11-13 years from randomly selected Lithuanian schools were enrolled. A point-of-care test with a fingertip sample was used to screen for the presence of IgA deficiency in children whose parents gave consent. Those with suspected IgA deficiency were referred to hospital for further clinical examination and confirmation of the diagnosis. In addition, their medical histories were compared with those of 30 age- and sex-matched healthy controls. RESULTS IgA deficiency was suspected in one girl and in three boys on the basis of the rapid test, and the diagnosis was confirmed for all four cases (prevalence 0.4%, 95% confidence interval 0.16-1.02%). There was no difference in disease history or complications between IgA-deficient children and healthy controls. CONCLUSIONS The rapid antibody test is a practical and accurate method to diagnose selective IgA deficiency in children. The prevalence of IgA deficiency among Lithuanian schoolchildren is 1:250.

Early recognition of coeliac disease through community pharmacies: a proof of concept study

Setting Fifteen community pharmacies in the UK. Objective Proof of concept study to test the use of community pharmacies for active case finding of patients with coeliac disease. Methods Customers accessing over-the counter and prescription medicines indicated in the treatment of possible symptoms of coeliac disease over a 6 month period were offered a free point of care test. All patients were given advice regarding the test results and those who tested positive were advised to make an appointment with their general practitioner. Patients and pharmacists involved in service provision were asked to complete a satisfaction survey. Pharmacists were additionally invited to undertake interviews to better understand their views on the service. Main outcome measures Feasibility of service, acceptability to stakeholders and proportion testing positive for coeliac disease. Results Of the 551 individuals tested, 52 (9.4 %) tested positive. 277 (50.3 %) were tested for accessing irritable bowel syndrome treatment, 142 (25.8 %) due to presenting for diarrhoea. The proportion of patients testing positive with different symptoms or for different treatments were similar. Of 43 customers who returned the satisfaction survey, all would recommend the service to others, believing the community pharmacy to be a suitable location. Community pharmacists believed that it enabled them to improve relationships with their customers and that medical practices were receptive to the service. Conclusion This proof of concept study has shown that community pharmacies using a point of care test can effectively recognise and refer patients for confirmatory coeliac disease testing with high levels of customer and service provider satisfaction.

Prevalence and Natural History of Celiac Disease in a Cohort of At-risk Children

OBJECTIVES

To assess the prevalence and clinical presentation of celiac disease (CD) in a cohort of children with HLA-DQ2 positive and evaluate the risk factors in the development of CD.

METHODS

Between July 2004 and July 2005, parents of all healthy full-term newborns in our hospital were invited to participate. HLA-DQ2 was tested in blood sample of the umbilical cord. A point of contact serological test was performed on children between 2 and 3 years of age. Positive results were confirmed by serum anti-transglutaminase 2 and endomysial antibodies. Children with high autoantibody titers underwent an intestinal biopsy. Children of the cohort diagnosed with CD before the screening study were included. Sex, mode of delivery, breast-feeding duration, and age of gluten introduction were studied.

RESULTS

Of 1291 children, 362 were HLA-DQ2 positive and 262 participated in the study. CD was diagnosed in 4.1% (95% confidence interval (CI) 1.9-6.3). In the whole cohort, 60% had gastrointestinal symptoms, 7% poor weight gain, and 33% were asymptomatic. Five children with potential CD and 6 with CD autoimmunity became negative (42.3%) and are still negative after 5 to 7 years. Female sex was at-risk factor odds ratio 5.7 (95% CI 1.5-20.9), whereas breast-feeding during gluten introduction had a protective effect odds ratio 0.1 (95% CI 0.01-0.8).

CONCLUSIONS

Prevalence of CD in this cohort was 4%, half of whom had digestive symptoms. Because a high proportion of children showed a spontaneous disappearance of antibodies, prevalence studies of CD in young children should be based on intestinal damage so as not to overestimate results.

Yield of coeliac screening in abdominal pain-associated functional gastrointestinal system disorders

AIM

Chronic abdominal pain (CAP) in childhood is common and in the majority functional. While CAP is one of the complaints of coeliac disease (CD), whether CAP as a sole complaint is indicative of CD is unclear. Our aim was to evaluate the relationship between CAP and CD.

METHODS

The study was conducted on 1047 children (61.1% female, mean age 9.6 ± 4.1 years) with CAP. Patients were evaluated according to the Rome III criteria. Patients with alarm symptoms and conditions known to be associated with CD were excluded. Patients were screened for CD using a rapid tissue transglutaminase (tTG) test; positive cases were tested by tTG ELISA, and duodenal biopsies were obtained if tTG was above the normal limit.

RESULTS

Functional dyspepsia (FD), irritable bowel syndrome (IBS) and functional abdominal pain (FAP) were diagnosed in 384 (36.7%), 274 (26.2%) and 389 (37.2%) patients, respectively. In 13 patients, the tTG rapid test was positive; 10 were also positive for tTG by ELISA and histopathological evaluations diagnosed CD in all 10 patients. The overall prevalence of CD was 0.95% (2.2%, 0.5% and 0.5% in patients with IBS, FD and FAP, respectively). The prevalence of CD in patients with IBS was higher than expected but with borderline statistical significance (P = 0.053).

CONCLUSIONS

CD is found as common in children with FD and FAP as in the general population. CD was more commonly diagnosed in IBS patients with borderline statistical significance. We suggest that particular attention be paid to children with IBS.

Diagnostic screening for subclinical celiac disease using a rapid test in children aged 2-4

BACKGROUND

Our aim is to study the prevalence of subclinical celiac disease (CD) and analyze the diagnostic yield of a new rapid test in children aged 2-4.

METHODS

We carried out a cross-sectional study in a sample population of children aged 2-4 from the same metropolitan area. We recruited apparently healthy subjects, and collected clinical, anthropometric, analytical, and serological variables. We also tested for anti-gliadin IgA and anti-transglutaminase IgG and IgA using a rapid immunochromatographic test CD1WB and CD2WB (Operon, Zaragoza, Spain).

RESULTS

One hundred and ninety-eight children were recruited, signed the informed consent form, and completed the protocol (mean age 32.3 ± 9.2 mo, 53% males). CD prevalence according to the serological tests was 3% (CI 95%, 1.4-6.4%). Biopsies were used to confirm the diagnosis in all suspected cases. The sensitivity and negative predictive value of the CD2WB immunochromatographic test strip were 100% and 1, respectively. The sensitivity of CD1WB was 16.6% and its specificity was high (89.1%).

CONCLUSION

The prevalence of subclinical CD in the sample group of 2-4-y old was higher than that found by other authors. The CD2WB immunochromatographic test strip is an excellent diagnostic screening tool with high sensitivity and negative predictive value.

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.

An electrochemical immunoassay for the screening of celiac disease in saliva samples

A highly sensitive electrochemical immunoassay for the initial diagnosis of celiac disease (CD) in saliva samples that overcomes the problems related to its high viscosity and to the low concentration of anti-transglutaminase antigen (tTG) IgA in this medium has been developed for the first time. The system uses magnetic beads (MBs) covered with tTG, which reacts with the anti-tTG IgA antibodies present in positive saliva samples. An anti-human IgA, conjugated with alkaline phosphate (AP) enzyme, was used as the label and a strip of eight magnetized screen-printed electrodes as the electrochemical transducer. In particular, two different immunoassay approaches were optimized and blindly compared to analyze a large number of saliva samples, whose anti-tTG IgA levels were independently determined by the radioimmunoassay (RIA) method. The obtained results, expressed as Ab index, were used to perform a diagnostic test evaluation through the construction of receiver operating characteristic (ROC) curves. The approach, involving a pre-incubation between the anti-human IgA-AP and saliva samples prior to the addition of MBs-tTG, showed a cutoff of 0.022 with 95% clinical sensitivity and 96% clinical specificity. The area under the ROC curve is equal to 1, a result that classifies our test as "perfect." This study demonstrates that it is possible to perform the screening of CD with a rapid, simple, inexpensive, and sensitive method able to detect anti-tTG antibodies in saliva samples, which are easily obtained by non-invasive techniques. This aspect is of fundamental importance to screen a large number of subjects, especially in the pediatric age.

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.

Advances in diagnosis and management of celiac disease

Celiac disease is an autoimmune disorder that is induced by dietary gluten in genetically predisposed individuals. It has a prevalence of approximately 1% in many populations worldwide. New diagnoses have increased substantially, owing to increased awareness, better diagnostic tools, and probable real increases in incidence. The breadth of recognized clinical presentations continues to expand, making the disorder highly relevant to all physicians. Newer diagnostic tools, including serologic tests for antibodies against tissue transglutaminase and deamidated gliadin peptide, greatly facilitate diagnosis. Tests for celiac-permissive HLA-DQ2 and HLA-DQ8 molecules are useful in defined clinical situations. Celiac disease is diagnosed by histopathologic examination of duodenal biopsy specimens. However, according to recent controversial guidelines, a diagnosis can be made without a biopsy in certain circumstances, especially in children. Symptoms, mortality, and risk for malignancy each can be reduced by adherence to a gluten-free diet. This treatment is a challenge, however, because the diet is expensive, socially isolating, and not always effective in controlling symptoms or intestinal damage. Hence, there is increasing interest in developing nondietary therapies.

Screening for celiac disease in the general population and in high-risk groups

BACKGROUND

Celiac disease (CD) occurs in approximately 1% of the Western population. It is a lifelong disorder that is associated with impaired quality of life (QOL) and an excessive risk of comorbidity and death.

OBJECTIVES

To review the literature on screening for CD in relation to the current World Health Organization (WHO) criteria for mass screening.

METHODS

We performed a PubMed search to identify indexed papers on CD screening with a publication date from 1900 until 1 June 2014. When we deemed an abstract relevant, we read the corresponding paper in detail.

RESULTS

CD fulfills several WHO criteria for mass screening (high prevalence, available treatment and difficult clinical detection), but it has not yet been established that treatment of asymptomatic CD may reduce the excessive risk of severe complications, leading to higher QOL nor that it is cost-effective.

CONCLUSIONS

Current evidence is not sufficient to support mass screening for CD, but active case-finding may be appropriate, as we recognize that most patients with CD will still be missed by this strategy. Although proof of benefit is still lacking, screening for CD may be appropriate in high-risk groups.