Evaluation of a point-of-care test based on deamidated gliadin peptides for celiac disease screening in a large pediatric population.
ABSTRACT OBJECTIVES: Celiac disease (CD) is nowadays known to be a common chronic enteropathy that is becoming a growing public health concern. Yet, it is estimated that more than 90% of patients remain undiagnosed. A point-of-care diagnostic test can be a rapid and cost-effective solution in the first-line screening of CD. The aim of this study is to evaluate the performance of a novel point-of-care screening test in a large pediatric population. MATERIALS AND METHODS: Serum samples were collected from a cohort of 250 children presenting either an increased risk or a clinical suspicion of CD. All sera were tested using the point-of-care test detecting IgA and IgG antibodies against a combination of three different deamidated gliadin peptides as well as total IgA. The results of the screening test were compared with an enzyme-linked tissue transglutaminase immunosorbent assay and with histology resulting from intestinal biopsies performed in patients with elevated titers of antitissue transglutaminase antibodies. RESULTS: The point-of-care test showed highly concordant results with the laboratory immunoassay, yielding a sensitivity of 93.1 (78-98.1%) and a specificity of 95% (91.2-97.2%), with a diagnostic accuracy of 94.8% (91.3-96.9%) and a negative predictive value of 99.1% (96.6-99.7%). The screening test identified all patients with celiac-type histology findings on biopsy, as well as all patients with concomitant IgA deficiency. CONCLUSION: With a high diagnostic accuracy, this novel point-of-care approach is an efficient tool for CD case finding in pediatric populations. It has the potential to improve the management of celiac patients in primary care by providing faster counseling and treatment.
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ABSTRACT: The serological diagnosis of celiac disease (CD) often relies on the presence of anti-tissue transglutaminase (tTG) IgA autoantibodies. Patients suffering from selective IgA deficiency (IgAD) are often not aware of their IgA deficiency and are tested as CD negative, delaying considerably the diagnosis. The detection of IgG against deamidated gliadin peptides (DGP) has high specificity and better sensitivity than IgG anti-tTG. A multi-analytic lateral-flow immunochromatographic assay (CD-LFIA) based on the detection of IgA and IgG anti-DGP and total IgA was shown to have a good diagnostic accuracy for CD. The aim of this study was to evaluate the clinical accuracy of its use in children suffering from IgAD.BMC Gastroenterology 11/2014; 14(1):186. DOI:10.1186/1471-230X-14-186 · 2.11 Impact Factor
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ABSTRACT: Objective Some of the conventional serological tests for coeliac disease (CD) are expensive, time-consuming and not readily available in developing countries, leading to a delay in diagnosis. Recently, point-of-care tests (POCT) have been manufactured and tested in Europe but have not been validated in our setting. We therefore aimed to study the diagnostic accuracy of the POCT 'Biocard' test in diagnosing CD in Indian children. Design Cross-sectional study. Setting Tertiary care centre in north India. Patients Children, aged 2-18 years, with chronic diarrhoea, short stature or refractory anaemia underwent serological testing for CD with antiendomysial antibodies (AEA), antitissue transglutaminase (tTG) antibodies and Biocard test followed by duodenal biopsy irrespective of serological results. CD was diagnosed with positive AEA and duodenal biopsy showing >grade 2 changes using modified Marsh criteria. Those who were both AEA negative and had normal histology were considered CD negative. Results Of 319 children who underwent the serological testing, 170 agreed for biopsy. Of these, 110 were diagnosed with CD and 30 were found to be CD negative. Remaining 30 had discordant AEA and histology results and were not included in analysis. Biocard test agreed with 92/110 positive and 27/30 negative diagnoses based on reference tests (83.6% sensitivity and 90% specificity). tTG was found to be 93.8% sensitive and 96.4% specific. Conclusions We successfully validated the POCT for CD in our setting. It could be used to increase case detection rates in developing countries with a large undiagnosed CD burden.Gastroenterology 06/2014; 99(11). DOI:10.1136/archdischild-2013-305567 · 13.93 Impact Factor
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ABSTRACT: The diagnosis of coeliac disease has advanced in the past decade owing to increased clinical awareness and improved tests. Coeliac disease is now regarded as a common disease presenting at any age with a broad spectrum of symptoms. Previous guidelines on diagnosis relied on the histological analysis of duodenal biopsy samples. However, contemporary antibody analysis is a diagnostic tool with a comparatively high accuracy that has reduced reliance on performing biopsies. Furthermore, determination of HLA-based genetic susceptibility to coeliac disease has become routine. European and North American guidelines utilize symptoms, coeliac antibodies (primarily tissue transglutaminase 2 IgA and endomysial IgA antibodies), HLA determination and histological analysis of biopsy tissue for diagnosis. Some guidelines conclude that the diagnostic accuracy of tissue transglutaminase 2 IgA antibodies is sufficient to omit duodenal biopsies in selected children with very high antibody levels, in the presence of clear symptom response as well as a positive endomysial antibody test and confirmation of genetic susceptibility. This Review discusses if such a strategy is appropriate for children and adults in all populations. The performance characteristics of antibody tests (particularly of the tissue transglutaminase 2 IgA test) including quality control and characterisation of the population in whom testing is performed are also discussed.Nature Reviews Gastroenterology & Hepatology 09/2014; 11(11). DOI:10.1038/nrgastro.2014.162 · 10.81 Impact Factor