Meta-analysis: High pooled positive predictive value of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition no-biopsy approach for coeliac disease testing in children

BACKGROUND

The European Society of Paediatric Gastroenterology, Hepatology and Nutrition established guidelines in 2012 for a no-biopsy approach to diagnose coeliac disease in children. This guideline required symptoms suggestive of coeliac disease, positive human leukocyte antigen (HLA) DQ2/DQ8 haplotypes, tissue transglutaminase type-2 immunoglobulin A antibody titre at levels greater than 10 times the upper limit of normal, and positive endomysial immune-globulin A antibody test. An updated 2020 guideline excluded the need for symptoms and positive HLA.

AIMS

To assess the pooled positive predictive value (PPV) of the no-biopsy approach with small bowel biopsy (SBB) data as the reference standard for comparison.

METHODS

Database searches (October 2023) provided data that we combined using a random-effects meta-analysis to provide a pooled PPV, representing the probability that a positive test result means that an individual truly has the condition.

RESULTS

We included 23 studies. Study sample sizes totalled 23,769 but only 3007 children had comparative SBB. The proportion of coeliac disease confirmed by the no-biopsy approach and SBB ranged from 79.2% to 100%, with an overall pooled PPV of 97.4% (95% confidence interval 96.0, 98.6). Sensitivity analysis showed higher PPV for the criteria that included HLA (98.5% vs. 96.8%; p = 0.017).

CONCLUSION

Both no-biopsy criteria exhibit high PPV when compared to the reference standard. These results provide a consistent message of accuracy and feasibility to inform change and improve outcomes.

A compact SPR biosensor device for the rapid and efficient monitoring of gluten-free diet directly in human urine

Celiac disease (CD) is a chronic autoimmune disorder induced in genetically susceptible individuals by the ingestion of gluten from wheat, rye, barley, or certain varieties of oats. A careful diet follow-up is necessary to avoid health complications associated with long-term gluten intake by the celiac patients. Small peptides (GIP, gluten immunogenic peptides) derived from gluten digestion, which are excreted in the urine and feces, have emerged as promising biomarkers to monitor gluten intake. We have implemented a simple and sensitive label-free point-of-care (POC) device based on surface plasmon resonance for the direct detection of these biomarkers in urine. The assay employs specific monoclonal antibodies and has been optimized for the detection of the 33-mer α2-gliadin, known as the main immunogenic peptide of wheat gluten, and for the detection of GIP. Direct detection in undiluted urine has been accomplished by using biosensing chips containing a robust and stable biorecognition layer, obtained after carefully optimizing the biofunctionalization protocol. Excellent limits of detection have been reached (1.6-4.0 ng mL^-1 using mAb G12 and A1, respectively), which ensures the detection of gluten peptides even when the gluten intake is around the maximum tolerable amount in the digestive tract (< 50 mg) for celiac individuals. No sample pretreatment, extraction, or dilution is required, and the analysis takes less than 15 min. The assays have excellent reproducibility' as demonstrated by measuring spiked urine samples containing the same target concentration using different biofunctionalized chips prepared and stored at different periods of time (i.e., CV% of 3.58% and 11.30%, for G12- and A1-based assays, respectively). The assay has been validated with real samples. These features pave the way towards an end-user easy-to-handle biosensor device for the rapid monitoring of gluten-free diet (GFD) and follow-up of the health status in celiac patients.

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.

Point of care testing for paediatric coeliac disease in the new ESPGHAN era

One of the challenges in coeliac disease is the significant under-diagnosis despite the increasing prevalence and international guidelines for serological screening in appropriate patient cohorts. Several point-of-care tests for coeliac disease have been developed over the past decade with the aim of improving case detection using rapid and convenient testing. Most point-of-care tests, such as Biocard, detect anti-tissue transglutaminase (tTG) IgA antibodies, whereas Simtomax uniquely detects anti-deamidated gliadin peptide (DGP) IgA/IgG antibodies. A recent head-to-head trial in adults comparing two tTG-based point-of-care tests (Biocard and Celiac Quick Test) and Simtomax found that Simtomax was superior to Biocard and Celiac Quick Test, with sensitivities of 92.7%, 72.2% and 77.8%, respectively.