Prospective Evaluation of the ESPGHAN Guidelines for Diagnosis of Celiac Disease in New Zealand Children.

OBJECTIVE: The 2012 European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guideline for diagnosis of celiac disease (CD) questioned the requirement for intestinal biopsy to confirm the diagnosis. The guideline recommends that in symptomatic patients with consistent human leukocyte antigen (HLA) subtypes, the diagnostic accuracy of strongly positive serology is sufficient to confirm the diagnosis. We prospectively assessed these guidelines in a "real-life" clinical setting. METHODS: One hundred and four children referred for evaluation of possible CD were prospectively recruited. Following informed consent, blood was drawn for serological testing and HLA analysis at upper gastrointestinal endoscopy. Histological findings according to Marsh criteria were correlated with blood results and the accuracy of the guideline analyzed.The study also examined the role of deamidated gliadin peptide (DGP) in the diagnosis of CD. RESULTS: For symptomatic patients with consistent HLA subtypes, strongly positive serology (as described in the ESPGHAN guidelines) accurately predicted biopsy-proven CD in >95% of cases. DGP was positive in fewer patients than anti-TG2 or EMA. Incorporation of DGP as a second confirmatory serological test in place of EMA was associated with maintained predictive value of guideline, but fewer patients fulfilling criteria for biopsy-free diagnosis. CONCLUSIONS: The ESPGHAN guideline performs well in our population. Adoption of the guideline would reduce the number of patients requiring endoscopy without compromise in diagnostic accuracy. The involvement of pediatric gastroenterological expertise, however, remains key to diagnosis of CD.

Diagnostic utility of modified gliadin peptide antibody assays in New Zealand children.

OBJECTIVE: The aim of the present study was to evaluate a panel of different antibody assays, including second-generation antigliadin kits, in a local paediatric population thought to be at risk for coeliac disease (CD). METHODS: Seventy-nine children, who tested positive for immunoglobulin A (IgA) antibodies to tissue transglutaminase (TG), underwent duodenal biopsy. At endoscopy, serum was collected from all of the patients, and 9 different coeliac antibody assays were performed, both as isolated assays and in combination. These included immunoglobulin A (IgA) anti-tissue transglutaminase (TGA), and IgA plus IgG anti-deamidated gliadin peptide (DGPAG). A diagnosis of CD was made if the biopsies showed Marsh grade 3 lesions. RESULTS: Twenty-four of 79 children had CD confirmed histologically. Only 39 of 79 were positive for Inova TGA, and 35 of 79 were positive for Inova DGPAG. Twenty-four of 39 who were TGA positive and 24 of 35 who were DGPAG positive had confirmed CD on biopsy. There was good correlation between TGA and DGPAG-positive predictive values. None of the modified gliadin tests produced false-negative results, and neither did the TGA. CONCLUSIONS: The Inova DGPAG and TGA assays have similar use in predicting CD in a selected paediatric population; however, in children who are positive for TGA when screened for CD, more than half have negative TGA serology when repeat testing is done at the time of biopsy. Those with persistent TGA positivity have only a 61.5% probability of having histologic CD, compared with 68.6% of those children positive for DGPAG.