Combining antibody tests and taking into account antibody levels improves serologic diagnosis of celiac disease.

Background: The European Society for Pediatric Gastroenterology and Nutrition states that if IgA anti-tissue transglutaminase (tTG) exceeds 10 times the upper limit of normal (ULN), there is the possibility to diagnose celiac disease (CD) without duodenal biopsy, if supported by anti-endomysium testing and human leukocyte antigen (HLA) typing. We aimed to evaluate whether combining IgA tTG and IgG anti-deamidated gliadin peptide (DGP) antibody testing and taking into account the antibody levels improves clinical interpretation.

Methods: We calculated likelihood ratios for various test result combinations using data obtained from newly diagnosed CD patients (n=156) [13 children <2 years, 45 children between 2 and 16 years, and 98 adults (>16 years)] and 974 disease controls.