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

Autor: Oyaert, Matthijs, Vermeersch, Pieter, De Hertogh, Gert, Hiele, Martin, Vandeputte, Nathalie, Hoffman, Ilse, Bossuyt, Xavier
Předmět:
Zdroj: Clinical Chemistry & Laboratory Medicine; Sep2015, Vol. 53 Issue 10, p1537-1546, 10p, 6 Charts, 2 Graphs
Abstrakt: 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. All patients and controls underwent duodenal biopsy. IgA anti-tTG and IgG anti-DGP assays were from Thermo Fisher and Inova. Results: Likelihood ratios for CD markedly increased with double positivity and increasing antibody levels of IgA anti-tTG and IgG anti-DGP. Patients with double positivity and high antibody levels (> 3 times, > 10 times ULN) had a high probability for having CD (likelihood ratio e 649 for > 3 times ULN and ∞ for > 10 times ULN). The fraction of CD patients with double positivity and high antibody levels was 59%-67% (depending on the assay) for > 3 ULN and 33%-36% (depending on the assay) for > 10 ULN, respectively. This fraction was significantly higher in children with CD than in adults. Conclusions: Combining IgG anti-DGP with IgA anti-tTG and defining thresholds for antibody levels improves the serologic diagnosis of CD. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index