Chemiluminescence and ELISA-based serum assays for diagnosing and monitoring celiac disease in children: a comparative study.

Background: Anti-transglutaminase (tTG) or anti-deamidated gliadin peptides (DGP) serum determination is the first step in diagnosing celiac disease (CD). Our aims were to: compare the performance of novel chemiluminescent tool in the detection of tTG and DGP (Q-Flash®, Inova) with that of the established ELISA (Q-Lite®, Inova) methods; identify the more reliable index for making a sound diagnosis and monitoring therapy.

Methods: Using Q-Flash® and Q-Lite®, IgA and IgG class tTG and DGP were measured in the sera of 155 CD pediatric patients and 166 healthy age-matched controls. Forty-two of the patients had a follow-up one year after starting gluten free diet (GFD).

Results: Q-Flash® IgA tTG, the more accurate (intra-assay CV for low, intermediate and high values: 2.2%, 1.6%, and 1.1%; inter-assay CV: 2.8%, 4%, and 3%), sensitive (96.1%) and specific (97%) test for diagnosing CD, was the only variable to be significantly correlated with CD at binary logistic regression analysis (r=0.263, p<0.0001, Exp(B)=1.0506, 95% CI=1.0286-1.0731). Q-Flash® IgA tTG or DGP screen were more accurate than Q-Lite® IgA tTG in monitoring CD patients on GFD (p=0.003).

Conclusion: Q- Flash® IgA tTG measurement is an extremely precise, sensitive and specific index for not only diagnosing CD, but also monitoring therapy.