Diagnostic accuracy of anti-gliadin antibodies in Non Celiac Gluten Sensitivity (NCGS) patients: A dual statistical approach

Background: Gluten is the target of several diseases such as wheat allergy (WA), celiac disease (CD) and non-celiac gluten sensitivity (NCGS). NCGS is a new clinical entity characterized by gastrointestinal and extraintestinal symptoms comparable to those of CD patients but to date still lacking of specific biomarkers so that NCGS diagnosis can be reached only by excluding CD and WA, and based on the direct association between gluten ingestion and symptoms onset. Previous studies showed that antigliadin antibodies (AGA) IgG are the most prevalent positive antibodies in NCGS population.

Aim: The first aim of the study was to estimate AGA distribution and prevalence in a NCGS population. The second aim was to identify a serological pattern to help the diagnosis and/or to mark the NCGS disease.

Methods: Sera from 59 patients with suspected NCGS, 90 CD patients and 70 healthy individuals were assessed for AGA IgG/IgA, IgG/IgA deamidated gliadin peptide antibodies (DGP-AGA), tissue transglutaminase antibodies IgA (tTGA), endomysial antibodies IgA (EmA) and HLA typing (Eurospital, Trieste, Italy).

Results: We evaluated data by a dual statistical approach: logistic regression and receiver operating characteristic (ROC) analysis; therefore, we showed a poor diagnostic accuracy of AGA IgG in NCGS condition.

Conclusion: Our preliminary data showed that AGA IgG didn't seem to be a strongly sensitive marker, even if it has been recently proposed as promising marker for NCGS condition, together with negativity for other celiac disease related antibodies. It can partially help the NCGS diagnosis, if it is integrated in the overall management of the patient. More in-depth clinical and laboratory researches are mandatory.