Diagnostic performances of celiac disease serological tests among Saudi patients

Background: The prevalence of celiac disease (CD) is relatively high in Saudi Arabia, and little is known about the accuracy of serological markers in the local population. This study aimed to assess the diagnostic performance of various serological markers for detecting CD in Saudi children and adults. Methods: We conducted a retrospective study of 148 CD patients and 512 controls to assess the diagnostic performances of IgA anti-tissue transglutaminase antibodies (TTG), IgG anti-TTG, IgA anti-deamidated gliadin peptide antibodies (anti-DGP), IgG anti-DGP, and endomysium antibodies (EMA).Results: Immunoglobulin A (IgA) anti-TTG was the most sensitive test [98.9% (95% confidence interval (CI) 94.1-99.8%)], while EMA was the most specific [100%, 95%CI 98.6-100%]. By applying the criteria of IgA anti-TTG titers >= 10 x upper limit of normal (ULN) and positive EMA, 57.3% of patients could have avoided intestinal biopsy. IgG anti-DGP test had a sensitivity of 85.9% (95% CI = 77.3-91.5%) and a specificity of 93.5% (95% CI = (90.0-95.9%). Titers of IgA anti-TTG, IgA anti-DGP, and IgG anti-DGP were higher in CD patients with the Marsh 3c class than in those with the Marsh 3b and Marsh 3a classes. IgG anti-TTG and IgA anti-DGP had no additional diagnostic value. Conclusions: IgA anti-TTG and EMA are excellent CD markers in children and adults. The use of IgA anti-TTG titers =10 x ULN and positive EMA as criteria for CD diagnosis in children and adults might be a good alternative to intestinal biopsy.