Objective: The aim of this study is to evaluate the diagnostic concordance of Tissue Transglutaminase (tTG), Endomysium (EMA), and Deamidated Gliadin Peptide (DGP) antibodies in patients with suspected Celiac Disease (CD), to examine age-related changes in seropositivity, and to identify differences between pediatric and adult populations. Materials and Methods: Data from 4.489 patients tested for suspected CD at the Medical Microbiology Laboratory of … Training and Research Hospital between May 2024 and December 2025 were retrospectively analyzed. tTG antibodies (IgA/IgG) were assayed by micro-ELISA, whereas EMA and DGP antibodies (IgA/IgG) by indirect immunofluorescence. Data were analyzed using chi-square and Cohen’s Kappa (κ) tests. Results: Of the patients, 63.2% were female. Seropositivity for tTG IgA was detected in 89 patients (2.0%). This rate increased significantly with age, rising from 0.9% in the 0-2 age group to 2.7% in the 18 age group (p=0.006). DGP IgA positivity was significantly higher in the 3-18 age group (5.2%). While EMA IgA showed the highest concordance with tTG IgA (κ=0.752), DGP IgG concordance was weak (κ=0.238). Isolated DGP IgG positivity was observed in 8.5% of tTG IgA-negative patients. Conclusion: The 2.0% prevalence detected in symptomatic patients is significantly higher than screenings of healthy populations in Türkiye and increases with age. The combination of tTG IgA and EMA IgA demonstrates strong serological concordance. However, due to its high discordance rate, the routine inclusion of DGP IgG in screening panels appears to offer limited additional value and may increase discordance. Its use may be more appropriately restricted to specific clinical indications, such as the 0-2 age group or suspected IgA deficiency.
Kutlu et al. (Sun,) studied this question.