Esophagus to Small Intestine
Gut. 2025;74:918-925
Serological screening for coeliac disease in an adult general population: The HUNT study
Background: A large proportion of individuals with coeliac disease (CeD) remain undiagnosed.
Objective: The aim of this study was to assess serological screening for CeD in the adult general population.
Design: The study was based on the fourth Trøndelag Health Study, a population-based study performed 2017–2019 in Nord-Trøndelag County, Norway, including 56,042 participants > 20 years of age (54% participation rate). Serum samples were analysed with a dual anti-transglutaminase 2 (TG2) IgA and IgG assay and seropositive participants were invited to endoscopy with duodenal biopsies. A CeD diagnosis was given if mucosal damage (Marsh grade 3) was found.
Results: Histological evaluation of 657 seropositive participants confirmed CeD in 423. The positive predictive value (PPV) of a positive TG2 IgA was 73.3% (95% confidence interval [CI]: 69.7–77.0%) for biopsy-confirmed CeD. TG2 IgA ≥ 10 times the upper limit of normal (ULN), as used in the no-biopsy approach in children, increased the PPV to 88.1% (95% CI: 84.8–91.4%). Primary TG2 IgG response was found in 87 participants, 5 of whom had biopsy-confirmed CeD. One of the participants with CeD primarily responding with TG2 IgG was IgA deficient. The PPV of a positive TG2 IgG was 5.8% (95% CI: 1.9–12.9%) and of TG2 IgG ≥ 10 x ULN was 9.5% (95% CI: 1.2–30.4%) for biopsy-confirmed CeD in TG2 IgA-negative individuals.
Conclusion: The dual anti-transglutaminase 2 (TG2) IgA assay showed excellent abilities as a screening tool for celiac disease (CeD) in the adult general population. However, the diagnostic accuracy of TG2 IgG was too poor for selectively identifying individuals with CeD.