Serological screening for coeliac disease in an adult general population: the HUNT study

Abstract

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 antitransglutaminase 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% CI 69.7% to 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% to 91.4%). Primary TG2 IgG response was found in 87 participants, five 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% to 12.9%) and of TG2 IgG ≥10× ULN was 9.5% (95% CI 1.2% to 30.4%) for biopsy-confirmed CeD in TG2 IgA-negative individuals. Conclusion The TG2 IgA assay showed excellent abilities as a screening tool for CeD in the adult general population. However, the diagnostic accuracy of TG2 IgG was too poor for selectively identifying individuals with CeD. Data are available upon reasonable request. Researchers with a PhD associated with Norwegian research institutes can apply for the use of HUNT material: data and samples - given approval by a Regional Committee for Medical and Health Research Ethics. Researchers from other countries are welcome to apply in cooperation with a Norwegian Principle Investigator. Access to the requested HUNT material is given after the application is approved of by HUNTs Data Access Committee (DAC) and an agreement is signed. The agreement gives the researcher(s) the right to research a specific topic for a limited time period and to publish a decided upon number of articles. For data information contact: HUNT Research Centre Forskningsveien 27600 Levanger, Norway. Phone +47 74 07 51 80 | +47 74 01 92 40 | +47 407 90 010. Mail: kontakt@hunt.ntnu.no