Background: Increasing numbers of individuals are now being diagnosed with coeliac disease. The only accepted treatment for coeliac disease is lifelong adherence to a strict gluten-free diet (GFD). Individuals' ability to adhere to the GFD varies, but systematic studies guiding the assessment of adherence are currently lacking.
Aim: We sought to compare the predictive value of self-report and four serologic tests compared to expert nutritionist evaluation.
Methods: In all, 154 individual adults with biopsy-proven coeliac disease rated their adherence to the GFD on a Likert scale. Serum antibody titres of IgA anti-tissue transglutaminase, and IgA and IgG anti-deamidated gliadin peptides were determined. Using anova and ROC analyses, results were compared to a standardized evaluation by an expert nutritionist blinded to the participants' self-rated adherence and serology results.
Results: All serologic measures as well as participant reported adherence were significantly associated with GFD adherence as assessed by expert nutritionist evaluation. However, on ROC analysis no measure performed satisfactorily. The performance of serologic testing, but not self-report, improved with increased time on the GFD.
Conclusion: Although current serologic tests have very high sensitivities and specificities for the diagnosis of coeliac disease, they cannot replace trained nutritionist evaluation in the assessment of GFD adherence.