Rising prevalence of celiac disease is not universal and repeated testing is needed for population screening.

Background: Recent studies suggest that the prevalence of celiac disease is rising. We previously established the prevalence of celiac disease in healthy blood donors in 2002. Objective: The purpose of this study was to examine whether the prevalence of celiac disease and celiac disease autoimmunity has changed over time by performing a similar prospective study. Methods: Healthy blood donors (n = 1908) were tested for tissue transglutaminase antibodies and for anti-endomysial antibodies when positive. Further evaluation followed accepted criteria for diagnosis. Results: Overall, 32 donors had abnormal tissue transglutaminase antibodies (1.68%). Eight donors had tissue transglutaminase antibodies >3 × upper limit of normal (0.42%), two of them with tissue transglutaminase antibodies >10 × upper limit of normal, while 24 donors had tissue transglutaminase antibodies <3 × upper limit of normal (1.26%). Most of the donors with positive tissue transglutaminase antibodies <3 × upper limit of normal had negative tissue transglutaminase antibodies levels on repeated testing (18/19). Celiac disease was diagnosed in four donors with positive tissue transglutaminase antibodies, establishing a prevalence of 1.68% (95% confidence interval 1.15-2.3) for celiac disease autoimmunity and 0.21% for celiac disease (95% confidence interval 0.07-0.5%). Conclusion: The prevalence of celiac disease in blood donors in Israel did not rise in the last 15 years, suggesting that the increased prevalence of diagnosed celiac disease is mainly due to increased awareness. As most of the donors with elevated tissue transglutaminase antibodies <3 × upper limit of normal were endomysial antibody negative and had a negative tissue transglutaminase antibodies result upon re-testing, repeated tissue transglutaminase antibodies testing is required when screening asymptomatic populations for celiac disease.