Abstract
Background Prevalence of Celiac disease (CD) increased worldwide in recent decades. Approximately 53% of the 33.4 million Saudi population are genetically susceptible and 1.5% develop CD. This underscores the importance of identification of factors associated with CD and the diagnostic accuracy of CD screening tests. Methods In this case-control study records of patients managed between January 2016 and July 2019 at Gastroenterology Department, King Abdul-Aziz Medical City, Riyadh, Saudi Arabia were reviewed. CD cases with confirmed intestinal biopsy were matched (1:1) by age with biopsy negative controls free of CD. Area under the curve (AUC) for anti-tissue transglutaminase IgA (TTG-IgA) and IgG (TTG-IgG) CD diagnostic tests were calculated and compared. Results The study included 270 cases and 270 controls. Sex distribution was similar in both groups. In a stepwise conditional logistic regression analysis, factors significantly associated with CD were family history (odds ratio (OR)=7.76, 95% confidence interval (CI): 2.26-26.63, P=0.001), Helicobacter pylori infection (OR=1.72, 95% CI: 1.10-2.71, P=0.018), diabetes mellitus (OR=3.37, 95% CI: 1.68-6.74, P=0.001), hypothyroidism (OR=2.46, 95% CI: 1.15-5.28, P=0.02) and respiratory infections (OR=4.89,95% CI 2.26-10.56, P<0.001). AUC for TTG-IgA test was 0.934 and for TTG-IgG was 0.787, P<0.001. The optimal cut-off for TTG-IgA was >=12.7 U/ml, with 89% sensitivity and 86% specificity, and for TTG-IgG was >=3.5 U/ml, with 70% sensitivity and 77% specificity.Conclusion The findings of this study can inform strategies for CD screening and prevention. Public awareness campaigns for CD are urgently needed, particularly, for high-risk groups.