HLA-DQ8 Predominance and HLA-DQ2/DQ8 Profile Distribution in Patients Undergoing Celiac Disease Genetic Testing in Costa Rica: A Retrospective Observational Study

Background/Objectives: Celiac disease (CD) is a chronic immune-mediated disorder associated with genetic susceptibility conferred primarily by HLA-DQ2 and HLA-DQ8. Although HLA genotyping cannot confirm CD because these profiles are common in individuals without the disease, it has a complementary role in the diagnostic evaluation, particularly when compatible HLA profiles are absent. Contemporary data on the distribution of CD-associated HLA profiles in Central America remain limited. This study aimed to characterize the distribution of HLA-DQ2.2, HLA-DQ2.5, and HLA-DQ8 profiles among patients referred for CD-related genetic testing in Costa Rica and to evaluate their distribution according to biological sex and age.