HLA-DQ Distribution and Risk Assessment of Celiac Disease in a Spanish Center

Aims: celiac disease is a multisystem immune-mediated disease triggered by gluten in genetically susceptible individuals. The HLA-DQ2 and/or HLA-DQ8 heterodimers are encoded by the main genetic predisposing factors and their presence is required for the development of the immunological response that leads to the disease. However, the HLA-conferred risk can differ within different countries. The aim of the study was to analyze the risk of Spanish children to develop celiac disease according to their HLA-DQ genotype.

Methods: a retrospective observational case-control study was performed using a sample of 475 celiac patients and 628 controls.

Results: children carrying the HLA-DQ2.5 had the highest disease risk, especially those with two HLA-DQB1*02 alleles. A similar high risk was observed in HLA-DQ8 homozygous individuals. A risk conferred by HLA-DQ8 in heterozygosity and HLA-DQ2.2 was also found and two patients with celiac disease carried the HLA-DQ7.5 haplotype as the only HLA risk factor.

Conclusions: there are four genetic risk categories according to the HLA-DQ genotype. The HLA-DQ7.5 genotype does not confer risk but should not be used to rule out celiac disease when a high suspicion of the disease exists. These findings could be relevant to determine when to perform serological screening in asymptomatic subjects at risk of celiac disease.