The Association of HLA-DQ2 with Celiac Disease

DQ2 is a surface receptor of class II MHC exposed on APC immune-competent cells. Its function is to recognize non-self-antigens and present them to CD4+ T-helper lymphocytes, which activate cytokine <21> production and control antibody production and cell response. The activation of T lymphocytes by peptides derived from gluten proteins and the production of antibodies directed against tTG in tissues where it is localized is the basis of the etiopathogenesis of celiac disease (CD). CD is frequently associated with the presence of specific HLA system genes encoding heterodimers DQ2 and DQ8, identifiable by the DQA1*0501/DQB1*0201 or DQA1*0501/DQB1*0202 and DQB1*0302 alleles. DQ2 is also associated with genetic, endocrinological and neurological diseases such as: type 1 diabetes, thyroiditis, pancreatitis and multiple sclerosis. Interactions between DQ2 and T lymphoma have also been demonstrated. The correlation between autoimmune diseases in patients with CD and therefore DQ2 is much more frequent than in healthy subjects.