Helicobacter pylori Infection and Autoimmune Thyroid Disease in Young Patients: The Disadvantage of Carrying the Human Leukocyte Antigen-DRB1*0301 Allele

Context and Objective: Pathogenesis of autoimmune thyroid disease (ATD) is multifactorial. Helicobacter pylori (Hp) infection has been proposed to be involved in nongastrointestinal conditions and reported more frequently in ATD adult patients. We evaluated the prevalence of Hp antibodies in young ATD patients and investigated the possibility that a susceptible immunogenetic profile could influence the development of ATD in subjects with Hp infection. Subjects and Methods: We retrospectively studied 90 children with ATD (median age 11.2 yr), 70 age- and sex-matched healthy subjects as controls, and 65 patients with Turner syndrome (median age 18.8 yr). Antibodies to Hp were determined at diagnosis in ATD patients and, in Turner patients, at the last control in cases without ATD and before the appearance of thyroid autoantibodies in the others. Serological and molecular human leukocyte antigen (HLA) typing for classes I and II polymorphisms was performed. Results: Prevalence of positive Hp serology resulte...