title: Associations between HLA-DQB1 high-risk alleles and type I diabetes do not depend on cytomegalovirus antibody status at onset: a case-parent study conducted in Chile.
abstract: The purpose of the present study is to ascertain whether the associations between HLA-DQB1*0201 and DQB1*0302 alleles and childhood diabetes depend on the presence of antibodies to human cytomegalovirus (CMV). A study of incident type I diabetes cases and parents was conducted in Santiago, Chile. HLA-DQB1 polymorphisms were determined in 85 case-parent trios (255 subjects), while the detection of CMV was carried out only in the incident cases. As expected, HLA-DQB1 polymorphisms are strongly associated with type I diabetes, with crude odds ratios of 3.7 (95% confidence interval (CI) 1.8-7.7) for the DQB1*0201 allele and 10.3 (95% CI 5.0-21.4) for the DQB1*0302 allele. In the subset of families with CMV+ cases, the odds ratios were estimated as 3.7 (95% CI 1.6-8.6) for the DQB1*0201 allele and 11.1 (95% CI 4.8-25.8) for the DQB1*0302 allele. In families with patients who tested negative for CMV antibodies, the odds ratios were calculated as 3.5 (95% CI 0.7-16.8) for the DQB1*0201 allele, and 8.0 (95% CI 1.8-34.7) for the DQB1*0302 allele. There was no evidence of statistical interaction between CMV antibodies and the DQB1*0201 allele (P value = 0.9) or the DQB1*0302 allele (P value = 0.7). In conclusion, alleles DQB1*0302 and DQB1*0201 do not display distinct associations with type I diabetes depending on the presence of antibodies for CMV.
authors.affiliation: Laboratory of Epidemiology, Institute of Nutrition and Food Technology and Division of Diabetes, Hospital San Juan de Dios, Faculty of Medicine, University of Chile, Santiago, Chile.
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
authors.forename: F
authors.initials: F
authors.lastname: Pérez-Bravo
authors.forename: E
authors.initials: E
authors.lastname: Carrasco
authors.forename: R
authors.initials: R
authors.lastname: Petri
authors.forename: M
authors.initials: M
authors.lastname: Calvillán
authors.forename: C
authors.initials: C
authors.lastname: Albala
mesh_terms: D000293:Adolescent; D000483:Alleles; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D002677:Chile; D003587:Cytomegalovirus / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D005260:Female; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012307:Risk Factors
chemical_list: D000914:Antibodies, Viral; D006683:HLA-DQ Antigens