Relationship Between Islet Autoantibodies And HLA-DQ Genotypes In Type 1 Diabetes

Part 1 Relationship between Islet Autoantibodies and HLA-DQ Genotypes in Healthy ControlsObjective: To investigate the frequencies of GADA, IA-2A, IAA and HLA-DQ genotypes in Chinese Han population.Methods: 376 healthy Han controls were recruited and measured for GADA and IA-2A, 300 ones were measured for IAA. Among them, 278 ones were typed for the polymorphisms of HLA-DQ genotypes with PCR sequencing-based typing method.Results: â‘ The positivity frequencies of GADA, IA-2A and IAA in 376 controls were 1.06%, 0.53% and 1.00%, respectively, which were nearly close to those of American ( reported by LaGasse),Japan, Korea,Taiwan and Hongkong, but GADA positivity was lower than that of Germany (2.97%,reported by Strebelow) and IA-2A positivity was lower than that of England (2.52%,reported by Bingley) (P<0.05).â‘¡The frequencies of high risk DQB1~*0201/0302 genotype,moderate risk DQBl~*0302/X(X indicates~*0302 or a nondefined allele) ones and DQBl~*0602/X(X indicates ~*0602 or a nondefined allele) decreased ones in Chinese Han controls were all lower than those of Caucasian (0.8%vs2.7%~3.3%, 5.2%vs 8.8% -10.8% and 37.9%vs46.7%~64.2%, respectively, P<0.05 ), and the difference was not significant for low risk genotypes (19.0% vs 19.8%~ 24.9%) . The frequencies of high, moderate and decreased risk genotypes in Caucasian were 3-4, 2 and 1.5 times higher than those in Chinese controls. â‘¢The frequency of HLA-DQA1 ~*03-DQB1~*0303 haplotype was highest in Chinese controls, but the frequencies of highest risk DQAl*0301-DQBl*0302 haplotype and decreased risk DQAl~*0102-DQB1~*0602 haplotype were lower than those of Caucasian (3.8%vs7.4%~19.3% and 5.3%vs 12.0% -19.2%, respectively,P<0.05 ) .However, the difference was not significant in Japanese, Korean, Taiwanese and Hongkong. â‘£Among five healthy controls with autoantibody positivity, four carry one kind of susceptible haplotype.