title: HLA-DQA1 genotyping in patients with rheumatoid arthritis in Taiwan.
abstract: To investigate the role of HLA-DQA1 genotypes and their interaction with HLA-DRB1 in the pathogenesis of rheumatoid arthritis (RA) in Taiwan, HLA-DQA1 was determined in 71 patients with RA and 108 healthy controls by SSP-PCR method. HLA-DRB1 and HLA-DQA1 were simultaneously detected in 55 RA patients and 101 healthy controls. PCR/SSOP method was used to determine the HLA-DRB1 genotypes, and the subtypes of HLA-DR4 were determined by cloning and sequencing. The phenotypic frequency of HLA-DQA1*0301 was significantly lower in RA than in controls, and, in contrast, the HLA-DQA1*0302 and DQA1*0303 were significantly higher in RA than in controls. The associations of DQA1*0301, *0302, and *0303 with RA were independent of DR4 and DRB1*0405. Moreover, the interactions between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303 could enhance the development of RA. We also found that the prevalence of bone erosion and seropositivity of rheumatoid factor (RF) were significantly higher in HLA-DQA1*0303 positive RA patients than in healthy controls. HLA-DQA1*0302 and DQA1*0303 are the risk factors for susceptibility to RA, while HLA-DQA1*0301 is a protective factor. A synergistic effect for the susceptibility to RA can be found between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303. We also found that the HLA-DQA1*0303 was related to bone erosion and seropositivity of RF in RA patients.
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Kaohsiung Medical University Hospital, No. 100, Shih-Chuan 1st Road, Kaohsiung City 807, Taiwan. jehsye@cc.kmu.edu.tw
authors.forename: J H
authors.initials: JH
authors.lastname: Yen
authors.forename: C J
authors.initials: CJ
authors.lastname: Chen
authors.forename: W C
authors.initials: WC
authors.lastname: Tsai
authors.forename: T T
authors.initials: TT
authors.lastname: Ou
authors.forename: C H
authors.initials: CH
authors.lastname: Lin
authors.forename: S C
authors.initials: SC
authors.lastname: Lin
authors.forename: H W
authors.initials: HW
authors.lastname: Liu
mesh_terms: D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D015804:HLA-DR4 Antigen / Q000235:genetics; D006801:Humans; D010641:Phenotype
chemical_list: D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D015804:HLA-DR4 Antigen