Associations of anti-beta(2)-glycoprotein I autoantibodies with HLA class II alleles in three ethnic groups

Objective. To determine any HLA associations with anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibodies in a large, retrospectively studied, multie thnic group of 262 patients with primary antiphospholipid antibody syndrome (APS), systemic lupus erythematosus (SLE), or another connective tissue di sease. Methods. Anti-beta(2)GPI antibodies were detected in sera using an enzyme-l inked immunosorbent assay. HLA class II alleles (DRB1, DQA1, and DQB1) were determined by DNA oligotyping. Results. The HLA-DQB1*0302 (DQ8) allele, typically carried on HLA-DR4 haplo types, was associated with anti-beta(2)GPI when compared with both anti-bet a(2)GPI-negative SLE patients and ethnically matched normal controls, espec ially in Mexican Americans and, to a lesser extent, in whites. Similarly, w hen ethnic groups were combined, HLA-DQB1*0302, as well as HLA-DQB1*03 alle les overall (DQB1*0301, *0302, and *0303), were strongly correlated with an ti-beta(2)GPI antibodies. The HLA-DR6 (DR13) haplotype DRB1*1302; DQB1*0604 /5 was also significantly increased, primarily in blacks. HLA-DR7 was not s ignificantly increased in any of these 3 ethnic groups, and HLA-DR53 (DRB4* 0101) was increased in Mexican Americans only. Conclusion. Certain HLA class II haplotypes genetically influence the expre ssion of antibodies to beta(2)GPI, an important autoimmune response in the APS, but there are variations in HLA associations among different ethnic gr oups.