title: Association of antiphosphatidylserine/prothrombin autoantibodies with HLA class II genes.
abstract: OBJECTIVE
  To investigate the associations between HLA class II genes and antiphosphatidylserine/prothrombin antibodies (aPS/PT) in a group of British caucasoid patients with antiphospholipid antibodies (aPL).
  
  
  METHODS
  This study included 82 patients with aPL. IgG aPS/PT were detected in sera using enzyme-linked immunosorbent assays. HLA-DQB1, DQA1, and DRB1 genotypes were determined by polymerase chain reaction using sequence-specific primers. All results were compared with 177 matched healthy control subjects.
  
  
  RESULTS
  IgG aPS/PT were present in 41 of 82 patients (50%). The frequencies of DQB1*0301/4, DQB1*0604/5/6/7/9, and DRB1*1302 alleles were increased in patients with aPS/PT compared with controls. To minimize the interference of the association between anti-beta2-glycoprotein I (anti-beta2GPI) and HLA, patients with anti-beta2GPI were excluded from further analyses, and only HLA-DQB1*0301/4 remained significant compared with controls (odds ratio [OR] 2.75, 95% confidence interval [95% CI] 1.2-6.5, P < 0.03). In the haplotype analysis, HLA-DQB1*0301/4;DQA1* 0301/2;DRB1*04 was significantly increased in patients with IgG aPS/PT compared with controls (OR 4.75, 95% CI 1.72-13.10, P = 0.0063).
  
  
  CONCLUSIONS
  The HLA-DQB1*0301/4;DQA1*0301/ 2;DRB1*04 haplotype and its components may influence the production of aPS/PT in the antiphospholipid syndrome, which partly explains the correlation between the lupus anticoagulant and DQB1*03.
authors.affiliation: Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: M L
authors.initials: ML
authors.lastname: Bertolaccini
authors.forename: T
authors.initials: T
authors.lastname: Atsumi
authors.forename: A R
authors.initials: AR
authors.lastname: Caliz
authors.forename: O
authors.initials: O
authors.lastname: Amengual
authors.forename: M A
authors.initials: MA
authors.lastname: Khamashta
authors.forename: G R
authors.initials: GR
authors.lastname: Hughes
authors.forename: T
authors.initials: T
authors.lastname: Koike
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000906:Antibodies / Q000378:metabolism; D017152:Antibodies, Antiphospholipid; D001323:Autoantibodies / Q000235:genetics*; D005260:Female; D005802:Genes, MHC Class II / Q000235:genetics; D006023:Glycoproteins / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010718:Phosphatidylserines / Q000276:immunology*; D011516:Prothrombin / Q000276:immunology*; D053482:beta 2-Glycoprotein I
chemical_list: D000906:Antibodies; D017152:Antibodies, Antiphospholipid; D001323:Autoantibodies; D006023:Glycoproteins; D000949:Histocompatibility Antigens Class II; D010718:Phosphatidylserines; D053482:beta 2-Glycoprotein I; D011516:Prothrombin