title: Anti-"Mi(a)" immunization is associated with HLA-DRB1*0901.
abstract: BACKGROUND
  Anti-"Mi(a)" is one of the most important irregular red blood cell antibodies found in Taiwan. The aim of this study was to investigate whether specific HLA-DRB1 alleles are associated with anti-"Mi(a)" production.
  
  
  METHODS
  A case-control retrospective study was performed on 68 patients showing presence of anti-"Mi(a)" and 219 unrelated control subjects from the Mackay Memorial Hospital. HLA-DRB1 genotyping was carried out using sequence-based typing method. Fisher's exact test using 2 x 2 contingency tables was used to analyze significance of the association between DRB1 polymorphisms and presence of anti-"Mi(a)" in patients.
  
  
  RESULTS
  HLA-DRB1*0901 allele frequency in the anti-"Mi(a)" group (30%) was significantly higher than in the control group (16%) with an odds ratio of 2.27 (95% confidence interval, 1.44-3.55; p = 0.0005; p(c) = 0.016).
  
  
  CONCLUSIONS
  HLA-DRB1*0901 is significantly more prevalent in the anti-"Mi(a)" patients group than in the control group. It is suggested that cells from DR9 individuals might present processed "Mi(a)" antigen-allospecific peptides more effectively than cells from individuals carrying other DR phenotypes. Finally, it was predicted that two epitopes, derived from the MiIII glycophorin amino acid sequence, were likely to bind preferentially with the DR9 molecule. Further work will be necessary to determine if these epitopes are responsible for anti-"Mi(a)" alloimmunization.
authors.affiliation: Transfusion Medicine Laboratory, Medical Research Department, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chen-Chung
authors.initials: CC
authors.lastname: Chu
authors.forename: Hsin-Tsung
authors.initials: HT
authors.lastname: Ho
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Lee
authors.forename: Yung-Shiu
authors.initials: YS
authors.lastname: Chan
authors.forename: Fong-Juan
authors.initials: FJ
authors.lastname: Chang
authors.forename: Chang-Ling
authors.initials: CL
authors.lastname: Wang
authors.forename: Marie
authors.initials: M
authors.lastname: Lin
mesh_terms: D000375:Aging; D000483:Alleles; D000595:Amino Acid Sequence; D000906:Antibodies / Q000276:immunology*; D001803:Blood Transfusion; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006021:Glycophorins / Q000276:immunology; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D059811:HLA-DRB1 Chains; D006801:Humans; D007114:Immunization; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010641:Phenotype; D016415:Sequence Alignment; D012727:Sex Characteristics; D013624:Taiwan
chemical_list: D000906:Antibodies; D006021:Glycophorins; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains