title: HLA-DRB1 alleles and Jk(a) immunization.
abstract: BACKGROUND
  In transfusion medicine, anti-Jk(a) has been implicated in hemolytic transfusion reactions. Development of anti-Jk(a) after transfusion does not always occur after Jk(a-) patients receive at least 1 unit of Jk(a+) blood unit. This study was designed to identify HLA-DRB1 alleles associated with predisposition to Jk(a) immunization after blood transfusion or pregnancy.
  
  
  METHODS
  Genotyping by polymerase chain reaction and sequence-specific oligonucleotide probe nonradioactive hybridization/sequence-specific primers was performed in 20 Jk(a)-immunized patients and 200 controls from the same southern European population.
  
  
  RESULTS
  Genotyping showed that HLA-DRB1*01 was significantly more frequent in Jk(a)-immunized patients than controls: 55 percent versus 17 percent (odds ratio [OR], 5.9; confidence interval [CI], 2.3-15.5; corrected p value<0.05). Because HLA-DRB1*0101, DRB1*0102, and DRB1*1001 share a common sequence in their B1 chain, that is, F in 13, R in 71, and A in 74, HLA genetic predisposition was analyzed by comparing patients and controls with respect to the distribution of F13/R71/A74-positive and -negative alleles. Results demonstrated greater positivity of the F13/R71/A74 sequence (DRB1*0101, *0102, or *1001) in patients than in controls: 65 percent versus 19.5 percent (OR, 7.7; CI, 2.9-20.5; p<0.001).
  
  
  CONCLUSIONS
  In conclusion, HLA-DRB1*0101, DRB1*0102, and DRB1*1001, which share a common DRB1 sequence, appeared to be overrepresented in Jk(a)-immunized patients.
authors.affiliation: Department of Human Polymorphism, EFS Alpes-Méditerranée, Marseille, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Reviron
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dettori
authors.forename: Virginie
authors.initials: V
authors.lastname: Ferrera
authors.forename: Dominique
authors.initials: D
authors.lastname: Legrand
authors.forename: Mhammed
authors.initials: M
authors.lastname: Touinssi
authors.forename: Pierre
authors.initials: P
authors.lastname: Mercier
authors.forename: Philippe
authors.initials: P
authors.lastname: de Micco
authors.forename: Jacques
authors.initials: J
authors.lastname: Chiaroni
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005602:France; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics*; D006801:Humans; D007114:Immunization; D007231:Infant, Newborn; D007667:Kidd Blood-Group System / Q000235:genetics* / Q000276:immunology*; D008297:Male; D011247:Pregnancy; D065227:Transfusion Reaction
chemical_list: D006684:HLA-DR Antigens; D007667:Kidd Blood-Group System