title: The Blood Group A Genotype Determines the Level of Expression of the Blood Group A on Platelets But Not the Anti-B Isotiter.
abstract: BACKGROUND
  The extent of expression of the blood group A on platelets is controversial. Further, the relation between platelets' blood group A expression and the titers of isoagglutinins has not been thoroughly investigated, so far.
  
  
  METHODS
  We evaluated the relation between the genotype with platelets' blood group A and H expression estimated by flow cytometry and the titers of isoagglutinins.
  
  
  RESULTS
  The A expression varied between genotypes and within genotypes. However, the expression in A1 was stronger than in all other genotypes (p < 0.0001). An overlap of expression levels was apparent between homozygous A1A1 and heterozygous A1 individuals. Still, The A1A1 genotype is associated with a particularly high antigen expression (p = 0.009). Platelets' A expression in A2 versus blood group O donors was also significant (p = 0.007), but there was again an overlap of expression. The secretor status had only little influence on the expression (p = 0.18). Also, isoagglutinin titers were not associated with genotypes.
  
  
  CONCLUSIONS
  To distinguish between A1 and A2 donors may reduce incompatible platelet transfusions and therefore be favorable on platelet transfusion increment. Clinical data are needed to support this notion.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Lehner
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Beate
authors.initials: B
authors.lastname: Eichelberger
authors.affiliation: Vienna Blood Center, Blood Service, Austrian Red Cross, Vienna, Austria.
authors.forename: Christof
authors.initials: C
authors.lastname: Jungbauer
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Panzer
keywords: Blood group A; Flow cytometry; Genotype; Isoagglutinins; Platelets