title: Genetic variation of the HNA-3a encoding gene.
abstract: BACKGROUND
  Antibodies against the human neutrophil alloantigen-3a (HNA-3a) play an important role in transfusion-related acute lung injury. The HNA-3a and -3b alloantigens result from a single-nucleotide exchange in the choline transporter-like protein 2 gene (CTL2). We sought for additional polymorphisms that might impair antibody binding to or genotyping of the HNA-3a or -3b antigens.
  
  
  METHODS
  CTL2-specific complementary DNA (cDNA) fragments were generated from 67 unrelated blood donors followed by DNA sequencing. Polymerase chain reaction with sequence-specific primers (PCR-SSP) was used to test a higher number of donors for relevant new single-nucleotide polymorphisms (SNPs). The granulocyte agglutination test recommended for HNA-3a antibody detection was performed to check HNA-3a antibody binding to the products of the CTL-2 gene variants.
  
  
  RESULTS
  Two new missense mutations were demonstrated in the CTL2 cDNA: a 537C>T* exchange leading to a Leu153Phe amino acid substitution and 988C>T variation predicting Thr301Met change. The inherited 537T variant is located in HNA-3a allele results impaired granulocyte agglutination by four of 14 antibodies tested while 988T remains nearly unaffected.
  
  
  CONCLUSIONS
  The Leu153Phe exchange next to the HNA-3a/b defining amino acid position can impede the binding of HNA-3a alloantibodies. The HNA-3a genotyping by PCR-SSP might produce misleading results in HNA-3ab heterozygous individuals with the additional CTL2-537T variation of the HNA-3a antigen. These findings must account for the development of new screening assays.
authors.affiliation: German Red Cross Blood Donation Service West, Bad Kreuznach, Germany. b.flesch@bsdwest.de
authors.forename: Brigitte K
authors.initials: BK
authors.lastname: Flesch
authors.forename: Angelika
authors.initials: A
authors.lastname: Reil
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bux
mesh_terms: D018076:DNA, Complementary / Q000737:chemistry; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007519:Isoantigens / Q000235:genetics* / Q000276:immunology; D008297:Male; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; C518134:HNA-3a antigen, human; D007106:Immune Sera; D007519:Isoantigens