title: Predictability of alloreactivity among unrelated individuals.
abstract: Extended haplotypes are specific HLA-B, BF, C2, C4A, C4B and DR allelic combinations that occur at high frequencies and show positive linkage disequilibrium among these highly polymorphic MHC markers. About 30% of all normal caucasian haplotypes are extended, and the matching of two extended haplotypes in unrelated individuals has been shown to match for the determinants of primary mixed lymphocyte reactivity (MLR-I). In this work we report that the matching of one extended haplotype and a serologically defined HLA-DR generic type on the second chromosome in unrelated individuals is associated with the absence of mixed lymphocyte reactivity in 15 to 30% of the cases studied. Our results suggest that, for those individuals who carry either one or two extended haplotypes, it is relatively easy to identify an unrelated MLR-I-matched subject. However, for individuals lacking at least one extended haplotype, it should be difficult to find an MLR-I-matched unrelated subject.
authors.affiliation: Center for Blood Research, Boston, MA.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Awdeh
authors.forename: C A
authors.initials: CA
authors.lastname: Alper
authors.forename: D
authors.initials: D
authors.lastname: Fici
authors.forename: E
authors.initials: E
authors.lastname: Eynon
authors.forename: A
authors.initials: A
authors.lastname: Bishara
authors.forename: E J
authors.initials: EJ
authors.lastname: Yunis
mesh_terms: D000483:Alleles; D002478:Cells, Cultured; D002874:Chromosome Mapping; D005787:Gene Frequency / Q000235:genetics / Q000276:immunology*; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D015235:HLA-B Antigens / Q000235:genetics / Q000276:immunology; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology; D006239:Haplotypes / Q000235:genetics / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D015810:Linkage Disequilibrium; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D011110:Polymorphism, Genetic / Q000235:genetics / Q000276:immunology; D011237:Predictive Value of Tests
chemical_list: D006680:HLA Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens