Predictability of alloreactivity among unrelated individuals.
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.
Awdeh
Z L
ZL
Center for Blood Research, Boston, MA.
Alper
C A
CA
Fici
D
D
Eynon
E
E
Bishara
A
A
Yunis
E J
EJ
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
D006680:HLA Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens