Analysis of HLA frequencies in donor population of Unrelated Bone Marrow Donor and Cord Blood Registry of Institute of Haematology and Blood Transfusion

The HLA alleles and haplotypes frequencies of Polish population are helpful in the routine work of HLA laboratory and in searching of unrelated bone marrow donors for Polish patients. HLA I class typing was performed by standard serological method in 2580 potential donors from Poland, and HLA DRB1 DNA typing by PCR-SSP or PCR-SSOP at low resolution level in 386 donors chosen by chance from the said population. Allelic and haplotypic (2 or 3 loci haplotype) gene frequencies were estimated by iterative maximum likelihood gene counting method supplemented by expectation maximization and Hardy-Weinberg equilibrium algorithm using ML-EM-HW v. 5.2 software elaborated in our Institute.
The resolution of used methods was: 24 specificities of HLA-A, 46 HLA-B, 11 HLA-Cw, and 17 HLA*DRB1. There was a different portion of HLA “blank” in each locus. Allele gene frequencies were comparable with other Central Europe population frequencies. Estimated and observed antigen phenotypic frequencies were very similar. Fit to Hardy-Weinberg equilibrium was tested by c2 test for each locus separately and was good (p=1.0000). The highest positive linkage was found in following two-locus haplotypes: A*01-B*08 (GF 0.0739, D 0.0613, p<0.0001), A*03-B*07 (GF 0.0504, D 0.0333, p<0.0001) and A*25-B*18 (GF 0.0334, D 0.0288, p<0.0001). Very high, but negative linkage was found for A*02-B*08 (GF 0.0075, D -0.0215, p<0.0001) and A*01-B*18 (GF 0.0010, D -0.0095, p<0.0001) two-locus haplotypes. Sixteen HLA-A-B-DRB1 three-locus haplotypes showed gene frequency above 1%. Alleles of each of these haplotypes are in strong positive gametic linkage. The most frequent haplotypes in Polish population are: A*01-B*08-DRB1*03 (7.5%) and A*03-B*07-DRB1*15 (3.4%). It was tested by Chi² test that Czech, Russian, German and Finn populations are most similar to Polish comparing three most frequent HLA-A,B,DRB1 haplotypes in these populations.