Application value of allele frequencies in direct identification of ambiguous HLA genotypes / 中国实验血液学杂志

This study was aimed to investigate the application value of allele frequencies in direct identification of the ambiguous HLA genotypes. The HLA-A, HLA-B and HLADRB1 loci in 658 Chinese Han donor were detected by PCR-SBT method, the ambiguous genotyping samples were identified by using high resolution PCR-SSP and heterozygous ambiguity resolution primers (HAPRs) methods. The relative probability of true genotypes was calculated by using allele frequencies and was compared with true results. The results indicated that the relative probability of true genotype > 95% in 220 HLA-A ambiguous samples, 238 HLA-B ambiguous samples and 107 HLA-DRB1 ambiguous samples were 99.5% (221/222), 95.8% (228/238) and 97.7% (104/107) respectively. As compared with phenotyping results detected by PCR-SSP and HARP methods, the matching ratios for HLA-A, HLA-B and HLA-DRB1 loci were 100% (222/222), 99.6% (237/238) and 99.1% (106/107) respectively, while the mismatch genotypes were observed only in B*3501/5501 and DRB1*1241/1504, the relative probability of them were 40.3% and 2.1% respectively. It is concluded that the detection method using allele frequencies to directly identify the ambiguous HLA genotypes in large scale PCR-SBT genotyping of donors not only can give higher accurate and reliable results, but also is a simple, rapid and cost-saving method. This method has to be used with great care in the identify-test of patient-donor pair before the transplantation.

DRB1 * 1454: the common allele of human leukocyte antigen-DRB1 * 14 in Chinese Han populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate and compare the distribution of HLA-DRB1 * 14 alleles between the southern and northern Chinese Han populations.</p><p><b>METHODS</b>Human leukocyte antigen (HLA)-DRB1 alleles of 436 southern and 713 northern Chinese Han bone marrow volunteers were genotyped by polymerase chain reaction (PCR)-sequence-based-typing (SBT) method, among them the DRB1 * 1401/1439/1454 ambiguous allele pairs were identified using DRB1 * 14 high-resolution PCR-sequence specific primer (SSP) kits. Also, the clinic samples previously reported as DRB1 * 1401 were re-genotyped using the same PCR-SSP kits. The allelic distribution of DRB1 * 14 in southern and northern Chinese Han population were compared by chi-square test method.</p><p><b>RESULTS</b>Eighty-one ambiguous allele pairs of DRB1 * 1401/1439/1454 and 54 clinic samples previously reported as DRB1 * 1401 were all identified as DRB1 * 1454. Among the 436 Southern Han donors, six subtypes of DRB1 * 14 allele were observed including DRB1 * 1454 (69.57%), DRB1 * 1402 (1.45%), DRB1* 1403 (1.45%), DRB1 * 1404 (4.35%), DRB1 * 1405 (20.29%) and DRB1 * 1407 (2.90%). In the 713 northern Han donors, a total of seven subtypes were observed including DRB1 * 1454 (35.48%), DRB1 * 1403 (12.90%), DRB1 * 1404 (6.45%), DRB1 * 1405 (37.63%), DRB1 * 1407 (4.30%), DRB1 * 1411 (1.08%) and DRB1 * 1412 (2.15%).</p><p><b>CONCLUSION</b>DRB1 * 1454 and DRB1 * 1405 were the most common alleles of HLA-DRB1 * 14 in Chinese Han populations. The distribution of HLA-DRB1 * 14 differ significantly between the southern and northern Chinese Han population, while DRB1 * 1405 showed similar distribution pattern in the two populations but DRB1 * 1454 had higher frequency in southern than in northern Chinese Han population.</p>