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To analyse the effect of HLA-DPA1 and HLA-DPB1 allelic mismatches on the outcomes of unrelated donor haematopoietic stem cell transplantation (URD-HSCT), we collected 258 recipients with haematological disease who underwent HLA-10/10 matched URD-HSCT. HLA-A, -B, -C, -DRB1, -DQB1, -DRB3/4/5, -DQA1, -DPA1 and -DPB1 typing was performed for the donors and recipients using next-generation sequencing (NGS) technology. After excluding 8 cases with DQA1 or DRB3/4/5 mismatches, we included 250 cases with HLA-14/14 matching for further analysis. Our results showed that the proportion of matched DPA1 and DPB1 alleles was only 10.4% (26/250). The remaining 89.6% of donors and recipients demonstrated DPA1 or DPB1 mismatch. In the DPA1 matched and DPB1 mismatched group, accounting for 18.8% (47/250) of the cohort, DPB1*02:01/DPB1*03:01 allelic mismatches were associated with decreased 2-year OS and increased NRM. DPB1*02:02/DPB1*05:01 and DPB1*02:01/DPB1*05:01 mismatches showed no impact on outcomes. Moreover, the specific allelic mismatches observed were consistent with the DPB1 T-cell epitope (TCE) classification as permissive and non-permissive. We innovatively established an analysis method for DPA1 ~ DPB1 linkage mismatch for cases with both DPA1 and DPB1 mismatched, accounting for 70% (175/250) of the total. DPA1*02:02 ~ DPB1*05:01/DPA1*02:01 ~ DPB1*17:01 linkage mismatches were associated with lower 2-year OS, especially among AML/MDS recipients. DPA1*02:02 ~ DPB1*05:01/DPA1*01:03 ~ DPB1*02:01 linkage mismatches showed no impact on outcomes. In conclusion, applying the DPA1 ~ DPB1 linkage mismatch analysis approach can identify different types of mismatches affecting transplant outcomes and provide valuable insight for selecting optimal donors for AML/MDS and ALL recipients., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The focus of this study was to analyze polymorphisms in the HLA gene at 11 loci in 4845 Chinese Han populations using next‐generation sequencing methods, and to compare common and well‐documented (CWD) allelic differences between China and other CWD lists. A total of 44 DPB1 alleles, 13 DPA1 alleles, 20 DQA1 alleles and 19 DRB3/4/5 alleles were detected in this study. About 20%–50% of the CWD alleles in China differ from the American Society for Histocompatibility and Immunogenetics and European Federation for Immunogenetics (EFI) data. The revised list of HLA‐CWD alleles in the Han population will provide additional data for the update of the IMGT/HLA database and contribute to a better understanding of hematopoietic stem cell transplantation and organ transplantation. [ABSTRACT FROM AUTHOR]

We collected HLA typing data from 653 families in the Eastern Han Chinese population. HLA‐A, B, C, DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, and DPB1 (HLA‐11 loci) typing of 1781 subjects was performed using a commercial next‐generation sequencing (NGS) method in our laboratory. The phasing of haplotypes in each family was determined by Mendelian segregation. Haplotype analysis revealed 1634 different haplotypes among a total of 2230 haplotypes. The predominant haplotype was A*30:01‐C*06:02‐B*13:02‐DRB1*07:01‐DRB4*01:03‐DQA1*02:01‐DQB1*02:02‐DPA1*02:01‐DPB1*17:01 (HF = 4.04%), followed by A*02:07‐C*01:02‐B*46:01‐DRB1*09:01‐DRB4*01:03‐DQA1*03:02‐DQB1*03:03‐DPA1*02:02‐DPB1*05:01 (HF = 1.84%) and A*33:03‐C*03:02‐B*58:01‐DRB1*03:01‐DRB3*02:02‐DQA1*05:01‐DQB1*02:01‐DPA1*01:03‐DPB1*04:01 (HF = 1.48%), accounting for 7.35% of the total. Meanwhile 76.41% of all haplotypes were observed only once or twice (HF < 0.1%). Different from HLA‐DRB3/4/5 and DQA1 loci, DP linkage markedly increased haplotype variation by 34.82% based on the 5‐locus haplotype. The much weaker linkage disequilibrium (LD) of DQB1‐DPB1 indicated the reason. We observed 10 analyzable recombination events, most of which occurred at DP loci. Even with the same common 5‐locus haplotype, HLA‐DP linkage alters the haplotype diversity and frequency. Analysis of related haplotype assignment and unrelated recipient‐donor pairs matching at the 9‐locus haplotype revealed that HLA‐DP affects the donor selection strategy. Haplotype study of a large sample size using NGS identified linkage haplotypes beyond the 5 loci. LD, recombination events, and haplotype variation caused by DP loci emphasized that HLA 9‐locus haplotype matching should be considered in donor selection, particularly the effect of DP loci. The finding lays the foundation for further studies on the effect of HLA‐DP mismatch on transplantation. [ABSTRACT FROM AUTHOR]

Abstract: Killer cell immunoglobulinlike receptors (KIRs) are a diverse family of receptors on natural killer cells. The KIR2DS4-deleted variant differs from the normal KIR2DS4 sequence by a 22-bp deletion in exon 5, which causes a frame shift, yielding a truncated KIR2DS4 protein with loss of the transmembrane and cytoplasmic domains of the full-length KIR2DS4 protein. A sequence-based testing and TOPO TA cloning system identifying and distinguishing alleles of the KIR2DS4 gene was established. The method was applied to 150 Chinese Han individuals: 75 patients who received T-depleted hematopoietic stem cells transplantation and their unrelated donors, establishing frequencies of 2DS4 allele and KIR gene within the local population. A majority (139) of the 150 samples (92.7%) were positive for KIR2DS4. The ratio of deleted to nondeleted versions of KIR2DS4 was approximately 1:2. Three KIR2DS4 novel alleles were identified. Forty-four percent individuals carried two group A haplotypes. The 17 KIR gene loci were found in 21.3%–100% in the population. Our findings suggest that the Chinese Han population is distinct in KIR gene frequencies and 2DS4 allele frequencies in comparison with some other populations. [Copyright &y& Elsevier]

Aim To analyze allele mismatches of HLA-A, -B, -C, -DRB1, -DQB1 and haplotype mismatch of donor-recipient pairs on the outcome of haploidentical transplantation combined with a third part cord blood unit. Methods 230 pairs of donor-recipient were performed HLA-A, B, C, DRB1, DQB1 typing using SBT and SSOP methods from January 2012 to December 2014. Results Pairs were divided into HLA-5/10, 6/10, 7/10 and ⩾8/10 groups according to HLA-A, B, C,DRB1 and DQB1 high resolution typing and matched degrees, the 3-year probability of overall survival (OS) for each group were 48.7%, 59.3%, 71.1%, 38.3%( P = 0.068) respectively. HLA>6/10 matched group associated with significant favorable effect on OS compared with HLA-5/10 matched one ( P = 0.041).When the HLA class I antigen matched on the recipient and donor, improved OS and event free survival (EFS) in HLA-6/10 matched group than in HLA-5/10 matched one ( P = 0.017, P = 0.088), especially in single HLA-A loci allele matched one ( P = 0.013, P = 0.013), were observed. As to the third part cord blood unit, sharing the same haplotype with the recipient-donor pairs produced better platelet recovery than the misfit one (95.3% vs 86.2%, P = 0.007), similar result was found in terms of neutrophil recovery (98.8% vs 96.1%, P = 0.022). Conclusions HLA locus mismatch and haplotype mismatch of the donor and recipient should be useful for selection of the most optimum donor. Co-infused of an unrelated cord blood unit sharing the same haplotype with the recipient-donor pairs could improve hematopoietic recovery. [ABSTRACT FROM AUTHOR]

Aim: Human Leukocyte Antigens (HLA), which is extremely polymorphic, plays an important role in stem cell transplantation. The Chinese Han comprise a large population of approximate 1.3 billion with diverse HLA alleles need to be characterized. Methods: Data from 3296 independent, unrelated Chinese Han individuals (1457 recipients and 1839 donors) were provided by China Marrow Donor Program (CMDP) for donor-recipient confirmatory typing. SBT, SSOP/HD-SSOP and SSP methods were used to obtain 4-digit alleles. Results: A total of 49, 86, 50, 63 and 24 HLA-A, B, C, DRB1, and DQB1 alleles were observed. Following ASHI CWD criteria, CWD alleles for Chinese Han in our laboratory test and other laboratory reports do not quite correlate with the ASHI CWD alleles: A∗11:53, A∗02:34, A∗02:53N, B∗27:24, B∗46:02, B∗55:12, C∗01:06, C∗03:17, C∗06:06, C∗07:66, C∗07:67, C∗08:22, DRB1∗12:10, DQB1∗03:13 and DQB1∗06:05 are CWD, but are not included in the ASHI CWD list. A series of alleles are Well-Documented alleles and listed in the ASHI CWD list. Conversely, A∗26:03, B∗51:03, C∗12:05, C∗15:09, C∗15:11, C∗17:03, DRB1∗11:07, DRB1∗11:11, DRB1∗13:05, DRB1∗13:13, DRB1∗14:06, DRB1∗14:12, DRB1∗14:22, DRB1∗14:25 and DQB1∗06:11 are rare alleles, but are included in the ASHI CWD list. Conclusions: HLA Ethnic diversity is the main reason for the differences in HLA alleles worldwide. The ASHI HLA CWD alleles help reduce the workload and expenses in high-resolution donor registries and the HLA allele frequencies provide a basis from which to predict the chances of finding HLA matching donors. Our data will be meaningful for the CMDP, for other worldwide donor registries, and for an updated ASHI CWD alleles list. [Copyright &y& Elsevier]