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Abstract: Human leukocyte antigen (HLA), which is extremely polymorphic, plays an important role in stem cell transplantation. The Chinese Han comprise a large population of approximately 1.3 billion with diverse HLA alleles that need to be characterized. Data from 3,296 independent, unrelated Chinese Han individuals (1,457 recipients and 1,839 donors) were provided by the China Marrow Donor Program (CMDP) for donor–recipient confirmatory typing. Sequence-based typing, sequence-specific oligonucleotide probe (SSOP)/High Definition-SSOP, and sequence-specific primer methods were used to obtain 4-digit alleles. A total of 49, 86, 50, 63, and 24 HLA-A, -B, -C, -DRB1, and -DQB1 alleles were observed. Following American Society for Histocompatibility and Immunogenetics (ASHI) common and well-documented (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 are 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. 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 allele list. [Copyright &y& Elsevier]

Highlights from the article: With the goal of improving the population-specific criterion to distinguish KIR haplotypes in the region, we complemented the KIR genes and haplotypes data of Eastern Han based on a large population and analyzed the distribution of KIR2DS5 between locations in Centromeric (Cen) and Telomeric (Tel) regions which may differ in the protection that they provide in HSCT. In the family panel (n = 1196), a total of 28 KIR haplotypes were identified, including 2 group A haplotypes and 26 group B haplotypes. The study on the distribution of KIR genes in the population may develop a complemented population-specific criterion to distinguish KIR haplotypes and indicate the direction for further gene functional studies.

Highlights from the article: According to simulation haplotype analysis of insufficient related donor haplotypes considering complete family haplotype table, better related donor can be selected for haploidentical transplantation. According to the integrity of family-based HLA haplotype frequencies, we divided that 3568 families into 3groups, including group1, that 1422 complete family-based HLA haplotype frequencies; group2, containing 1310 patients and one of their either parents or children and group3, that 836 patients and their HLA-5/10 matching sibling donor. According to simulation haplotype analysis of insufficient related donor haplotypes considering complete family haplotype table, better related donor can be selected for haploidentical transplantation.

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 To investigate the impact of patients with anti-HLA antibodies or with donors mismatched at HLA-DP locus on outcomes after unrelated-donor hematopoietic stem cell transplantation (HSCT). Method We explored the data from 123 patients that received allo-HSCT matched for HLA-A, B, C, DRB1, DQB1, and DQA1 (12/12) from unrelated donors from the CMDP with a 2-year follow up. The examination of anti-HLA antibodies was scheduled at 3 time points: before the start of conditioning treatment and 1 month, 3 months after transplantation. Results The presence of anti-HLA antibodies detected before and 1 month, 3 months after transplantation was 37.4% (46/123), 40.2% (47/117), 22.6% (24/106), respectively. 16.4% (18/110) recipients with donors matched in HLA-DPA1 and HLA -DPB1 loci, and the mismatched rate was 83.6% (92/110). Patients with preformed anti-HLA antibodies had delayed platelet recovery. Anti-HLA antibodies detected before and after transplantation were responsible for increased occurrence of grade 2–4 acute graft-versus host disease (aGVHD) and reduced overall survival (OS), especially in acute myeloid leukemia and myelodysplastic syndrome patients. Pre-existing HLA-Ab was an independent risk factor for the GVHD and OS. Unfortunately, we found that HLA-DP mismatches have nothing to do with outcomes after transplantation. For HLA-Ab negative group, HLA-DP matched subgroup had a modest trend towards a lower rate of aGVHD, and a higher occurrence of OS and DFS compared with HLA-DP mismatched subgroup. Conclusions Our results suggest that anti-HLA antibodies detected before and after transplantation had a negative effect of outcomes, but HLA-DP loci mismatches have no significance after HLA- 12/12 matched unrelated donor of allo-HSCT. Anti-HLA antibodies should be the primary consideration in the setting of HLA 12/12-matched unrelated-donor HSCT, followed by the status of HLA-DP matching. [ABSTRACT FROM AUTHOR]

Aim To study the distributed characteristics of KIR2DL1 alleles frequencies and the recognition HLA-C ligand in the Chinese Han population. Methods The 111 patients and 116 donors from CMDP were performed the KIR2DL1 high-resolution typing and KIR genotyping using sequence-based testing (SBT) and PCR-SSP methods. Results A total of 224 individuals with KIR2DL1 locus was predominantly observed and accounted for 98.68% (224/227). There were 3 difference KIR2DL1 alleles, include of KIR2DL1 ∗ 00302, ∗ 00201 and ∗ 00401 alleles polymorphism. The most commonly of phenotype frequency were observed KIR2DL1 ∗ 00302(84.82%, 380/448), KIR2DL1 ∗ 00201 (12.05%, 54/448) and KIR2DL1 ∗ 00401 (3.13%, 14/448), present at allele genetype frequencies of 61.04%, 6.22% and 1.58%. The allele homozygotic type of KIR2DL1 ∗ 00302 and KIR2DL1 ∗ 00302 was the most frequency in the six gene complex of KIR2DL1 allele by high resolution typing. The allele heterozygous type of KIR2DL1 ∗ 00302 and KIR2DL1 ∗ 00401 had present statistically significant difference in haplotypes A/A and B/x( P = 0.001), and KIR2DL1 ∗ 00401 was lacked all A/A haplotype. The KIR2DL1 ∗ 00302 and KIR2DL1 ∗ 00201 allele had significant positive associations between different KIR pairs of KIR2DS1,KIR2DS4,KIR2DS5,KIR2DL3 and KIR3DL1/S1 using linkage disequilibrium analysis ( P ⩽ 0.001), respectively. In the receptor-ligand of KIR/HLA model after allo-HSCT, KIR2DL1 ∗ 00302 alleles and their HLA-C2 group ligands had correlation. KIR2DL1 ∗ 00302 and HLA-C ∗ 06:02 was the most common of combination ligand model, but KIR2DL1 ∗ 00302 and HLA-C ∗ 01:02 was the most frequent mismatch ligand model that it could be develop of NK cell-induced alloreactivity, meanwhile there was statistically significant difference of frequency distribution ( P < 0.05). Conclusion The KIR2DL1 ∗ 00302 is the most frequency allele in Chinese Han population. The KIR2DL1 high resolution typing would be beneficial for predicting donor NK cells alloactivity after hematopoietic stem cell transplantation and selecting suitable donors. [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 investigate the role of donor killer cell immunoglobulin-like receptor (KIR) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) and to develop a donor selection strategy for Chinese population. Methods In this 5-year retrospective study, we performed KIR genotyping on a total of 626 donor and recipient pairs by PCR-SSP. All patients underwent HSCT, comprising 219 HLA-identical sibling HSCT, 210 HLA-identical unrelated donor (URD) HSCT, and 197 HLA haplo-identical HSCT, for treatment of myeloid and lymphoid leukemia. Results Donor KIR genotypes and KIR gene motifs influenced transplantation outcomes for AML/MDS but not ALL/NHL patients in 3 models of transplants. In sibling HSCT for AML/MDS patients (n = 128), KIR mismatch between patient and donor had a better overall survival (OS; 87.3% versus 69.3%; P = 0.027) and reduced grade III to IV acute graft-versus-host disease (aGVHD; 4.6% versus 13.6%; P = 0.029). However, the effect was not observed in URD (n = 122) and haplo-identical HSCT (n = 108) for AML/MDS patients. Multivariate analysis indicated that centromeric B motifs contributed to improved survival in all models of transplants: (1) In sibling HSCT, donors’ haplotype cB-tA/tB were associated with improved OS compared with cA-tB (96.6% versus 71.2%; P = 0.021) or cA-tA (96.6% versus 72.1%; P = 0.017); (2) In URD-HSCT, donors with Cen -B were associated with a significantly improved OS (HR = 0.256; 95% CI, 0.084 to 0.774; P = 0.016) and RFS (HR = 0.252; 95% CI, 0.084 to 0.758; P = 0.014); (3) In haplo-identical HSCT, the same effect of Cen -B was observed on OS (HR, 0.335; 95% CI, 0.164 to 0.667; P = 0.002), RFS (HR, 0.331; 95% CI, 0.167 to 0.657; P = 0.002), and NRM (HR, 0.286; 95% CI, 0.120 to 0.683; P = 0.005). Regarding the KIR genotypes, compared with other donor KIR B/x genotypes: (1) In sibling HSCT, genotype Bx1 was a risk factor for lower OS (HR, 8.667; 95% CI, 2.321 to 32.37; P = 0.001) and RFS (HR, 9.207; 95% CI, 2.631 to 32.22; P = 0.001); (2) The same negative effect of Bx1 was also found in URD-HSCT (OS: P = 0.047; RFS: P = 0.041) and haplo-identical HSCT (OS: P = 0.002; RFS: P = 0.002). Conclusions Avoiding the selection of Bx1 donors is strongly advisable for AML/MDS patients undergoing both related and unrelated HSCT whereas the presence of the Cen -B motifs was rather recommended in donor selection. [ABSTRACT FROM AUTHOR]

Aim To investigate the impact of donor Killer Immunoglobulin-like Receptors (KIR) genotypes and centromeric motif B (Cen-B) on clinical outcomes after unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) for Chinese population. Method A total of 210 Chinese patients underwent URD-HSCT were investigated in this 4-year retrospective study. KIR genotyping and HLA typing were performed for the population. Results The risk of transplant from Bx1 donors and the benefit of the presence of Cen-B (ignoring the number) were observed for standard risk AML/MDS patients Donor KIR genotype Bx was associated with significant improved OS (P = .026) and RFS (P = .021), and reduced NRM (P = .017) for AML/MDS patients. A much worse survival was observed for transplants from Bx1donors compared to Bx2, Bx3, and Bx4 donors for patients in CR1, ( n = 82; OS: P = .024; RFS: P = .021). Transplant form donors with Cen-B improved OS (HR = .256; 95% CI = .084 to .774; P = .016) and RFS (HR = .252; 95% CI = .084 to .758; P = .014) for AML/MDS patients in CR1. However, the effect did not increase with the number of Cen-B motifs (cB/B vs. cA/B; OS: P = .755; RFS: P = .768). No effect was observed for high risk AML/MDS and ALL/NHL, CML patients. Conclusions Avoiding the selection of HSCT donors with KIR genotype Bx1 is strongly advisable for AML/MDS patients of standard risk. The presence of cen-B motif rather than the number was more important in donor selection for Chinese population. [ABSTRACT FROM AUTHOR]

Aim To analyze the association between CYP3A5 single nucleotide polymorphisms (SNPs) and tacrolimus (Tac) or cyclosporine (CsA) level in renal transplant recipients during a 4-year follow-up. Methods 103 renal transplant patients were recruited and assigned into three groups according to their CYP3A5 allele ∗ 3/ ∗ 3, ∗ 1/ ∗ 3, or ∗ 1/ ∗ 1. The concentrations of Tac or CsA at time zero (C0) were measured before the drug administration. And the association between different alleles with Tac or CsA dose-adjusted C0 were further analyzed. Results During the first month after transplantation, recipients with CYP3A5 ∗ 3/ ∗ 3 allele exhibited significantly higher Tac C0 than the recipients with CYP3A5 ∗ 1/ ∗ 1 allele. The Tac dose/day used for recipients with CYP3A5 ∗ 3/ ∗ 3 allele was significantly lower than that for recipients with CYP3A5 ∗ 1/ ∗ 1 or CYP3A5 ∗ 1/ ∗ 3 allele. The Tac C0 of recipients with CYP3A5 ∗ 3/ ∗ 3 allele was significantly difference than that of the recipients with CYP3A5 ∗ 1/ ∗ 3 and CYP3A5 ∗ 1/ ∗ 1 allele at 3 months, 6 months, 12 months, 24 months and 48 months respectively during the 4-year follow-up after transplantation. The trough concentrations/doses of CsA were not associated with the CYP3A5 SNPs. Conclusion Patients with homozygous CYP3A5 ∗ 3/ ∗ 3 allele need less dosage of Tac to maintain a therapeutic concentration after renal transplantation. [ABSTRACT FROM AUTHOR]