Cord blood index predicts engraftment and early non-relapse mortality in adult patients with single-unit cord blood transplantation.

How to select optimal cord blood (CB) remains an important clinical question. We developed and validated an index of CB engraftment, the cord blood index (CBI), which uses three weighted variables representing cell doses and HLA mismatches. We modeled the neutrophil engraftment time with competing events by random survival forests for competing risks as a function of the predictors: total nucleated cells, CD34, colony-forming units for granulocytes/macrophages, and the number of HLA mismatches at the antigen and allele levels. The CBI defined three groups that had different neutrophil engraftment rates at day 30 (High, 83.7% [95% CI, 79.2-88.1%]; Intermediate, 77.0% [95% CI, 73.7-80.2%]; Low, 68.4% [95% CI, 63.6-73.2%]), platelet engraftment rates at day 60 (High, 70.4% [95% CI, 64.9-75.9%]; Intermediate, 62.3% [95% CI, 58.5-66.0%]; Low, 49.3% [95% CI, 44.2-54.5%]), and non-relapse mortality at day 100 (High, 14.1% [95% CI, 9.9-18.3%]; Intermediate, 16.4% [95% CI, 13.5-19.3%]; Low, 21.3% [95% CI, 17.1-25.5%]). This novel approach is clinically beneficial and can be adopted immediately because it uses easily obtained pre-freeze data of CB.

Combined impact of HLA-allele matching and the CD34-positive cell dose on optimal unit selection for single-unit cord blood transplantation in adults.

The combined effects of HLA-allele matching at six-loci (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1) and CD34+ cell dose on clinical outcomes were analyzed in 1,226 adult cases with single-unit unrelated cord blood transplantation. In the six-loci analysis, low HLA-allele matches did not significantly increase the overall mortality compared to higher matches, whereas in the five-loci analysis excluding HLA-DPB1, they caused a higher overall mortality (HR 1.42, p = .002), possibly due to the graft-versus-leukemia effect of HLA-DPB1 mismatches. A lower CD34+ cell dose (<.50 × 105/kg) resulted in higher mortality and lower engraftment; these inferior outcomes were offset by high HLA-allele matches (7-10/10 match), while the inferior outcomes of low HLA-allele matches were improved by increasing the CD34+ cell dose. Consideration of the combined effects of the CD34+ cell dose and HLA matching may expand the options for transplantable units when HLA matching or the CD34+ cell dose is inadequate.

Donor UNC-93 Homolog B1 genetic polymorphism predicts survival outcomes after unrelated bone marrow transplantation.

UNC-93 homolog B1 (UNC93B1) is a key regulator of toll-like receptors (TLRs), pattern recognition receptors that sense invading pathogens and manage the innate immune response and deliver them from the endoplasmic reticulum to their respective endosomal signaling compartments. Several types of TLRs are known to contribute to the inflammatory process after allogeneic hematopoietic stem cell transplantation (SCT), so UNC93B1 might play integral roles there. We investigated the influence of the UNC93B1 single-nucleotide polymorphism (SNP) rs308328 (T>C) on transplant outcomes in a cohort of 237 patients undergoing unrelated HLA-matched bone marrow transplantation (BMT) for hematologic malignancies through the Japan Marrow Donor Program. The donor UNC93B1 C/C genotype was associated with a better 3-year overall survival than the donor UNC93B1 C/T or T/T genotype. An analysis of the UNC93B1 rs308328 genotype may therefore be useful for selecting the donor, estimating the prognosis, and creating therapeutic strategies after allogeneic SCT.

Resistance of KIR Ligand-Missing Leukocytes to NK Cells In Vivo in Patients with Acquired Aplastic Anemia.

The loss of killer cell Ig-like receptor ligands (KIR-Ls) due to the copy number-neutral loss of heterozygosity of chromosome 6p (6pLOH) in leukocytes of patients with acquired aplastic anemia (AA) may alter the susceptibility of the affected leukocytes to NK cell killing in vivo. We studied 408 AA patients, including 261 who were heterozygous for KIR-Ls, namely C1/C2 or Bw6/Bw4, for the presence of KIR-L-missing [KIR-L(-)] leukocytes. KIR-L(-) leukocytes were found in 14 (5.4%, C1 [n = 4], C2 [n = 3], and Bw4 [n = 7]) of the 261 patients, in whom corresponding KIR(+) licensed NK cells were detected. The incidence of 6pLOH in the 261 patients (18.0%) was comparable to that in 147 patients (13.6%) who were homozygous for KIR-L genes. The percentages of HLA-lacking granulocytes (0.8-50.3%, median 15.2%) in the total granulocytes of the patients with KIR-L(-) cells were significantly lower than those (1.2-99.4%, median 55.4%) in patients without KIR-L(-) cells. KIR2DS1 and KIR3DS1 were only possessed by three of the 14 patients, two of whom had C2/C2 leukocytes after losing C1 alleles. The expression of the KIR3DS1 ligand HLA-F was selectively lost on KIR-L(-) primitive hematopoietic stem cells derived from 6pLOH(+) induced pluripotent stem cells in one of the KIR3DS1(+) patients. These findings suggest that human NK cells are able to suppress the expansion of KIR-L(-) leukocytes but are unable to eliminate them partly due to the lack of activating KIRs on NK cells and the low HLA-F expression level on hematopoietic stem cells in AA patients.

Donor Heme Oxygenase-1 Promoter Gene Polymorphism Predicts Survival after Unrelated Bone Marrow Transplantation for High-Risk Patients.

Heme oxygenase-1 (HO-1), an intracellular enzyme that catalyzes the degradation of heme into biliverdin, free iron, and carbon monoxide, exerts anti-inflammatory and cytoprotective effects against endothelial cell injury. The HO-1 promoter gene has one important single-nucleotide polymorphism (SNP) rs2071746 (-413A>T) that is functional, and the A allele has been reported to be associated with higher HO-1 expression levels than the T allele. We investigated the influence of the HO-1 rs2071746 SNP on the transplant outcomes in 593 patients with hematological malignancies undergoing unrelated, human leukocyte antigen (HLA)-matched, T-cell-replete bone marrow transplantation (BMT) through the Japan Donor Marrow Program. In patients with high-risk diseases, the donor A/A or A/T genotype was associated with better 5 year overall survival (35% vs. 25%; p = 0.03) and 5 year disease-free survival (35% vs. 22%; p = 0.0072), compared to the donor T/T genotype. These effects were not observed in patients with low-risk diseases. The current findings therefore indicate that HO-1 rs2071746 genotyping could be useful for selecting donors and tailoring transplant strategies for patients with high-risk hematologic malignancies.

Recipient ADAMTS13 Single-Nucleotide Polymorphism Predicts Relapse after Unrelated Bone Marrow Transplantation for Hematologic Malignancy.

Relapse remains a major obstacle to the survival of patients with hematologic malignancies after allogeneic hematopoietic stem cell transplantation. A disintegrin-like and metalloprotease with a thrombospondin type 1 motif (ADMATS13), which cleaves von Willebrand factor multimers into less active fragments, is encoded by the ADAMTS13 gene and has a functional single-nucleotide polymorphism (SNP) rs2285489 (C > T). We retrospectively examined whether ADAMTS13 rs2285489 affected the transplant outcomes in a cohort of 281 patients who underwent unrelated human leukocyte antigen (HLA)-matched bone marrow transplantation for hematologic malignancies. The recipient ADAMTS13 C/C genotype, which putatively has low inducibility, was associated with an increased relapse rate (hazard ratio [HR], 3.12; 95% confidence interval [CI], 1.25⁻7.77; P = 0.015), resulting in a lower disease-free survival rate in the patients with a recipient C/C genotype (HR, 1.64; 95% CI, 1.01⁻2.67; P = 0.045). Therefore, ADAMTS13 rs2285489 genotyping in transplant recipients may be a useful tool for evaluating pretransplantation risks.

Risk of HLA Homozygous Cord Blood Transplantation: Implications for Induced Pluripotent Stem Cell Banking and Transplantation.

Clinical application of induced pluripotent stem cells (iPS) in autologous settings has just begun. To overcome the high time and cost barriers in the individual production of autologous iPS, the use of allogeneic iPS with a homozygous human leukocyte antigen (HLA) haplotype (HLA-homo HP) has been proposed. Cord blood transplantation (CBT) is a suitable model for evaluating the allogeneic immunogenicity of iPS transplantation from HLA-homo donors. We analyzed 1,374 Japanese single cord blood transplant pairs who were retrospectively typed as HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1. Among these, six pairs with donor HLA homo-patient-HLA hetero (homo-hetero) were found, all of which showed favorable neutrophil engraftment. Multivariate analysis revealed a significantly elevated engraftment risk (HR = 1.59) compared with hetero-hetero pairs with HLA 1-2 locus mismatch (789 pts) and comparative risk (HR = 1.23) compared with hetero-hetero pairs with 0 mismatch (104 pts). These results for CBT with HLA-homo HP cord blood carry an important implication, namely the possibility that HLA-homo iPS transplantation results in favorable engraftment. Furthermore, we obtained detailed information on HLA alleles and haplotypes of HLA-homo. All donor HLA-homo HPs had a common specific ethnicity and high conservation of the HLA region, and one of two patient heterogeneous HPs invariably shared the same HP as donor HLA-homo HP, and another non-shared patient HP was mismatched with 1 to 4 HLA alleles of HLA-A, -B, -C, and -DRB1 loci in the GVH direction. These findings indicate that patients possessing a single common HLA haplotype have a higher chance of yielding HLA-homo iPS. Stem Cells Translational Medicine 2018;7:173-179.

Evolutionary basis of HLA-DPB1 alleles affects acute GVHD in unrelated donor stem cell transplantation.

HLA-DPB1 T-cell epitope (TCE) mismatching algorithm and rs9277534 SNP at the 3' untranslated region (3'UTR) in the HLA-DPB1 gene are key factors for transplant-related events in unrelated hematopoietic cell transplantation (UR-HCT). However, the association of these 2 mechanisms has not been elucidated. We analyzed 19 frequent HLA-DPB1 alleles derived from Japanese healthy subjects by next-generation sequencing of the entire HLA-DPB1 gene region and multi-SNP data of the HLA region in 1589 UR-HCT pairs. The risk of acute graft-versus-host disease (aGVHD) was analyzed in 1286 patients with single HLA-DPB1 mismatch UR-HCT. The phylogenetic tree constructed using the entire gene region demonstrated that HLA-DPB1 alleles were divided into 2 groups, HLA-DP2 and HLA-DP5. Although a phylogenetic relationship in the genomic region from exon 3 to 3'UTR (Ex3-3'UTR) obviously supported the division of HLA-DP2 and HLA-DP5 groups, which in exon 2 showed intermingling of HLA-DPB1 alleles in a non-HLA-DP2 and non-HLA-DP5-group manner. Multi-SNP data also showed 2 discriminative HLA-DPB1 groups according to Ex3-3'UTR. Risk of grade 2-4 aGVHD was significantly higher in patient HLA-DP5 group mismatch than patient HLA-DP2 group mismatch (hazard ratio, 1.28; P = .005), regardless of donor mismatch HLA-DP group. Regarding TCE mismatch, increasing risk of aGVHD in patient HLA-DP5 group mismatch and TCE-nonpermissive mismatch were observed only in patients with TCE-permissive mismatch and patient HLA-DP2 group mismatch, respectively. Evolutionary analysis revealed that rs9277534 represented a highly conserved HLA-DPB1 Ex3-3'UTR region and may provoke aGVHD differently to TCE mismatching algorithm, reflecting exon 2 polymorphisms. These findings enrich our understanding of the mechanism of aGVHD in HLA-DPB1 mismatch UR-HCT.

The recipient CCR5 variation predicts survival outcomes after bone marrow transplantation.

The chemokine receptor CCR5 plays roles in the trafficking of effector cells towards the site of inflammation. We retrospectively examined the impact of the CCR5 variation (rs1800023, -2086A>G) on transplant outcomes in a cohort of 329 patients who underwent unrelated HLA-matched bone marrow transplantation (BMT) for hematologic malignancies through the Japan Marrow Donor Program. A multivariate analysis showed that the recipient CCR5 -2086A/A genotype was significantly associated with a lower relapse rate but not with the development of graft-versus-host disease (GVHD) or transplant-related mortality, thereby resulting in better disease-free and overall survival rates than other variations. The donor CCR5 -2086A/A genotype was associated with a lower incidence of grades 3-4 acute GVHD, which did not improve the survival outcomes. These findings suggest that the recipient CCR5 -2086A/A genotype affects the induction of the graft-versus-tumor effect without augmenting the development of GVHD. CCR5 genotyping in transplant recipients may therefore be a useful tool for evaluating pretransplantation risks.

Toll-like receptor genetic variations in bone marrow transplantation.

The Toll-like receptor family mediates the innate immune system through recognizing the molecular patterns of microorganisms and self-components and leading the synthesis of the inflammatory mediators. We retrospectively examined whether or not genetic variations in toll-like receptor 1 (rs5743551, -7202GQ>A), toll-like receptor 2 (rs7656411, 22215G>T), and toll-like receptor 4 (rs11536889, +3725G>C) affected transplant outcomes in a cohort of 365 patients who underwent unrelated HLA-matched bone marrow transplantation (for hematologic malignancies through the Japan Marrow Donor Program. Only donor toll-like receptor 4 variation significantly improved the survival outcomes. A multivariate analysis showed that the donor toll-like receptor 4 +3725G/G genotype was significantly associated with a better 5-year progression-free survival and a lower 5-year transplant-related mortality than other variations. Furthermore, the donor toll-like receptor 4 +3725G/G genotype was associated with a significantly lower incidence of fatal infections than other variations. The validation study of 502 patients confirmed that the donor toll-like receptor 4 +3725G/G genotype was associated with better survival outcomes. Toll-like receptor4 genotyping in transplant donors may therefore be a useful tool for optimizing donor selection and evaluating pretransplantation risks.

Identification of an HLA class I allele closely involved in the autoantigen presentation in acquired aplastic anemia.

To identify HLA alleles closely involved in the autoantigen presentation in acquired aplastic anemia (AA), we studied the HLA allelic loss frequencies of 312 AA patients, including 43 patients with loss of heterozygosity of 6p chromosome (6pLOH). An analysis of the HLA alleles contained in the lost haplotype revealed HLA-B*40:02 to be the most frequently lost allele. When we examined 28 AA (12 6pLOH[+] and 16 6pLOH[-]) patients with HLA-B*40:02 for the presence of leukocytes lacking HLA-B4002 (B4002-) using a new monoclonal antibody specific to this allele, B4002- granulocytes were detected not only in all 6pLOH(+) patients but also in 9 (56%) of the 16 6pLOH(-) patients. Furthermore, 10 (83%) of the 12 6pLOH(+) patients possessed 1.0% to 78% B4002- granulocytes that retained the HLA-A allele on the same haplotype (B4002-A+), suggesting the frequent coexistence of granulocytes that underwent mutations restricted to HLA-B*40:02 with 6pLOH(+) (B4002-A-) granulocytes. Deep sequencing of the HLA-B*40:02 of sorted B4002-A+ granulocytes revealed various somatic mutations, such as frameshift, nonsense, and splice site mutations, in all 15 patients studied. Surprisingly, missense mutations in the α-3 domain of HLA-B*40:02 that are not involved in the antigen presentation were detected exclusively in the B4002+ granulocytes of 3 patients possessing B4002- granulocytes. The markedly high prevalence of leukocytes lacking HLA-B4002 as a result of either 6pLOH or structural gene mutations, or both, suggests that antigen presentation by hematopoietic stem/progenitor cells to cytotoxic T cells via the HLA-B allele plays a critical role in the pathogenesis of AA.

High-density Association Mapping and Interaction Analysis of PLA2R1 and HLA Regions with Idiopathic Membranous Nephropathy in Japanese.

Although recent studies showed anti-PLA2R antibody plays a crucial role in idiopathic membranous nephropathy (IMN), detailed HLA mapping and interaction between the HLA genes and PLA2R1 have not been investigated in IMN. We genotyped across the PLA2R1 gene and the HLA region, using 183 IMN patients and 811 healthy controls. Five SNPs around the PLA2R1 gene were significantly associated with IMN. In addition to the two SNPs previously reported to be strongly associated with IMN, rs3749119 and rs35771982 (OR 3.02 and 2.93, P = 3.24E-14 and 4.64E-14, respectively), two novel intronic SNPs (rs2715928 and rs16844715) were also identified as IMN-associated SNPs (OR = 2.30 and 2.51, P = 3.15E-10 and 5.66E-13, respectively). In the HLA gene analysis, DRB1*1501 and DQB1*0602 were strongly associated with IMN (P = 1.14E-11 and 1.25E-11, respectively). The interaction was strongest between HLA-DRB1*15:01 - HLA-DQB1*06:02 and the intronic SNP rs2715928 (OR = 17.53, P = 4.26E-26). Furthermore, positive interaction was also observed between HLA-DRB1*15:01 - HLA-DQB1*06:02 and the missense SNP rs35771982 (OR = 15.91, P = 2.76E-29), which is in strong linkage disequilibrium with 5'UTR SNP rs3749119, and intronic SNP rs16844715 (OR = 15.91, P = 2.30E-26) for IMN. Neither HLA-DRB1*15:01 nor HLA-DQB1*06:02 was associated with steroid responsiveness, overall survival and renal survival during the observation period of mean 11 years though limited number of analysis.

Toll-like receptor 1 variation increases the risk of transplant-related mortality in hematologic malignancies.

Toll-like receptor 1 (TLR1) genetic variant (rs5743551, -7202A>G) has been reported to be associated with susceptibility to various infectious diseases. We retrospectively examined the impact of TLR1 variation on transplant outcomes in a cohort of 320 patients who underwent unrelated HLA-matched bone marrow transplantation (BMT) for hematologic malignancies. A multivariate analysis showed that the G/G genotype in the recipients and the donors was associated with a significantly lower 3-year transplant-related mortality (TRM). The recipient G/G genotype also resulted in a better 3-year progression-free survival. This study suggests that the recipient and donor TLR1 G/G genotypes are comparably associated with a reduced risk of death that was not related to relapse. Thus, TLR1 genotyping may be useful for selecting the donor, managing patients in a risk-adapted manner, and creating therapeutic strategies to prevent complications after hematopoietic stem cell transplantation.

Aberrant PD-L1 expression through 3'-UTR disruption in multiple cancers.

Successful treatment of many patients with advanced cancer using antibodies against programmed cell death 1 (PD-1; also known as PDCD1) and its ligand (PD-L1; also known as CD274) has highlighted the critical importance of PD-1/PD-L1-mediated immune escape in cancer development. However, the genetic basis for the immune escape has not been fully elucidated, with the exception of elevated PD-L1 expression by gene amplification and utilization of an ectopic promoter by translocation, as reported in Hodgkin and other B-cell lymphomas, as well as stomach adenocarcinoma. Here we show a unique genetic mechanism of immune escape caused by structural variations (SVs) commonly disrupting the 3' region of the PD-L1 gene. Widely affecting multiple common human cancer types, including adult T-cell leukaemia/lymphoma (27%), diffuse large B-cell lymphoma (8%), and stomach adenocarcinoma (2%), these SVs invariably lead to a marked elevation of aberrant PD-L1 transcripts that are stabilized by truncation of the 3'-untranslated region (UTR). Disruption of the Pd-l1 3'-UTR in mice enables immune evasion of EG7-OVA tumour cells with elevated Pd-l1 expression in vivo, which is effectively inhibited by Pd-1/Pd-l1 blockade, supporting the role of relevant SVs in clonal selection through immune evasion. Our findings not only unmask a novel regulatory mechanism of PD-L1 expression, but also suggest that PD-L1 3'-UTR disruption could serve as a genetic marker to identify cancers that actively evade anti-tumour immunity through PD-L1 overexpression.

Clinical significance and origin of leukocytes that lack HLA-A allele expression in patients with acquired aplastic anemia.

To gain insight into the origin and clinical significance of leukocytes that lack human leukocyte antigen A (HLA-A) allele expression caused by a copy-number-neutral loss of heterozygosity in the short arm of chromosome 6 in patients with acquired aplastic anemia (AA), we used a high-sensitivity flow cytometry assay to investigate the presence of HLA-A allele-lacking leukocytes (HLA-LLs) in 144 AA patients. HLA-LLs, accounting for 0.2-99.8% of each leukocyte population, were detected in 18 of 71 (25.4%) newly diagnosed patients and in 25 of 73 (34.2%) previously treated patients. The lineage combination patterns of the HLA-LLs in the 43 HLA-LL(+) patients were granulocytes (Gs), monocytes (Ms), B cells (Bs), and T cells (Ts; GMBT) in 13 cases, GMB in 16 cases, GM in 11 cases, and B alone in three cases. The response rate to antithymocyte globulin plus cyclosporine therapy (100%) and the 2-year, failure-free survival rate (100%) in 8 newly diagnosed HLA-LL(+) patients were significantly higher than in 23 HLA-LL(-) patients (52.2% for both). These data suggest that HLA-LLs are a useful marker of the presence of immune pathophysiology in AA and that T-cell attacks against hematopoietic progenitor cells, rather than against hematopoietic stem cells, can trigger bone marrow failure in AA patients.

High-risk HLA alleles for severe acute graft-versus-host disease and mortality in unrelated donor bone marrow transplantation.

HLA molecules play an important role for immunoreactivity in allogeneic hematopoietic stem cell transplantation. To elucidate the effect of specific HLA alleles on acute graft-versus-host disease, we conducted a retrospective analysis using 6967 Japanese patients transplanted with T-cell-replete marrow from an unrelated donor. Using unbiased searches of patient and donor HLA alleles, patient and/or donor HLA-B*51:01 (patient: HR, 1.37,P<0.001; donor: HR, 1.35,P<0.001) and patient HLA-C*14:02 (HR, 1.35,P<0.001) were significantly associated with an increased risk of severe acute graft-versus-host disease. The finding that donor HLA-C*14:02 was not associated with severe acute graft-versus-host disease prompted us to elucidate the relation of these high-risk HLA alleles with patient and donor HLA-C allele mismatches. In comparison to HLA-C allele match, patient mismatched HLA-C*14:02 showed the highest risk of severe acute graft-versus-host disease (HR, 3.61,P<0.001) and transplant-related mortality (HR, 2.53,P<0.001) among all patient mismatched HLA-C alleles. Although patient HLA-C*14:02 and donor HLA-C*15:02 mismatch was usually KIR2DL-ligand mismatch in the graft-versus-host direction, the risk of patient mismatched HLA-C*14:02 for severe acute graft-versus-host disease was obvious regardless of KIR2DL-ligand matching. The effect of patient and/or donor HLA-B*51:01 on acute graft-versus-host disease was attributed not only to strong linkage disequilibrium of HLA-C*14:02 and -B*51:01, but also to the effect of HLA-B*51:01 itself. With regard to clinical implications, patient mismatched HLA-C*14:02 proved to be a potent risk factor for severe acute graft-versus-host disease and mortality, and should be considered a non-permissive HLA-C mismatch in donor selection for unrelated donor hematopoietic stem cell transplantation.

Genome-wide surveillance of mismatched alleles for graft-versus-host disease in stem cell transplantation.

Acute graft-versus-host disease (aGVHD) represents one of the major complications in allogeneic stem cell transplantation and is primarily caused by genetic disparity between the donor and recipient. In HLA-matched transplants, the disparity is thought to be determined by loci encoding minor histocompatibility antigens (minor H antigens), which are presented by specific HLA molecules. We performed a genome-wide association study (GWAS) to identify minor H antigen loci associated with aGVHD. A total of 500 568 single nucleotide polymorphisms (SNPs) were genotyped for donors and recipients from 1589 unrelated bone marrow transplants matched for HLA-A, -B, -C, -DRB1, and -DQB1, followed by the imputation of unobserved SNPs. We interrogated SNPs whose disparity between the donor and recipient was significantly associated with aGVHD development. Without assuming HLA unrestriction, we successfully captured a known association between HLA-DPB1 disparity (P = 4.50 × 10(-9)) and grade II-IV aGVHD development, providing proof of concept for the GWAS design aimed at discovering genetic disparity associated with aGVHD. In HLA-restricted analyses, whereby association tests were confined to major subgroups sharing common HLA alleles to identify putative minor H antigen loci, we identified 3 novel loci significantly associated with grade III-IV aGVHD. Among these, rs17473423 (P = 1.20 × 10(-11)) at 12p12.1 within the KRAS locus showed the most significant association in the subgroup, sharing HLA-DQB1*06:01. Our result suggested that a GWAS can be successfully applied to identify allele mismatch associated with aGVHD development, contributing to the understanding of the genetic basis of aGVHD.

A donor thrombomodulin gene variation predicts graft-versus-host disease development and mortality after bone marrow transplantation.

Thrombomodulin, encoded by the THBD gene, is a critical regulator of coagulation and innate immunity. Its gene variant (rs3176123, 2729A>C) in the 3' untranslated region has been reported to be associated with vasculopathies. The present study analyzed the impact of THBD variation on transplant outcomes in a cohort of 317 patients who underwent unrelated HLA-matched bone marrow transplantation (BMT) for hematologic malignancies through the Japan Marrow Donor Program. The donor A/C or C/C genotype vs. the donor A/A genotype resulted in a lower incidence of grades II-IV acute graft-versus-host disease [GVHD; hazard ratio (HR) 0.66; 95 % confidence interval (CI) 0.44-0.99; P = 0.05] according to a multivariate analysis. In patients with grades II-IV acute GVHD, the donor A/C or C/C genotype vs. the donor A/A genotype was associated with significantly better overall survival rates (HR 0.45; 95 % CI 0.21-0.99, P = 0.05), while this effect was absent in other patients. A functional analysis using lymphocytes obtained from healthy individuals revealed that the 2729C allele has a higher level of THBD mRNA than the 2729A allele. These findings suggest the functional relevance of the rs3176123 variation and indicate that higher thrombomodulin expression by individuals with the 2729C allele likely accounts for their decreased risk for acute GVHD development and subsequent mortality.

A polymorphism in CCR1/CCR3 is associated with narcolepsy.

Etiology of narcolepsy-cataplexy involves multiple genetic and environmental factors. While the human leukocyte antigen (HLA)-DRB1*15:01-DQB1*06:02 haplotype is strongly associated with narcolepsy, it is not sufficient for disease development. To identify additional, non-HLA susceptibility genes, we conducted a genome-wide association study (GWAS) using Japanese samples. An initial sample set comprising 409 cases and 1562 controls was used for the GWAS of 525,196 single nucleotide polymorphisms (SNPs) located outside the HLA region. An independent sample set comprising 240 cases and 869 controls was then genotyped at 37 SNPs identified in the GWAS. We found that narcolepsy was associated with a SNP in the promoter region of chemokine (C-C motif) receptor 1 (CCR1) (rs3181077, P=1.6×10(-5), odds ratio [OR]=1.86). This rs3181077 association was replicated with the independent sample set (P=0.032, OR=1.36). We measured mRNA levels of candidate genes in peripheral blood samples of 38 cases and 37 controls. CCR1 and CCR3 mRNA levels were significantly lower in patients than in healthy controls, and CCR1 mRNA levels were associated with rs3181077 genotypes. In vitro chemotaxis assays were also performed to measure monocyte migration. We observed that monocytes from carriers of the rs3181077 risk allele had lower migration indices with a CCR1 ligand. CCR1 and CCR3 are newly discovered susceptibility genes for narcolepsy. These results highlight the potential role of CCR genes in narcolepsy and support the hypothesis that patients with narcolepsy have impaired immune function.