Allogeneic transplantation for adult T-cell leukemia/lymphoma in adolescent and young adults and young patients: A nationwide retrospective study by the ATL working group of the Japan society for transplantation and cellular therapy.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) provides durable remission for patients with adult T-cell leukemia/lymphoma (ATL); however, few studies have focused on post-transplant outcomes in ATL patients ≤49 years. To clarify prognostic factors in ATL among patients <40 years (adolescents and young adult [AYA]; n = 73) and 40-49 years (Young; n = 330), we conducted a nationwide retrospective study. Estimated 3-year overall survival (OS) rates were 61.8% and 43.1% in AYA and Young patients, respectively (p = 0.005). In the multivariate analysis, Young patients showed worse OS (Hazard ratio (HR) [95% confidential interval] 1.62 [1.10-2.39], p = 0.015), chronic graft-versus-host disease (GVHD)-free and relapse-free survival (CRFS) (HR 1.54 [1.10-2.14], p = 0.011), and GVHD-free and relapse-free survival (GRFS) (HR 1.40 [1.04-1.88], p = 0.026) than AYA patients. No significant differences were observed in OS, CRFS, or GRFS between the myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC) regimens; however, non-relapse mortality was significantly lower in patients with the RIC regimen than those with the MAC regimen (HR 0.46 [0.24-0.86], p = 0.015). In summary, OS was worse in Young patients than in AYA patients in the allo-HSCT setting for ATL. Furthermore, the RIC regimen has potential as an alternative treatment option for ATL patients ≤49 years.

Individual HLAs affect survival after allogeneic stem cell transplantation in adult T-cell leukaemia/lymphoma.

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for adult T-cell leukaemia/lymphoma (ATL). Specific HLAs are associated with outcomes of immunotherapy and allo-HSCT. We hypothesised that individual HLAs would affect the clinical outcomes of ATL patients after allo-HSCT. Using data from a Japanese registry, we retrospectively analysed 829 patients with ATL who received transplants from HLA-identical sibling donors or HLA-A, -B, -C or -DRB1 allele-matched unrelated donors between 1996 and 2015. We evaluated the overall mortality risk of HLA-A, -B and -DR antigens with frequencies exceeding 3%. Outcomes were compared between transplants with or without specific HLA antigens. Of the 25 HLAs, two candidates were identified but showed no statistically significant differences by multiple comparison. HLA-B62 was associated with a lower risk of mortality (hazard ratio [HR], 0.68; 95% confidence interval [CI]: 0.51-0.90; p = 0.008), whereas HLA-B60 was associated with a higher risk of mortality (HR, 1.64; 95% CI: 1.19-2.27; p = 0.003). In addition, HLA-B62 was associated with a lower risk of transplant-related mortality (TRM) (HR, 0.52; 95% CI: 0.32-0.85, p = 0.009), whereas HLA-B60 was associated with a higher risk of grades III-IV acute graft-versus-host disease (HR, 2.63; 95% CI: 1.62-4.27; p < 0.001). Neither HLA influenced relapse. The higher risk of acute GVHD in HLA-B60-positive patients and the lower risk of TRM in HLA-B62-positive patients were consistent with previously obtained results from patients with other haematological malignancies. Consideration of HLA in ATL patients may help to predict risk and outcomes after allo-HSCT.

Mechanisms of action and resistance in histone methylation-targeted therapy.

Epigenomes enable the rectification of disordered cancer gene expression, thereby providing new targets for pharmacological interventions. The clinical utility of targeting histone H3 lysine trimethylation (H3K27me3) as an epigenetic hallmark has been demonstrated1-7. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumour cells remain unclear. Here we show the potency and mechanisms of action and resistance of the EZH1-EZH2 dual inhibitor valemetostat in clinical trials of patients with adult T cell leukaemia/lymphoma. Administration of valemetostat reduced tumour size and demonstrated durable clinical response in aggressive lymphomas with multiple genetic mutations. Integrative single-cell analyses showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, including tumour suppressor genes. Nevertheless, subsequent long-term treatment encounters the emergence of resistant clones with reconstructed aggregate chromatin that closely resemble the pre-dose state. Acquired mutations at the PRC2-compound interface result in the propagation of clones with increased H3K27me3 expression. In patients free of PRC2 mutations, TET2 mutation or elevated DNMT3A expression causes similar chromatin recondensation through de novo DNA methylation in the H3K27me3-associated regions. We identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Targeting epigenetic drivers and chromatin homeostasis may provide opportunities for further sustained epigenetic cancer therapies.

HLA haploidentical stem cell transplantation from HLA homozygous donors to HLA heterozygous donors may have lower survival rates than haploidentical transplantation from HLA heterozygous donors to HLA heterozygous donors: a retrospective nationwide analysis.

In HLA haploidentical stem cell transplantation, patients and donors usually share one HLA haplotype and have one different HLA haplotype (hetero-to-hetero). However, there are rare cases of transplantation from HLA homozygous donors to heterozygous recipients (homo-to-hetero), resulting in mismatches only in the graft-versus-host direction. We previously reported that homo-to-hetero transplants have a lower survival rate in a mouse model than hetero-to-hetero transplants due to stronger graft-versus-host disease (GVHD) but inferior graft-versus-leukemia effect. To examine whether homo-to-hetero transplant effects also occur in humans, we retrospectively compared the results of 59 homo-to-hetero and 4,539 hetero-to-hetero cases in the Japanese transplant registry data. The results showed no statistical difference between the homo-to-hetero and hetero-to-hetero groups in the cumulative incidences of neutrophil engraftment (83.1% vs 89.0%), acute GVHD II-IV (36.8% vs 38.8%), III-IV (16.8% vs 17.4%), chronic GVHD (32.7% vs 30.7%), relapse (52.9% vs 49.0%), and non-relapse mortality (31.6% vs 28.2%). In contrast, overall survival was significantly lower in the homo-to-hetero group than in the hetero-to-hetero group (12.6% vs 26.2%, p = 0.0308). The inferior effect of homo-to-hetero transplantation on overall survival remained significant in multivariate analyses.

Scoring system for optimal cord blood unit selection for single cord blood transplantation.

BACKGROUND: We conducted a retrospective study to categorize the cord blood unit (CBU)s to identify the optimal units. METHODS: A total of 8503 adults (female, n = 3592; male, n = 4911) receiving their first single cord blood transplantation (CBT) in 2000-2019 were analyzed. Factors associated with CBUs affecting overall survival (OS) and neutrophil engraftment were selected to create ranked categorization for each outcome, followed by comparison with transplantation using HLA-matched bone marrow (BMT)/peripheral blood stem cell (PBSCT) from unrelated (n = 6052) and related donors (n = 4546). RESULTS: Sex-mismatch, CD34+ cell and CFU-GM counts were selected in the OS analysis. Considering the strong interaction between sex mismatch and CD34+ cell counts, we analyzed females and males separately. For females, female CBU with CD34+ cell counts {greater than or equal to} 0.5 × 10e5/kg and CFU-GM counts {greater than or equal to} 15 × 10e3/kg offered the best OS (Group I), followed by other groups with any (Groups II-IV) or all (Group V) of the risk factors. Group I consistently showed favorable OS (Group IV: HR1.22, P = 0.027; Group V: HR1.31, P = 0.047), comparable to those of rBMT/PBSCT (OS: HR1.02, P = 0.654) and uBM/PBSCT in patients with higher rDRI (HR1.07, P = 0.353). Male patients lacked significant factors affecting OS. Categorization for neutrophil engraftment consisting of CD34+ cell and CFU-GM counts, sex-mismatch, presence of donor-specific antibodies, and the number of HLA-mismatches was effective but not predicted OS. CONCLUSION: Our ranked categorizations sufficiently predicted female OS and engraftment. The best-ranked CBUs offered preferable outcomes comparable to conventional BM/PB donors in female but not in male patients.

Outcomes in human T-cell leukemia virus type I carriers after hematopoietic stem cell transplantation for diseases other than adult T cell leukemia/lymphoma: a Japanese national survey.

Background: Human T-cell leukemia virus type I (HTLV-1) is a retrovirus known to cause adult T-cell leukemia/lymphoma (ATL). There are few reports on hematopoietic stem cell transplantation (HSCT) for HTLV-1 carriers with diseases other than ATL. Methods: A total of 25,839 patients (24,399 adults and 1440 children) with pre-transplant HTLV-1 serostatus information recorded in the Japanese National Survey Database who had undergone their first HSCT were analyzed. We investigated the overall survival (OS), transplant-related mortality (TRM), and disease-related mortality (DRM) after HSCT in relation to HTLV-1 serologic status. Findings: Three hundred and forty-eight patients were HTLV-1 antibody carriers. The number of HTLV-1 carriers and noncarriers among adult patients who received allogeneic HSCT (allo-HSCT) or autologous HSCT (auto-HSCT) was 237/15,777 and 95/8920, respectively, and was 16/1424 among pediatric patients who received allo-HSCT. No pediatric HTLV-1 carrier recipients undergoing auto-HSCT were identified. There were no significant differences between HTLV-1 carriers and non-carriers regarding stem cell source, disease risk, or HCT-CI score prior to allo-HSCT. Multivariate analysis of OS (P = 0.020) and TRM (P = 0.017) in adult patients showed that HTLV-1 positive status was a significant prognostic factor. In children, TRM was significantly higher (P = 0.019), but OS was not significantly different. In adult patients who underwent auto-HSCT, HTLV-1 positive status was not a significant prognostic factor. In adult allo-HSCT patients, cytomegalovirus reactivation was significantly more common in HTLV-1 carriers (P = 0.001). Interpretation: HTLV-1 antibody positivity was shown to have a poor prognosis in OS and TRM after allo-HSCT in adult patients and in TRM after allo-HSCT in pediatric patients. Funding: This work was supported in part by the practical research programs of the Japan Agency for Medical Research and Development (AMED) under grant number 17ck0106342h0001.

Antibody-mediated pathogenesis of chronic GVHD through DBY/HLA class II complexes and induction of a GVL effect.

Chronic graft-versus-host disease (cGVHD) is a multiorgan syndrome with clinical features resembling those of autoimmune diseases. Thus, understanding commonalities in the pathophysiology of cGVHD and autoimmune diseases, such as the presence of disease-risk HLA alleles, is imperative for developing novel therapies against cGVHD. Alloantibodies against H-Y antigens encoded on the Y-chromosome are well-described risk factors for cGVHD in female-to-male transplantation. However, because H-Y antigens generally localize intracellularly in the male reproductive organs, how they emerge at affected organ levels remains elusive. Here, by analyzing nationwide registry data stratified per donor-recipient sex, we identified specific HLA class II alleles that contributed to susceptibility to male cGVHD after transplantation from HLA-identical female siblings (HLA-DRB1∗15:02: hazard ratio, 1.28; 95% confidence interval, 1.03-1.58; P = .025). Coexpression of HLA-DRB1∗15:02 efficiently transported full-length H-Y antigens, especially DBY, to the surface. The presence of alloantibodies against DBY/HLA class II complexes significantly predicted the occurrence of cGVHD (68.8% vs 31.7% at 1 year; P = .002). Notably, the ability of HLA class II molecules to transport and present DBY to alloantibodies was closely associated with the susceptibility of HLA class II alleles to cGVHD. DBY specifically colocalized with HLA class II molecules on the dermal vascular endothelium in cGVHD and provoked complement-dependent cytotoxicity. Moreover, these complexes were observed in some male leukemic cells. Altogether, these findings suggest that vascular endothelial cells facilitate alloantibody-mediated cGVHD and highlight that alloantibodies against DBY/HLA class II complexes could be common targets for cGVHD and a graft-versus-leukemia effect.

Impact of HLA-mismatched unrelated transplantation in patients with adult T-cell leukemia/lymphoma.

This Japanese nationwide retrospective study investigated the impact of HLA-mismatched unrelated transplantation for adult T-cell leukemia-lymphoma (ATL) patients who received transplantation between 2000 and 2018. We compared 6/6 antigen-matched related donor (MRD), 8/8 allele-matched unrelated donor (8/8MUD), and 1 allele-mismatched unrelated donor (7/8MMUD) in the graft-versus-host direction. We included 1191 patients; 449 (37.7%) were in the MRD group, 466 (39.1%) in the 8/8MUD group, and 276 (23.7%) in the 7/8MMUD group. In the 7/8MMUD group, 97.5% of patients received bone marrow transplantation, and no patients received post-transplant cyclophosphamide. The cumulative incidences of non-relapse mortality (NRM) and relapse at 4 years, and the probabilities of overall survival at 4 years in the MRD group were 24.7%, 44.4%, 37.5%, in the 8/8MUD group were 27.2%, 38.2%, and 37.9%, and in the 7/8MMUD group were 34.0%, 34.4%, and 35.3%, respectively. The 7/8MMUD group had a higher risk of NRM (hazard ratio (HR) 1.50 [95% CI, 1.13-1.98; P = 0.005]) and a lower risk of relapse (HR 0.68 [95% CI, 0.53-0.87; P = 0.003]) than the MRD group. The donor type was not a significant risk factor for overall mortality. These data suggest that 7/8MMUD is an acceptable alternative donor when an HLA-matched donor is unavailable.

A Comprehensive Study of the Immunophenotype and its Clinicopathologic Significance in Adult T-Cell Leukemia/Lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell tumor caused by human T-lymphotropic virus type 1 (HTLV-1). The typical ATLL immunophenotypes are described in the 2017 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (positive: CD2, CD3, CD5, CD4, and CD25; negative: CD7, CD8, and cytotoxic markers; and partially positive: CD30, CCR4, and FOXP3). However, limited studies are available on the expression of these markers, and their mutual relationship remains unknown. Furthermore, the expression status of novel markers associated with T-cell lymphomas, including Th1 markers (T-bet and CXCR3), Th2 markers (GATA3 and CCR4), T follicular helper markers (BCL6, PD1, and ICOS), and T-cell receptor (TCR) markers, and their clinicopathologic significance is unclear. In this study, we performed >20 immunohistochemical stains in 117 ATLL cases to determine the comprehensive immunophenotypic profile of ATLL, which were compared on the basis of clinicopathologic factors, including morphologic variants (pleomorphic vs anaplastic), biopsy locations, treatments, Shimoyama classification-based clinical subtype, and overall survival. CD3+/CD4+/CD25+/CCR4+ was considered a typical immunophenotype of ATLL, but approximately 20% of cases did not conform to this pattern. Simultaneously, the following new findings were obtained: (1) most cases were negative for TCR-ß and TCR-δ (104 cases, 88.9%), indicating the usefulness of negative conversion of TCR expression to provide differentiation from other T-cell tumors; (2) the positivity of CD30 and CD15 and the negativity of FOXP3 and CD3 were significantly associated with anaplastic morphology; and (3) atypical cases, such as T follicular helper marker-positive (12 cases, 10.3%) and cytotoxic molecule-positive cases (3 cases, 2.6%), were identified. No single markers could predict the overall survival among patients with acute/lymphoma subtypes of ATLL. The results of this study illustrate the diversity of ATLL phenotypes. In T-cell tumors occurring in HTLV-1 carriers, the possibility of ATLL should not be eliminated even when the tumor exhibits an atypical phenotype, and the confirmation of HTLV-1 in the tissue is recommended.

Fatal acquired coagulation factor V deficiency after hepatectomy for advanced hepatocellular carcinoma as a possible immune checkpoint inhibitor-related adverse event: a case report.

BACKGROUND: Atezolizumab plus bevacizumab therapy was recently introduced as the first line for unresectable advanced hepatocellular carcinoma (HCC), but immune-related adverse events (IrAEs) due to atezolizumab are a great concern. Here, we report the case of a patient who developed fatal acquired coagulation factor deficiency after hepatectomy for HCC, treated with atezolizumab and bevacizumab before surgery. CASE PRESENTATION: A 70-year-old man received right trisegmentectomy of the liver with hepaticojejunostomy for advanced HCC with bile duct invasion, after atezolizumab and bevacizumab therapy. The patient suffered the sudden onset of severe multiple coagulation factor deficiency (II, V, VII, VIII, IX, X, XI and XII) immediately following reoperation for anastomotic leakage of hepaticojejunostomy, 7 days after hepatectomy. The coagulation factor deficiency did not reverse even with intensive treatment, and the patient died of uncontrollable bleeding 32 days after hepatectomy. An IrAE due to atezolizumab was suspected because the patient had developed the possible IrAE of enthesitis of the right gastrocnemius muscle before surgery, and specific inhibitors against factor V and anti-factor V autoantibodies were detected, leading to an ultimate diagnosis of autoimmune FV/5 deficiency (AiF5D). CONCLUSION: Severe acquired coagulopathy should be recognized as a possible life-threatening IrAE when using atezolizumab and bevacizumab for HCC.

Clinically amyopathic dermatomyositis manifested after the allogeneic haematopoietic stem cell transplantation: Case presentation and literature review.

Clinically amyopathic dermatomyositis (CADM) lacks muscle symptoms, associated with rapidly progressive interstitial lung disease. Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody has been identified as a disease-labelling autoantibody. We report two cases of CADM manifested after the allogeneic haematopoietic stem cell transplantation (allo-HSCT)-Case 1: a 56-year-old man with acute leukaemia received the allo-HSCT and Case 2: a 45-year-old female patient with lymphoma received the allo-HSCT. She received donor lymphocyte infusion because of a post-transplant relapse. After allo-HSCT or donor lymphocyte infusion, Gottron papules emerged, and both patients were diagnosed as CADM based on dermatological findings coupled with the positivity of anti-MDA-5 antibody, accompanied by interstitial shadows consistent with ILD on chest computed tomography. Case 2 was initially diagnosed as a kind of chronic graft versus host disease. Their symptoms were improved by the combination of immunosuppressive agents with a concomitant decrease in anti-MDA-5 antibody levels. For Case 2, rituximab was subsequently started for relapse of lymphoma, resulting in a substantial decrease in the level of anti-MDA-5 antibody and improvement in rash and ILD. Our cases raise a possibility that CADM emerges after the HSCT, highlighting the importance of early diagnosis to avoid fated progression into ILD.

An open-label, single-arm phase 2 trial of valemetostat for relapsed or refractory adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive non-Hodgkin lymphoma with poor prognosis and few treatment options for patients with relapsed, recurrent, or refractory disease. We evaluated the efficacy and safety of valemetostat, a potent enhancer of zeste homolog 2 (EZH2) and EZH1 inhibitor, in treating relapsed or refractory (R/R) ATL. This multicenter phase 2 trial enrolled patients with R/R aggressive ATL (acute, lymphoma, unfavorable chronic type). Patients received valemetostat 200 mg/day orally until progressive disease or unacceptable toxicity. The primary end point was overall response rate (ORR) centrally assessed by an independent efficacy assessment committee (IEAC). Secondary end points included best response in disease compartments, duration of response (DOR), pharmacokinetics, and safety. Twenty-five patients (median age, 69.0 years) with a median of 3 prior lines of therapy were enrolled; 24 had prior mogamulizumab treatment. The primary end point was met with a centrally reviewed ORR of 48.0% (90% confidence interval [CI], 30.5-65.9), including 5 complete and 7 partial remissions. Patients pretreated with mogamulizumab had an ORR of 45.8% (4 complete and 7 partial remissions). IEAC-assessed median DOR was not reached (NR) (95% CI, 1.87 to NR; months). Treatment-emergent adverse events (TEAEs) were manageable. TEAEs that occurred in ≥20% of patients included thrombocytopenia, anemia, alopecia, dysgeusia, neutropenia, lymphopenia, leukopenia, decreased appetite, and pyrexia. Grade ≥3 TEAEs included thrombocytopenia, anemia, lymphopenia, leukopenia, and neutropenia. Valemetostat demonstrated promising efficacy and tolerability in heavily pretreated patients, warranting further investigation in treating R/R ATL. This trial was registered at www.clinicaltrials.gov as #NCT04102150.

Sequence Variations Within HLA-G and HLA-F Genomic Segments at the Human Leukocyte Antigen Telomeric End Associated With Acute Graft-Versus-Host Disease in Unrelated Bone Marrow Transplantation.

Acute graft-versus-host disease (aGVHD) is defined as a syndrome of an immunological response of graft to the host that occurs early after allogeneic hematopoietic stem cell transplantation (HCT). This disease is frequently observed even in HCT matched for human leukocyte antigen (HLA) alleles at multiple gene loci. Although the HLA region represents complex and diverse genomic characteristics, detailed association analysis is required for the identification of uncharacterized variants that are strongly associated with aGVHD. We genotyped three loci, OR2H2, HLA-F-AS1, and HLA-G, that are located in the 460 kb of HLA telomeric region and statistically analyzed the genotypes including HLA-DPB1 with clinical and transplantation outcomes using 338 unrelated bone marrow transplantation (UR-BMT) patient-donor pairs who were matched for HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 (HLA-10/10). Multivariate analyses demonstrated that HLA-F-AS1 and HLA-DPB1 mismatches were associated with grade II-IV aGVHD (hazard ratio (HR), 1.76; 95% CI, 1.07-2.88; p = 0.026; and HR, 1.59; CI, 1.02-2.49; p = 0.042, respectively). There was no confounding between HLA-F-AS1 and HLA-DPB1 (p = 0.512), suggesting that the HLA-F-AS1 mismatch has a strong effect on aGVHD independently of HLA-DPB1. Moreover, a stratified analysis suggested possible associations of HLA-F-AS1, HLA-DPB1, and/or HLA-G mismatches with grade II-IV aGVHD and the more severe grade III-IV aGVHD. These findings provide new insights into understanding the molecular mechanism of aGVHD caused by HLA-matched UR-BMT.

Impact of human leukocyte antigen mismatch on outcomes after unrelated bone marrow transplantation in paediatric patients: A retrospective analysis by the JSTCT HLA working group.

The impact of human leukocyte antigen (HLA) mismatching at the HLA-A, -B, -C, and -DRB1 loci after unrelated bone marrow transplantation in paediatric patients with haematological malignancies has not been fully examined. Here, we analysed patients with haematological malignancies (all aged ≤15 years; n = 1330) who underwent a first unrelated bone marrow transplantation between 1993 and 2017 in Japan. The results show that although an HLA mismatch was significantly associated with a low relapse rate, it was also associated with higher non-relapse mortality. There was a significant association between HLA mismatch and low overall survival. Locus mismatch analysis revealed that, as in adults, an HLA-C mismatch had a significant negative impact on survival; however, in paediatric patients, an HLA-DRB1 mismatch did not have a negative impact, although these HLA mismatch effects are weakened in recent cases. Taken together, the results suggest that an HLA-matched donor should be the first candidate for paediatric patients; however, for patients without a matched sibling or matched unrelated donor, we can select an unrelated donor with a mismatch at HLA-DRB1 if available.

Improved outcomes of single-unit cord blood transplantation for acute myeloid leukemia by killer immunoglobulin-like receptor 2DL1-ligand mismatch.

The impact of the killer immunoglobulin-like receptor (KIR)-ligand mismatch between donor and recipient in hematopoietic stem cell transplantation is controversial. Recently, it has been suggested that their effect on cord blood transplantation (CBT) differs among types of mismatched KIR-ligand and graft-versus-host disease (GVHD) prophylaxis. To investigate their role in acute myeloid leukemia (AML), mismatch of KIR2DL1, KIR3DL1, and KIR3DL2-ligand (HLA-C2, Bw4, and A3/11) were retrospectively assessed in patients undergoing CBT with GVHD prophylaxis comprising a calcineurin inhibitor plus methotrexate (CNI/MTX) or mycophenolate mofetil (CNI/MMF). In patients who received CNI/MTX, a favorable effect of KIR-ligand mismatch on relapse was noted in HLA-C2 mismatched cases (24.8% at 3 years post-CBT [no HLA-C2 mismatch, n = 1602] vs. 15.4% [HLA-C2 mismatch, n = 161], P = 0.0116). In this group, overall survival (OS) was also superior (68.2%, P = 0.0083) compared to the other group (55.0%). Multivariate analysis results supported these findings (hazard ratio [HR] 0.61 for relapse, P = 0.017 and HR 0.72 for OS, P = 0.016). However, the KIR-ligand mismatch effect was not observed in patients with KIR-ligand mismatch types other than HLA-C2 and those using CNI/MMF for GVHD prophylaxis. These results suggest that HLA-C2 mismatch in CBT using CNI/MTX as GVHD prophylaxis may improve the outcomes of patients with AML.

Effect of Multiple HLA Locus Mismatches on Outcomes after Single Cord Blood Transplantation.

The effect of single or multiple mismatches at each HLA locus on outcomes after cord blood transplantation (CBT) is controversial. We analyzed the effects of single or multiple HLA locus mismatches on the outcomes after single CBT using Japanese registry data from the Japan Society for Hematopoietic Cell Transplantation. Patients age ≥16 years with acute leukemia and myelodysplastic syndromes who underwent their first CBT between 2003 and 2017 (n = 4074) were included. The effect of the number of HLA locus mismatches (0, 1, or 2 for the HLA-A, -B, -C, and -DRB1 loci) on outcomes was analyzed after adjusting for other significant variables. The patient cohort had a median age of 54 years. The median total nucleated and CD34 cell doses were 2.6 × 107/kg and .8 × 105/kg, respectively. The number of CBTs with single or double mismatches were 2099 and 292, respectively, for the HLA-A locus, 2699 and 341 for the HLA-B locus, 2555 and 609 for the HLA-C locus, and 2593 and 571 for the HLA-DRB1 locus. Single and double HLA-DRB1 mismatches were associated with a higher risk of grade II-IV acute graft-versus-host disease (GVHD; single: hazard ratio [HR], 1.29, P < .001; double: HR, 1.49, P < .001; P for trend <.001). Single and double mismatches at HLA-DRB1 as well as single mismatches at HLA-A and HLA-B also were associated with grade III-IV acute GVHD. Single and double HLA-B mismatches and double HLA-DRB1 mismatches were associated with a high risk of nonrelapse mortality (NRM). On the other hand, double mismatches at HLA-A or HLA-DRB1 and single mismatches at HLA-B were associated with a lower risk of relapse. HLA-DRB1 double mismatch was associated with high risk of grade II-IV and grade III-IV acute GVHD and NRM but lower risk of relapse. Not only the locus mismatch, but also the number of mismatches, should be considered in cord blood unit selection.

Impact of anti-diabetic sodium-glucose cotransporter 2 inhibitors on tumor growth of intractable hematological malignancy in humans.

Under the dysfunction of mitochondria, cancer cells preferentially utilize both glycolytic and pentose phosphate pathways rather than electron transport chains to desperately generate adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH), classically recognized as the Warburg effect. Based on this background, the present study tested the hypothesis that anti-diabetic sodium-glucose cotransporter 2 (SGLT2) inhibitors would exert a tumor-suppressive impact on intractable human hematological malignancies via the modulation of glucose metabolism within cells and cell cycles. The level of mRNA for SGLT2 was remarkably elevated in leukemic cells from patients with adult T-cell leukemia (ATL), one of the most intractable blood cancers in humans, and as well as in two kinds of ATL cell lines (MT-1 and MT-2). Two kinds of SGLT2 inhibitors, Luseogliflozin and Tofogliflozin substantially suppressed the proliferation of MT-1 and MT-2 cells in both adherent and anchorage-independent culture conditions. Such a suppressive effect on tumor cell growth was reproduced by Luseogliflozin in leukemic cells in peripheral blood from patients with ATL. In MT-2 cells, both of SGLT2 inhibitors considerably attenuated glucose uptake, intracellular ATP levels, and NADPH production, resultantly enhancing cell cycle arrest at the G0/G1 phase. From the standpoint of metabolic oncology, the present study suggests that SGLT2 inhibitors would be a promising adjunctive option for the treatment of the most intractable human hematological malignancies like ATL.

Race and Survival in Unrelated Hematopoietic Cell Transplantation.

Survival after hematopoietic cell transplantation depends on race/ethnicity and histocompatibility (HLA) between the patient and transplant donor. HLA sequence variation is a genetic construct of continental populations, but its role in accounting for racial disparities of transplant outcome is unknown. To determine disparities in transplant survivorship among patients of diverse race while accounting for patient and donor HLA variation. A total of 26,945 self-described Japanese, U.S. Asian, White, Hispanic, and Black patients received an unrelated donor transplant for the treatment of a life-threatening blood disorder. The risk of mortality with and without adjustment for known HLA risk factors (number and location of donor mismatches; patient HLA-B leader genotype and HLA-DRß peptide-binding motif) was studied using multivariable models. Survival after HLA-matched transplantation for patients with optimal leader and peptide-binding features was estimated for each race, as was the improvement in survival over calendar-year time by considering year of transplantation as a continuous linear variable. The number, location, and nature of donor HLA mismatches and the frequency of patient HLA-B and HLA-DRB1 sequence motifs differed by race. Japanese patients had superior survival compared to other races without consideration of HLA. After HLA adjustment, three mortality risk strata were identified: Japanese and U.S. Asian (low-risk); White and Hispanic (intermediate-risk), and Black patients (high-risk). Survival for patients with optimal donor and HLA characteristics was superior for Japanese, intermediate for U.S. Asian, White, and Hispanic, and lowest for Black patients. Five-year increments of transplant year were associated with greater decreases in mortality hazards for Black and Hispanic patients than for Japanese, U.S. Asian and White patients. Transplant survivorship disparities are influenced by HLA as a genetic construct of race. A more complete understanding of the factors that influence transplant outcomes provides opportunities to narrow disparities for future patients.