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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., (© 2024 John Wiley & Sons Ltd.)

Background Aims: Pre-transplant lung dysfunction is known to be a risk factor for non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). It is unclear which cell source gives better outcomes for patients with pulmonary dysfunction., Methods: We analyzed 3289 adult patients with standard-risk disease who had received HLA-matched allo-HCT, and compared outcomes between those who received peripheral blood stem cell (PBSC) vs. bone marrow (BM) in two cohorts based on the presence of a lung score by the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI): the Lung-scored (LS) and non-LS cohorts., Results: In the LS cohort, the 2-year overall survival (OS) in the BM group tended to be higher than that in the PBSC group (72.4% vs. 61.4%; P = 0.044). In the non-LS cohort, there was no significant difference between the two groups (71.7% vs. 73.2%; P = 0.13). Multivariate analyses confirmed that PBSC was significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.66; 95% CI, 1.09-2.54; P = 0.019). On the other hand, the cell source did not affect OS in the non-LS cohort (HR, 0.92; 95% CI, 0.76-1.12; P = 0.41). We found that PBSC was associated with an increased risk of NRM in the LS cohort (HR, 2.17; 95% CI, 1.16-4.05; P = 0.016), while the cell source did not significantly affect NRM in the non-LS cohort. PBSC was not identified as a risk factor for relapse in either cohort., Conclusions: Our results suggest that BM might be beneficial for recipients with lung dysfunction in HLA-matched allo-HCT., Competing Interests: Declaration of Competing Interest The authors have no commercial, proprietary, or financial interest in the products or companies described in this article., (Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Autologous hematopoietic cell transplantation (AHCT) is a commonly used treatment in multiple myeloma (MM). However, real-world global demographic and outcome data are scarce. We collected data on baseline characteristics and outcomes from 61 725 patients with newly diagnosed MM who underwent upfront AHCT between 2013 and 2017 from nine national/international registries. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), relapse incidence (RI) and non-relapse mortality (NRM). Median OS amounted to 90.2 months (95% CI 88.2-93.6) and median PFS 36.5 months (95% CI 36.1-37.0). At 24 months, cumulative RI was 33% (95% CI 32.5%-33.4%) and NRM was 2.5% (95% CI 2.3%-2.6%). In the multivariate analysis, superior outcomes were associated with younger age, IgG subtype, complete hematological response at auto-HCT, Karnofsky score of 100%, international staging scoring (ISS) stage 1, HCT-comorbidity index (CI) 0, standard cytogenetic risk, auto-HCT in recent years, and use of lenalidomide maintenance. There were differences in the baseline characteristics and outcomes between registries. While the NRM was 1%-3% at 12 months worldwide, the OS at 36 months was 69%-84%, RI at 12 months was 12%-24% and PFS at 36 months was 43%-63%. The variability in these outcomes is attributable to differences in patient and disease characteristics as well as the use of maintenance and macroeconomic factors. In conclusion, worldwide data indicate that AHCT in MM is a safe and effective therapy with an NRM of 1%-3% with considerable regional differences in OS, PFS, RI, and patient characteristics. Maintenance treatment post-AHCT had a beneficial effect on OS., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

Promoting access to and excellence in hematopoietic cell transplantation (HCT) by collecting and disseminating data on global HCT activities is one of the principal activities of the Worldwide Network for Blood and Marrow Transplantation, a non-governmental organization in working relations with the World Health Organization. HCT activities are recorded annually by member societies, national registries and individual centers including indication, donor type (allogeneic/autologous), donor match and stem cell source (bone marrow/peripheral blood stem cells/cord blood). In 2018, 1,768 HCT teams in 89 countries (6 World Health Organization regions) reported 93,105 (48,680 autologous and 44,425 allogeneic) HCT. Major indications were plasma cell disorders and lymphoma for autologous, and acute leukemias and MDS/MPN for allogeneic HCT. HCT numbers increased from 48,709 in 2007. Notable increases were seen for autoimmune diseases in autologous and hemoglobinopathies in allogeneic HCT. The number of allogeneic HCT more than doubled with significant changes in donor match. While HCT from HLA-identical siblings has seen only limited growth, HCT from non-identical related donors showed significant increase worldwide. Strongest correlation between economic growth indicator of gross national income/capita and HCT activity/10 million population was observed for autologous HCT (correlation coefficient [r]=0.79). HCT from unrelated donors showed strong correlation (r=0.68), but only moderate correlation was detected from related donors (r=0.48 for HLA-identical sibling; r=0.45 for other). The use of HCT doubled in about a decade worldwide at different speed and with significant changes regarding donor match as a sign of improved access to HCT worldwide. Although narrowing, significant gaps remain between developing and non-developing countries.

This nationwide study retrospectively examined the center effect on allogeneic hematopoietic stem cell transplantation (allo-HSCT) for adult B-cell acute lymphoblastic leukemia. The cohort analyses were separated into Philadelphia chromosome (Ph)-positive and -negative cases. The patients were divided into low- and high-volume groups according to the number of allo-HSCTs at each facility. The primary endpoint was 5-year overall survival (OS). This study included 1156 low-volume and 1329 high-volume Ph-negative and 855 low-volume and 926 high-volume Ph-positive cases. In Ph-negative cases, 5-year OS was significantly higher in the high-volume centers at 52.7% (95% confidence interval [CI]: 49.9-55.5) versus 46.8% (95% CI: 43.8-49.7) for the low-volume centers (P < 0.01). Multivariate analysis identified high volume as a favorable prognostic factor (hazard ratio [HR]: 0.81 [95% CI: 0.72-0.92], P < 0.01). Subgroup analysis in Ph-negative cases revealed that the center effects were more evident in patients aged ≥40 years (HR: 0.72, 95% CI: 0.61-0.86, P < 0.01) and those receiving cord blood transplantation (HR: 0.62, 95% CI: 0.48-0.79, P < 0.01). In Ph-positive cases, no significant difference was observed between the high and low-volume centers for 5-year OS (59.5% [95% CI: 56.2-62.7] vs. 54.9% [95% CI: 51.3-58.3], P = 0.054). In multivariate analysis, center volume did not emerge as a significant prognostic indicator. This study showed center effects on survival in Ph-negative but not in Ph-positive cases, highlighting the heterogeneity of the center effect in allo-HSCT for B-cell acute lymphoblastic leukemia. Collaborative efforts among transplant centers and further validation are essential to improve outcomes., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Peptide-binding motif (PBM) model, a hierarchical clustering of HLA class I based on their binding specificity, was developed to predict immunopeptidome divergence. The effect of PBM mismatches on outcomes is unknown in HLA-haploidentical haematopoietic cell transplantation with post-transplant cyclophosphamide (PTCy-haplo). We therefore conducted a retrospective study using national registry data in PTCy-haplo. Overall, 1352 patients were included in the study. PBM-A bidirectional mismatch was associated with an increased risk of overall mortality in multivariable analysis (hazard ratio, 1.26; 95% confidence interval, 1.06 to 1.50; p = 0.010). None of relapse, non-relapse mortality (NRM) and graft-versus-host disease showed significant differences according to PBM-A bidirectional mismatch status in the entire cohort. The impact of PBM-A bidirectional mismatch on overall survival (OS) was preserved within the HLA-A genotype bidirectional mismatch population, and their lower OS stemmed from higher relapse rate in this population. The worse OS due to high NRM with PBM-A bidirectional mismatch was prominent in lymphoid malignancies receiving reduced-intensity conditioning. The PBM model may predict outcomes more accurately than HLA genotype mismatches. In conclusion, this study demonstrated that the presence of PBM-A bidirectional mismatch elevated the risk of mortality of PTCy-haplo. Avoiding PBM-A bidirectional mismatch might achieve better outcomes in PTCy-haplo., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

The impact of letermovir (LTV)-an anti-cytomegalovirus (CMV) drug-on human herpesvirus-6 (HHV-6) encephalitis is unclear. We hypothesized that LTV prophylaxis may increase the incidence of HHV-6 encephalitis by reducing anti-CMV therapies after allogeneic hematopoietic stem cell transplantation (HSCT). To evaluate the association between HHV-6 encephalitis and antiviral prophylaxis, 7985 adult patients from a nationwide registry who underwent their first HSCT between January 2019 and December 2021 were analyzed. The incidence of HHV-6 encephalitis on day 100 after HSCT was 3.6%; 11.5% for the broad-spectrum antiviral group (foscarnet, ganciclovir, or valganciclovir); 2.8% for the LTV group, and 3.8% for the other antiviral group (p < 0.001). These differences persisted when cord blood transplantation (CBT) was analyzed separately (14.1%, 5.9%, and 7.4%, p < 0.001). In the multivariate analysis, CBT (hazard ratio [HR]: 2.90), broad-spectrum antiviral prophylaxis (HR: 1.91), and grade II-IV acute graft-versus-host disease requiring systemic corticosteroids (HR: 2.42) were independent risk factors for encephalitis (all p < 0.001). The findings of this large modern database study indicate that broad-spectrum antiviral prophylaxis, rather than LTV prophylaxis, is paradoxically associated with HHV-6 encephalitis in the LTV era. This paradoxical finding needs to be further explored in future studies., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Reduced-intensity conditioning regimens are commonly used in allogeneic haematopoietic cell transplantation for non-Hodgkin lymphoma (NHL); however, the optimal regimen remains unknown. In this study, the outcomes of adult patients with NHL who received fludarabine plus reduced-dose busulfan (6.4 mg/kg; Flu/Bu2) (n = 286) and fludarabine plus low-dose melphalan (80 or 100 mg/m 2 ; Flu/Mel80-100) (n = 283) between January 2009 and December 2020 were compared using Japanese registry data. The primary end-point was the 5-year overall survival (OS). The 5-year OS was 53.8% (95% CI, 47.6-59.6) and 42.4% (95% CI, 35.6-49.0) in the Flu/Bu2 and Flu/Mel80-100 groups respectively (p = 0.030). After inverse probability of treatment weighting adjustment, the adjusted HR of Flu/Bu2 compared with Flu/Mel80-100 group for 5-year OS was 0.77 (95% CI, 0.60-0.99, p = 0.046), 0.97 (95% CI, 0.78-1.21, p = 0.798) for 5-year progression-free survival, 0.65 (95% CI, 0.45-0.94, p = 0.022) for 5-year cumulative risk of non-relapse mortality and 1.25 (95% CI, 0.95-1.64, p = 0.115) for 5-year cumulative risk of relapse. In this study, patients with NHL who received Flu/Bu2 were associated with better OS and lower non-relapse mortality than those who received Flu/Mel80-100., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Prognosis for patients undergoing hematopoietic cell transplantation (HCT) has been improving. Short-term survival information, such as crude survival rates that consider deaths immediately after the transplantation, may not be sufficiently useful for assessing long-term survival. Using the data of the Japanese HCT registry, the net survival rate of patients who survived for a given period was determined according to age, disease, and type of transplant. We included a total of 41,716 patients who received their first allogeneic hematopoietic cell transplantation between 1991 and 2015. For each disease, age group, graft source subcategory, net survival was calculated using the Pohar-Perme method, and 5-year conditional net survival (CS) was calculated. Ten-year net survivals of total patient cohort were 41.5% and 47.4% for males and females, respectively. Except for myelodysplastic syndrome, multiple myeloma, and adult T-cell leukemia/lymphoma, 5-year CS for 5-year transplant survivors exceeded 90%. CS was especially high for aplastic anemia, of which was over 100% for children and younger adults receiving cord blood, suggesting that these patients have similar longevity to an equivalent group from the general population. These findings provide useful information for long-term survival, and can serve as benchmark for comparisons among registries, including other cancers., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important therapeutic option for patients with hematologic malignancies. However, the development of graft-versus-host disease (GVHD) after allo-HSCT remains a challenge. Although systemic steroid therapy is the established first-line therapy for acute GVHD (aGVHD) and chronic GVHD (cGVHD), many patients are unresponsive or resistant to corticosteroid therapy, and the response is insufficient. This study aimed to evaluate the clinical characteristics of patients who developed aGVHD and cGVHD after allo-HSCT. This noninterventional, retrospective study used large national registry data from the Transplant Registry Unified Management Program. The study included 29,690 patients with a hematologic disease who underwent their first allo-HSCT between January 2010 and December 2019. The primary study endpoints were the cumulative incidence of aGVHD and cGVHD. The secondary endpoints were overall survival (OS) and nonrelapse mortality (NRM) of patients with aGVHD and cGVHD and OS and NRM of patients who received second-line therapy for aGVHD. Of 29,690 patients who underwent allo-HSCT, the graft source was related bone marrow (RBM) in 2807, related peripheral blood (RPB) in 6167, unrelated bone marrow in 10,556, unrelated peripheral blood (UPB) in 774, and unrelated cord blood in 9339. The cumulative incidence of grade II-IV aGVHD at 100 days was high after the related and unrelated mismatched transplantation. The response rates for first- and second-line therapy for aGVHD were low in the RBM/RPB-mismatched (59.6%/61.6%) and UPB-mismatched subgroups (45.5%), respectively. The 3-year NRM in patients with aGVHD was high in the RPB and UPB mismatched subgroups (37.9% and 31.2%, respectively). Developing a novel treatment for steroid-refractory aGVHD is necessary to improve transplantation outcomes, particularly for patients undergoing HLA-mismatched allo-HSCT., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Abstract: Chronic graft-versus-host disease (GVHD) is 1 of the major complications after allogeneic hematopoietic cell transplantation (allo-HCT). Although various risk factors for chronic GVHD have been reported, limited data are available regarding the impact of acute GVHD on chronic GVHD. We examined the association between acute and chronic GVHD using a Japanese registry data set. The landmark point was set at day 100 after allo-HCT, and patients who died or relapsed before the landmark point were excluded. In total, 14 618 and 6135 patients who underwent allo-HCT with bone marrow or peripheral blood (BM/PB) and with umbilical cord blood (UCB), respectively, were analyzed. In the BM/PB cohort, the risk for chronic GVHD that requires systemic steroids increased with each increase in acute GVHD grade from 0 to 2 (grade 0 vs 1 [hazard ratio (HR), 1.32; 95% confidence interval (CI), 1.19-1.46; P < .001]; grade 1 vs 2 [HR, 1.41; 95% CI, 1.28-1.56; P < .001]), but the risk was similar between acute GVHD grade 2 and grade 3 to 4 (HR, 1.02; 95% CI, 0.91-1.15; P = 1.0). These findings were confirmed in the UCB cohort. We further observed that the risk for severe chronic GVHD increased with each increment in the grade of acute GVHD, even between acute GVHD grade 2 and grade 3 to (grade 2 vs 3-4: HR, 1.70; 95% CI, 1.12-2.58; P = .025). In conclusion, the preceding profiles of acute GVHD should help to stratify the risk for chronic GVHD and its severity, which might be useful for the development of risk-adopted preemptive strategies for chronic GVHD., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

The impact of absolute neutrophil count (ANC) before allogenic hematopoietic stem cell transplantation (HSCT) on the outcomes for patients with aplastic anemia (AA) remains unclear. We retrospectively evaluated the relationship between ANC before transplantation and patient outcomes, involving 883 adult Japanese patients with AA who underwent allogeneic HSCT as their first transplantation between 2008 and 2020. Patients were divided into three groups based on ANC: 0/µL (n = 116); 1-199 (n = 210); and ≥ 200 (n = 557). In the low ANC groups (ANC < 200), patient age was higher, previous anti-thymocyte globulin (ATG) treatments were infrequent, duration from diagnosis to transplantation was shorter, hematopoietic cell transplantation-comorbidity index (HCT-CI) was higher, ATG-based conditioning was used infrequently, and peripheral blood stem cell from related donor and cord blood were used frequently. In multivariate analysis, patient age, previous ATG treatment, HCT-CI, stem cell source, and ANC before transplantation were significantly associated with 5-year overall survival (OS) ("ANC ≥ 200": 80.3% vs. "ANC 1-199": 71.7% vs. "ANC 0": 64.4%). The cumulative incidence of bacterial infection, invasive fungal disease, and early death before engraftment were significantly higher in the low ANC groups. Among patients with ANC of zero before transplantation, younger patient age, shorter duration from diagnosis to transplantation, HCT-CI of 0, and bone marrow from related donor as stem cell source were significantly associated with better OS. Consequently, ANC before allogeneic HSCT was found to be a significant prognostic factor in adult patients with AA. Physicians should pay attention to ANC before transplantation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Poor prognostic factors, such as transfusion dependency and chromosomal risk, need to be considered in the indication of allogeneic hematopoietic cell transplantation (allo-HCT) for patients harboring myelodysplastic syndromes with less than 5% marrow blasts (MDS-Lo). We analyzed the post-transplant outcomes of 1229 MDS-Lo patients who received myeloablative (MAC)(n = 651), reduced-intensity (RIC)(n = 397), and non-myeloablative conditioning (NMAC) regimens (n = 181). The multivariate analysis revealed that the RIC group had better chronic graft-versus-host disease (GVHD)- and relapse-free survival (CRFS) (P = 0.021), and GVHD- and relapse-free survival (GRFS) than the MAC group (P = 0.001), while no significant differences were observed between the NMAC and MAC groups. In the subgroup analysis, the MAC group has better overall survival (P = 0.008) than the RIC group among patients with an HCT-comorbidity index (HCT-CI) score of 0, while the RIC group had better overall survival (P = 0.029) than the MAC group among those with an HCT-CI score ≥3. According to the type of conditioning regimen, total body irradiation 12 Gy-based MAC regimen showed better OS and CRFS than the other MAC regimen, and comparable outcomes to the RIC regimen. In conclusion, the RIC and NMAC regimens are promising options for MDS-Lo patients in addition to the MAC regimen., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

The eighth workshop of the Worldwide Network for Blood and Marrow Transplantation (WBMT) was held in Islamabad, Pakistan, from September 22 to 23, 2022, aiming to foster hematopoietic stem cell transplant (HSCT) activity in the World Health Organization (WHO) Eastern Mediterranean Region (EMRO). Participating countries, including Pakistan, Oman, Iran, and Saudi Arabia, reported increased HSCT in the last few years, whereas others from the EMRO and beyond, including Qatar, United Arab Emirates, Nepal, and Bangladesh, started HSCT recently and have developed HSCT programs with excellent results. During educational sessions and open dialog, participating teams and international experts from the WBMT shared their experience and discussed minimum essential requirements for establishing and expanding HSCT in emerging countries, indications for HSCT training and dissemination of knowledge, stem cell donor selection and safety, quality assurance in transplant centers, and the value and importance of transplant outcome databases. International support, collaboration, and local engagement, including government participation and WHO assistance, are valuable in increasing HSCT access worldwide., (Copyright © 2024 Hematology/Oncology and Stem Cell Therapy.)

Cytomegalovirus (CMV) reactivation is a prominent complication associated with adverse outcomes in allogeneic hematopoietic stem cell transplantation (HSCT). However, CMV reactivation after allogeneic HSCT may be associated with a lower incidence of relapse in some hematological malignancies. This study analyzed the Japanese registry data from 1082 patients with myelodysplastic syndrome (MDS) who underwent their first allogeneic HSCT and survived for 100 days after transplantation without graft failure or disease relapse to investigate this association. Patients who received cord blood transplants, demonstrated in vivo T cell depletion, underwent prophylactic anti-CMV treatment, or diagnosed with secondary MDS were excluded. CMV reactivation measured by pp65 antigenemia within 100 days after allogeneic HSCT was observed in 57.5% of patients, with a median time of 46 days from transplant. The 5-yr overall survival and cumulative incidence of relapse (CIR) in the cohort were 60.5% and 15.6%, respectively. The 5-yr CIR showed no significant difference between patients with and without CMV reactivation (14.4% versus 17.2%; P = .185). Interestingly, CMV reactivation within 100 days was significantly associated with a lower 5-yr CIR (7.6% versus 16.4%; P = .002) in patients with <5% myeloblasts in the bone marrow (BM) just before HSCT. Furthermore, this relevancy confirmed even when excluding patients with Grade II to IV acute GVHD (Hazard ratio: 0.38; 95% confidential intervals: 0.18-0.801; P = .011). Our findings indicate a correlation between early CMV reactivation and MDS relapse, based on the proportion of myeloblasts in the BM. These results may contribute to the development of effective CMV prophylaxis post-HSCT., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

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., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Hematopoietic cell transplantation (HCT) was developed more than 65 years ago to treat malignant blood disorders and irreversible bone marrow failures, with the aim of replacing a diseased hematopoietic system with a healthy one (allogeneic HCT). Decades later, the procedure was adapted to apply maximal chemotherapy or radiotherapy, which would result in bone marrow failure, but could be remedied by an infusion of a patient's own cryopreserved bone marrow (autologous HCT). Both treatments are high-risk and complex, especially during the initial phases. However, concerted efforts, vision, and collaboration between physicians and centers worldwide have resulted in HCT becoming a standard of care for many hematological disorders with progressive improvements in outcomes. Registries and the collaboration of societies worldwide have enabled the delivery of this curative therapy to many patients with fatal hematological diseases. More than 1.5 million HCT were performed between 1957 and 2019, and activity is continuously increasing worldwide., Competing Interests: Declaration of cometing interest NH reports advisory board honoraria from Janssen, Novartis, Takeda, Abbvie, Roche, Astellas and Bigene. YA reports consulting fees from JCR Pharmaceuticals Co., Ltd. and Kyowa Kirin Co., Ltd., lecture fees from Otsuka Pharmaceutical Co., Ltd, Chugai Pharmaceutical Co., Ltd., Novartis Pharma KK, AbbVie GK, and honorarium from Meiji Seika Pharma Co., Ltd. MI is affiliated with the Department of Promotion for Blood and Marrow Transplantation at the Aichi Medical University School of Medicine, and the department is endowed by AIR WATER INC., Clinigen K.K., and JCR Pharmaceuticals Co., Ltd. CF reports support for attending meetings from Casa Bollar and support for attending meetings and travel from Diaz Gill Lab and Prosalud. LG reports consulting fees from Sanofi, Janssen Pharmaceutical, Bristol Myers Squibb, and GlaxoSmithKline Pharmaceuticals and support for attending meetings and travel from Pfizer and Sanofi. KK reports honoraria from Pierre Fabre, Medac, and Novartis. J Snowden reports consulting fees from Jazz Pharmaceuticals, Medac Pharma, Vertex Pharmaceuticals, and participation in a Data Safety Monitoring Board in Kiadis Pharma. NW reports consulting and speakers fees from BMS Celgene, Kite Gilead, Miltenyi BioTec, Novartis, Piere Fabre and Therakos Mallinckrodt. The other authors report no conflicts of interest to disclose., (Copyright © 2024. Published by Elsevier Ltd.)

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings., (© 2024. The Author(s).)

Background Aims: Haploidentical hematopoietic stem cell transplantation (haplo-HCT) is an appropriate option when an HLA-matched related or unrelated donor is not available. Haplo-HCT using post-transplant cyclophosphamide (PTCy) is being increasingly performed worldwide due to its effective suppression of GVHD and its safety., Methods: We conducted a large nationwide cohort study to retrospectively analyze 366 patients with acute myeloid leukemia undergoing haplo-HCT with PTCy between 2010 and 2019 and to identify prognostic factors., Results: A multivariate Cox analysis revealed that an older recipient age (≥60 years), a male donor to a male recipient, a cytomegalovirus IgG-negative donor to a cytomegalovirus IgG-positive recipient, a poor cytogenetic risk, a noncomplete remission status at the time of transplantation, and a history of HCT were independently associated with worse overall survival (OS). Based on each hazard ratio, these factors were scored (1-2 points) and stratified by their total score into three groups: favorable (0-1 points), intermediate (2-3 points), and poor (4 points or more) groups, and 2-year OS rates were 79.9%, 49.2%, and 25.1%, respectively (P < 0.001)., Conclusions: The present study revealed significant prognostic factors in haplo-HCT with PTCy, and a scoring system based on these factors may be used to predict outcomes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Background and Objectives: ABO blood group mismatch between the donor and the recipient can affect the success of the transplant as well as problems with the red blood cells during allogeneic haematopoietic cell transplantation (HCT). However, the impact of the Rhesus (Rh) D mismatch on transplant outcomes in allogeneic HCT has been poorly elucidated., Materials and Methods: We retrospectively evaluated the impact of the RhD mismatch on post-transplant outcomes in 64,923 patients who underwent allogeneic HCT between 2000 and 2021 using a Japanese registry database., Results: Out of the whole group, 64,293, 322, 270 and 38 HCTs were done when the recipient or donor was RhD-mismatched with (+/+), (-/+), (+/-) or (-/-) combinations. The difference in RhD between recipient/donor (-/+), (+/-) and (-/-) did not affect haematopoietic recovery, acute and chronic graft-versus-host disease (GVHD), overall survival (OS), non-relapse mortality (NRM) or relapse when RhD (+/+) was used as the reference group in multivariate analysis., Conclusion: Our registry-based study demonstrated that RhD mismatch between recipient and donor did not significantly impact haematopoietic recovery, GVHD, OS, NRM or relapse after allogeneic HCT. These data suggest that RhD mismatches may not need to be avoided for recipient and donor combinations in allogeneic HCT., (© 2024 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)

Despite emergence of novel therapies to treat hematologic malignancies, allogeneic hematopoietic cell transplantation (allo-HCT) remains an essential treatment modality capable of curing these diseases. Allo-HCT has been also shown to be curative in benign hematologic disorders such as aplastic anemia, sickle cell disease, and thalassemia, among others. Recently, the American Society for Transplantation and Cellular Therapy (ASTCT) published standardized definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism. To attempt broader international consensus, a panel of adult and pediatric physician transplant experts was assembled from European Society for Blood and Marrow Transplantation (EBMT), ASTCT, the Center for International Blood and Marrow Transplant Research (CIBMTR), and Asia-Pacific Blood and Marrow Transplantation (APBMT). Consensus was defined as ≥70% of voting members strongly agreeing or somewhat agreeing with a definition. With few exceptions, there was a consensus to endorse the prior ASTCT definitions. Importantly, we revised existing EBMT and CIBMTR data collection forms to align with these harmonized definitions that will facilitate research and international collaboration among transplant researchers and across transplant registries., (© 2024. The Author(s).)

To assess the benefits of HLA-haploidentical haematopoietic stem cell transplantation using post-transplant cyclophosphamide (PTCy-haplo) relative to those of umbilical cord blood (UCB) transplantation in acute lymphoblastic leukaemia (ALL), we analysed 1999 patients (PTCy-haplo, 330; UCB, 1669), using the nationwide Japanese registry. PTCy-haplo was associated with a significantly higher relapse rate, but lower non-relapse mortality, which results in overall survival and disease-free survival, comparable to those of UCB. Among patients in CR1, PTCy-haplo showed a significantly higher survival than UCB regardless of the CD34 + cell dose. Our findings provide valuable insights into the donor selection algorithm in allogeneic HSCT for adult patients with ALL., (© 2024 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

This study aimed to investigate the usefulness of allogeneic stem cell transplantation (allo-SCT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) in the first complete remission (CR1) with complete molecular remission (CMR). We compared the outcomes between Ph+ALL patients who did or did not undergo allo-SCT in CR1. We included patients enrolled in the prospective clinical studies in the tyrosine kinase inhibitor era conducted by the Japan Adult Leukemia Study Group, who achieved CMR within 3 months. A total of 147 patients (allo-SCT: 101; non-SCT: 46) were eligible for this analysis. In the multivariate analyses, allo-SCT was significantly associated with both superior overall survival (OS) (adjusted hazard ratio (aHR): 0.54; 95% CI: 0.30-0.97; p = .04) and relapse-free survival (RFS) (aHR: 0.21; 95% CI: 0.12-0.38; p < .001). The 5-year adjusted OS and RFS were 73% and 70% in the allo-SCT cohort, whereas they were 50% and 20% in the non-SCT cohort. Despite the higher non-relapse mortality (aHR: 3.49; 95% CI: 1.17-10.4; p = .03), allo-SCT was significantly associated with a lower relapse rate (aHR: 0.10; 95% CI: 0.05-0.20; p < .001). In addition, allo-SCT was also associated with superior graft-versus-host disease-free, relapse-free survival (aHR: 0.43; 95% CI: 0.25-0.74; p = .002). Propensity score-matched analyses confirmed the results of the multivariate analyses. In patients who achieved CMR within 3 months, allo-SCT in CR1 had superior survival and lower relapse compared with the non-SCT cohort., (© 2024 Wiley Periodicals LLC.)

The present study compared lower-dose melphalan (80 mg/m 2 , FM80) and higher-dose melphalan (140 mg/m 2 , FM140) when administering reduced-intensity conditioning with fludarabine in adult patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed nationwide registry data (2006 to 2019) and compared transplant outcomes between the 2 groups. Ninety-two patients (median age, 61 [interquartile range, 56 to 65] years) were assigned to the FM80 and FM140 groups by propensity score matching. The 3-year overall survival (OS) rate in the FM140 group (63.9%; 95% confidence interval [CI], 52.9% to 73.0%) was significantly higher than that in the FM80 group (54.2%; 95% CI, 37.1% to 52.1%) (P = .038). The FM140 group had a nonsignificantly (P = .095) lower 3-year cumulative incidence of relapse (15.5%; 95% CI, 8.9% to 23.8% versus 26.0%; 95% CI, 17.3% to 35.5%). The 3-year cumulative incidences of nonrelapse mortality were 22.3% (95% CI, 14.1% to 31.8%) and 23.7% (95% CI, 15.4% to 33.2%) in the FM80 and FM140 groups, respectively (P = .49). The beneficial effect of FM140 was more evident in patients with a poor cytogenetic risk. Our findings suggest the superiority of FM140 in patients with MDS undergoing allo-HSCT, especially in high-risk patients., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

This study aimed to address the prognostic impact of center experience based on the data of 7821 adults with acute myeloid leukemia who underwent allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2019 in Japan, where medical care was provided within a uniform healthcare system. Center experience was defined based on the number of allogeneic HCTs performed for any indication during the study period, by which centers were divided into low-, intermediate-, and high-volume centers. After adjusting for known confounding factors, the risk of overall mortality was lowest for the high-volume centers and highest for the low-volume centers, with the difference between the center categories attributed primarily to the risk of relapse. Patients transplanted at high-volume centers had higher risks of acute and chronic graft-versus-host diseases but without an increased risk of non-relapse mortality (NRM). These findings reveal the presence of a center effect in allogeneic HCT conducted during the past decade in Japan, highlighting the difference in relapse based on center experience. The weaker effect on NRM compared with that on relapse suggests that the transplantation care quality is becoming equalized across the country., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disorder characterized by systemic hyperinflammation. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only potentially curative treatment for primary and relapsed/refractory HLH, the optimal strategy has not been established. We retrospectively analyzed 56 adult patients (≥18 years) with primary and secondary HLH (mainly consisting of Epstein-Barr virus-associated HLH) who underwent allo-HSCT using the registry database of the Japanese Society for Transplantation and Cellular Therapy, including 26 patients who underwent cord blood transplantation (CBT). One-fourth of patients received myeloablative conditioning (MAC), mainly consisting of total body irradiation-based regimens. The 3-year overall survival (OS) was 40.6%, while the 3-year cumulative incidences of relapse and non-relapse mortality (NRM) were 19.8% and 39.6%, respectively. In univariable analysis, age at allo-HSCT (the 3-year OS: 27.5% for ≥ 25 years old vs 58.0% for < 25 years old, P = .025), conditioning intensity (7.1% for MAC vs 51.8% for reduced-intensity conditioning (RIC), P = .002), and donor source (26.0% for CBT vs 52.9% for bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT), P = .030) were associated with significantly inferior OS. In multivariable analysis, older age at allo-HSCT (≥ 25 years old) (Hazard ratio [HR], 2.37; 95% CI, 1.01 to 5.58; P = .048), MAC (HR, 2.45; 95% CI, 1.09 to 5.53; P = .031), and CBT (HR, 2.21; 95% CI, 1.04 to 4.71; P = .040) were independently associated with worse OS. In addition, only conditioning intensity predicted higher NRM (the 3-year NRM: 78.6% for MAC vs 26.6% for RIC), while no factors were associated with the relapse rate. This study includes the largest number of adult HLH patients undergoing CBT. Although the use of CBT is acceptable, BMT/PBSCT are more favorable strategies in allo-HSCT in adult HLH. Regarding conditioning intensity, RIC regimens are more beneficial in this setting., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Delayed neutrophil recovery is an important limitation to the administration of cord blood transplantation (CBT) and leaves the recipient vulnerable to life-threatening infection and increases the risk of other complications. A predictive model for neutrophil recovery after single-unit CBT was developed by using a machine learning method, which can handle large and complex datasets, allowing for the analysis of massive amounts of information to uncover patterns and make accurate predictions. Japanese registry data, the largest real-world dataset of CBT, was selected as the data source. Ninety-eight variables with observed values for >80% of the subjects known at the time of CBT were selected. Model building was performed with a competing risk regression model with lasso penalty. Prediction accuracy of the models was evaluated by calculating the area under the receiver operating characteristic curve (AUC) using a test dataset. The primary outcome was neutrophil recovery at day (D) 28, with recovery at D14 and D42 analyzed as secondary outcomes. The final cord blood engraftment prediction (CBEP) models included 2991 single-unit CBT recipients with acute leukemia. The median AUC of a D28-CBEP lasso regression model run 100 times was .74, and those for D14 and D42 were .88 and .68, respectively. The predictivity of the D28-CBEP model was higher than that of 4 different legacy models constructed separately. A highly predictive model for neutrophil recovery by 28 days after CBT was constructed using machine learning techniques; however, identification of significant risk factors was insufficient for outcome prediction for an individual patient, which is necessary for improving therapeutic outcomes. Notably, the prediction accuracy for post-transplantation D14, D28, and D42 decreased, and the model became more complex with more associated factors with increased time after transplantation., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Abstract: Higher rate of nonrelapse mortality (NRM) remains yet to be resolved in umbilical cord blood transplantation (UCBT). Considering that UCBT has some unique features compared with allogeneic hematopoietic cell transplantation from other graft sources, a UCBT-specific NRM risk assessment system is required. Thus, in this study, we sought to develop a UCBT-specific NRM Risk Assessment (CoBRA) score. Using a nationwide registry database, we retrospectively analyzed 4437 recipients who had received their first single-unit UCBT. Using the backward elimination method, we constructed the CoBRA score in a training cohort (n = 2687), which consisted of recipients age ≥55 years (score 2), hematopoietic cell transplantation-specific comorbidity index ≥3 (score 2), male recipient, graft-versus-host disease prophylaxis other than tacrolimus in combination with methotrexate, performance status (PS) 2 to 4, HLA allele mismatch ≥ 2, refined Disease Risk Index high risk, myeloablative conditioning, and CD34+ cell doses < 0.82 × 105/kg (score 1 in each). The recipients were categorized into 3 groups: low (0-4 points), intermediate (5-7 points), and high (8-11 points) groups according to the CoBRA score. In the validation cohort (n = 1750), the cumulative incidence of NRM at 2 years was 14.9%, 25.5%, and 47.1% (P < .001), and 2-year overall survival (OS) was 74.2%, 52.7%, and 26.3% (P < .001) in the low, intermediate, and high groups, respectively. In summary, the CoBRA score could predict the NRM risk as well as OS after UCBT. Further external validation will be needed to confirm the significance of the CoBRA score., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Haploidentical haematopoietic cell transplantation (haplo-HCT) using post-transplant cyclophosphamide (PTCY) as graft-versus-host disease (GVHD) prophylaxis is the standard of care for various haematological malignancies. The original PTCY dose after haplo-HCT was 100 mg/kg, but no dose-finding studies have been performed to identify the optimal dose. We performed a retrospective analysis to compare standard-dose PTCY (100 mg/kg) with reduced-dose PTCY (80 mg/kg): 969 in the standard-dose group and 538 in the reduced-dose group. As there was a significant difference between the two groups regarding patient and transplant characteristics, we performed propensity score (PS) matching. After PS matching, 425 patients in each group were included. The probabilities of 2-year OS were 55.9% in the standard-dose group and 47.0% in the reduced-dose group (p = 0.36). The cumulative incidences of 2-year non-relapse mortality were 21.3% in the standard-dose group and 20.5% in the reduced-dose group (p = 0.55). There was no significant difference in the incidence of acute (grade II-IV 29.2% [95% CI, 24.9-33.6] vs. 25.3% [95% CI, 21.3-29.6]; grade III-IV 7.3% [95% CI, 5.1-10.0] vs. 6.6% [95% CI, 4.5-9.3]) or chronic GVHD. In conclusion, reduced- and standard-dose PTCY were comparable in terms of major clinical outcomes., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

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., (Copyright © 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Survival rates of patients with Philadelphia chromosome-positive ALL (Ph+ALL) have improved considerably with the introduction of tyrosine kinase inhibitors (TKI); however, hematopoietic stem cell transplantation (HSCT) continues to play an important role. Reduced-intensity conditioning (RIC) regimens have been widely applied particularly for older patients, but their validity for children and adolescents with Ph+ALL has not been investigated. In this study, data from patients receiving HSCT for de novo Ph+ALL in first or second remission at ages younger than 25 years and with a history of pre-HSCT TKI therapy were retrospectively collected through the nationwide registry in Japan. In 265 patients who received myeloablative conditioning (MAC) and 33 patients receiving RIC, 5-year leukemia-free survival (LFS) rates were 67.3% and 79.8%, respectively (p = 0.142). Multivariate analysis of LFS, focusing on patients with good performance status, identified RIC as a significant prognostic factor for LFS (hazard ratio 0.32, p = 0.032), as well as older age, higher leukocyte count at diagnosis, and disease with additional chromosomal abnormalities. These trends were similar when we focused on patients who received prophylactic post-HSCT TKI treatment, as 5-year LFS was 81.0% for MAC and 84.4% for RIC (p = 0.748). In summary, HSCT with RIC regimen showed at least comparable LFS to HSCT with MAC regimen, and RIC was an independent favorable prognostic factor on multivariate analysis adjusting potential prognostic factors. While patient numbers were limited, our data suggest that RIC may be safely applied in this group, particularly combined with prophylactic post-HSCT TKI maintenance therapy., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Allogeneic hematopoietic cell transplantation (HCT) is the last option for long-term survival for patients with chemotherapy-refractory acute myeloid leukemia (AML). By using the Japanese nationwide registry data, we analyzed 6927 adults with AML having undergone first allogeneic HCT while not in complete remission (CR) between 2001 and 2020. The 5-year overall survival (OS), relapse, and non-relapse mortality (NRM) rates were 23%, 53%, and 27%, respectively. Multivariate analysis identified several factors predictive of OS mainly through their effects on relapse (cytogenetics, percentage of blasts in the peripheral blood, and transplantation year) and NRM (age, sex, and performance status). As regards disease status, relapsed disease was associated with a higher risk of overall mortality than primary induction failure (PIF). The shorter duration of the first CR increased the risks of relapse and overall mortality for the relapsed group, and the longer time from diagnosis to transplantation did so for the PIF group. Our experience compiled over the past two decades demonstrated that >20% of patients still enjoy long-term survival with allogeneic HCT performed during non-CR and identified those less likely to benefit from allogeneic HCT. Future efforts are needed to reduce the risk of posttransplant relapse in these patients., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a currative treatment modality for diffuse large B-cell lymphoma (DLBCL) because of the intrinsic graft-versus-lymphoma effect. However, limited information is available regarding which patients with relapsed or refractory DLBCL are likely to benefit from allo-HSCT. We retrospectively analyzed data from 1268 DLBCL patients who received allo-HSCT. The overall survival and progression-free survival (PFS) rates were 30.3% and 21.6% at 3 years, respectively. Multivariate analysis revealed that stable or progressive disease at transplantation, male patient, poorer performance status at transplantation, and shorter intervals from previous transplantation were associated independently with a lower PFS. Four prognostic factors were used to construct a prognostic index for PFS, predicting 3-year PFS of 55.4%, 43.7%, 20.4% and 6.6%, respectively. The prognostic model predicted relapse rates following allo-HSCT accordingly (P < 0.0001), whereas did not predict transplantation-related mortality (P = 0.249). The prognostic index can identify a subgroup of DLBCL patients who benefit from allo-HSCT and it is worthwhile to evaluate whether this model is also applicable to patients undergoing allo-HSCT in cases of relapse after chimeric antigen receptor engineered T-cell therapy, although the application of allo-HSCT has been declining with the increase of novel immunotherapies., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Umbilical cord blood (UCB) is a valuable alternative donor source for allogeneic hematopoietic stem cell transplantation. Various conditioning regimens and graft-versus-host disease (GVHD) prophylaxis regimens aimed at improving the outcomes of umbilical cord blood transplantation (UCBT) have been explored; however, the differences in their effects remain unclear. This study was conducted to elucidate the differences in the effects of conditioning and GVHD prophylaxis regimens on UCBT outcomes by disease type in a nationwide, retrospective study. We retrospectively analyzed the effects of conditioning and GVHD prophylaxis regimens on the outcomes of UCBT performed with cyclophosphamide (Cy)/total body irradiation (TBI)-based regimens in patients with acute myeloid leukemia (AML; n = 1126), acute lymphoblastic leukemia (ALL; n = 620), myelodysplastic syndrome (MDS; n = 170), and lymphoma (n = 128). Multivariate analysis for overall survival (OS) demonstrated the benefit of adding high-dose cytarabine to the Cy/TBI regimen for the AML group (relative risk [RR], .76; P = .003) and lymphoma group (RR, .54; P = .02), but not for the ALL and MDS groups. In the ALL group, adding etoposide to the Cy/TBI regimen was associated with a lower OS (RR, 1.45; P = .03). For GVHD prophylaxis, a tacrolimus/methotrexate regimen was associated with a lower OS compared with a cyclosporine/methotrexate regimen in the AML group (RR, 1.26; P = .01); this difference was not observed in the other groups. These differences in OS according to the conditioning and GVHD prophylaxis regimen were attributable mainly to differences in relapse risk. Our data show that the effects of conditioning regimens and GVHD prophylaxis on UCBT outcomes differed according to disease type. UCBT outcomes could be improved by selecting optimal conditioning regimens and GVHD prophylaxis for each disease type., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background: As the Japanese population may have less genetic diversity than other ethnic groups, treatment outcomes may be affected when allogeneic hematopoietic cell transplantation is performed in other races. However, evidence explaining the effect of racial differences is limited., Methods: We used the Japanese National Database to examine the outcomes of first allogeneic bone marrow transplantations (BMTs) performed between Japanese and non-Japanese patients from 1996 to 2021. We performed propensity score matching using sex, age group, underlying disease group, HLA mismatch, conditioning regimen intensity, and BMT implementation age to select Japanese-to-Japanese BMT patients as the controls., Results: The numbers of non-Japanese-to-Japanese and Japanese-to-non-Japanese BMT cases included in the analysis were 48 and 75, respectively, and the following outcomes were compared: overall survival, non-relapse mortality, acute graft-vs-host disease (GVHD) ≥ grade II, chronic GVHD, and engraftment of neutrophils and platelets. Most parameters did not differ when comparing BMTs according to ethnicity; only platelet engraftment was delayed in Japanese-to-non-Japanese BMT but not in non-Japanese-to-Japanese BMT., Conclusions: The results of this study suggested that BMT performed in Japanese and non-Japanese patients has little effect on treatment outcomes. The results of this study may be useful for donor selection in Japan, where internationalization has progressed in recent years., Competing Interests: Declaration of competing interest All the authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Various complications can influence hematopoietic cell transplantation (HCT) outcomes. Renal complications can occur during the early to late phases of HCT along with various factors. However, studies focusing on fatal renal complications (FRCs) are scarce. Herein, we analyzed 36,596 first allogeneic HCT recipients retrospectively. Overall, 782 patients died of FRCs at a median of 108 (range, 0-3,440) days after HCT. The cumulative incidence of FRCs was 1.7% and 2.2% at one and five years, respectively. FRCs were associated with older age, male sex, non-complete remission (non-CR), lower performance status (PS), and HCT comorbidity index (HCT-CI) associated with renal comorbidity in multivariate analysis. The risk factors within 100 days included older age, multiple myeloma, PS, and HCT-CI comorbidities (psychiatric disturbance, hepatic disease, obesity, and renal disease). Older age and male sex were risk factors between 100 days and one year. After one year, HCT-CI was associated with the presence of diabetes and prior solid tumor; total body irradiation was identified as a risk factor. Non-CR was a common risk factor in all three phases. Furthermore, acute and chronic graft-versus-host disease, reactivation of cytomegalovirus, and relapse of underlying disease also affected FRCs. Systematic follow-up may be necessary based on the patients' risk factors and post-HCT events., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Chronic graft-versus-host disease (cGVHD) is a complication of allogeneic hematopoietic stem cell transplantation (HSCT), negatively impacting quality of life (QoL) and increasing the risk of death. Complexity in cGVHD diagnosis and treatment causes significant variations in cGVHD management strategies across medical centers and physicians despite the existence of published guidelines. Thus, we hypothesized that center volume is associated with cGVHD incidence and outcomes after cGVHD develops. This study aimed to evaluate the effect of center volume on the incidence of cGVHD in patients who underwent HSCT and outcomes in patients with cGVHD. Our retrospective study included 28,786 patients who underwent their first HSCT (overall cohort) and 7664 who developed cGVHD (cGVHD cohort). We categorized institutions into quartiles (very low, low, high, and very high) using the number of HSCTs performed during the study period. We assessed cGVHD incidence in overall cohort and overall survival (OS) in cGVHD cohort. The very high-volume group showed significantly higher cGVHD incidence (adjusted hazard ratio [HR], 1.38; 95% confidence interval [CI]: 1.30 to 1.46) compared to the very low-volume group. However, the cGVHD incidence was similar among very low-, low- and high-volume groups. Low, high, and very high-volume groups showed significantly higher OS with adjusted HRs of 0.83 (95% CI: 0.73 to 0.94), 0.69 (95% CI: 0.61 to 0.79), and 0.68 (95% CI: 0.60 to 0.76), respectively, compared with the very low-volume group. In conclusion, we revealed a higher incidence of cGVHD in the very high-volume group and a poor survival outcome in the very low-volume group in patients with cGVHD., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Abstract: To clarify the different characteristics and prognostic factors of cord blood transplantation (CBT) in adult patients with lymphoid neoplasms in Europe and Japan, we conducted a collaborative study. Patients aged 18-75 years receiving their first CBT (Europe: single CBT, n = 192; double CBT, n = 304; Japan: single CBT, n = 1150) in 2000-2017 were analyzed. Fewer patients with Hodgkin lymphoma (Europe vs Japan, 26% vs 5%), and older patients (≥50 years) (39% vs 59%) with a higher refined disease risk index (rDRI) (high-very high: 49% vs 14%) were included in the Japanese registry. High-very high rDRI was associated with inferior overall survival (OS) (vs low rDRI, Europe: hazard ratio [HR], 1.87; P = .001; Japan: HR, 2.34; P < .001) with higher progression/relapse risks. Total body irradiation (TBI)-containing conditioning contributed to superior OS both in Europe (vs TBI-reduced-intensity conditioning [RIC], non-TBI-RIC: HR, 1.93; P < .001; non-TBI-Myeloablative conditioning [MAC]: HR, 1.90; P = .003) and Japan (non-TBI-RIC: HR, 1.71; P < .001; non-TBI-MAC: HR 1.50, P = .007). The impact of HLA mismatches (≥2) on OS differed (Europe: HR, 1.52; P = .007; Japan: HR, 1.18; P = .107). CBT for lymphoid neoplasms, especially in those with high rDRI showed poor outcomes despite all the different characteristics in both registries. TBI should be considered in conditioning regimens to improve these outcomes. The different impacts of HLA mismatches call attention to the fundamental differences among these populations., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

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., (© 2024. Japanese Society of Hematology.)

Background Aims: This study aimed to comprehensively assess the impact of stem cell selection between bone marrow (BM) and peripheral blood (PB) in unrelated hematopoietic stem cell transplantation (HSCT) for hematological malignancies. Our objective was to identify specific factors associated with better transplant outcomes., Methods: A retrospective analysis was conducted using data from the Japanese HSCT registry. Inclusion criteria were patients aged 0-70 years who underwent their first unrelated HSCT with BM or PB, with an 8/8 or 7/8 allele HLA match for hematological malignancies between 2010 and 2020., Results: Among 10 295 patients, no significant difference was observed in overall survival, relapse, graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) or non-relapse mortality between the groups. Patients who received PB showed no clear difference in acute GVHD but had a greater rate of chronic GVHD, resulting in poor chronic GVHD-free, relapse-free survival (CRFS). Subgroup analyses highlighted the importance of patient-specific factors in source selection. Patients with non-Hodgkin lymphoma and a greater hematopoietic cell transplantation-comorbidity index showed better CRFS and GRFS when BM was the preferred source. Similar trends were observed among patients with standard-risk disease for CRFS. However, no such trends were evident among patients aged 0-24 years, indicating that both sources are viable choices for young patients., Conclusions: This real-world retrospective analysis showed similar basic outcomes for BM and PB in an unrelated setting. The results support that BM may still be preferred over PB, especially when the long-term quality of life is a major concern. A consideration of individual factors can further optimize transplant success. Further research is warranted to explore the long-term implications of stem cell source selection., Competing Interests: Declaration of Competing Interest The authors have no commercial, proprietary or financial interest in the products or companies described in this article., (Copyright © 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Allogeneic haematopoietic stem cell transplantation (HCT) is the curative treatment for myelodysplastic syndrome with a complex karyotype (CK-MDS). However, only a few studies have been limited to patients with CK-MDS undergoing allogeneic HCT. This study aimed to identify the risk factors for patients with CK-MDS undergoing allogeneic HCT. We included 691 patients with CK-MDS who received their first allogeneic HCT. The overall survival (OS) was the primary end-point, estimated using the Kaplan-Meier method. Prognostic factors were identified using a Cox proportional hazards model. The 3-year OS was 29.8% (95% confidence interval [CI]: 26.3-33.3). In the multivariable analysis, older age (hazard ratio [HR]: 1.44, 95% CI: 1.11-1.88), male sex (HR: 1.38, 95% CI: 1.11-1.71), poor haematopoietic cell transplant comorbidity index (HR: 1.47, 95% CI: 1.20-1.81), red blood cell transfusion requirement (HR: 1.58, 95% CI: 1.13-2.20), platelet transfusion requirement (HR: 1.85, 95% CI: 1.46-2.35), not-complete remission (HR: 1.55, 95% CI: 1.16-2.06), a high number of karyotype abnormality (HR: 1.63, 95% CI: 1.18-2.25) and monosomal karyotype (HR: 1.49, 95% CI: 1.05-2.12) were significantly associated with OS. Thus, the 3-year OS of allogeneic HCT was 29.8% in patients with CK-MDS, and we identified risk factors associated with poor OS., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

Fludarabine/busulfan and fludarabine/melphalan are viable options as conditioning regimens. However, the optimal fludarabine-based conditioning in cord blood transplantation (CBT) remains unclear. Therefore, this retrospective, registry-based study aimed to analyze the impact of five fludarabine-containing conditioning regimens on 1395 adult patients (median age, 61 years) with acute myeloid leukemia, myelodysplastic syndrome, and chronic myeloid leukemia who underwent their first CBT. Treatment outcomes of fludarabine combined with melphalan (100-140 mg/m 2 ) and low-dose total body irradiation (TBI; FM140T); melphalan (80-99 mg/m 2 ) and TBI (FM80T); busulfan (12.8 mg/kg) and melphalan (FB4M); busulfan (12.8 mg/kg) and TBI (FB4T); and busulfan (6.4 mg/kg) and TBI (FB2T) were compared. The 3-year survival rate was 67%, 53%, 44%, 36%, and 39%, respectively (p < .0001). The FM140T survival rate was the most favorable after adjusting for confounders, and the hazard ratios (vs. FM140T) for overall mortality were as follows: FM80T, 1.6 (95% confidence interval [CI], 1.2-2.2); FB4M, 2.1 (95% CI, 1.6-2.8); FB4T, 2.7 (95% CI, 2.0-3.7); and FB2T, 2.2 (95% CI, 1.6-3.1). The better survival observed with FM140T, regardless of the disease, disease risk, age, or transplant year, was attributed to the lower relapse rate and lower non-relapse mortality (NRM) associated with fewer infectious deaths. Conversely, FB4T was associated with a higher relapse rate and higher NRM. The findings indicate that the outcomes of CBT in myeloid malignancies were highly dependent on both the alkylating agent and its dose in combination with fludarabine. Therefore, compared with fludarabine/busulfan-based conditioning, FM140T may be the preferred regimen., (© 2024 Wiley Periodicals LLC.)

We retrospectively evaluated the effect of 17 individual comorbidities, defined by the hematopoietic cell transplantation (HCT)-specific comorbidity index, on non-relapse mortality (NRM) and overall survival (OS) in 9531 patients aged between 16 and 70 years who underwent their first allogeneic HCT from 8/8 and 7/8 allele-matched unrelated donors (8/8 and 7/8 MUDs) or single-unit unrelated cord blood (UCB) between 2011 and 2020 using data from a Japanese registry database. In the multivariate analysis, infection (adjusted hazard ratio [HR], 1.62, 95% confidence interval [CI], 1.33-1.99 for 8/8 and 7/8 MUDs; adjusted HR, 1.33, 95%CI, 1.12-1.58 for UCB) and moderate/severe hepatic comorbidity (adjusted HR, 1.57, 95%CI, 1.04-2.38 for 8/8 and 7/8 MUDs; adjusted HR, 1.53, 95%CI, 1.09-2.15 for UCB) had a significant impact on NRM in both donor groups. Cardiac comorbidity (adjusted HR, 1.40, 95%CI, 1.08-1.80), mild hepatic comorbidity (adjusted HR, 1.22, 95%CI, 1.01-1.48), rheumatologic comorbidity (adjusted HR, 1.67, 95%CI, 1.11-2.51), renal comorbidity (adjusted HR, 2.44, 95%CI, 1.46-4.09), and severe pulmonary comorbidity (adjusted HR, 1.40, 95%CI, 1.11-1.77) were significantly associated with an increased risk of NRM but only in UCB recipients. Renal comorbidity had the strongest impact on poor OS in both donor groups (adjusted HR, 1.73, 95%CI, 1.10-2.72 for 8/8 and 7/8 MUDs; adjusted HR, 2.24, 95%CI, 1.54-3.24 for UCB). Therefore, unrelated donor selection should be taken into consideration along with the presence of specific comorbidities, such as cardiac, rheumatologic, renal, mild hepatic, and severe pulmonary comorbidities., (© 2024 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Cytomegalovirus (CMV) infection is a major infectious complication following allogeneic hematopoietic cell transplantation (allo-HCT). Although letermovir (LMV) prophylaxis dramatically reduces the incidence of early clinically significant CMV (csCMV) infection, it remains unclear whether it has a beneficial effect on nonrelapse mortality (NRM) and overall survival (OS). Herein, we evaluated the impact of LMV prophylaxis on posttransplant outcomes using the registry database of the Japanese Society for Transplantation and Cellular Therapy. Adult patients who underwent allo-HCT between 2017 and 2019 were analyzed (n = 6004). LMV prophylaxis was administered to 1640 patients (LMV group) and it significantly reduced the incidence of csCMV infection compared with those not administered LMV prophylaxis (15.4% vs 54.1%; p < 0.01). However, it did not improve the 1-year NRM (hazard ratio [HR], 0.93; p = 0.40) and OS (HR, 0.96; p = 0.49). In the LMV group, 74 patients had breakthrough csCMV infection and showed inferior NRM (HR, 3.44; p < 0.01) and OS (HR, 1.93; p = 0.02) compared with those without infection. After completing LMV prophylaxis, 252 patients had late csCMV infection and showed inferior NRM (HR, 1.83; p < 0.01) and OS (HR, 1.58; p < 0.01). Our findings suggest that managing breakthrough and late csCMV infections is important for improving long-term outcomes., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Allogeneic hematopoietic stem cell transplantation (HCT) remains the only potential curative therapeutic modality for advanced myelodysplastic syndrome (MDS). Within HCT, the advancement of cord blood transplantation (CBT) procedures has resulted in a drastic expansion of CBT as a donor source for MDS. However, data comparing matched sibling donors (MSDs) HCT with CBT for advanced MDS, which was defined as refractory anemia with an excess of blasts (RAEB)-1 and RAEB-2 according to the World Health Organization classification at the time of HCT, have not been explored. We retrospectively compared survival and other posttransplant outcomes in 999 adult patients with advanced MDS after receiving allogeneic HCT in Japan between 2011 and 2020, using either MSD (n = 331) or single-unit unrelated cord blood (UCB) (n = 668). In the multivariate analysis, there were no significant differences in overall survival (hazard ratio [HR], 1.10; 95% confidence interval [CI], 0.90-1.34; P = 0.347), disease-free survival (HR, 1.01; 95% CI, 0.84-1.23; P = 0.845), relapse (HR, 0.88; 95% CI, 0.68-1.15; P = 0.370), or non-relapse mortality (HR, 1.15; 95% CI, 0.87-1.50; P = 0.310) between MSD recipients and UCB recipients. UCB was significantly associated with lower neutrophil (HR, 0.28; 95% CI, 0.24-0.33; P < 0.001) and lower platelet (HR, 0.29; 95% CI, 0.23-0.36; P < 0.001) recovery compared to MSD. UCB was significantly associated with a lower incidence of chronic graft-versus-host disease (GVHD) (HR, 0.57; 95% CI, 0.44-0.75; P < 0.001) and extensive chronic GVHD (HR, 0.46; 95% CI, 0.32-0.67; P < 0.001) compared to MSD. Similar results were observed after adjusting for differences between MSD and UCB recipients by propensity score matching analysis. Our study demonstrated that single CBT and MSD HCT had similar survival outcomes for adult patients with advanced MDS despite the lower hematopoietic recovery in CBT recipients and higher chronic GVHD in MSD recipients., (© 2023 The Authors. Hematological Oncology published by John Wiley & Sons Ltd.)