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Background: Post-transplant cyclophosphamide (PTCy) is a commonly used graft-vs-host disease (GVHD) prophylaxis, particularly in the setting of haploidentical (haplo) hematopoietic cell transplantation (HCT). The rate of graft failure has been reported to be as high as 12% to 20% in haplo-HCT recipients using PTCy. The objective of this study was to determine whether donor type influenced the risk of late graft failure following reduced-intensity conditioning (RIC) HCT using PTCy-based GVHD prophylaxis., Study Design: A retrospective cohort analysis using the Center for International Blood and Marrow Transplant Research (CIBMTR) database among adult patients who underwent first RIC haplo or 8/8 matched unrelated donor (MUD) HCT between 2011 and 2018 for acute myeloblastic leukemia (AML), acute lymphoblastic leukemia (ALL) or myelodysplastic syndrome (MDS) with PTCy GVHD prophylaxis. The primary outcome was incidence of late graft failure, defined as secondary graft loss in the absence of relapse or poor graft function requiring a cellular therapy intervention., Results: A total of 1336 patients met the eligibility criteria (1151 haplo, 185 MUD). Patients in the MUD group were older (65 vs. 61 years), less ethnically diverse (95% vs. 72% White), received fewer bone marrow grafts (45% vs. 16%), and had younger donors (median age, 28 vs. 37 years old). Conditioning regimens were predominately fludarabine, cyclophosphamide, and total body irradiation (TBI; 87% haplo and 38% MUD). At 2 years, the adjusted probabilities of late graft failure for the haplo group was 6.5% (95% confidence interval [CI], 5.2-8.0) versus 5.9% (95% CI, 2.7%-10.9%) for the MUD group (P = .79). Multivariate analysis for risk factors associated with late graft failure found associations with a diagnosis of MDS (HR, 1.98; 95% CI, 1.22-3.20; P = .005), and earlier year of HCT (2015-2018 vs. 2011-2014; HR, 0.39; 95% CI, 0.24-0.64; P = .0002). A post-hoc sensitivity analysis was performed to evaluate the effect of donor age and use of peripheral blood stem cell (PBSC) grafts. Graft failure did not differ between haplo and MUD HCT (HR, 1.19; P = .67) when adjusted for donor age nor when restricted to PBSC grafts only (HR, 0.85; P = .70)., Conclusion: In this registry-based analysis of patients undergoing RIC HCT for AML, ALL, or MDS using GVHD prophylaxis with PTCy, there was no significant difference in late graft failure rates between haplo and MUD donors. Overall rates of late graft failure were high., Competing Interests: Declaration of competing interest Dr. Grunwald reports consulting fees from Amgen, Aptitude Health, Astellas Pharma, Blueprint Medicines, Bristol Myers Squibb, Cardinal Health, Daiichi Sankyo, Genentech, GSK, Incyte Corporation, Jazz Pharmaceuticals, OncLive, Pfizer, Premier, Sanofi, Servier, and Sobi; research funding from Ajax Pharmaceuticals, Incyte Corporation, Janssen, and Merck; and equity/stockholder from Medtronic. Dr. Cutler reports consulting fees/honoraria from Sanofi, CSL Behring, Incyte, CareDx, and Syndax; and consulting fees/equity from Cimeio, Oxford Immune Algorithmics, and OrcaBio. Dr. Soiffer reports consulting fees from Astellas, Amgen, Vor Biopharma, Smart Immune, Neovii, Bluesphere Bio, and Jasper; and is on the Data Safety Monitoring Board for BMS and Board of Directors for NMDP., (Copyright © 2025 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Abstract: Measurable residual disease (MRD) by multiparametric flow cytometry (MFC) before allogeneic hematopoietic cell transplantation (HCT) identifies patients at high risk of acute myeloid leukemia (AML) relapse, often occurring early after allografting. To examine the role of MFC MRD testing to predict later relapses, we examined 935 adults with AML or myelodysplastic neoplasm/AML transplanted in first or second morphologic remission who underwent bone marrow restaging studies between day 70 and 100 after HCT and were alive and without relapse by day +100. Of 935 adults, 136 (15%) had MRD before HCT, whereas only 11 (1%) had MRD at day +70 to +100. In day +100 landmark analyses, pre-HCT and day +70 to +100 MFC MRD were both associated with relapse (both P < .001), relapse-free survival (RFS; both P < .001) overall survival (OS; both P < .001), and, for post-HCT MRD, nonrelapse mortality (P = .001) after multivariable adjustment. Importantly, although 126/136 patients (92%) with MRD before HCT tested negative for MRD at day +70 to +100, their outcomes were inferior to those without MRD before HCT and at day +70 to +100, with 3-year relapse risk of 40% vs 15% (P < .001), 3-year RFS of 50% vs 72% (P < .001), and 3-year OS of 56% vs 76% (P < .001), whereas 3-year nonrelapse mortality estimates were similar (P = .53). Thus, despite high MRD conversion rates, outcomes MRD positive/MRD negative (MRDneg) patients are inferior to those of MRDneg/MRDneg patients, suggesting all patients with pre-HCT MRD should be considered for preemptive therapies after allografting., (© 2025 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.)

Lack of HLA-matched related/unrelated donor remains a barrier to allogeneic hematopoietic cell transplantation (HCT) for adult acute myeloid leukemia (AML), with ongoing uncertainty about optimal donor type if more than one alternative donor is available. To assess the relationship between donor type, pre-HCT measurable residual disease (MRD), and post-HCT outcomes, we retrospectively analyzed 1265 myelodysplastic neoplasm (MDS)/AML and AML patients allografted in first or second remission with an HLA-matched sibling (MSD) or unrelated donor (MUD), HLA-mismatched unrelated donor (MMD), an HLA-haploidentical donor, or umbilical cord blood (UCB) at a single institution. Relapse risk was non-significantly higher after HLA-haploidentical and lower after UCB HCT. Non-relapse mortality (NRM) was significantly higher in patients undergoing MMD HCT, HLA-haploidentical HCT, and UCB, translating into significantly lower relapse-free survival (RFS) and overall survival for MMD and HLA-haploidentical HCT. There was a significant interaction between conditioning intensity and post-HCT outcomes for UCB HCT with better RFS for UCB HCT after MAC but higher NRM after non-MAC. In patients with pre-HCT MRD receiving MAC, relapse risk was significantly lower and RFS higher in those who underwent UCB HCT in comparison to MSD/MUD. Together, UCB HCT is a valuable alternative for MAC HCT, particularly in patients with pre-HCT MRD., Competing Interests: Competing interests: Employment or Leadership Position: none; Consultant or Advisory Role: none: Stock Ownership: none; Honoraria: none; Research Funding: none; Expert Testimony: none; Patents: none; Other Remuneration: none. Ethics approval: All patients were treated on Institutional Review Board (IRB)-approved research protocols (all registered with ClinicalTrials.gov) or standard treatment protocols. All analyses conducted herein were performed under a research protocol approved by the Fred Hutchinson Cancer Center’s IRB (#FH2562). Consent for publication: All patients gave informed consent for study participation in accordance with the Declaration of Helsinki., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Outcomes of adults with AML after allografting vary widely. While numerous covariates have been associated with relapse, non-relapse mortality (NRM), and/or shorter survival, the impact of incomplete blood count recovery before transplantation has remained unclear. To address this uncertainty, we examined all adults with AML or MDS/AML who received an allograft in first or second remission between 2006 and 2023 at a single institution. Of 1264 patients, 891 (70%) met criteria for CR, whereas 291 (23%), 24 (2%), and 58 (5%) were classified as CRh, CRi, and morphologic leukemia-free state (MLFS), respectively. CR, CRh, CRi, and MLFS patients differed significantly regarding demographics, disease biology, pre-transplant measurable residual disease, and types of transplants. After multivariable adjustment, outcomes for CRh and CRi patients were not significantly different from each other or from those of CR patients. In contrast, outcomes of MLFS patients were substantially worse than those of CR and CRh patients, with significantly higher risk of NRM and relapse, and significantly shorter relapse-free and overall survival. Similar results were obtained in several distinct subsets. Together, our analysis provides empiric evidence for the importance of distinguishing MLFS from CR and CRh patients for optimized risk assessment and, possibly, individualized treatment decision making., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

With advancements in novel therapeutics, it is unclear whether third hematopoietic cell transplantation (HCT3) has a place in the treatment of recurrent hematopoietic malignancies. We evaluated patients with hematologic malignancies who underwent HCT3 between 2000-2020. Nine patients, with a median age of 18 (9-68) years at HCT3 with acute myelogenous leukemia (n = 5), acute lymphoblastic leukemia (n = 2), myelodysplastic syndrome (n = 1), or undifferentiated acute leukemia (n = 1), were identified. The median time between first HCT and HCT3 was 3.9 (0.7-13.6) years. Indication for HCT3 was relapse (n = 8) or graft failure (n = 1) after second HCT. At HCT3, seven of nine patients were in complete remission by flow cytometry. All experienced robust donor engraftment by one month after HCT3 (≥ 90% CD3) while one died at day + 24 of multi-organ failure and was not evaluable for chimerism. In total, eight patients died from relapse (n = 4), non-relapse, (n = 3) or unknown (n = 1) causes at a median of 0.6 (range, 0.1 - 9.9) years after HCT3. After HCT3, estimated overall survival at 6 months, 1 year, and 5 years was 88%, 63%, and 22%, respectively. In this highly selected group, HCT3 provided a treatment option although long-term survival was still dismal., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Second allogeneic hematopoietic cell transplantation (HCT2) is potentially curative for adults with acute myeloid leukemia (AML) or myelodysplastic neoplasm (MDS)/AML experiencing relapse after a first allograft (HCT1), but prognostic factors for outcomes are poorly characterized. To provide a detailed analysis of HCT2 outcomes and associated prognostic factors in a large single-center cohort, with a focus on identifying predictors of relapse and nonrelapse mortality (NRM), we studied adults ≥18 years who underwent HCT2 at a single institution between April 2006 and June 2022 for relapsed AML (n = 73) or MDS/AML (n = 8). With a median follow-up among survivors of 74.0 (range: 10.4 to 187.3) months, there were 30 relapses and 57 deaths, of which 29 were NRM events, contributing to the estimates for relapse, overall survival (OS), relapse-free survival (RFS), and NRM. Three-year estimates for relapse, RFS, and OS were 37% (95% confidence interval: 27% to 48%), 32% (23% to 44%), and 35% (26% to 47%). The rate of NRM at 100 days and 18 months was 20% (12% to 29%) and 28% (19% to 39%). Outcomes differed markedly across patient subsets and were substantially worse for patients who underwent HCT2 with active disease (ie, morphologic evidence of bone marrow and/or extramedullary disease), for patients who relapsed ≤6 months after HCT1, and for patients with higher HCT-specific Comorbidity Index (HCT-CI) or treatment-related mortality (TRM) scores. After multivariable adjustment, active disease was associated with a higher risk of relapse (hazard ratio [HR] = 3.19, P = .006) and shorter RFS (HR = 2.41, P = .008) as well as OS (HR = 2.17, P = .027) compared to transplant in morphologic remission without multiparameter flow cytometric evidence of measurable residual disease. Similarly, a relapse-free interval ≤6 months after the first allograft was associated with higher risk of relapse (HR = 5.86, P < .001) and shorter RFS (HR = 2.86; P = .001) and OS (HR = 2.45, P = .003). Additionally, a high HCT-CI score was associated with increased NRM (HR = 4.30, P = .035), and shorter RFS (HR = 3.87, P = .003) and OS (HR = 3.74, P = .006). Likewise, higher TRM scores were associated with increased risk of relapse (HR = 2.27; P = .024) and NRM (HR = 2.01, P = .001), and inferior RFS (HR = 1.90 P = .001) and OS (HR = 1.88, P = .001). A significant subset of patients with AML or MDS/AML relapse after HCT1 are alive and leukemia-free 3 years after undergoing HCT2. Our study identifies active leukemia at the time of HCT2 and early relapse after HCT1 as major adverse prognostic factors, highlighting patient subsets in particular need of novel therapeutic approaches, and supports the use of the HCT-CI and TRM scores for outcome prognostication., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Multiparameter flow cytometry (MFC) measurable residual disease (MRD) before allogeneic hematopoietic cell transplantation (HCT) independently predicts poor outcomes in acute myeloid leukemia (AML). Conversely, its prognostic value in the newly defined disease entity, myelodysplastic neoplasm (MDS)/AML is unknown. To assess the relationship between disease type, pre-HCT MRD, and post-HCT outcomes, we retrospectively analyzed 1265 adults with MDS/AML (n = 151) or AML (n = 1114) who received a first allograft in first or second morphologic remission at a single institution between April 2006 and March 2023. At 3 years, relapse rates (29% for MDS/AML vs. 29% for AML, p = .98), relapse-free survival (RFS; 50% vs. 55%, p = .22), overall survival (OS; 52% vs. 60%, p = .073), and non-relapse mortality (22% vs. 16%, p = .14) were not statistically significantly different. However, a significant interaction was found between pre-HCT MFC MRD and disease type (MDS/AML vs. AML) for relapse (p = .009), RFS (p = .011), and OS (p = .039). The interaction models indicated that the hazard ratios (HRs) for the association between pre-HCT MRD and post-HCT outcomes were lower in patients with MDS/AML (for relapse: HR = 1.75 [0.97-3.15] in MDS/AML vs. 4.13 [3.31-5.16] in AML; for RFS: HR = 1.58 [1.02-2.45] vs. 2.98 [2.48-3.58]; for OS: HR = 1.50 [0.96-2.35] vs. 2.52 [2.09-3.06]). On the other hand, residual cytogenetic abnormalities at the time of HCT were equally informative in MDS/AML as in AML patients. Our data indicate that MFC-based pre-HCT MRD testing, but not testing for residual cytogenetic abnormalities, is less informative for MDS/AML than AML patients when used for prognostication of post-HCT outcomes., (© 2024 Wiley Periodicals LLC.)

Racial and socioeconomic disparities impact outcomes after chemotherapy and limit access to allogeneic hematopoietic cell transplantation (HCT) in acute myeloid leukemia (AML), yet studies have yielded mixed results on the influence of disparities on post-HCT outcomes. Therefore, we studied 1024 adults with AML who underwent allogeneic HCT between 5/2006 and 10/2021 at a single large university-affiliated cancer center. Collected data included non-biologic and demographic characteristics (including race/ethnicity, marital status, distance traveled, and household size), transplant- and disease-related characteristics, and area-level and individual-level socioeconomic factors (i.e., area deprivation index and occupational status). After multivariable adjustment, no socioeconomic- or non-biologic factors were associated with non-relapse mortality (NRM), overall survival (OS), relapse-free survival (RFS), or relapse except being married (associated with improved NRM: hazard ratio [HR] = 0.7 [0.50-0.97]) and having no insurance (associated with worse OS: HR = 1.49 [1.05-2.12] and RFS: HR = 1.41 [1.00-1.98]). Despite a relatively racially homogenous cohort, Asian race was associated with improved NRM (HR = 0.47 [0.23-0.93]) and American Indian/Alaskan Native race was associated with higher relapse risk (HR = 2.45 [1.08-5.53]). In conclusion, in our retrospective analysis, socioeconomic-, demographic-, and non-biologic factors had limited impact on post-HCT outcomes in AML patients allografted in morphologic remission. Further research is needed to investigate disparities among HCT-eligible patients., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

During the Coronavirus disease 2019 pandemic, cryopreservation of allogeneic donor stem cell products ensured the availability of products at the start of conditioning for hematopoietic cell transplantation (HCT). Following recommendations from unrelated donor registries, including the National Marrow Donor Program, many centers began to cryopreserve related donor peripheral blood stem cell (PBSC) products. Throughout this process, several centers have published outcomes with cryopreserved versus fresh products, some with conflicting results. Even though cryopreservation was initially considered only a temporary measure driven by the pandemic, potential advantages include greater flexibility of transplantation timing. However, concerns about detrimental effects of cryopreservation, including increased risk of graft rejection, relapse, and consequent mortality, remained. The primary objective of the present study was to describe our center's experience comparing outcomes following PBSC transplantation with cryopreserved versus fresh grafts. This was an observational case study with a retrospective review comparing cryopreserved grafts (n = 213) to a recent historical cohort (controls) using fresh grafts (n = 167). In multivariable analyses, the adjusted hazard ratio (HR) for fresh versus cryopreserved grafts was 1.20 (95% confidence interval [CI], .79 to 1.82; P = .40) for overall mortality, .99 (95% CI, .55 to 1.77; P = .98) for nonrelapse mortality, and .94 (95% CI, .60 to 1.48; P = .80) for relapse. The adjusted HR for platelet engraftment was 1.31 (95% CI, 1.05 to 1.63; P = .02) and the odds ratio of grade III-IV acute GVHD was 1.75 (95% CI, 1.01 to 3.04; P = .05) with fresh grafts compared to cryopreserved grafts. There was no demonstrable difference in the risk of chronic GHVD. Although longer-term follow-up is needed, these data provide preliminary reassurance that in the event of another pandemic or should the logistical need arise in individual patients, cryopreservation of PBSC products is a reasonably safe alternative., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Importance: Certain antibiotic exposures have been associated with increased rates of acute graft-vs-host disease (aGVHD) after allogeneic hematopoietic cell transplantation (allo-HCT). Since antibiotic exposure can both affect and be affected by infections, analyzing time-dependent exposure in the presence of multiple potential confounders, including prior antibiotic exposures, poses specific analytical challenges, necessitating both a large sample size and unique approaches., Objective: To identify antibiotics and antibiotic exposure timeframes associated with subsequent aGVHD., Design, Setting, and Participants: This cohort study assessed allo-HCT at a single center from 2010 to 2021. Participants included all patients aged at least 18 years who underwent their first T-replete allo-HCT, with at least 6 months of follow-up. Data were analyzed from August 1 to December 15, 2022., Exposures: Antibiotics between 7 days before and 30 days after transplant., Main Outcomes and Measures: The primary outcome was grade II to IV aGVHD. The secondary outcome was grade III to IV aGVHD. Data were analyzed using 3 orthogonal methods: conventional Cox proportional hazard regression, marginal structural models, and machine learning., Results: A total of 2023 patients (median [range] age, 55 [18-78] years; 1153 [57%] male) were eligible. Weeks 1 and 2 after HCT were the highest-risk intervals, with multiple antibiotic exposures associated with higher rates of subsequent aGVHD. In particular, exposure to carbapenems during weeks 1 and 2 after allo-HCT was consistently associated with increased risk of aGVHD (minimum hazard ratio [HR] among models, 2.75; 95% CI, 1.77-4.28), as was week 1 after allo-HCT exposure to combinations of penicillins with a β-lactamase inhibitor (minimum HR among models, 6.55; 95% CI, 2.35-18.20)., Conclusions and Relevance: In this cohort study of allo-HCT recipients, antibiotic choices and schedules in the early course of transplantation were associated with aGVHD rates. These findings should be considered in antibiotic stewardship programs.

Background: Some respiratory viruses have been evaluated for the association between viral burden and respiratory disease progression in hematopoietic cell transplant (HCT) recipients, and no significant association has been reported., Objectives: To assess whether initial viral burden of respiratory viruses predicts risk of progression to lower respiratory tract infection (LRTI) among adult allogeneic HCT recipients who presented with upper respiratory tract infection (URTI) with 12 viruses in the PCR era., Study Design: We reviewed adult allogeneic HCT recipients (4/2008-9/2018) who presented with their first symptomatic respiratory viral infection following transplantation at the Fred Hutchinson Cancer Center. Cox proportional hazards models were used to investigate whether viral burden as measured by initial Ct values at the diagnosis of URTI is associated with progression to LRTI within 90 days for each virus, treating death as a competing risk., Results: Among 2,148 adult HCT recipients during the study periods, 1,102 episodes of URTI met the study inclusion criteria. Higher viral burden (lower Ct value) were associated with an increased risk of progression to LRTI for influenza after adjusting for immunodeficiency scoring index and initiation of antiviral therapy, respectively. The association between viral burden and progression to LRTI was not found for other viruses., Conclusions: Our findings suggest that routine reporting of viral burden in current molecular diagnostic platforms may be beneficial. Further studies are needed to investigate the impact of viral burden on LRTI in other populations including pediatric HCT recipients., (Copyright © 2022. Published by Elsevier B.V.)

There is long-standing interest in estimating non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) for AML, but existing tools have limited discriminative capacity. Using single-institution data from 861 adults with AML, we retrospectively examined the Treatment-Related Mortality (TRM) score, originally developed to predict early mortality following induction chemotherapy, as a predictor of post-HCT outcome. NRM risks increased stepwise across the four TRM score quartiles (at 3 years: 9% [95% confidence interval: 5-13%] in Q1 vs. 28% [22-34%] in Q4). The 3-year risk of relapse was lower in patients with lower TRM score (26% [20-32%] in Q1 vs. 37% [30-43%] in Q4). Consequently, relapse-free survival (RFS) and overall survival (OS) estimates progressively decreased (RFS at 3 years: 66% [59-72%] in Q1 vs. 36% [29-42%] in Q4; OS at 3 years: 72% [66-78%] in Q1 vs. 39% [33-46%] in Q4). With a C-statistic of 0.661 (continuous variable) or 0.642 (categorized by quartile), the TRM score predicted NRM better than the Pretransplantation Assessment of Mortality (PAM) score (0.603) or the HCT-CI/age composite score (0.576). While post-HCT outcome prediction remains challenging, these findings suggest that the TRM score may be useful for risk stratification for adults with AML undergoing allogeneic HCT., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

In acute myeloid leukemia (AML), measurable residual disease (MRD) before or after allogeneic hematopoietic cell transplantation (HCT) is an established independent indicator of poor outcome. To address how peri-HCT MRD dynamics could refine risk assessment across different conditioning intensities, we analyzed 810 adults transplanted in first or second remission after myeloablative conditioning (MAC; n = 515) or non-MAC (n = 295) who underwent multiparameter flow cytometry-based MRD testing before as well as 20 to 40 days after allografting. Patients without pre- and post-HCT MRD (MRDneg/MRDneg) had the lowest risks of relapse and highest relapse-free survival (RFS) and overall survival (OS). Relative to those patients, outcomes for MRDpos/MRDpos and MRDneg/MRDpos patients were poor regardless of conditioning intensity. Outcomes for MRDpos/MRDneg patients were intermediate. Among 161 patients with MRD before HCT, MRD was cleared more commonly with a MAC (85 of 104; 81.7%) than non-MAC (33 of 57; 57.9%) regimen (P = .002). Although non-MAC regimens were less likely to clear MRD, if they did, the impact on outcome was greater. Thus, there was a significant interaction between conditioning intensity and "MRD conversion" for relapse (P = .020), RFS (P = .002), and OS (P = .001). Similar findings were obtained in the subset of 590 patients receiving HLA-matched allografts. C-statistic values were higher (indicating higher predictive accuracy) for peri-HCT MRD dynamics compared with the isolated use of pre-HCT MRD status or post-HCT MRD status for prediction of relapse, RFS, and OS. Across conditioning intensities, peri-HCT MRD dynamics improve risk assessment over isolated pre- or post-HCT MRD assessments in patients with AML., (© 2022 by The American Society of Hematology.)

Background: Limited data exist regarding the impact of human bocavirus (BoV) in hematopoietic cell transplant (HCT) recipients., Methods: In a longitudinal surveillance study among allogeneic HCT recipients, pre-HCT and weekly post-HCT nasal washes and symptom surveys were collected through day 100, then at least every 3 months through 1 year post-HCT at the Fred Hutchinson Cancer Research Center (2005-2010). Samples were tested by multiplex semiquantitative polymerase chain reaction (PCR) for 12 viruses. Plasma samples from BoV + subjects were analyzed by PCR. Separately, we conducted a retrospective review of HCT recipients with BoV detected in lower respiratory tract specimens., Results: Among 51 children and 420 adults in the prospective cohort, 21 distinct BoV respiratory tract infections (RTIs) were observed by 1 year post-HCT in 19 patients. Younger age and exposure to children were risk factors for BoV acquisition. Univariable models among patients with BoV RTI showed higher peak viral load in nasal samples (P = .04) and presence of respiratory copathogens (P = .03) were associated with presence of respiratory symptoms, but BoV plasma detection was not. Only watery eyes and rhinorrhea were associated with BoV RTI in adjusted models. With additional chart review, we identified 6 HCT recipients with BoV detected in lower respiratory tract specimens (incidence rate of 0.4% [9/2509] per sample tested). Although all cases presented with hypoxemia, 4 had respiratory copathogens or concomitant conditions that contributed to respiratory compromise., Conclusions: BoV RTI is infrequent in transplant recipients and associated with mild symptoms. Our studies did not demonstrate convincing evidence that BoV is a serious respiratory pathogen., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The in vivo depletion of recipient and donor T lymphocytes using antithymocyte globulin (ATG; Thymoglobulin) is widely adopted in allogeneic hematopoietic stem cell transplantation (HCT) to reduce the incidence of both graft failure and graft-versus-host disease (GVHD). However, excess toxicity to donor lymphocytes may hamper immune reconstitution, compromising antitumor effects and increasing infection. Granulocyte-colony stimulating factor (G-CSF) administered early after HCT may increase ATG-mediated lymphotoxicity. This study aimed to investigate the effect of an interaction between ATG and post-transplantation granulocyte colony-stimulating factor (G-CSF) on allogeneic HCT outcomes, using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. We studied patients age ≥18 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who received Thymoglobulin-containing preparative regimens for HLA-matched sibling/unrelated or mismatched unrelated donor HCT between 2010 and 2018. The effect of planned G-CSF that was started between pretransplantation day 3 and post-transplantation day 12 was studied in comparison with transplantations that did not include G-CSF. Cox regression models were built to identify risk factors associated with outcomes at 1 year after transplantation. A total of 874 patients met the study eligibility criteria, of whom 459 (53%) received planned G-CSF. HCT with planned G-CSF was associated with a significantly increased risk for nonrelapse mortality (NRM) (hazard ratio [HR] 2.03; P <.0001; 21% versus 12%) compared to HCT without G-CSF. The 6-month incidence of viral infection was higher with G-CSF (56% versus 47%; P = .007), with a particular increase in Epstein-Barr virus infections (19% versus 11%; P = .002). The observed higher NRM with planned G-CSF led to lower overall survival (HR, 1.52; P = .0005; 61% versus 72%). There was no difference in GVHD risk between the treatment groups. We performed 2 subgroup analyses showing that our findings held true in patients age ≥50 years and in centers where G-CSF was used in some, but not all, patients. In allogeneic peripheral blood HCT performed with Thymoglobulin for AML and MDS, G-CSF administered early post-transplantation resulted in a 2-fold increase in NRM and a 10% absolute decrement in survival. The use of planned G-CSF in the early post-transplantation period should be carefully considered on an individual patient basis, weighing any perceived benefits against these risks., (Copyright © 2021 The American Society for Transplantation and Cellular Therapy. All rights reserved.)

We have consistently noticed in our clinical practice eczematous dermatitis (EcD) without other pathologic findings of graft-versus-host disease (GVHD) in recipients of unrelated cord blood transplantation (CBT). We hypothesized that the incidence of EcD was higher in CBT compared with other donor types, and our objective in this study was to compare the frequency, clinical course, and response to therapy of EcD between CBT and non-CBT recipients. We conducted a retrospective study of 720 consecutive adult recipients of allogeneic hematopoietic cell transplants from 2010 to 2016 from any donor type and with follow-up for at least 1 year after transplantation. After using keyword-based automated scanning to identify "eczema," "dermatitis," or "spongiosis" terms in medical records, we retrieved 217 cases for manual record review. We identified 23 EcD cases (12 in CBT recipients and 11 in patients with other types of donors) with a median onset at 8 months after transplantation. The 2-year cumulative incidence of EcD was 20% (95% confidence interval [CI], 11.2% to 31.5%) after CBT and 1.7% (95% CI, .90% to 2.90%) with other types of donors (P < .0001). Fifteen cases had a skin biopsy without distinctive pathologic features of GVHD. The most common EcD-involved sites in CBT recipients were face (75%), neck (50%), and antecubital fossae (50%). Compared with patients with other types of donors, EcD after CBT was more likely to involve three or more sites (10 of 12 vs. 2 of 10; P = .008) and had a more protracted course (lasting >6 months in 6 of 58 vs. 1 of 661; P < .0001). In both groups, EcD responded to topical therapy, and only a few cases required systemic therapy. EcD is a relatively frequent skin condition among recipients of unrelated CBT. Irrespective of donor type, most cases of EcD can be successfully managed with only topical therapy. These findings will help providers recognize EcD, avoid potentially harmful systemic therapy, and better counsel transplant recipients., (Copyright © 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has emerged as an important treatment modality. Most reports comparing haplo-HSCT with posttransplant cyclophosphamide (PTCy) and other donor sources have focused on outcomes in older adults treated with reduced intensity conditioning. Therefore, in the current study, we evaluated outcomes in patients with hematological malignancy treated with myeloablative conditioning prior to haplo- (n = 375) or umbilical cord blood (UCB; n = 333) HSCT. All haplo recipients received a 4 of 8 HLA-matched graft, whereas recipients of UCB were matched at 6-8/8 (n = 145) or ≤5/8 (n = 188) HLA antigens. Recipients of 6-8/8 UCB transplants were younger (14 years vs 21 and 29 years) and more likely to have lower comorbidity scores compared with recipients of ≤5/8 UCB and haplo-HSCT (81% vs 69% and 63%, respectively). UCB recipients were more likely to have acute lymphoblastic leukemia and transplanted in second complete remission (CR), whereas haplo-HSCT recipients were more likely to have acute myeloid leukemia in the first CR. Other characteristics, including cytogenetic risk, were similar. Survival at 3 years was similar for the donor sources (66% haplo- and 61% after ≤5/8 and 58% after 6-8/8 UCB). Notably, relapse at 3 years was lower in recipients of ≤5/8 UCB (21%, P = .03) compared with haplo- (36%) and 6-8/8 UCB (30%). However, nonrelapse mortality was higher in ≤5/8 UCB (21%) compared with other groups (P < .0001). These data suggest that haplo-HSCT with PTCy after myeloablative conditioning provides an overall survival outcome comparable to that after UCB regardless HLA match group., (© 2021 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.)

Cytomegalovirus (CMV)-seropositive umbilical cord blood transplantation (CBT) recipients have a high incidence of CMV-associated complications. There are limited data regarding the efficacy of letermovir for preventing clinically significant CMV infection (CS-CMVi), and the impact of letermovir prophylaxis on delayed-onset CMV reactivation after letermovir discontinuation, in CBT recipients. We compared the cumulative incidence of CS-CMVi and CMV detection in 21 CMV-seropositive CBT recipients receiving letermovir prophylaxis with a historical cohort of 40 CBT recipients receiving high-dose valacyclovir prophylaxis. Letermovir was administered on day +1 up to day +98. The cumulative incidence of CS-CMVi was significantly lower by day 98 in the letermovir cohort (19% vs 65%). This difference was lost by 1 year due to a higher incidence of delayed-onset CMV reactivation in the letermovir cohort. No patients developed CMV disease in the letermovir cohort within the first 98 days compared with 2 cases (2.4%) in the high-dose valacyclovir cohort; 2 patients developed CMV enteritis after discontinuing letermovir. Median viral loads were similar in both cohorts. Thus, letermovir is effective at preventing CS-CMVi after CBT, but frequent delayed-onset infections after letermovir discontinuation mandate close monitoring and consideration for extended prophylaxis., (© 2021 by The American Society of Hematology.)

Posttransplant cyclophosphamide (PTCy) graft-versus-host disease (GVHD) prophylaxis has enabled haploidentical (Haplo) transplantation to be performed with results similar to those after matched unrelated donor (MUD) transplantation with traditional prophylaxis. The relative value of transplantation with MUD vs Haplo donors when both groups receive PTCy/calcineurin inhibitor/mycophenolate GVHD prophylaxis is not known. We compared outcomes after 2036 Haplo and 284 MUD transplantations with PTCy GVHD prophylaxis for acute leukemia or myelodysplastic syndrome in adults from 2011 through 2018. Cox regression models were built to compare outcomes between donor types. Recipients of myeloablative and reduced-intensity regimens were analyzed separately. Among recipients of reduced-intensity regimens, 2-year graft failure (3% vs 11%), acute grades 2 to 4 GVHD (hazards ratio [HR], 0.70; P = .022), acute grades 3 and 4 GVHD (HR, 0.41; P = .016), and nonrelapse mortality (HR, 0.43; P = .0008) were lower after MUD than with Haplo donor transplantation. Consequently, disease-free (HR, 0.74; P = .008; 55% vs 41%) and overall (HR, 0.65; P = .001; 67% vs 54%) survival were higher with MUD than with Haplo transplants. Among recipients of myeloablative regimens, day-100 platelet recovery (95% vs 88%) was higher and grades 3 and 4 acute (HR, 0.39; P = .07) and chronic GVHD (HR, 0.66; P = .05) were lower after MUD than with Haplo donor transplantation. There were no differences in graft failure, relapse, nonrelapse mortality, and disease-free and overall survival between donor types with myeloablative conditioning regimens. These data extend and confirm the importance of donor-recipient HLA matching for allogeneic transplantation. A MUD is the preferred donor, especially for transplantations with reduced-intensity conditioning regimens.

The incidence of graft-versus-host disease (GVHD) after cord blood (CB) transplantation (CBT) is lower than expected given the marked degree of human leukocyte antigen (HLA)-mismatch of CB grafts. While the exact mechanism that underlies this biology remains unclear, it is hypothesized to be due to the low number of mostly immature T-cells infused as part of the graft1,2, and increased tolerance of CB-derived lymphocytes induced by the state of pregnancy. Nevertheless, acute GVHD (aGVHD) is a significant complication of CBT. In contrast, the incidence of chronic GVHD (cGVHD) following CBT is lower than what is observed following matched related or unrelated donor HSC transplantation (HSCT)3-6. This review outlines the guidelines for the prevention and management of acute and chronic GVHD following CBT., (Copyright © 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

As an alternative stem cell source, cord blood (CB) has many advantages. However, delayed engraftment, lack of transferred immunity, and a significant incidence of acute graft-versus-host disease renders CB transplant (CBT) recipients at high risk of infectious complications. This guidance written by CBT and infectious disease experts outlines evidence-based recommendations for the prevention and treatment of opportunistic infections in adult patients undergoing CBT. Topics addressed include bacterial, fungal, viral, pneumocystis jirovcii and toxoplasmosis prophylaxis, suggested PCR monitoring for viruses, therapy for the most commonly encountered infections after CBT. We review key concepts including the recent important role of letermovir in the prevention of CMV reactivation. In instances where there is a paucity of data, practice recommendations are provided, including the duration of antimicrobial prophylaxis., (Copyright © 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Cord blood transplantation (CBT) is associated with low risk of leukemia relapse. Mechanisms underlying antileukemia benefit of CBT are not well understood, however a previous study strongly but indirectly implicated cells from the mother of the cord blood (CB) donor. A fetus acquires a small number of maternal cells referred to as maternal microchimerism (MMc) and MMc is sometimes detectable in CB. From a series of 95 patients who underwent double or single CBT at our center, we obtained or generated HLA-genotyping of CB mothers in 68. We employed a technique of highly sensitive HLA-specific quantitative-PCR assays targeting polymorphisms unique to the CB mother to assay CB-MMc in patients post-CBT. After additional exclusion criteria, CB-MMc was evaluated at multiple timepoints in 36 patients (529 specimens). CB-MMc was present in seven (19.4%) patients in bone marrow, peripheral blood, innate and adaptive immune cell subsets, and was detected up to 1-year post-CBT. Statistical trends to lower relapse, mortality, and treatment failure were observed for patients with vs. without CB-MMc post-CBT. Our study provides proof-of-concept that maternal cells of the CB graft can be tracked in recipients post-CBT, and underscore the importance of further investigating CB-MMc in sustained remission from leukemia following CBT.

Background: Cord blood transplant (CBT) recipients have a high incidence of herpes zoster (HZ) in the context of short-term peritransplant antiviral prophylaxis. In 2009, international guidelines recommended HZ prophylaxis for at least 1 year after hematopoietic cell transplant. The impact of longer-term antiviral prophylaxis on HZ incidence after CBT is unknown., Methods: We retrospectively analyzed varicella zoster virus (VZV)-seropositive CBT recipients who were transplanted between 2006 and 2016. We abstracted HZ events and other variables for up to 5 years post-CBT. We calculated the cumulative incidence of HZ and used Cox proportional hazards regression to identify variables associated with HZ., Results: The study cohort consisted of 227 patients. Among 1-year survivors, 91% were still receiving prophylaxis, for a median duration of 20.6 months. HZ occurred in 44 patients (19%) at a median of 23.6 months. The cumulative incidence of HZ by 1 year after CBT was 1.8% (95% confidence interval [CI], .1%-4%), but increased to 26% (95% CI, 19%-33%) by 5 years. In a multivariable analysis, acute graft-vs-host disease was associated with increased risk, whereas antiviral prophylaxis was associated with reduced risk for HZ (adjusted hazard ratio, 0.19 [95% CI, .09-.4]). There was no association between CD4+ T-cell counts at 1 year post-CBT and subsequent risk for HZ., Conclusions: We found a high incidence of HZ after CBT despite antiviral prophylaxis for > 1 year. Based on these findings, we suggest longer duration of prophylaxis for HZ after CBT. Compliance with antiviral prophylaxis, VZV-specific immune monitoring, and vaccination to mitigate HZ after CBT also require further study., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Optimal cord blood (CB) unit selection is critical to maximize the likelihood of successful engraftment and survival after CB transplantation (CBT). However, unit selection can be complex because multiple characteristics must be considered including unit cell dose, donor-recipient human leukocyte antigen (HLA) match, and unit quality. This review provides evidence-based and experience-based comprehensive guidelines for CB unit selection. Topics addressed include the use of both the TNC and the CD34 + cell dose, as well as the CD34 + cell to TNC content ratio to evaluate unit progenitor cell content and engraftment potential, the acceptable TNC and CD34 + cell dose criteria that define an adequate single-unit graft, and the indication and acceptable cell dose criteria for double-unit grafts. The acceptable criteria for 6-loci (HLA-A, -B antigen, -DRB1 allele) and 8-allele (HLA-A, -B, -C, -DRB1) donor-recipient HLA match, the evaluation of patients with donor-specific HLA antibodies, and the multiple determinants of unit quality are also reviewed in detail. Finally, a practical step-by-step guide to CB searches and the principles that guide ultimate graft selection are outlined., (Copyright © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

The COVID-19 pandemic has created significant barriers to timely donor evaluation, cell collection, and graft transport for allogeneic hematopoietic stem cell transplantation (allo-HCT). To ensure availability of donor cells on the scheduled date of infusion, many sites now collect cryopreserved grafts before the start of pretransplantation conditioning. Post-transplantation cyclophosphamide (ptCY) is an increasingly used approach for graft-versus-host disease (GVHD) prophylaxis, but the impact of graft cryopreservation on the outcomes of allo-HCT using ptCY is not known. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we compared the outcomes of HCT using cryopreserved versus fresh grafts in patients undergoing HCT for hematologic malignancy with ptCY. We analyzed 274 patients with hematologic malignancy undergoing allo-HCT between 2013 and 2018 with cryopreserved grafts and ptCY. Eighteen patients received bone marrow grafts and 256 received peripheral blood stem cell grafts. These patients were matched for age, graft type, disease risk index (DRI), and propensity score with 1080 patients who underwent allo-HCT with fresh grafts. The propensity score, which is an assessment of the likelihood of receiving a fresh graft versus a cryopreserved graft, was calculated using logistic regression to account for the following: disease histology, Karnofsky Performance Score (KPS), HCT Comorbidity Index, conditioning regimen intensity, donor type, and recipient race. The primary endpoint was overall survival (OS). Secondary endpoints included acute and chronic graft-versus-host disease (GVHD), non-relapse mortality (NRM), relapse/progression and disease-free survival (DFS). Because of multiple comparisons, only P values <.01 were considered statistically significant. The 2 cohorts (cryopreserved and fresh) were similar in terms of patient age, KPS, diagnosis, DRI, HCT-CI, donor/graft source, and conditioning intensity. One-year probabilities of OS were 71.1% (95% confidence interval [CI], 68.3% to 73.8%) with fresh grafts and 70.3% (95% CI, 64.6% to 75.7%) with cryopreserved grafts (P = .81). Corresponding probabilities of OS at 2 years were 60.6% (95% CI, 57.3% to 63.8%) and 58.7% (95% CI, 51.9% to 65.4%) (P = .62). In matched-pair regression analysis, graft cryopreservation was not associated with a significantly higher risk of mortality (hazard ratio [HR] for cryopreserved versus fresh, 1.05; 95% CI, .86 to 1.29; P = .60). Similarly, rates of neutrophil recovery (HR, .91; 95% CI, .80 to 1.02; P = .12), platelet recovery (HR, .88; 95% CI, .78 to 1.00; P = .05), grade III-IV acute GVHD (HR, .78; 95% CI, .50 to 1.22; P = .27), NRM (HR, 1.16; 95% CI, .86 to 1.55; P = .32) and relapse/progression (HR, 1.21; 95% CI, .97 to 1.50; P = .09) were similar with cryopreserved grafts versus fresh grafts. There were somewhat lower rates of chronic GVHD (HR, 78; 95% CI, .61 to .99; P = .04) and DFS (HR for treatment failure, 1.19; 95% CI, 1.01 to 1.29; P = .04) with graft cryopreservation that were of marginal statistical significance after adjusting for multiple comparisons. Overall, our data indicate that graft cryopreservation does not significantly delay hematopoietic recovery, increase the risk of acute GVHD or NRM, or decrease OS after allo-HCT using ptCY., (Copyright © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

BK polyomavirus (BKPyV) has been associated with hemorrhagic cystitis (HC) after allogeneic hematopoietic cell transplantation (HCT), but the natural history of HC and factors associated with the clinical course are incompletely understood. We retrospectively analyzed allogeneic HCT patients transplanted from 2007-2017 who presented after platelet engraftment or after day 28 post-HCT with BKPyV-associated HC (BKPyV-HC), which was defined as a positive urine BKPyV PCR, ≥1 plasma BKPyV viral load result, and macroscopic hematuria (Bedi grade ≥2). Factors associated with resolution of macroscopic hematuria and resolution of all cystitis symptoms within 90 days after HC diagnosis were investigated in multivariable models. In 128 patients with BKPyV-HC, the median times from diagnosis to resolution of all symptoms, macroscopic hematuria, and urinary clots (present in 55% [71/128]) were 24 days (15-44), 17 days (10-30), and 14 days (5-26), respectively. Ninety percent of patients had BKPyV viremia at the onset of HC with a median viral load of 1850 copies/mL (interquartile range, 240-8550). In multivariable models, high plasma viral load (≥10 000 copies/mL) and cytopenias at the beginning of BKPyV-HC were significantly associated with longer macroscopic hematuria and cystitis symptoms. Use of cidofovir was not associated with shorter duration of illness. In conclusion, BKPyV-HC after allogeneic HCT is characterized by prolonged and severe symptoms and requires improved management strategies. High-grade viremia and cytopenias were associated with a longer duration of BKPyV-associated HC. Accurate descriptions of disease and factors associated with prolonged recovery will inform end points of future clinical trials., (© 2020 by The American Society of Hematology.)

Our current knowledge of idiopathic pneumonia syndrome (IPS) predates improved specificity in the diagnosis of IPS and advances in hematopoietic cell transplantation (HCT) and critical care practices. In this study, we describe and update the incidence, risk factors, and outcomes of IPS. We performed a retrospective cohort study of all adults who underwent allogeneic HCT at the Fred Hutchinson Cancer Research Center between 2006 and 2013 (n = 1829). IPS was defined using the National Heart, Lung, and Blood Institute consensus definition: multilobar airspace opacities on chest imaging, absence of lower respiratory tract infection, and hypoxemia. We described IPS incidence and mortality within 120 and 365 days after HCT. We examined conditioning intensity (nonmyeloablative versus myeloablative with high-dose total body irradiation [TBI] versus myeloablative with low-dose TBI) as an IPS risk factor in a time-to-event analysis using Cox models, controlled for age at transplant, HLA matching, stem cell source, and pretransplant Lung function Score (a combined measure of impairment in Forced Expiratory Volume in the first second (FEV 1 ) and Diffusion capacity for carbon monoxide (DLCO)). Among 1829 HCT recipients, 67 fulfilled IPS criteria within 120 days (3.7%). Individuals who developed IPS were more likely to be black/non-Hispanic versus other racial groups and have severe pulmonary impairment but were otherwise similar to participants without IPS. In adjusted models, myeloablative conditioning with high-dose TBI was associated with increased risk of IPS (hazard ratio, 2.5; 95% confidence interval, 1.2 to 5.2). Thirty-one patients (46.3%) with IPS died within the first 120 days of HCT and 47 patients (70.1%) died within 365 days of HCT. In contrast, among the 1762 patients who did not acquire IPS in the first 120 days, 204 (11.6%) died within 120 days of HCT and 510 (29.9%) died within 365 days of HCT. Our findings suggest that although the incidence of IPS may be declining, it remains associated with post-transplant mortality. Future study should focus on early detection and identifying pathologic mediators of IPS to facilitate timely, targeted therapies for those most susceptible to lung injury post-HCT., (Copyright © 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Since the first hematopoietic stem cell transplant, over a million transplants have been performed worldwide. In the last decade, the transplant field has witnessed a progressive decline in bone marrow and cord blood utilization and a parallel increase in peripheral blood as a source of stem cells. Herein, we review the use of bone marrow and cord blood in the hematopoietic stem cell transplant setting, and we describe the recent advances made in different medical fields using cells derived from cord blood and bone marrow., Competing Interests: No competing interests were disclosed.No competing interests were disclosed.Competing interests: David S. Allan is the Medical Director of Stem Cells at Canadian Blood Services., (Copyright: © 2020 Xue E and Milano F.)

Allogeneic hematopoietic cell transplantation (allo-HCT) is offered to selected patients after chimeric antigen receptor-modified T-cell (CAR-T) therapy. Lymphodepleting chemotherapy and CAR-T therapy have immunosuppressive and immunomodulatory effects that could alter the safety profile of subsequent allo-HCT. We reviewed our experience with 32 adults (acute lymphoblastic leukemia [ALL], n = 19; B-cell non-Hodgkin lymphoma [NHL]/chronic lymphocytic leukemia [CLL], n = 13) who received an allo-HCT after CAR-T therapy, with a focus on posttransplant toxicities. Myeloablative conditioning (MAC) was used in 74% of ALL patients and 39% of NHL/CLL patients. The median time from CAR-T therapy to allo-HCT was 72 days in ALL patients and 122 days in NHL/CLL patients. Cumulative incidences of grade 3-4 acute graft-versus-host disease (GVHD) and chronic GVHD were 25% and 10%, respectively. All patients had neutrophil recovery (median, 18.5 days) and all but 3 had platelet recovery (median, 12 days). Twenty-two percent had viral or systemic fungal infection within 100 days after allo-HCT. The 100-day and 1-year cumulative incidences of NRM were 16% and 21%, respectively, for ALL patients and 15% and 33%, respectively, for NHL/CLL patients. In ALL patients, later utilization of allo-HCT after CAR-T therapy was associated with higher mortality. In NHL/CLL patients, MAC was associated with higher mortality. Toxicities did not exceed the expected incidences in this high-risk population., (© 2019 by The American Society of Hematology.)

The Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) was developed and validated to weigh the burden of pretransplantation comorbidities and estimate their impact on post-transplantation risks of nonrelapse mortality (NRM). Recently, the HCT-CI was augmented by the addition of both age and the values of 3 markers: ferritin, albumin, and platelet count. So far, research involving The HCT-CI has been limited almost exclusively to recipients of allogeneic hematopoietic cell transplantation (HCT) from HLA-matched grafts. To this end, we sought to investigate the discriminative capacity of an augmented comorbidity/age index among 724 recipients of allogeneic HCT from HLA-mismatched (n = 345), haploidentical (n = 117), and umbilical cord blood (UCB; n = 262) grafts between 2000 and 2013. In the overall cohort, the augmented comorbidity/age index had a higher c-statistic estimate for prediction of NRM compared with the original HCT-CI (.63 versus .59). Findings were similar for recipients of HLA-mismatched (.62 versus .59), haploidentical (.60 versus .54), or UCB grafts (.65 versus .61). Compared with patients with an HCT-CI score ≥4, those with a score <4 had a higher survival rate among recipients of HLA-mismatched (55% versus 39%; P < .0008), HLA-haploidentical (58% versus 38%; P = .01), or UCB (67% versus 48%; P = .004) grafts. Our results demonstrate the utility of the augmented comorbidity/age index as a valid prognostic tool among recipients of allogeneic HCT from alternative graft sources., (Copyright © 2018 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

When hematopoietic stem cell transplant (HSCT) is necessary for children with acute myeloid leukemia (AML), there remains debate about the best stem cell source. Post-HSCT relapse is a common cause of mortality, and complications such as chronic graft versus host disease (cGVHD) are debilitating and life-threatening. To compare post-HSCT outcomes of different donor sources, we retrospectively analyzed consecutive transplants performed in several international centers from 2005 to 2015. A total of 317 patients were studied: 19% matched sibling donor (MSD), 23% matched unrelated donor (MUD), 39% umbilical cord blood (UCB), and 19% double UCB (dUCB) recipients. The median age at transplant was 10 years (range, 0.42-21 years), and median follow-up was 4.74 years (range, 4.02-5.39 years). Comparisons were made while controlling for patient, transplant, and disease characteristics. There were no differences in relapse, leukemia-free survival, or nonrelapse mortality. dUCB recipients had inferior survival compared with matched sibling recipients, but all other comparisons showed similar overall survival. Despite the majority of UCB transplants being HLA mismatched, the rates of cGVHD were low, especially compared with the well-matched MUD recipients (hazard ratio, 0.3; 95% confidence interval, 0.14-0.67; P = .02). The composite measure of cGVHD and leukemia-free survival (cGVHD-LFS), which represents both the quality of life and risk for mortality, was significantly better in the UCB compared with the MUD recipients (HR, 0.56; 95% confidence interval, 0.34-1; P = .03). In summary, the use of UCB is an excellent donor choice for pediatric patients with AML when a matched sibling cannot be identified., (© 2019 by The American Society of Hematology.)

Purpose of Review: Cellular therapy using T cells modified to express chimeric antigen receptors (CAR-T cells) has had striking success in patients that have failed previous treatment for CD19 + B cell non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), or acute lymphoblastic leukemia (ALL). Curative therapy for this group of diseases has previously been limited to allogeneic hematopoietic cell transplantation HCT (alloHCT). The recent results of CAR-T cell therapy raise the question of how best to integrate CAR-T cell therapy and alloHCT in the care of these patients., Recent Findings: Within the past 2 years, results from larger trials and increased follow-up of patients treated with CD19 CAR-T cell therapy suggest that some may achieve durable remission without transplant. The balance of efficacy and toxicity for CAR-T cell therapy and alloHCT vary by disease type, disease status at the time of treatment, patient characteristics, and the specific therapy employed. There are early signals that subsequent transplantation of patients who have achieved remission with CAR-T may be a potentially viable (though expensive) strategy.

Background: Improved understanding of double-stranded DNA (dsDNA) virus kinetics after hematopoietic cell transplantation (HCT) would facilitate development of therapeutic strategies., Methods: We tested weekly plasma samples from 404 patients through day 100 after allogeneic HCT for cytomegalovirus (CMV), human herpesvirus (HHV) 6A and 6B, BK polyomavirus (BKV), adenovirus (AdV), and Epstein-Barr virus (EBV) using quantitative polymerase chain reaction. Episodes lasting ≤1 week were defined as blips and >1 week as persistent. We described virus-specific kinetics, analyzed the association of virus area under the curve (AUC) with overall mortality, and identified risk factors for persistent episodes., Results: We identified 428 episodes of CMV, 292 of BKV, 224 of HHV-6B, 46 of AdV, and 53 of EBV. CMV and BKV had the highest proportions of persistent episodes (68% and 80%, respectively). Detection and kinetics varied by virus. HHV-6B episodes reached maximum levels fastest and had the shortest intervals between detection and end-organ disease. End-organ disease occurred within 14 days of viremia in 68% of cases, generally during persistent episodes. For all viruses, higher viral load AUC increased risk for overall mortality through day 365, persistent episodes had higher viral load than blips, and higher first positive viral load significantly increased risk for persistent episodes. First viral load >2 log10 copies/mL (range, 2.04-3.06 per virus) had high specificity for persistent episodes., Conclusions: Persistent high viral load dsDNA viremia episodes after allogeneic HCT predict mortality. Virus-specific kinetics can guide timing and thresholds for early intervention in studies of novel agents., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Strategies to prevent active infection with certain double-stranded DNA (dsDNA) viruses after allogeneic hematopoietic cell transplantation (HCT) are limited by incomplete understanding of their epidemiology and clinical impact. We retrospectively tested weekly plasma samples from allogeneic HCT recipients at our center from 2007 to 2014. We used quantitative PCR to test for cytomegalovirus, BK polyomavirus, human herpesvirus 6B, HHV-6A, adenovirus, and Epstein-Barr virus between days 0 and 100 post-HCT. We evaluated risk factors for detection of multiple viruses and association of viruses with mortality through day 365 post-HCT with Cox models. Among 404 allogeneic HCT recipients, including 125 cord blood, 125 HLA-mismatched, and 154 HLA-matched HCTs, detection of multiple viruses was common through day 100: 90% had ≥1, 62% had ≥2, 28% had ≥3, and 5% had 4 or 5 viruses. Risk factors for detection of multiple viruses included cord blood or HLA-mismatched HCT, myeloablative conditioning, and acute graft-versus-host disease ( P values < .01). Absolute lymphocyte count of <200 cells/mm 3 was associated with greater virus exposure on the basis of the maximum cumulative viral load area under the curve (AUC) ( P = .054). The maximum cumulative viral load AUC was the best predictor of early (days 0-100) and late (days 101-365) overall mortality (adjusted hazard ratio [aHR] = 1.36, 95% confidence interval [CI] [1.25, 1.49], and aHR = 1.04, 95% CI [1.0, 1.08], respectively) after accounting for immune reconstitution and graft-versus-host disease. In conclusion, detection of multiple dsDNA viruses was frequent after allogeneic HCT and had a dose-dependent association with increased mortality. These data suggest opportunities to improve outcomes with better antiviral strategies., (© 2017 by The American Society of Hematology.)

The hematopoietic syndrome of acute radiation syndrome (h-ARS) is characterized by severe bone marrow aplasia, resulting in a significant risk for bleeding, infections, and death. To date, clinical management of h-ARS is limited to supportive care dictated by the level of radiation exposure, with a high incidence of mortality in those exposed to high radiation doses. The ideal therapeutic agent would be an immediately available, easily distributable single-agent therapy capable of rapid in vivo hematopoietic reconstitution until recovery of autologous hematopoiesis occurs. Using a murine model of h-ARS, we herein demonstrate that infusion of ex vivo expanded murine hematopoietic stem and progenitor cells (HSPCs) into major histocompatibility complex mismatched recipient mice exposed to a lethal dose of ionizing radiation (IR) led to rapid myeloid recovery and improved survival. Survival benefit was significant in a dose-dependent manner even when infusion of the expanded cell therapy was delayed 3 days after lethal IR exposure. Most surviving mice (80%) demonstrated long-term in vivo persistence of donor T cells at low levels, and none had evidence of graft versus host disease. Furthermore, survival of donor-derived skin grafts was significantly prolonged in recipients rescued from h-ARS by infusion of the mismatched expanded cell product. These findings provide evidence that ex vivo expanded mismatched HSPCs can provide rapid, high-level hematopoietic reconstitution, mitigate IR-induced mortality, and convey donor-specific immune tolerance in a murine h-ARS model. Stem Cells Translational Medicine 2017;6:566-575., (© 2016 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Adult umbilical cord blood transplantation (CBT) has emerged as an important option for patients lacking matched related (MRD) and matched unrelated donors (MUD). We compared chronic GVHD (cGVHD) incidence, immunosuppression burden and late infections and hospitalizations in consecutive patients undergoing CBT (n=51) versus peripheral blood MUD transplant (n=57) at our center between June 2009 and April 2014. At 3 years post transplantation, the cumulative incidence (CI) of moderate to severe cGVHD was 44% following MUD versus 8% following CBT (P=0.0006) and CI of any cGVHD was 68% following MUD versus 32% following CBT (P=0.0017). Median time to being off immunosuppression among CB patients was 268 days versus not reached among MUD patients (P<0.0001). Late infections and late hospitalized days were reduced in CB patients (P=0.1 and <0.001, respectively). Three-year CI of transplant-related mortality (TRM) and relapse as well as 3-year overall survival (OS) were similar following CB and MUD transplantation. We demonstrate a significantly lower incidence of cGVHD, immunosuppression burden and late complication rate following UCB versus peripheral blood MUD transplant without decreased OS, increased relapse or early TRM. Combined with the rapid availability of UCB, these findings have led our center to move primarily to UCB over peripheral blood MUD when a MRD is not available.

For patients with disease relapse or graft failure after allogeneic hematopoietic cell transplantation (HCT), there are few treatment options and survival rates are exceedingly low. Because of the unacceptably high risk of transplantation-related mortality, second allogeneic HCTs are often not considered. Herein, we report the outcomes of 23 patients (median age, 33 years) undergoing a second allogeneic transplantation with unrelated cord blood donor grafts between 2006 and 2013. Indications for second HCT were relapse (n = 19), graft failure (n = 3), and donor-derived myelodysplastic syndrome (n = 1). Ten patients received reduced-intensity conditioning and 13 patients received either myeloablative (MAC) or middle-intensity (MIDI) conditioning. Twenty patients received a double cord blood transplantation. All patients engrafted at a median of 22 days (range, day 6 to 49). Death before day 100 occurred in 5 patients. Overall disease-free survival (DFS), treatment-related mortality, and relapse at 2 years were 31%, 33%, and 35%, respectively. Two-year DFS in the 13 patients receiving MAC or MIDI conditioning was slightly higher at 46%. Our results demonstrate that second allogeneic HCT using cord blood as the graft source should be considered in patients who have relapsed or experience graft failure after an allogeneic HCT., (Copyright © 2016 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Allogeneic hematopoietic cell transplantation (HCT) offers curative therapy for many patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). However, post-HCT relapse remains a major problem, particularly in patients with high-risk cytogenetics. In this prospective phase II trial, we assessed the efficacy and toxicity of treosulfan, fludarabine, and 2 Gy total body irradiation (TBI) as conditioning for allogeneic HCT in patients with MDS or AML. Ninety-six patients with MDS (n = 36: 15 refractory cytopenia with multilineage dysplasia, 10 refractory anemia with excess blasts type 1, 10 refractory anemia with excess blasts type 2, 1 chronic myelomonocytic leukemia type 1) or AML (n = 60: 35 first complete remission [CR], 18 second CR, 3 advanced CR, 4 refractory relapse) were enrolled; median age was 51 (range, 1 to 60) years. Twelve patients had undergone a prior HCT with high-intensity conditioning. Patients received 14 g/m(2)/day treosulfan i.v. on days -6 to -4, 30 mg/m(2)/day fludarabine i.v. on days -6 to -2, and 2 Gy TBI on day 0, followed by infusion of hematopoietic cells from related (n = 27) or unrelated (n = 69) donors. Graft-versus-host disease prophylaxis consisted of tacrolimus and methotrexate. With a median follow-up of 30 months, the 2-year overall survival (OS), relapse incidence, and nonrelapse mortality were 73%, 27%, and 8%, respectively. The incidences of grades II to IV (III to IV) acute and chronic graft-versus-host disease were 59% (10%) and 47%, respectively. Two-year OS was not significantly different between MDS patients with poor-risk and good/intermediate-risk cytogenetics (69% and 85%, respectively) or between AML patients with unfavorable and favorable/intermediate-risk cytogenetics (64% and 76%, respectively). In AML patients, minimal residual disease (MRD; n = 10) at the time of HCT predicted higher relapse incidence (70% versus 18%) and lower OS (41% versus 79%) at 2 years, when compared with patients without MRD. In conclusion, treosulfan, fludarabine, and low-dose TBI provided effective conditioning for allogeneic HCT in patients with MDS or AML and resulted in low relapse incidence, regardless of cytogenetic risk. In patients with AML, MRD at the time of HCT remained a risk factor for post-HCT relapse., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Most reports of chronic GVHD after cord blood transplantation (CBT) have utilized traditional diagnostic criteria. We used traditional criteria and National Institutes of Health (NIH) criteria prospectively to evaluate chronic GVHD in a cohort of 87 adult and pediatric recipients of single or double unrelated CBT for treatment of hematologic malignancies. Fifty-four patients developed traditionally defined chronic GVHD, for an estimated 2-year probability of 64%. Among 54 patients, 25 (46%) met the NIH criteria for persistent, recurrent or late acute GVHD at onset. Twenty-four (44%) had overlap chronic GVHD, including one who presented initially with late acute GVHD, and only seven (13%) had classic chronic GVHD, including one who also presented initially with late acute GVHD. Among patients who successfully discontinued all systemic immunosuppression (SI), the median time to discontinuation of corticosteroid treatment was 315 days (range 28-977), and the median time to discontinuation of all SI was 353 days (range 67-977). Chronic GVHD diagnosed by traditional criteria after CBT had a predominance of acute GVHD clinical features.

Purpose: Allogeneic hematopoietic cell transplantation (HCT) benefits many patients with acute myeloid leukemia (AML) in first remission. Hitherto, little attention has been given to the prognostic impact of pretransplantation minimal residual disease (MRD)., Patients and Methods: We retrospectively studied 99 consecutive patients receiving myeloablative HCT for AML in first morphologic remission. Ten-color multiparametric flow cytometry (MFC) was performed on bone marrow aspirates before HCT. MRD was identified as a cell population showing deviation from normal antigen expression patterns compared with normal or regenerating marrow. Any level of residual disease was considered MRD positive., Results: Before HCT, 88 patients met morphologic criteria for complete remission (CR), whereas 11 had CR with incomplete blood count recovery (CRi). Twenty-four had MRD before HCT as determined by MFC. Two-year estimates of overall survival were 30.2% (range, 13.1% to 49.3%) and 76.6% (range, 64.4% to 85.1%) for MRD-positive and MRD-negative patients; 2-year estimates of relapse were 64.9% (range, 42.0% to 80.6%) and 17.6% (range, 9.5% to 27.9%). After adjustment for all or a subset of cytogenetic risk, secondary disease, incomplete blood count recovery, and abnormal karyotype pre-HCT, MRD-positive HCT was associated with increased overall mortality (hazard ratio [HR], 4.05; 95% CI, 1.90 to 8.62; P < .001) and relapse (HR, 8.49; 95% CI, 3.67 to 19.65; P < .001) relative to MRD-negative HCT., Conclusion: These data suggest that pre-HCT MRD is associated with increased risk of relapse and death after myeloablative HCT for AML in first morphologic CR, even after controlling for other risk factors.

Little is known about clinical and virologic manifestations of rhinovirus (HRV) and coronavirus (HCoV) infections after hematopoietic cell transplantation (HCT). We performed surveillance for 1 year and describe the natural history of these infections during the first 100 days after allogeneic HCT, when symptom surveys and upper respiratory samples were collected weekly. Samples were tested using RT-PCR for HRVs and HCoVs (OC43, 229E, HKU1, and NL63). Among 215 patients, 64 (30%) patients had 67 infections. Day 100 cumulative incidence estimate was 22.3% for HRV and 11.1% for HCoV. Median duration of viral shedding was 3 weeks; prolonged shedding of at least 3 months occurred in 6 of 45 patients with HRV and 3 of 22 with HCoV. Six patients with HRV and 9 with HCoV were asymptomatic. HRV infection was associated with rhinorrhea, congestion, postnasal drip, sputum, and cough; HCoV infection was not associated with respiratory symptoms or hepatic dysfunction. Lower respiratory infection developed in 2 patients with HRV before day 100, and 1 each with HRV and HCoV after day 100. HRV and HCoV infections are common in the first 100 days after HCT, viral shedding lasts more than 3 weeks in half, and lower respiratory infection is rare.

The authors reflect on the use of umbilical cord blood as a viable alternative stem cell source for patients with hematologic diseases requiring a hematopoietic stem cell transplantation. They cite several studies that support the claims on fetal maternal immunity and antileukemia activity in cord blood transplantation (CBT). The authors think that CBT has an immunological potential for patients with hematological malignancies.