The health risk of social disadvantage is transplantable into a new host.

Low socioeconomic status (SES) is a risk factor for mortality and immune dysfunction across a wide range of diseases, including cancer. However, cancer is distinct in the use of allogeneic hematopoietic cell transplantation (HCT) as a treatment for hematologic malignancies to transfer healthy hematopoietic cells from one person to another. This raises the question of whether social disadvantage of an HCT cell donor, as assessed by low SES, might impact the subsequent health outcomes of the HCT recipient. To evaluate the cellular transplantability of SES-associated health risk, we analyzed the health outcomes of 2,005 HCT recipients who were transplanted for hematologic malignancy at 125 United States transplant centers and tested whether their outcomes differed as a function of their cell donor's SES (controlling for other known HCT-related risk factors). Recipients transplanted with cells from donors in the lowest quartile of SES experienced a 9.7% reduction in overall survival (P = 0.001) and 6.6% increase in treatment-related mortality within 3 y (P = 0.008) compared to those transplanted from donors in the highest SES quartile. These results are consistent with previous research linking socioeconomic disadvantage to altered immune cell function and hematopoiesis, and they reveal an unanticipated persistence of those effects after cells are transferred into a new host environment. These SES-related disparities in health outcomes underscore the need to map the biological mechanisms involved in the social determinants of health and develop interventions to block those effects and enhance the health of both HCT donors and recipients.

Placenta-Derived Decidua Stromal Cells: A New Frontier in the Therapy of Acute Graft-Versus-Host Disease.

Acute graft-versus-host disease (GVHD) is a frequent and potentially life-threatening complication following allogeneic hematopoietic cell transplantation (HCT). Mesenchymal stromal cells (MSCs), rare precursors found in all body tissues, possess immunosuppressive properties and can inhibit alloreactivity both in vitro and in vivo. Two decades ago, we introduced bone marrow-derived (BM) MSCs as a novel therapy for acute GVHD. While some patients responded to BM-MSCs, the response was not universal. Commercially available BM-MSCs are now used for acute GVHD treatment in Canada, Japan, and New Zealand. The fetus is protected from the mother's immune system by the placenta, and our research found that placenta-derived decidua stromal cells (DSCs) offer a stronger immunosuppressive effect than other sources of stromal cells. Safety studies in rabbits, rats, mice, and humans have shown negligible or no side effects from BM-MSCs or DSCs. In a phase I/II trial for severe acute GVHD, we treated 21 patients (median age, 49 years; range 1.6-72 years) with severe biopsy-proven gastrointestinal acute GVHD. The median cell dose of DSCs was 1.2 × 106 (range 0.9-2.9) cells/kg body weight, with a median of 2 (range 1-6) infusions given 1 week apart. The cell viability of DSCs was 93% (range, 69%-100%), and the median cell passage number was 4 (range, 2-4). All patients responded, with a complete response of acute GVHD in 11 patients and partial response in 10 and 1-year survival of 81%. Randomized trials are needed to prove the superiority of DSCs compared to ruxolitinib and/or other novel immunosuppressive therapies.

Allogeneic hematopoietic cell transplantation is effective for p47phox chronic granulomatous disease: A Primary Immune Deficiency Treatment Consortium study.

BACKGROUND: P47phox (neutrophil cytosolic factor-1) deficiency is the most common cause of autosomal recessive chronic granulomatous disease (CGD) and is considered to be associated with a milder clinical phenotype. Allogeneic hematopoietic cell transplantation (HCT) for p47phox CGD is not well-described. OBJECTIVES: We sought to study HCT for p47phox CGD in North America. METHODS: Thirty patients with p47phox CGD who received allogeneic HCT at Primary Immune Deficiency Treatment Consortium centers since 1995 were included. RESULTS: Residual oxidative activity was present in 66.7% of patients. In the year before HCT, there were 0.38 CGD-related infections per person-years. Inflammatory diseases, predominantly of the lungs and bowel, occurred in 36.7% of the patients. The median age at HCT was 9.1 years (range 1.5-23.6 years). Most HCTs (90%) were performed after using reduced intensity/toxicity conditioning. HCT sources were HLA-matched (40%) and -mismatched (10%) related donors or HLA-matched (36.7%) and -mismatched (13.3%) unrelated donors. CGD-related infections after HCT decreased significantly to 0.06 per person-years (P = .038). The frequency of inflammatory bowel disease and the use of steroids also decreased. The cumulative incidence of graft failure and second HCT was 17.9%. The 2-year overall and event-free survival were 92.3% and 82.1%, respectively, while at 5 years they were 85.7% and 77.0%, respectively. In the surviving patients evaluated, ≥95% donor myeloid chimerism at 1 and 2 years after HCT was 93.8% and 87.5%, respectively. CONCLUSIONS: Patients with p47phox CGD suffer from a significant disease burden that can be effectively alleviated by HCT. Similar to other forms of CGD, HCT should be considered for patients with p47phox CGD.

Epidemiological Characteristics and Outcome of Viral Respiratory Tract Infections in the First Year After Allogeneic Hematopoietic Cell Transplantation.

Adverse outcomes of viral respiratory tract infections (RTIs) have been reported in recipients of allogeneic hematopoietic cell transplantation. Using a laboratory-developed multiparameter polymerase chain reaction in a consecutive series of 242 patients, we found the highest incidence of viral RTI in the preengraftment phase. The occurrence of multiple episodes of viral RTI or viral pneumonia was significantly associated with a higher hazard of nonrelapse mortality in the first year after transplantation. We observed a 90-day mortality of 19.7% after viral RTI, which was significantly different between patient groups stratified according to the immunodeficiency scoring index.

Revealing the unseen: next generation sequencing for early detection of drug-resistant cytomegalovirus variants upon letermovir prophylaxis failure.

In allogeneic hematopoietic cell transplant (HCT)-recipients, prophylactic management strategies are essential for preventing CMV-reactivation and associated disease. We report on a 63-year-old male patient with a D-/R+ CMV-serostatus, who showed ongoing low-level CMV-replication post-HCT despite receiving letermovir prophylaxis. Sanger-sequencing failed to detect drug resistance mutations (DRM) until CMV-pneumonitis developed, revealing a UL56-C325R-DRM linked to high-level letermovir resistance. Retrospective analysis with next-generation-sequencing (NGS) revealed the DRM at a low frequency of 6% two weeks prior to detection by Sanger-sequencing. This study highlights the importance of advanced NGS-methods for early detection of CMV-DRMs, allowing for faster adjustments in antiviral treatment strategies.

Revisiting Cytomegalovirus Serology in Allogeneic Hematopoietic Cell Transplant Recipients.

BACKGROUND: Allogeneic hematopoietic cell transplant recipients (allo-HCTRs) with positive cytomegalovirus (CMV) serology may have false-positive results due to blood product transfusion-associated passive immunity. METHODS: This single-center cohort study included allo-HCTRs with negative baseline (at malignancy diagnosis) CMV serology and indeterminate/low-positive (CMV IgG titer, ≥0.6-<50 U/mL) pretransplant CMV serology with negative pretransplant plasma CMV DNAemia. The CMV status of those patients was reclassified from R+ to R- (CMVR- reclassification group). We compared those patients to allo-HCTRs with negative (CMV IgG titer <0.6 U/mL) pretransplant CMV IgG (CMVR- group). We describe the number and type of patients whose pretransplant CMV status was reclassified from indeterminate/positive to negative. We reviewed all plasma CMV DNAemia tests performed during the first 6 months posttransplant in both groups to assess the safety of this approach. RESULTS: Among 246 (84.5%) of 291 transplanted patients identified as CMVR+ pretransplant, 60 (24.4%) were reclassified from CMV serology indeterminate (N:10)/low-positive (N:50) to R-. Only 1 of 60 patients (1.67%) in the CMVR- reclassification group versus 3 of 44 (6.8%; P = .30) in the CMVR- group developed CMV DNAemia during the follow-up period. There were no significant differences in the number of CMV DNAemia tests performed, CMV DNAemia range, and time posttransplant between the 2 groups. CONCLUSIONS: One of 4 allo-HCT CMVR+ may be falsely flagged as R+, with significant impact on donor selection and prophylaxis administration. A 2-step approach including CMV serology testing at hematologic malignancy diagnosis in allo-HCT candidates and careful review of pretransplant CMV IgG titers may help correctly classify CMV serology status.

A single-institution pre-post comparison of subcutaneous immunoglobulin replacement therapy in allogeneic haematopoietic cell transplantation recipients.

Immunoglobulin replacement therapy (IgRT) reduces the risk of infection in hypogammaglobulinaemia secondary to chronic lymphocytic leukaemia and multiple myeloma. However, the benefit of IgRT, especially subcutaneous IgRT (ScIgRT), has not been assessed in hypogammaglobulinaemia after allogeneic haematopoietic cell transplantation (allo-HCT). We performed a pre-post comparison of the clinical impact of ScIgRT after allo-HCT in a retrospective analysis of 209 patients who underwent allogeneic HCT at our institution from 2011 to 2019. Since ScIgRT became available at our institution in April 2017, we categorized patients treated from January 2011 to March 2017 as the Pre-ScIgRT group (n = 118) and those treated from April 2017 to December 2019 as the Post-ScIgRT group (n = 91). The 2-year overall survival rate was 65% in the Pre-ScIgRT group and 81% in the Post-ScIgRT group (p = 0.02). The cumulative incidence (CI) of non-relapse mortality at 2 years was 18% and 7% (p = 0.02). There were 78 infectious events in 44 patients in the Pre-ScIgRT group and 28 such events in 19 patients in the Post-ScIgRT group. The CI of the documented infection during the observation period was between 38% and 21% (p = 0.01). Our study suggests that ScIgRT may reduce infection rates and improve prognosis after allo-HCT.

Unconventional T Cells Influence Clinical Outcome After Allogeneic Hematopoietic Cell Transplantation.

We evaluated the impact of early recovery of mucosal-associated invariant T cells (MAIT) and gamma-delta (γδ) T cells, especially Vδ2+ T cells, on the clinical outcomes of 76 patients who underwent allogeneic hematopoietic cell transplantation (allo-HCT). MAIT cells were identified at day 20-30 post-transplant using flow cytometry and defined as CD3+ TCRVα7.2+CD161+. Two subsets of Vδ2+ T cells were analyzed according to the expression of CD26. The cytotoxicity profile of MAIT and Vδ2+ T cells was analyzed according to the intracellular expression of perforin and granzyme B, and intracellular IFN-γ was evaluated after in vitro activation. CD26+Vδ2+ T cells displayed higher intracellular levels of IFN-γ, whereas CD26- Vδ2+ T were found to be more cytotoxic. Moreover, MAIT cell frequency was correlated with the frequency of Vδ2+ T cells with a better correlation observed with Vδ2+CD26+ than with the Vδ2+CD26- T cell subset. By using the composite endpoint graft-versus-host disease (GvHD)-free, relapse-free survival (GRFS) as the primary endpoint, we found that patients with a higher MAIT cell frequency at day 20-30 after allo-HCT had a significantly increased GRFS and a better overall survival (OS) and disease-free survival (DFS). Moreover, patients with a low CD69 expression by MAIT cells had an increased cumulative incidence of grade 2-4 acute GvHD (aGvHD). These results suggest that MAIT cell reconstitution may provide mitigating effects early after allo-HCT depending on their activation markers and functional status. Patients with a high frequency of Vδ2+CD26+ T cells had a significantly higher GRFS, OS and DFS, but there was no impact on cumulative incidence of grade 2-4 aGVHD, non-relapse mortality and relapse. These results revealed that the impact of Vδ2+ T cells on the success of allo-HCT may vary according to the frequency of the CD26+ subset.

High Torque teno virus load and outcome of patients undergoing allogeneic hematopoietic cell transplantation.

Quantification of Torque teno virus (TTV) load emerged as a marker of immunosuppression. Associations of TTV load with complications and survival after allogeneic hematopoietic cell transplantation (allo-HCT) were controversial in published studies. In this prospective study, we aimed to identify factors influencing TTV load after allo-HCT and to determine whether the TTV load is associated with complications or outcomes. Seventy allo-HCT recipients were included. TTV DNA load was quantified in 469 plasma samples of 70 patients from Day (D) 15 before D120 after transplantation. The influence of transplant characteristics on TTV load and the associations of TTV load with viral infections, acute graft versus host disease, mortality, and relapse were analyzed. More than 80% of patients were TTV DNA positive from D30 after transplantation onwards. Median TTV load increased between D30 and D60 post-transplantation. Patients with lymphoid malignancies had higher TTV load than those with myeloid malignancies. Myeloablative conditioning was associated with higher TTV loads. Patients with no measurable residual disease at transplant had higher TTV loads. High TTV load at D90 post-transplantation was associated with lower overall survival and at D120 post-transplantation was associated with higher relapse rate. In conclusion, TTV load at time points later than D90 after allo-HCT may be useful to assess prognosis.

Endothelial Activation and Stress Index in adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide-based prophylaxis.

BACKGROUND AIMS: Post-transplant cyclophosphamide (PTCY)-based prophylaxis is becoming widespread for allogeneic hematopoietic cell transplantation (allo-HCT) performed independently of the selected donor source. In parallel, use of the Endothelial Activation and Stress Index (EASIX)-considered a surrogate parameter of endothelial activation-for predicting patient outcomes and clinical complications is gaining popularity in the allo-HCT setting. METHODS: We first investigated whether the dynamics of EASIX after allo-HCT differ between patients receiving PTCY and patients receiving other prophylaxis. We then investigated whether the predictive capacity of EASIX persists in PTCY-based allo-HCT. A total of 328 patients transplanted between 2014 and 2020 were included, and 201 (61.2%) received PTCY. RESULTS: EASIX trends differed significantly between the groups. Compared with patients receiving other prophylaxis, patients receiving PTCY had lower EASIX on day 0 and higher values between day 7 and day 100. In patients receiving PTCY, higher EASIX correlated significantly with higher non-relapse mortality (NRM) and lower overall survival (OS) when measured before and during the first 180 days after allo-HCT. In addition, higher EASIX scores measured at specific time points were predictors of veno-occlusive disease (VOD), transplant-associated thrombotic microangiopathy (TA-TMA) and grade 2-4 acute graft-versus-host disease (aGVHD) risk. CONCLUSIONS: This study demonstrates how EASIX trends vary during the first 180 days after allo-HCT in patients receiving PTCY and those not receiving PTCY and validates the utility of this index for predicting NRM, OS and risk of VOD, TA-TMA and grade 2-4 aGVHD in patients receiving PTCY.

Investigation of biomarkers to predict outcomes in allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Various biomarkers have been developed and evaluated to predict the prognosis and complications of allogeneic hematopoietic cell transplantation (HCT). Most previous studies conducted on different biomarkers evaluated single effects such as those associated with inflammation, immunology, iron metabolism, and nutrition, and only a few studies have comprehensively analyzed markers. OBJECTIVE: The study aimed to survey comprehensive multiple markers prior to HCT and extract those that significantly predict the outcomes. STUDY DESIGN: A prospective multicenter observational study was performed. (UMIN000013506) Patients undergoing HCT for hematologic diseases were consecutively enrolled. Besides the usual clinical biomarkers, serum samples for extra-clinical biomarkers were collected and cryopreserved before starting the conditioning regimen. A total of 32 candidate biomarkers were selected, 23 from hematology, biochemistry, immunology, nutrition, and iron metabolism, and 9 from composite markers. Based on the area under the curve (AUC) values for survival, promising biomarkers was extracted. Internal validation for these markers was applied based on bootstrap methods. Setting the cut-off values for them, log-rank test was applied and outcomes including overall survival (OS), relapse, and non-relapse mortality (NRM) were evaluated using multivariate analyses. Furthermore, detailed analysis including transplant-related complications and external validation were conducted focusing on C-reactive protein (CRP) to platelet (Plt) ratio. RESULTS: A total of 152 patients with hematologic malignancies were enrolled from April 2014 to March 2017. CRP, soluble interleukin-2 receptor (IL2R), CRP to albumin (Alb) ratio, CRP to Plt ratio, Plt to IL2R ratio, and IL2R to Alb ratio were identified as promising markers. Internal validation successfully confirmed their reliability of AUC and multivariate analysis demonstrated the statistical significance between the higher and the lower markers. Above all, a higher CRP to Plt ratio was significantly associated with a lower OS (hazard ratio [HR] 2.77; 95% confidence interval [CI] 1.30-5.91; P = 0.008) and higher non-relapse mortality rates (HR 2.79; 95%CI 1.14-6.80; P = 0.024) at 180 days. Furthermore, univariate analysis showed that a higher CRP to Plt ratio was significantly associated with a higher incidence of sinusoidal obstructive syndrome (P < 0.001) and bloodstream infection (P = 0.027). An external validation test confirmed the significance of the CRP to Plt ratio for these outcomes. CONCLUSION: The multicenter prospective observational study successfully identified significant biomarkers in patients with hematologic malignancies who received HCT. In particular, CRP to Plt ratio was identified as a novel and useful biomarker for predicting transplant outcomes. Further investigations are needed to validate the novel markers, analysis of the pathophysiology, and application to treatment settings other than HCT.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical sibling donors for hematological malignancies in 6064 adults from 2003 to 2020: different impacts on survival according to time period.

BACKGROUND: Mobilized peripheral blood stem cells (PBSC) have been widely used instead of bone marrow (BM) as the graft source for allogeneic hematopoietic cell transplantation (HCT). Although early studies demonstrated no significant differences in survival between PBSC transplantation (PBSCT) and BM transplantation (BMT) from human leukocyte antigen (HLA)-identical sibling donors to adults with hematological malignancies, recent results have been unclear. OBJECTIVE: The objective of this retrospective study was to compare overall survival (OS), relapse, non-relapse mortality (NRM), hematopoietic recovery and graft-versus-host disease (GVHD) between PBSCT and BMT according to the time period of HCT (2003-2008, 2009-2014, or 2015-2020). STUDY DESIGN: We retrospectively compared the outcomes after PBSCT versus BMT in 6064 adults with hematological malignancies using a Japanese registry database between 2003 and 2020. RESULTS: The adjusted probability of OS was significantly higher in BMT recipients compared to PBSCT recipients during the early period of 2003-2008 (adjusted hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.70-0.91; P < 0.001) and the middle period of 2009-2014 (adjusted HR, 0.80; 95% CI, 0.70-0.91; P < 0.001). However, during the late period of 2015-2020, the adjusted probability of OS was comparable between BMT and PBSCT recipients (adjusted HR, 0.94; 95% CI, 0.79-1.13; P = 0.564), which were mainly due to the reduction of NRM. There was no significant difference in the relapse rate between the groups, irrespective of the time period. Compared to BMT, PBSCT led to faster neutrophil and platelet recovery and the cumulative incidences of grades II-IV and grades III-IV acute and overall and extensive chronic GVHD were significantly higher in PBSCT recipients, irrespective of the time period. CONCLUSIONS: PBSCT and BMT had similar survival outcomes and relapse rates in adult patients with hematological malignancies during the late time period of 2015-2020 despite the hematopoietic recovery and acute and chronic GVHD being higher in PBSCT recipients in all time periods.

Single-unit unrelated cord blood transplantation versus HLA-matched sibling transplantation in adults with advanced myelodysplastic syndrome: A registry-based study from the adult MDS working group of the Japanese society for transplantation and cellular therapy.

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.

Outcomes of allogeneic hematopoietic cell transplantation under letermovir prophylaxis for cytomegalovirus infection.

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.

Impact of letermovir prophylaxis in CMV reactivation and disease after allogenic hematopoietic cell transplantation: a real-world, observational study.

Letermovir for CMV prevention in CMV-seropositive adults undergoing allo-HCT was implemented at our program in 2021. This study investigates the results from the use of letermovir. The study includes all the 140 CMV-seropositive patients who underwent an allo-HCT during the years 2020, 2021, and 2022 at our institution. Thirty-eight (27.4%) of these patients received letermovir, administered from day + 7 to day + 100 and restarted if patients were on treatment with steroids. The day + 180 and 1-year cumulative incidences of CMV reactivation were 5.3% and 12.1% for patients who received letermovir and 52.9% and 53.9% for those who did not (P < 0.001) (HR 0.19, P < 0.001). Four (10.5%) of these thirty-eight patients had a CMV reactivation, but only 2 (5.3%) cases occurred during the administration of letermovir. During the first year after allo-HCT, 13 (9.2%) patients had CMV disease; the day + 180 and 1-year cumulative incidences were 2.6% and 6.0% for patients who received letermovir and 9.9% and 12.3% for those who did not (P = 0.254) (HR 1.01, P = 0.458). Two (4.2%) of the patients included in the letermovir group had CMV disease, but both of them after letermovir discontinuation. Letermovir induced a protective effect on CMV reactivation risk, but its use was not associated with a significant reduction of CMV disease. The fact that the CMV disease in patients who received letermovir occurred after the discontinuation of the drug, questions whether CMV prophylaxis should be used in patients with high risk for CMV reactivation or disease.

Allogeneic hematopoietic cell transplantation from alternative donors in acute myeloid leukemia.

Allogeneic hematopoietic cell transplantation (HCT) potentially provides a cure for patients with acute myeloid leukemia (AML) who are unlikely to be cured with chemotherapy alone. Previously, human leukocyte antigen (HLA)-matched related donors were used exclusively, which made the procedure available for a limited proportion of patients. The introduction of high-resolution HLA-typing technology, innovations in immunosuppressive therapy, and improved supportive care measures have significantly changed the situation. Now, patients without a matched related donor have an ample opportunity to receive allogeneic HCT with the use of matched or mismatched unrelated donors, umbilical cord blood grafts, or haploidentical related donors. The outcomes of alternative donor transplantations have improved over the past decades, and the growth of unrelated donor registries as well as the donor diversification have enhanced the chance of finding a suitable donor. With multiple alternative donor choices available for most patients, the donor selection is becoming increasingly important. To discuss the optimal donor choice in case of unavailability of an HLA-matched related donor, this article reviews the existing literature of retrospective and prospective comparisons of different alternative donor transplantations in AML and discusses the current state-of-art modalities in allogeneic HCT using alternative donors.

Myeloablative or reduced-intensity/non-myeloablative hematopoietic cell transplantation for Philadelphia-positive acute lymphoblastic leukemia in adults older than 40 years old - a secondary analysis of a CIBMTR database.

Few studies have addressed the role of reduced-intensity conditioning (RIC) and non-myeloablative (NMA) regimens in older adults with Philadelphia acute lymphoblastic leukemia (Ph + ALL). The objective of this current study was to compare the outcomes of RIC/NMA versus TBI-based myeloablative (MAC) regimens in Ph + ALL patients older than 40 years old who underwent hematopoietic cell transplantation (HCT) in CR1. We used a freely available database from the CIBMTR. Transplants were performed between 2013 and 2017. With a median follow-up of 37.6 months, we have included 629 patients. We used propensity score weighting. Three-year OSs were 64% in the TBI-MAC group and 66% in the RIC/NMA group. OS was not different (HR = 0.92; p = 0.69). Three-year relapse incidences were 21.6% and 27.6% in the TBI-MAC and RIC/NMA groups. RIC/NMA was not associated with an increase in relapse rate (HR 1.02; p = 0.91). Three-year NRMs were 24.3% in the TBI-MAC group and 20.3% in the RIC/NMA group. RIC/NMA was not associated with superior NRM (HR 0.88; p = 0.57). In summary, we have shown that RIC/NMA regimens achieve outcomes comparable to TBI-based MAC in Ph+ ALL older patients in CR1 who may tolerate a TBI-based MAC regimen.

Letermovir as secondary prophylaxis of cytomegalovirus infection after allogeneic hematopoietic cell transplantation: A single center experience.

Letermovir, a novel anti-cytomegalovirus (CMV) agent acts by inhibiting the viral terminase complex and is approved for primary prophylaxis in CMV seropositive patients post allogeneic hematopoietic cell transplantation (HCT). The favorable efficacy and safety profile make it an attractive option for use as secondary prophylaxis in patients at high-risk for CMV reactivation. In this study, we report the efficacy and safety of letermovir secondary prophylaxis after at least one treated episode of CMV reactivation in a cohort of 39 high-risk patients. Thirty two (82%) patients received anti-thymocyte globulin (ATG), 27 (69%) received a combination of ATG and post-transplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis. Twenty one patients (54%) received CMV seronegative grafts. In addition, 18 (46%) patients had HLA mismatched unrelated or haploidentical donors while 18 (46%) had active GVHD requiring immunosuppression at the time of commencing secondary prophylaxis. Letermovir was initiated at a median of 47 days (range, 41-56) after HCT and was administered for a median duration of 77 days (range, 46-90). A single breakthrough CMV reactivation was noted in this high-risk cohort. Four additional episodes of CMV reactivation occurred at a median of 28 days (range, 23-59 days) after discontinuation of secondary prophylaxis. The drug was well tolerated and 77% of the cohort completed the planned duration of secondary prophylaxis. None of the patients discontinued treatment due to treatment-related adverse effects. In conclusion, letermovir is effective and well tolerated and may be considered for secondary prophylaxis in patients at high risk for CMV reactivation. Prospective studies are required to validate these findings.

Outcomes of older adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide based prophylaxis.

This study evaluates the feasibility of using post-transplant cyclophosphamide (PTCY) prophylaxis in allo-hematopoietic cell transplantation (HCT) for adults aged 65 and older. PTCY is increasingly used to prevent graft-versus-host disease (GVHD) across all donor types, but concerns remain about potential risks, especially in older patients. Fifty-seven adults aged 65 or older with hematological malignancies, undergoing their first allo-HCT with PTCY prophylaxis between January 2011 and January 2023 were included. Overall, 94.8% of patients achieved primary engraftment. The median durations for neutrophil and platelet engraftments were 19 and 21 days. The day +30 cumulative incidence of bacterial bloodstream infection was 43.9%. No CMV reactivations occurred within the first 100 days after letermovir implementation. The day +180 cumulative incidences of grade II-IV and III-IV acute GVHD, and the 2-year cumulative incidence of moderate/severe chronic GVHD were 26.3%, 10.5%, and 4.8%. Eighteen patients (31.6%) relapsed, and 30 (52.6%) died, with relapse (16.4%) and infection (11.5%) being the main causes of death. The estimated 2-year overall survival, non-relapse mortality, cumulative incidence of relapse, and GVHD-free relapse-free survival rates were 45.5%, 27.1%, 33.9%, and 37.0%. Adults aged 70 or older had similar outcomes to those aged 65-69. This study confirms the safety and feasibility of PTCY-based allo-HCT in older adults.

Leveraging machine learning for predicting acute graft-versus-host disease grades in allogeneic hematopoietic cell transplantation for T-cell prolymphocytic leukaemia.

Orphan diseases, exemplified by T-cell prolymphocytic leukemia, present inherent challenges due to limited data availability and complexities in effective care. This study delves into harnessing the potential of machine learning to enhance care strategies for orphan diseases, specifically focusing on allogeneic hematopoietic cell transplantation (allo-HCT) in T-cell prolymphocytic leukemia. The investigation evaluates how varying numbers of variables impact model performance, considering the rarity of the disease. Utilizing data from the Center for International Blood and Marrow Transplant Research, the study scrutinizes outcomes following allo-HCT for T-cell prolymphocytic leukemia. Diverse machine learning models were developed to forecast acute graft-versus-host disease (aGvHD) occurrence and its distinct grades post-allo-HCT. Assessment of model performance relied on balanced accuracy, F1 score, and ROC AUC metrics. The findings highlight the Linear Discriminant Analysis (LDA) classifier achieving the highest testing balanced accuracy of 0.58 in predicting aGvHD. However, challenges arose in its performance during multi-class classification tasks. While affirming the potential of machine learning in enhancing care for orphan diseases, the study underscores the impact of limited data and disease rarity on model performance.