"Worldwide Network for Blood & Marrow Transplantation (WBMT) special article, challenges facing emerging alternate donor registries"

Systematic identification of minor histocompatibility antigens predicts outcomes of allogeneic hematopoietic cell transplantation

T cell alloreactivity against minor histocompatibility antigens (mHAgs)-polymorphic peptides resulting from donor-recipient (D-R) disparity at sites of genetic polymorphisms-is at the core of the therapeutic effect of allogeneic hematopoietic cell transplantation (allo-HCT). Despite the crucial role of mHAgs in graft-versus-leukemia (GvL) and graft-versus-host disease (GvHD) reactions, it remains challenging to consistently link patient-specific mHAg repertoires to clinical outcomes. Here we devise an analytic framework to systematically identify mHAgs, including their detection on HLA class I ligandomes and functional verification of their immunogenicity. The method relies on the integration of polymorphism detection by whole-exome sequencing of germline DNA from D-R pairs with organ-specific transcriptional- and proteome-level expression. Application of this pipeline to 220 HLA-matched allo-HCT D-R pairs demonstrated that total and organ-specific mHAg load could independently predict the occurrence of acute GvHD and chronic pulmonary GvHD, respectively, and defined promising GvL targets, confirmed in a validation cohort of 58 D-R pairs, for the prevention or treatment of post-transplant disease recurrence.

Global Trial Representation and Availability of Tyrosine Kinase Inhibitors for Treatment of Chronic Myeloid Leukemia

Background: Evaluating clinical trial representation for countries with different socio-demographic index (SDI) and tyrosine kinase inhibitor (TKI) availability for chronic myeloid leukemia (CML). Methods: CML incidence rates (IRs) and disability-adjusted life years (DALYs) (1999-2019) from the Institute of Health Metrics and Evaluation were analyzed. Trials investigating TKI use in CML were obtained from ClinicalTrials.gov. Site data for eligible trials (N = 30) and DALYs were analyzed. TKI approvals, DALYs, and IRs were summarized by SDI. Results: North America (NA) had significant decreases in annual percent change (APC) in DALYs and incidence rates from 1999 to 2004. IRs were highest in Europe and Central Asia (ECA) and NA, while DALYs were highest in South Asia (SAsia) and Sub-Saharan Africa (SSA). Countries in the high-SDI quintile were likely to have lower DALYs than lower-SDI quintiles. Differences in regional DALYs vs. sites in TKI trials were significant for SAsia, SSA, and ECA. High-SDI countries were included in all 30 trials, and TKI approvals were prominent in high-SDI (142) vs. low-SDI (14) countries. Conclusions: The inclusion of disproportionately affected countries during the design of and recruitment into clinical trials should occur, as should TKI availability. The lack of representation demonstrates healthcare disparities.

American Society for Transplantation and Cellular Therapy International Affairs Committee: Report of the 4th Workshop on Quality as a Development Tool for Hematopoietic Cell Transplantation Programs at the 2023 Tandem BMT Meetings

We provide a summary of the 4th ASTCT International Workshop with presentations from experts from Chile ("Setting Up a Transplantation Program in Chile," by Dr Pablo Ramirez), Saudi Arabia ("Developing Quality Programs in North Africa," by Dr Amal Alseraihy), and Japan ("The Japanese Transplant Registry Unified Management Program [TRUMP]: Current Issues and the Future," by Dr Yoshiko Atsuta). Workshop objectives included: (1) recognizing the benefits and importance for low- and middle-income countries of developing quality criteria and programs beyond existing accreditation programs, such as the Foundation for the Accreditation of Cellular Therapy (FACT) and the Joint Accreditation Committee ISCT-Europe and EBMT (JACIE); (2) describing the relationships among monitoring outcomes, including mortality, improvement of care, data reporting, and associated costs; and (3) reviewing how quality structures have been implemented and are improving care worldwide.

An undergraduate service-learning project to teach immunology concepts while increasing healthcare equity by enhancing access to stem cell donors among underrepresented populations

Active learning has been shown to increase STEM student engagement and decrease the achievement gap among underrepresented students. As a parallel to the lack of equity in STEM education, BIPOC patients who require a life-saving hematopoietic cell transplantation (HCT) are much less likely-sometimes less than half as likely-than individuals of White-European descent to find a suitable donor when using the National Marrow Donation Program (NMDP). The Be the Match (BtM) Registry has made significant improvements in the likelihood of matching underrepresented patients, but the disparity persists. This activity uses a service-learning project to teach undergraduate students about stem cell donation and to add potential stem cell donors to the BtM Registry. A small data set of pre-/post-surveys from one cohort shows learning gains on the topic of HCT. The approach is flexible and scalable, and students overwhelmingly reported the project as a great use of class time and very rewarding.

Altered microbial bile acid metabolism exacerbates T cell-driven inflammation during graft-versus-host disease

Microbial transformation of bile acids affects intestinal immune homoeostasis but its impact on inflammatory pathologies remains largely unknown. Using a mouse model of graft-versus-host disease (GVHD), we found that T cell-driven inflammation decreased the abundance of microbiome-encoded bile salt hydrolase (BSH) genes and reduced the levels of unconjugated and microbe-derived bile acids. Several microbe-derived bile acids attenuated farnesoid X receptor (FXR) activation, suggesting that loss of these metabolites during inflammation may increase FXR activity and exacerbate the course of disease. Indeed, mortality increased with pharmacological activation of FXR and decreased with its genetic ablation in donor T cells during mouse GVHD. Furthermore, patients with GVHD after allogeneic hematopoietic cell transplantation showed similar loss of BSH and the associated reduction in unconjugated and microbe-derived bile acids. In addition, the FXR antagonist ursodeoxycholic acid reduced the proliferation of human T cells and was associated with a lower risk of GVHD-related mortality in patients. We propose that dysbiosis and loss of microbe-derived bile acids during inflammation may be an important mechanism to amplify T cell-mediated diseases.

Expert consensus on fertility preservation in hematopoietic stem cell transplantation in girls in China

Aims: Preconditioning before hematopoietic stem cell transplantation (HSCT) seriously damages the ovarian function and causes female infertility. This consensus focuses on the fertility preservation(FP) for girls needing HSCT, aim to make doctors in different disciplines aware of the importance, necessity and technique of ovarian protection.Materials and methods: Summarizing relevant literature and organizing multidisciplinary experts, including obstetrics and gynecology, reproductive medicine, oncology, pediatrics and hematology for full discussion.Results: Individuals exposed to HSCT in childhood are at higher risk of loss of fertility. Considering the high risk of premature ovarian insufficiency (POI) after conditioning and negative impact of POI on fertility, physical and mental health, it is absolutely necessary to protect fertility before HSCT conditioning. Ovarian tissue cryopreservation is the main fertility preservation option for these population.Conclusions: Fertility preservation before HSCT conditioning is crucial. Ovarian tissue cryopreservation is often the only option for these population.

Chronic graft-versus-host disease is characterized by high levels and distinctive tissue-of-origin patterns of cell-free DNA

Chronic graft-versus-host disease (cGvHD) is a devastating complication of hematopoietic stem cell transplantation (HSCT). Effective early detection may improve the outcome of cGvHD. The potential utility of circulating cell-free DNA (cfDNA), a sensitive marker for tissue injury, in HSCT and cGvHD remains to be established. Here, cfDNA of prospectively collected plasma samples from HSCT recipients (including both cGvHD and non-cGvHD) and healthy control (HC) subjects were evaluated. Deconvolution methods utilizing tissue-specific DNA methylation signatures were used to determine cfDNA tissue-of-origin. cfDNA levels were significantly higher in HSCT recipients than HC and significantly higher in cGvHD than non-cGvHD. cGvHD was characterized by a high level of cfDNA from innate immune cells, heart, and liver. Non-hematologic tissue-derived cfDNA was significantly higher in cGvHD than non-cGvHD. cfDNA temporal dynamics and tissue-of-origin composition have distinctive features in patients with cGvHD, supporting further exploration of the utility of cfDNA in the study of cGvHD.

Updates in hematopoietic cell transplant and cellular therapies that enhance the risk for opportunistic infections

BACKGROUND

Infectious disease physicians may be asked to evaluate and manage a variety of infections in immunocompromised hosts undergoing hematopoietic cell transplant (HCT) and cellular therapies. Over the last decade, several advances in cellular therapy have occurred, with implications for the types of infectious complications that may be seen.

AIMS

The purpose of this review is to update the infectious disease physician on newer advances in HCT and cellular therapy, including haploidentical transplant, expanding indications for transplant in older individuals and children, and chimeric antigen receptor T-cells. We will review how these advances might influence infectious disease complications following HCT. We will also provide a perspective that infectious disease physicians can use to evaluate the degree of immune suppression in an individual patient to help determine the type of infections that may be encountered.

5 years DKMS Chile: approach, results and impact of the first unrelated stem cell donor center in Chile

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed worldwide to treat blood cancer and other life-threatening blood disorders. As successful transplantation requires an HLA-compatible donor, unrelated donor centers and registries have been established worldwide to identify donors for patients without a family match. Ethnic minorities are underrepresented in large donor registries. Matching probabilities are higher when donors and patients share the same ethnic background, making it desirable to increase the diversity of the global donor pool by recruiting donors in new regions. Here, we report the establishment and the first 5 years of operation of the first unrelated stem cell donor center in Chile, a high-income country in South America with a population of over 19 million.

Methods

We used online and in-person donor recruitment practices through patient appeals and donor drives in companies, universities, the armed forces, and public services. After confirmatory typing donors were subjected to medical work-up and cleared for donation.

Results

We recruited almost 170,000 donors in 5 years. There were 1,488 requests received for confirmatory typing and donor availability checks, of which 333 resulted in medical work-up, leading to 194 stem cell collections. Products were shipped to Chile (48.5%) and abroad. Even when the COVID-19 pandemic challenged our activities, the number of donors recruited and shipped stem cell products remained steady. In Chile there was an almost 8-fold increase in unrelated donor transplantation activity from 16 procedures in 2016-2018 to 124 procedures in 2019-2021, mainly for pediatric patients following the center's establishment. We estimate that 49.6% of Chilean patients would find at least one matched unrelated donor in the global DKMS donor pool.

Discussion

Establishing a DKMS donor center in Chile has significantly increased donor availability for Chilean patients and contributed to an increase of unrelated donor stem cell transplant activity.

Worldwide sources of data in haematology: Importance of clinician-biostatistician collaboration

The field of haematology has benefitted greatly from registry-based observational research. Medical and technical advances, changes in regulations and events such as the global pandemic is changing the landscape for registries. This review describes features of high-quality registries, statistical approaches and study design needed, an overview of worldwide hematologic registries, and how registries are evolving and expanding. The importance of collaborations between biostatisticians and haematologists in designing and conducting registry-related research is highlighted.

Reducing barriers of access and care related to hematopoietic cell transplantation and cellular therapy: The mission-driven role of the national marrow donor program

The treatment of malignant and nonmalignant hematologic disorders continues to benefit from significant scientific advancement and progress in the use of hematopoietic cell transplantation and cellular therapies. However, barriers associated with receiving these lifesaving treatments and care remain, which necessitate innovative approaches to overcome, so all persons in need can receive these therapies. This article reviews barriers to receiving hematopoietic cell transplantation and cellular therapies, and highlights novel approaches taken by the National Marrow Donor Program in reducing barriers for all patients in need.

'Be the Match'. Predictors of Decisions Concerning Registration as a Potential Bone Marrow Donor-A Psycho-Socio-Demographic Study

(1) Background: The study was aimed at a better understanding of the factors determining making a decision to become a potential bone marrow donor, in a Polish research sample; (2) Methods: The data was collected using a self-report questionnaire among persons who voluntarily participated in the study concerning donation, conducted on a sample of the Polish population via Internet. The study included 533 respondents (345 females and 188 males), aged 18-49. Relationships between the decision about registration as potential bone marrow donor and psycho-socio-demographic factors were estimated using the machine learning methods (binary logistic regression and classification & regression tree); (3) Results. The applied methods coherently emphasized the crucial role of personal experiences in making the decision about willingness for potential donation, f.e. familiarity with the potential donor. They also indicated religious issues and negative health state assessment as main decision-making destimulators; (4) Conclusions. The results of the study may contribute to an increase in the effectiveness of recruitment actions by more precise personalization of popularizing-recruitment actions addressed to the potential donors. It was found that selected machine learning methods are interesting set of analyses, increasing the prognostic accuracy and quality of the proposed model.

Bacterial Pathogens Causing Pneumonia Post Hematopoietic Stem Cell Transplant: The Chronic GVHD Population

Allogeneic stem cell transplantation is a lifesaving treatment for many malignancies. Post-transplant patients may suffer from graft versus host disease in the acute and/or the chronic form(s). Post-transplantation immune deficiency due to a variety of factors is a major cause of morbidity and mortality. Furthermore, immunosuppression can lead to alterations in host factors that predisposes these patients to infections. Although patients who receive stem cell transplant are at an increased risk of opportunistic pathogens, which include fungi and viruses, bacterial infections remain the most common cause of morbidity. Here, we review bacterial pathogens that lead to pneumonias specifically in the chronic GVHD population.

An Analysis of the Worldwide Utilization of Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) has an aggressive course and a historically dismal prognosis. For many patients, hematopoietic stem cell transplantation (HSCT) represents the best option for cure, but access, utilization, and health inequities on a global scale remain poorly elucidated. We wanted to describe patterns of global HSCT use in AML for a better understanding of global access, practices, and unmet needs internationally. Estimates of AML incident cases in 2016 were obtained from the Global Burden of Disease 2019 study. HSCT activities were collected from 2009 to 2016 by the Worldwide Network for Blood and Marrow Transplantation through its member organizations. The primary endpoint was global and regional use (number of HSCT) and utilization of HSCT (number of HSCT/number of incident cases) for AML. Secondary outcomes included trends from 2009 to 2016 in donor type, stem cell source, and remission status at time of HSCT. Global AML incidence has steadily increased, from 102,000 (95% uncertainty interval: 90,200-108,000) in 2009 to 118,000 (104,000-126,000) in 2016 (16.2%). Over the same period, a 54.9% increase from 9659 to 14,965 HSCT/yr was observed globally, driven by an increase in allogeneic (64.9%) with a reduction in autologous (-34.9%) HSCT. Although the highest numbers of HSCT continue to be performed in high-resource regions, the largest increases were seen in resource-constrained regions (94.6% in Africa/East Mediterranean Region [AFR/EMR]; 34.7% in America-Nord Region [AMR-N]). HSCT utilization was skewed toward high-resource regions (in 2016: AMR-N 18.4%, Europe [EUR] 17.9%, South-East Asia/Western Pacific Region [SEAR/WPR] 11.7%, America-South Region [AMR-S] 4.5%, and AFR/EMR 2.8%). For patients <70 years of age, this difference in utilization was widened; AMR-N had the highest allogeneic utilization rate, increasing from 2009 to 2016 (30.6% to 39.9%) with continued low utilization observed in AFR/EMR (1.7% to 2.9%) and AMR-S (3.5% to 5.4%). Across all regions, total HSCT for AML in first complete remission (CR1) increased (from 44.1% to 59.0%). Patterns of donor stem cell source from related versus unrelated donors varied widely by geographic region. SEAR/WPR had a 130.2% increase in related donors from 2009 to 2016, and >95% HSCT donors in AFR/EMR were related; in comparison, AMR-N and EUR have a predilection for unrelated HSCT. Globally, the allogeneic HSCT stem cell source was predominantly peripheral blood (69.7% of total HSCT in 2009 increased to 78.6% in 2016). Autologous HSCT decreased in all regions from 2009 to 2016 except in SEAR/WPR (18.9%). HSCT remains a central curative treatment modality in AML. Allogeneic HSCT for AML is rising globally, but there are marked variations in regional utilization and practices, including types of graft source. Resource-constrained regions have the largest growth in HSCT use, but utilization rates remain low, with a predilection for familial-related donor sources and are typically offered in CR1. Further studies are necessary to elucidate the reasons, including economic factors, to understand and address these health inequalities and improve discrepancies in use of HSCT as a potentially curative treatment globally.

A Case of Daratumumab-Induced Significant Decrease in Donor-Specific HLA Antibodies and Remission Induction Before Haploidentical Stem Cell Transplantation in a Refractory B-ALL Patient

Objective:

To explore the method of eliminating donor-specific anti-HLA antibodies (DSA) in haploidentical stem cell transplantation (haplo-SCT).

Methods:

We present a refractory B-cell acute lymphoblastic leukemia (ALL) patient who had strongly positive DSA, but had no human leukocyte antigen–matched donor. Although CD38 expression on leukemia cells was negative, daratumumab combined with etoposide and venetoclax therapy was chosen for her.

Results:

She achieved a significant decrease in DSA levels and complete remission on the combination therapy with daratumumab. She then received a haplo-SCT from a daughter as a donor and had a successful engraftment of donor stem cell. In haplo-SCT, strongly positive DSA levels, directed against donor HLA antigens, could be significantly reduced by daratumumab therapy before transplantation and successfully bridge subsequent haplo-SCT.

Conclusion:

Although CD38 expression is negative in leukemia cells, refractory B-ALL patients may still benefit from combination therapy with daratumumab. We need further clinical observation.

Updated Trends in Hematopoietic Cell Transplantation in the United States with an Additional Focus on Adolescent and Young Adult Transplantation Activity and Outcomes

Hematopoietic cell transplantation (HCT) has been successfully used to treat many malignant and nonmalignant conditions. As supportive care, donor selection, and treatment modalities evolve, documenting HCT trends and outcomes is critical. This report from the Center for International Blood and Marrow Transplant Research (CIBMTR) provides an update on current transplantation activity and survival rates in the United States. Additional data on the use and outcomes of HCT in the adolescent and young adult (AYA) population are included. AYA patients more frequently receive peripheral blood stem cell grafts than pediatric patients, which may reflect differences in practice in pediatric versus adult treatment centers. The proportions of donor types also differ those in adult and pediatric populations. Outcomes for patients in the AYA age range are similar to those of pediatric patients for acute myelogenous leukemia but worse for acute lymphoblastic leukemia. Outcomes for both leukemias are better in AYA patients compared with older adults. Comparing the time periods 2000 to 2009 and 2010 to 2019 revealed significant improvement in overall survival across the age spectrum, but the greatest improvement in the AYA age group.

One and a half million hematopoietic stem cell transplants: continuous and differential improvement in worldwide access with the use of non-identical family donors

The Worldwide Network of Blood and Marrow Transplantation (WBMT) pursues the mission of promoting hematopoietic cell transplantation (HCT) for instance by evaluating activities through member societies, national registries and individual centers. In 2016, 82,718 first HCT were reported by 1,662 HCT teams in 86 of the 195 World Health Organization member states representing a global increase of 6.2% in autologous HCT and 7.0% in allogeneic HCT and bringing the total to 1,298,897 procedures. Assuming a frequency of 84,000/year, 1.5 million HCT were performed by 2019 since 1957. Slightly more autologous (53.5%) than allogeneic and more related (53.6%) than unrelated HCT were reported. A remarkable increase was noted in haploidentical related HCT for leukemias and lymphoproliferative diseases, but even more in non-malignant diseases. Transplant rates (TR; HCT/10 million population) varied according to region reaching 560.8 in North America, 438.5 in Europe, 76.7 in Latin America, 53.6 in South East Asia/Western Pacific (SEA/WPR) and 27.8 in African/East Mediterranean (AFR/EMR). Interestingly, haploidentical TR amounted to 32% in SEA/WPR and 26% in Latin America, but only 14% in Europe and EMR and 4.9% in North America of all allogeneic HCT. HCT team density (teams/10 million population) was highest in Europe (7.7) followed by North America (6.0), SEA/WPR (1.9), Latin America (1.6) and AFR/EMR (0.4). HCT are increasing steadily worldwide with narrowing gaps between regions and greater increase in allogeneic compared to autologous activity. While related HCT is rising, largely due to increase in haploidentical HCT, unrelated HCT is plateauing and cord blood HCT is in decline.

Increasing access to hematopoietic cell transplantation in Latin America: results of the 2018 LABMT activity survey and trends since 2012

A total of 5642 hematopoietic cell transplants (HCT) in 5445 patients (2196-40% allogeneic and 3249-60% autologous) were reported by 127 teams in 14 Latin American countries that answered the 2018 LABMT/WBMT Global Transplant Activity survey. The transplant rate (defined as the number of first transplants per 10 million inhabitants per year) was 85 (51 autologous and 34 allogeneic) in 2018. The main indications for allogeneic HCT were acute leukemias (60%), while plasma cell disorders and lymphomas were the most common conditions warranting autologous HCT (50 and 36%, respectively). In the allogeneic HCT, HLA-identical siblings were the main type of donor (44%) followed by related mismatched/haploidentical donors (32%). Peripheral blood stem cells were used in 98% of the autologous and in 64% of the allogeneic transplants. From 2012 to 2018, there was a 64% increase of reported HCT (54% in autologous and 80% in allogeneic). In the allogeneic setting, the most pronounced increase in donor type was observed in haploidentical relatives (from 94 procedures in 2012 up to 710 in 2018), surpassing unrelated donors as of 2017. Significant trends detected in Latin America include rising numbers of the procedures reported, a faster increase in allogeneic HCT compared with autologous HCT and a significant increase in family mismatched/haploidentical donors. The LABMT/WBMT activity survey provides useful data to understand the HCT activity and trends in Latin America.

The Reconstitution Dynamics of Cultivated Hematopoietic Stem Cells and Progenitors Is Independent of Age

Hematopoietic stem cell transplantation (HSCT) represents the only curative treatment option for numerous hematologic malignancies. While the influence of donor age and the composition of the graft have already been examined in clinical and preclinical studies, little information is available on the extent to which different hematological subpopulations contribute to the dynamics of the reconstitution process and on whether and how these contributions are altered with age. In a murine model of HSCT, we therefore simultaneously tracked different cultivated and transduced hematopoietic stem and progenitor cell (HSPC) populations using a multicolor-coded barcode system (BC32). We studied a series of age-matched and age-mismatched transplantations and compared the influence of age on the reconstitution dynamics. We show that reconstitution from these cultured and assembled grafts was substantially driven by hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs) independent of age. The reconstitution patterns were polyclonal and stable in all age groups independently of the variability between individual animals, with higher output rates from MPPs than from HSCs. Our experiments suggest that the dynamics of reconstitution and the contribution of cultured and individually transduced HSPC subpopulations are largely independent of age. Our findings support ongoing efforts to expand the application of HSCT in older individuals as a promising strategy to combat hematological diseases, including gene therapy applications.

Increasing access to allogeneic hematopoietic cell transplant: an international perspective

Allogeneic hematopoietic cell transplantation (allo-HCT) is a highly complex, costly procedure for patients with oncologic, hematologic, genetic, and immunologic diseases. Demographics and socioeconomic status as well as donor availability and type of health care system are important factors that influence access to and outcomes following allo-HCT. The last decade has seen an increase in the numbers of allo-HCTs and teams all over the world, with no signs of saturation. More than 80 000 procedures are being performed annually, with 1 million allo-HCTs estimated to take place by the end of 2024. Many factors have contributed to this, including increased numbers of eligible patients (older adults with or without comorbidities) and available donors (unrelated and haploidentical), improved supportive care, and decreased early and late post-HCT mortalities. This increase is also directly linked to macro- and microeconomic indicators that affect health care both regionally and globally. Despite this global increase in the number of allo-HCTs and transplant centers, there is an enormous need for increased access to and improved outcomes following allo-HCT in resource-constrained countries. The reduction of poverty, global economic changes, greater access to information, exchange of technologies, and use of artificial intelligence, mobile health, and telehealth are certainly creating unprecedented opportunities to establish collaborations and share experiences and thus increase patient access to allo-HCT. A specific research agenda to address issues of allo-HCT in resource-constrained settings is urgently warranted.

Hematopoietic Stem Cell Mobilization: Current Collection Approaches, Stem Cell Heterogeneity, and a Proposed New Method for Stem Cell Transplant Conditioning

Hematopoietic stem cells naturally traffic out of their bone marrow niches into the peripheral blood. This natural trafficking process can be enhanced with numerous pharmacologic agents - a process termed "mobilization" - and the mobilized stem cells can be collected for transplantation. We review the current state of mobilization with an update on recent clinical trials and new biologic mechanisms regulating stem cell trafficking. We propose that hematopoietic mobilization can be used to answer questions regarding hematopoietic stem cell heterogeneity, can be used for non-toxic conditioning of patients receiving stem cell transplants, and can enhance gene editing and gene therapy strategies to cure genetic diseases.

Historical perspective and a glance into the antibody-based conditioning regimens: A new era in the horizon?

The hematopoietic cell transplantation practice has changed significantly over the years. More than 1500 centers around the globe are offering transplant for different types of diseases. This growth was driven by improving the efficacy and the safety of the procedure and the ability to use alternate donors. These improvements made the procedure feasible in virtually all patients in need for it. With the availability of novel therapies and targeted agents, we may be witnessing a new transplant-era. These agents may help to circumvent some of the remaining limitations of the procedure and open the doors for new indications. Herein, we review historical transplant milestones, the accomplishments that led to the modern transplant practice and we discuss the idea of minimal-intensity conditioning and the possibility to adopt chemotherapy and radiation-free preparative regimens in the near future.

Hematopoietic stem cell transplantation activity in China 2019: a report from the Chinese Blood and Marrow Transplantation Registry Group

Between 2008 and 2019, 58,914 hematopoietic stem cell transplantations (HSCTs) were reported to the Chinese Blood and Marrow Transplantation Registry Group (CBMTRG) throughout China. In this report, we focus on 2019 data and describe current trends in HSCT in China. There was continued growth in transplant activity in China, with a rapid increase in haploidentical HSCT. In 2019, a total of 12,323 cases of HSCT were reported from 149 transplant teams, 78% (9597 cases) were allogeneic HSCTs. Haploidentical donor (HID) HSCT accounted for 60% (5771 cases) of allogeneic HSCT. The most common indications for allogeneic HSCT for malignant disease were acute myeloid leukemia (AML) (37%) and acute lymphoblastic leukemia (ALL) (24%), and the largest proportion of non-malignant diseases comprised aplastic anemia (AA) (13%). Multiple stem cell source composed 70% of HID and 28% of MSD, which was typical in China. The BuCy based regimen (59%) was the most popular conditioning regimen for allogeneic HSCT, followed by the BuFlu based regimen (23%) and TBI-based regimen (12%). This survey clearly shows comprehensive information about the current state and recent trends for HSCT in China. Further efforts should be made to obtain detailed information.

High-throughput sequencing defines donor and recipient HLA B-cell epitope frequencies for prospective matching in transplantation

Compatibility for human leukocyte antigen (HLA) genes between transplant donors and recipients improves graft survival but prospective matching is rarely performed due to the vast heterogeneity of this gene complex. To reduce complexity, we have combined next-generation sequencing and in silico mapping to determine transplant population frequencies and matching probabilities of 150 antibody-binding eplets across all 11 classical HLA genes in 2000 ethnically heterogeneous renal patients and donors. We show that eplets are more common and uniformly distributed between donors and recipients than the respective HLA isoforms. Simulations of targeted eplet matching shows that a high degree of overall compatibility, and perfect identity at the clinically important HLA class II loci, can be obtained within a patient waiting list of approximately 250 subjects. Internal epitope-based allocation is thus feasible for most major renal transplant programs, while regional or national sharing may be required for other solid organs.

Tran et al. combine high throughput sequencing, structural biology and computational simulation to determine the HLA allele and antibody-defined epitope frequencies in renal transplant patients and donors. These results demonstrate the feasibility of HLA epitope matching using data from a national transplantation program.

A Study on Hematopoietic Stem Cell Donation Volunteer Retention between Swab Sampling Approach and Blood Sampling Approach: Evidence from Shanghai, China

The loss of hematopoietic stem cell donation (HSCD) volunteers is widespread worldwide. This study analyzed the distribution characteristics of volunteer retention between the swab sampling approach and blood sampling approach. The Shanghai branch of the China Bone Marrow Donation Program conducted a telephone follow-up with 18,963 volunteers to understand volunteer retention. Multiple logistic regression was used to analyze the distribution characteristics of volunteer retention between two different sampling approaches, and a forest plot was used to observe the distribution trend. Only 32.37% of the volunteers could be contacted, and the loss of volunteers was severe. The volunteer retention is influenced by sampling approaches and demographic characteristics, and Shanghai natives, the highly educated, and students had better retention. The volunteer retention of the swab group was better among young people and technicians, while the volunteer retention of the blood sample group was lower among public officials and workers, and the volunteer retention in the blood sample group was more significantly affected by changes in population characteristics. To enhance the stability of volunteers, managers should improve the contact channels and frequency, expand the ratio of stable volunteers, strengthen volunteer education in the process of collecting blood samples, and respect individuals’ willingness.

Quality of life and changes in the social dimension of hematopoietic stem cell transplants recipients

OBJECTIVES

to assess/correlate health-related quality of life with the social dimension of hematopoietic, autologous and allogeneic stem cell transplant patients in the three years post-transplant.

METHODS

longitudinal, observational study with 55 patients, in a reference hospital in Latin America, from September 2013 to February 2019, using the Quality of Life Questionnaire-Core and Functional Assessment Cancer Therapy Bone Marrow Transplantation.

RESULTS

A total of 71% underwent allogeneic transplantation. The social dimension had low averages since the baseline stage (55, 21) and low scores (56) for quality of life in pancytopenia. There was a significant positive correlation between social dimension, quality of life in pancytopenia (p<0.01) and follow-up after hospital discharge (p<0.00). There is a significant difference (p<0.00) throughout the stages, however, not in terms of the type of transplant (p>0.36/0.86).

CONCLUSIONS

patients with better assessments in the social dimension have a better quality of life. Interventions focusing on the multidimensionality of the quality of life construct are necessary.

Comparison of haplo-SCT and chemotherapy for young adults with standard-risk Ph-negative acute lymphoblastic leukemia in CR1

Abstract

Human leukocyte antigen (HLA) haploidentical stem cell transplantation (haplo-SCT) as a postremission treatment for standard risk Philadelphia chromosome-negative acute lymphoblastic leukemia (SR Ph-ALL) in the first complete remission (CR1) has not been defined. In this multicenter, phase 3 study (NCT02042690), of the 131 consecutive Ph-ALL young adult patients (YA, aged 18–39 years) without high-risk features who achieved CR1, 114 patients without HLA-matched donors received consolidation with an adult chemotherapy regimen (n = 55) or haplo-SCT (n = 59). In the landmark analysis, haplo-SCT resulted in a lower 2-year cumulative incidence of relapse (CIR, 12.8% vs 46.7%, P = 0.0017) and superior 2-year leukemia-free survival (LFS, 80.9% vs 51.1%, P = 0.0116) and 2-year overall survival (OS, 91.2% vs 75.7 [64.8–93.2] %, P = 0.0408) than chemotherapy. In the time-dependent multivariate analysis with propensity score adjustment, postremission treatment (haplo-SCT vs chemotherapy) was an independent risk factor for the CIR (HR 0.195, 95% CI 0.076–0.499, P = 0.001), LFS (HR 0.297, 95% CI 0.131–0.675, P = 0.003), and OS (HR 0.346, 95% CI 0.140–0.853, P = 0.011). In all subgroups, CIR was lower in haplo-SCT. Myeloablative haplo-SCT with ATG+G-CSF might be one of the preferred therapies for YA patients with standard-risk Ph-ALL.

Trial registration

ClinicalTrials.gov. Registered on 23 January 2014, https://clinicaltrials.gov/ct2/show/NCT02042690

Optimal Delivery of Follow-Up Care After Allogeneic Hematopoietic Stem-Cell Transplant: Improving Patient Outcomes with a Multidisciplinary Approach

The increasing indications for allogeneic stem-cell transplant in patients with hematologic malignancies and non-malignant diseases combined with improved clinical outcomes have contributed to increase the number of long-term survivors. However, survivors are at increased risk of developing a unique set of complications and late effects, besides graft-versus-host disease and disease relapse. In this setting, the management capacity of a single health-care provider can easily be overwhelmed. Thus, to provide appropriate survivorship care, a multidisciplinary approach for the long-term follow-up is essential. This review aims at summarizing the most relevant information that a health-care provider should know to establish a follow-up care plan, in the light of individual exposures and risk factors, that includes all organ systems and considers the psychological burden of these patients.

Immunogenetics in stem cell donor registry work: The DKMS example (Part 2)

DKMS is a leading stem cell donor registry with more than 9 million donors. Donor registry activities share many touch points with topics from immunogenetics or population genetics. In this two-part review article, we deal with these aspects of donor registry work by using the example of DKMS. In the second part of the review, we focus on donor typing of non-HLA genes, the impact of donor age, gender and CMV serostatus on donation probabilities, the identification of novel HLA, KIR and MIC alleles by high-throughput donor typing, the activities of the Collaborative Biobank and pharmacogenetics in the donor registry context.

Health-related quality of life in peripheral blood stem cell donors and bone marrow donors: a prospective study in Japan

Understanding of the impact of stem cell donation on donors' health-related quality of life (HRQOL) remains limited. A prospective observational study of eligible unrelated donors enrolled in the Japan Marrow Donor Program was conducted to compare HRQOL and adverse events (AEs) between peripheral blood stem cell (PBSC) and bone marrow (BM) donors. In total, 107 PBSC donors and 108 BM donors were enrolled. HRQOL scores for physical status were significantly lower in BM donors 1 week post-harvest (P < 0.001), but there were no significant differences between the two groups at baseline or 3 months post-harvest. PBSC donors were more likely to experience AEs before harvest (P < 0.001). However, at harvest, moderate-to-severe AEs were more common in BM donors (P = 0.001). After harvest, all grades of AEs were significantly higher in BM donors (P < 0.001). Among BM donors, a lower total physical score at baseline [odds ratio (OR) 1.21], female sex [OR 2.71], and young donors (OR 3.08) were risk factors for moderate-to-severe AEs at harvest, while among PBSC donors, only female sex (OR 4.86) was a risk factor. Our findings show better HRQOL during PBSC donation. These data help support decision-making by potential donors.

The role of serum uric acid in the prediction of graft-versus-host disease in allogeneic hematopoietic stem cell transplantation

Background

Uric acid (UA) level is of the valuable signs of inflammation. However, the role of UA in the outcomes of hematopoietic stem cell transplantation (HSCT) such as GVHD and patients’ overall survival is still a matter of debate. In this study, we aimed to evaluate the relationship between UA levels and GVHD incidence and overall survival in allogeneic HSCT patients.

Methods

A total of 201 patients who were admitted for allogeneic transplantation at Taleghani hospital, Tehran, Iran, were considered for retrospective analysis. Serum UA levels from 1 week before transplantation until 2 weeks after transplantation were used to determine thresholds and find out the association of serum UA levels with GVHD and overall survival.

Results

We showed that the determined thresholds using receiver operating characteristic curves have poor predictive value for GVHD and overall survival. The patients with serum UA higher than 3.4 mg/dL had 37% lower odds of GVHD incidence and 35% lower hazard of death than patients with UA lower than 3.4 mg/dL.

Conclusion

Our results indicated that serum UA levels lower than 3.4 mg/dL could significantly increase the incidence of GVHD and hazard of death. The antioxidant functions of UA could explain the lower incidence of GVHD in hyperuricemic patients. However, the inconsistencies of the previous studies require further investigation to elucidate the role of UA in the prediction of GVHD.

Cyclosporine H Improves the Multi-Vector Lentiviral Transduction of Murine Haematopoietic Progenitors and Stem Cells

Haematopoietic stem cells (HSCs) have the potential for lifetime production of blood and immune cells. The introduction of transgenes into HSCs is important for basic research, as well as for multiple clinical applications, because HSC transplantation is an already established procedure. Recently, a major advancement has been reported in the use of cyclosporine H (CsH), which can significantly enhance the lentivirus (LV) transduction of human haematopoietic stem and progenitor cells (HSPCs). In this study, we employed CsH for LV transduction of murine HSCs and defined haematopoietic progenitors, confirming previous findings in more specific subsets of primitive haematopoietic cells. Our data confirm increased efficiencies, in agreement with the published data. We further experimented with the transduction with the simultaneous use of several vectors. The use of CsH yielded an even more robust increase in rates of multi-vector infection than the increase for a single-vector. CsH was reported to reduce the innate resistance mechanism against LV infection. We indeed found that additional pretreatment could increase the efficiency of transduction, in agreement with the originally reported results. Our data also suggest that CsH does not reduce the efficiency of transplantation into immune-competent hosts or the differentiation of HSCs while enhancing stable long-term expression in vivo. This new additive will surely help many studies in animal models and might be very useful for the development of novel HSC gene therapy approaches.

Genetic Engineering to Induce Fetal-Like Hematopoietic Stem Cells

Bone marrow transplantation (BMT) or hematopoietic stem cell transplantation (HSCT) is an archetype of cellular therapy. However, to date BMT still suffers from several complications. Recent technological advances have encouraged us to think about an alternative to traditional BMT. Specifically, we propose in utero HSCT (IUHSCT). For this purpose, we suggest that induced fetal-like hematopoietic stem cells (ifHSCs) might be suitable for IUHSCT, and should be seriously evaluated.