Factors associated with granulocyte colony-stimulating factor-induced peripheral blood stem cell yield in healthy donors

Lactate dehydrogenase as a hematopoietic stem cell mobilization biomarker in autologous transplantation

INTRODUCTION

Pre-apheresis peripheral blood CD34+ cell count (PBCD34+) is the most important predictor of good cell mobilization before hematopoietic stem cell transplantation, albeit flow cytometry is not always immediately available. Identification of surrogate markers can be useful. The CD34+ cells proliferate after mobilization, resulting in elevated lactate dehydrogenase (LDH) activity and correlating with the PBCD34+ count.

OBJECTIVE

To determine the LDH cut-off value at which adequate CD34+ cell mobilization is achieved and its diagnostic yield.

MATERIALS AND METHODS

A total of 103 patients who received an autologous stem cell transplantation (ASCT) between January 2015 and January 2020 were included. Demographic and laboratory characteristics were obtained, including complete blood count, pre-apheresis PBCD34+ and LDH levels. Receiver operating characteristic (ROC) curves were performed to identify the optimal serum LDH activity cut-off points for ≥ 2 and ≥ 4 × 106 cells/kg post-mobilization CD34+ count and their diagnostic yield.

RESULTS

A post-mobilization serum LDH cut-off value of 462 U/L yielded a sensitivity (Se) = 86.8% (positive predictive value [PPV] = 72.7%), a pre- and post-mobilization serum LDH difference cut-off value of 387 U/L, an Se = 45.7% (PPV = 97%) and an LDH ratio of 2.46, with an Se = 47.1% (PPV = 97%) for an optimal mobilization count (CD34+ ≥ 4 × 106).

CONCLUSION

The LDH measurement represents a fast and affordable way to predict PBCD34+ mobilization in cases where flow cytometry is not immediately available. According to the LDH diagnostic yield, it could be used as a surrogate marker in transplant centers, supporting the CD34+ count, which remains the gold standard.

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/μL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×10⁹/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Severe short-term adverse events in related bone marrow or peripheral blood stem cell donors

The incidence of severe adverse events (SAEs) and associated risk factors in hematopoietic cell transplantation donors needs to be clarified for related donors (relatives of the transplant recipient), whose criteria for donation are more lenient than for unrelated donors. Data from related donors registered in the Japanese national data registry database between 2005 and 2021 were evaluated to determine the association of short-term SAE incidence with donor characteristics at registration.Fourteen of 4339 bone marrow (BM) donors (0.32%) and 54 of 10,684 peripheral blood stem cell (PBSC) donors (0.51%) experienced confirmed SAEs during the short donation period. No deaths were observed. Past medical history was a common risk factor for SAEs in both BM and PBSC donors. Age of 60 years or older and female sex were identified as risk factors for SAEs in PBSC donors. Female sex was also a risk factor for poor mobilization, which resulted in discontinuation of PBSC collection.Although donors should be selected carefully, a certain level of safety is ensured for related donors in Japan. Donor safety should be further increased by improving the selection method for related donors and extending the follow-up period.

The Impact of Pre-Apheresis Health Related Quality of Life on Peripheral Blood Progenitor Cell Yield and Donor's Health and Outcome: Secondary Analysis of Patient-Reported Outcome Data from the RDSafe and BMT CTN 0201 Clinical Trials

There is a lack of evidence about how health-related quality of life (HRQoL), including psychosocial factors, might affect donation-related experiences and clinical markers in the context of hematopoietic stem cell donation. The broader literature suggests that psychological factors, including anxiety and depression, are associated with higher levels of inflammatory burden leading to poorer postprocedural outcomes including longer hospital stays and increased pain perception. In this study, we aimed to evaluate whether predonation HRQoL markers predict toxicity profile and stem cell yield after peripheral blood stem cell (PBSC) donation in healthy donors. The study population comprised adult granulocyte colony-stimulating factor mobilized PBSC-related donors (RD) (n = 157) and unrelated donors (URD) (n = 179) enrolled in the related donor safety study (RDSafe) and Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0201 clinical trials. Pre-donation HRQoL was assessed using the Short-Form-12 (SF-12) in RDSafe and SF-8 questionnaire in BMT CTN 0201 (higher score is better). The aims of this study were to (a) determine the impact of pre-donation HRQoL on peri-collection pain and acute toxicities experienced and (b) to investigate the pre-procedural HRQoL indicators on stem cells yield. URDs were younger than RDs (median age 35 versus 63). A higher proportion of RDs were female (50% versus 40%) and obese (41% versus 35%). A higher proportion of RD PBSC donations required 2 days or more of apheresis (44% versus 21%). More RD collections were lower volume procedures (<18L, 16% versus 28%), and required a central line (28% versus 11%). RDs were more likely to report pre-donation grade 1-2 pain (27% versus 8%) and other toxicities (16% versus 6%). Among RDs, a lower pre-donation physical component summary (PCS) score was associated with significantly more grade 2-4 pain at 1 month (P = .004) and at 1-year after donation (P = .0099) in univariable analyses. In multivariable analysis, pre-donation PCS remained significantly associated with grade 2-4 pain 1 month after donation (P = .0098). More specifically, RDs with predonation PCS scores in the highest quartile were less likely to report pain compared with donors with PCS scores in the lowest quartile (odds ratio 0.1; 95% confidence interval 0.01-0.83; P = .005). There was also a trend toward higher grade 2-4 pain at 1-year post-donation among RDs with lower predonation PCS score (P = .018). Among URDs, neither PCS nor mental component summary (MCS) scores were associated with pain or toxicities at any time point after donation based on the univariable analysis. Because of low rates of postdonation grade 2-4 pain and toxicities, multivariable analysis was not performed in the URD setting. Moreover, there was no correlation between preapheresis HRQoL score (PCS or MCS) and PBSC collection yield in either the RD or URD setting. Our study demonstrates that pre-donation HRQoL scores are significantly associated with the toxicity profile after PBSC donation in the RD setting, with adult RDs with lower predonation physical HRQoL experiencing higher levels of pain at 1 month and persisting up to 12 months after a PBSC collection procedure. There were no such associations found in URD. Our findings can help clinicians identify donors at higher risk of pain with donation, and lead to personalized information and interventions for specific donors. Lack of correlation between predonation HRQoL and stem cell yield may be due to a small sample size and warrants further evaluation.

Correlation of Body Mass Index and Proinflammatory Cytokine Levels with Hematopoietic Stem Cell Mobilization

This study investigated the correlation of body mass index (BMI) and proinflammatory cytokine levels with hematopoietic stem cell (HSC) mobilization triggered by granulocyte colony-stimulating factor (G-CSF). Stem cell donors (n = 309) were recruited between August 2015 and January 2018 and grouped into four groups according to their BMI: underweight (BMI < 18.5 kg/m2, n = 10), normal (18.5 kg/m2 ≦ BMI < 25 kg/m2, n = 156), overweight (25 kg/m2 ≦ BMI < 30 kg/m2, n = 102), and obese (BMI ≧ 30 kg/m2, n = 41). The participants were then administered with five doses of G-CSF and categorized as good mobilizers (CD34 ≧ 180/μL, n = 15, 4.85%) and poor mobilizers (CD34 ≦ 25/μL, n = 14, 4.53%) according to the number of CD34+ cells in their peripheral blood after G-CSF administration. The correlation between BMI and HSC mobilization was then analyzed, and the levels of proinflammatory cytokines in the plasma from good and poor mobilizers were examined by ProcartaPlex Immunoassay. Results showed that BMI was highly correlated with G-CSF-triggered HSC mobilization (R2 = 0.056, p < 0.0001). Compared with poor mobilizers, good mobilizers exhibited higher BMI (p < 0.001) and proinflammatory cytokine [interferon gamma (IFN-γ) (p < 0.05), interleukin-22 (IL-22) (p < 0.05), and tumor necrosis factor alpha (TNF-α) levels (p < 0.05)]. This study indicated that BMI and proinflammatory cytokine levels are positively correlated with G-CSF-triggered HSC mobilization.

Use of plerixafor to mobilize haematopoietic progenitor cells in healthy donors

Increased transplant activity calls for improved stem cell collection, especially when peripheral blood is the preferred source of haematopoietic progenitor cells (HPCs). Plerixafor is a bicyclam molecule that mobilizes CD34+ cells by reversibly disrupting CXCR4-CXCL12-supported HPC retention. Plerixafor is given with granulocyte colony-stimulating factor (G-CSF) to help harvest autologous CD34+ cells for transplantation when mobilization with G-CSF fails. Mobilization protocols with the same doses of plerixafor and G-CSF have been used off-label in healthy allogeneic donors, with equal success and scarce side effects, both in adult and paediatric patients. Plerixafor has also been used as a sole mobilization agent. Plerixafor alone or coupled with G-CSF might lead to harvesting distinct cellular populations conferring improved engraftment properties and increased survival. Those characteristics might make plerixafor an especially attractive mobilization agent, particularly for non-related donations. However, available data are limited, and long-term follow-up is needed to clarify the best scenario for using plerixafor with or without G-CSF in healthy donors. In this review, we will summarize the evidence supporting this practice, highlighting the practical aspects and providing clues for an expanded use of plerixafor.

Weighty choices: selecting optimal G-CSF doses for stem cell mobilization to optimize yield

There are limited data on the effect of donor body mass index (BMI) on peripheral blood stem cell (PBSC) mobilization response to granulocyte colony-stimulating factor (G-CSF), especially in unrelated donors. Obesity has been associated with persistent leukocytosis, elevated circulating progenitor cells, and enhanced stem cell mobilization. Therefore, we hypothesized that adequate collection of CD34+ cells may be achieved with lower doses (per kilogram of body weight) of G-CSF in donors with higher BMI compared with donors with lower BMI. Using the Center for International Blood and Marrow Transplant Research database, we evaluated the impact of donor BMI on G-CSF-mobilized PBSC yield in healthy unrelated donors. We examined 20 884 PBSC donations collected at National Marrow Donor Program centers between 2006 and 2016. We found significantly higher collection yields in obese and severely obese donors compared with normal and overweight donors. An increase in average daily G-CSF dose was associated with an increase in stem cell yield in donors with normal or overweight BMI. In contrast, an increase in average daily G-CSF dose beyond 780 μg per day in obese and 900 μg per day in severely obese donors did not increase cell yield. Pain and toxicities were assessed at baseline, during G-CSF administration, and postcollection. Obesity was associated with higher levels of self-reported donation-related pain and toxicities in the pericollection and early postdonation recovery periods. This study suggests a maximum effective G-CSF dose for PBSC mobilization in obese and severely obese donors, beyond which higher doses of G-CSF add no increased yield.

Donor-intrinsic variables determine mobilization efficiency: analyses from a cohort of sixty twice-mobilized stem cell donors

Background

Healthy volunteer registry donors have become the backbone of stem cell transplantation programs. While most registrants will never become actual donors, a small minority are called upon twice, most commonly for the same patient because of poor graft function. Anecdotal evidence provides no hard reasons to disallow second-time mobilized apheresis, but few centers have treated enough two-time donors for definitive conclusions. Moreover, for reasons unknown, the efficiency of G-CSF varies greatly between donations.

Methods

Comparison of outcomes of first vs. second donations can formally confirm G-CSF responsiveness as intrinsically, likely genetically, determined. In our database, we identified 60 donors (1.3%) who received two cycles of G-CSF 24 days to 4 years apart and systematically compared mobilization outcomes.

Results

First and second mobilization and collection proceeded without severe or unusual adverse effects. First-time mobilization efficiency was highly predictive of second-time mobilization. Neither mobilization efficiency nor time lag between donations affected the similarity of first- and second-time mobilization outcomes.

Conclusions

With the caveat that only donors with an unremarkable first donation were cleared for a second, our data indicate that a second donation is feasible, equally tolerable as a first donation, and efficient. Moreover, the data strongly support the notion of donor-intrinsic variables dictating mobilization response and argue against relevant damage to the stem cell compartment during mobilization with rhG-CSF.

Old is bad? The effect of age on peripheral stem cell mobilization and transplantation outcomes

INTRODUCTION

Allogeneic stem cell transplantation (Allo-SCT) is a well-established treatment option for hematological malignancies. With the introduction of reduced-intensity conditioning regimens (RIC) and better supportive measures the elderly are able to receive Allo-SCT. A considerable number of patients are elderly, and often their HLA matched sibling donor is elderly, moreover. Here, we aim to explore the effect of donors' age on stem cell harvesting, engraftment duration after Allo-SCT, and product quality.

METHOD

Sixty-one healthy allogeneic stem cell donors aged 50 years and older who underwent stem cell mobilization at our center between 2009-2019 were enrolled for the study. All donors received 4-5 days of G-CSF, mostly filgrastim or lenograstim and their biosimilar equivalents were given subcutaneously as a total dose of 10 mcg/kg/day. Groups were separated into three groups as aged 50-54 group A, 55-59 group B, aged 60 and older group C.

RESULTS

Pre-apheresis peripheral blood CD34+ count was similar all groups (p = 0.2). One day apheresis was sufficient for 72.7 % of group A, 27.3 % for group B and 47.1 % for group C (p = 0.02). Total harvested CD34+ cells were comparable among groups (p = 0.5).

CONCLUSION

Adequate stem cell harvest in older donors is feasible. Older donors may require more than one apheresis procedure and generally procedure was well tolerated. When assessing donors, age should represent less significance.

Seasonal variation of human physiology does not influence the harvest of peripheral blood CD34+ cells from unrelated hematopoietic stem cell donors

There are many reports on factors predicting the outcome of PBSC (peripheral blood stem cell) mobilization, such as the donor's gender, age, weight, white blood cell count, platelets pre apheresis, LDH and iron status. Although there are reports of seasonal variation in the physiology of the human immune system and hematopoiesis there are no data that such differences play a role in the response to G-CSF in healthy hematopoietic stem cell donors. The response to G-CSF could also impact the collection results during different seasons. To assess the possible impact of seasonal variation we performed a retrospective, single-center analysis of mobilization and harvest of PBSC in 330 healthy unrelated donors. We found no significant differences in the number of CD34+ cells in peripheral blood after G-CSF mobilization and in collection results when all donors were analyzed. In the subgroup of male donors the number of CD34+ stem cells after G-CSF mobilization was higher than average in summer and autumn (p = 0.036), however, it did not translate into clinically relevant differences in stem cell harvest. We conclude that although there is possible seasonal variation in the response to G-CSF in male donors there is no impact on PBSC harvest in healthy unrelated donors.

Allogeneic Peripheral Blood Stem Cell Transplant: Correlation of Donor Factors with Yield, Engraftment, Chimerism, and Outcome: Retrospective Review of a Single Institute During a 3-Year Period

BACKGROUND

Donor factors have a variable correlation with cluster of differentiation (CD)34+ cell dose in allogeneic peripheral blood stem cell (PBSC) harvests. CD34+ cell dose affects the speed of hematopoietic recovery and percentage of donor chimerism in the recipient.

METHODS

A total of 25 allogeneic PBSC transplants performed during a 3-year period were included. All donors underwent mobilization with filgrastim. Leukapheresis, flowcytometric CD34+ cell enumeration, and chimerism analysis were performed and correlated with recipient outcome.

RESULTS

Besides age, all other donor parameters had a positive correlation with CD34+ cell count. Engraftment kinetics and chimerism had a positive correlation with the CD34+ yield of the PBSC product. Acute graft-vs-host disease (GVHD) was observed in patients with complete chimerism at day 30 after transplantation.

CONCLUSION

Adequate CD34+ cell yield happens in healthy donors, independent of donor demographic patterns with G-CSF only. A diverse population of donors can thus be approached for Matched Unrelated Donor (MUD) transplants. An accurate quantitative analysis of early donor chimerism in the recipient (at day 30) is an excellent tool for post-transplant monitoring for acute GvHD.

Analysis of a large single institution cohort of related donors fails to detect a relation between SDF1/CXCR4 or VCAM/VLA4 genetic polymorphisms and the level of hematopoietic progenitor cell mobilization in response to G-CSF

We studied a cohort of 367 healthy related donors who volunteered to donate their hematopoietic stem cells for allogeneic transplantation. All donors were homogeneously cared for at a single institution, and received rhG-CSF as a mobilization treatment prior to undergoing apheresis. Peripheral blood CD34+ cell counts were used as the main surrogate marker for rhG-CSF induced mobilization. We searched whether inter-individual variations in known genetic polymorphisms located in genes whose products are functionally important for mobilization, could affect the extent of CD34+ mobilization, either individually or in combination. We found little or no influence of individual SNPs or haplotypes for the SDF1, CXCR4, VCAM and VLA4 genes, whether using CD34+ cell counts as a continuous or a categorical variable. Simple clinical characteristics describing donors such as body mass index, age and possibly sex are more potent predictors of stem cell mobilization. The size of our cohort remains relatively small for genetic analyses, however compares favorably with cohorts analyzed in previously published reports suggesting associations of genetic traits to response to rhG-CSF; notwithstanding this limitation, our data do not support the use of genetic analyses when the choice exists of several potential donors for a given patient.

Collection of Peripheral Blood Progenitor Cells in 1 Day Is Associated with Decreased Donor Toxicity Compared to 2 Days in Unrelated Donors

Peripheral blood stem cells (PBSCs) have been increasingly used for allogeneic hematopoietic cell transplantation instead of bone marrow stem cells. Current National Marrow Donor Program policy recommends 5 days of daily filgrastim, followed by either 1 or 2 days of apheresis for unrelated donors, depending on collection center choice. To date, there are no published studies comparing the differences in donor experience between 1 day and 2 days of apheresis. We examined 22,348 adult unrelated donor collections in 184 centers between 2006 and 2016. Of these 22,348 donors, 20,004 (89.5%) had collection on 1 day, and the other 2344 (9.5%) had collection over 2 days. Information on why donors underwent apheresis in 1 day or 2 days was not available. Donors who underwent apheresis in 1 day were more likely to be male (67% versus 46%; P < .001), younger (age <30 years, 48% versus 36%; P < .001), and have a higher body weight (83.0 kg versus 75.9 kg; P< .001) and body mass index (BMI; >30, 30% versus 22%; P < .001). Successful collection of the requested CD34⁺ cell count was achieved on the first day in 82% of 1-day collections and in 16% of 2-day collections. Despite not administering filgrastim the evening after the first day of collection in patients who underwent 2 days of apheresis, the median concentration of CD34⁺ cells/L in the product was higher on the second day of apheresis compared with the first day (23.8 × 10⁶ CD34⁺/L on day 1 versus 28.7 × 10⁶ CD34⁺/L on day 2; P< .001). Donors who underwent collection in 1 day were less likely to experience citrate toxicity (36% versus 52%; P< .001), hospitalization (1% versus 6%; P< .001), and other side effects related to apheresis (Modified Toxicity Criteria incidence: 20% versus 26%; P < .001). Female sex, older age, collection via central lines, and higher BMI were factors associated with greater likelihood for the development of toxicity, whereas less toxicity was noted in those with higher CD34⁺ counts and more blood processed on the first day of collection. We conclude that although unrelated donors can be successfully collected in 1 day or 2 days, 1-day apheresis procedures were associated with less overall toxicity, and thus we recommend single-day collections, especially if the requested number of cells have been collected in 1 day.

The effect of serum vitamin B12, folate, ferritin levels and transferrin saturation on stem cell mobilization in allogeneic donors

INTRODUCTION

Peripheric blood derived stem cells are used in 75 % of allogeneic stem cell transplantations. Iron, vitamin B12 and folate involve in hematopoiesis. Therefore serum levels of iron, vitamin B12 and folat may effect stem cell mobilization. We aimed to analyze the effects of iron status, vitamin B12 and folate levels on peripheric blood stem cell mobilization in healthy donors.

METHOD

The mobilization results of 218 allogeneic donors were analyzed retrospectively.

RESULTS

In 64 donors, serum ferritin level was <15 μg / L and transferrin saturation was <20 %. When we compared the donors with iron deficiency to the donors without iron deficiency, the number of collected CD34 + cell was significantly higher in donors without iron deficiency. We did not find any impact of serum vitamin B12 and folate level on CD34+ cells collected.

CONCLUSION

Our study shows that serum ferritin and transferrin saturation have a greater effect on the amount of CD34+ cells collected from donors than serum vitamin B12 and folate levels. Consequently, when compliance tests of allogeneic donors are performed, the evaluation of vitamin B12 and folate levels is not necessary; whereas iron deficiency must be assessed and -if possible- corrected before apheresis is performed.

Donor Evaluation for Hematopoietic Stem and Progenitor Cell Collection

With the increasing incidence of hematopoietic allogeneic cell transplantation (allo-HCT), the importance of securing a cellular product, safely from a donor, and ensuring that the product is without additional risk to the recipient, continues to be of paramount importance. The evaluation of the donor’s medical eligibility and suitability is designed to identify and limit the risk of transmitting infectious, genetic, or neoplastic diseases to the recipient through the product. It also aims to ensure a maximum level of safety for the donor and informs them of the risks of donation. Several regulatory agencies, national and international registries, and accreditation bodies have facilitated the availability and safe provision of human cells, tissues, and cellular- and tissue-based products not only at local institutions but also through international exchange.

Prior blood donations do not affect efficacy of G-CSF mobilization nor outcomes of haematopoietic stem cell collection in healthy donors

BACKGROUND AND OBJECTIVES

Many consider volunteer blood donors as ideal candidates for unrelated haematopoietic progenitor cell (HPC) donation. However, frequent blood donations could influence the results of HPC mobilization. To our best knowledge, there are no data on the possible impact of repeated blood donation on efficiency of subsequent HPC mobilization by granulocyte colony-stimulating factor (G-CSF).

MATERIALS AND METHODS

We compared outcomes of HPC mobilization in unrelated donors with and without a history of blood donation. We conducted a prospective study on 287 consecutive donors admitted to the Department of Hematology since January 2016. The final analysis included 153 donors who agreed to take part in the study and had undergone stem cell mobilization with G-CSF.

RESULTS

History of blood donations prior to haematopoietic stem cell mobilization with G-CSF does not have a significant impact on the number of collected CD34+ cells in the first leucocytapheresis (516.2 x 10⁶ (170-1148) in blood donors vs 490.5 x 10⁶ (101-1154) in non-donors) (P = 0.32). In all donors, in this study mobilization of HPC was successful: 87.5% of blood donors and 85.6% of non-donors collected the required cell number in a single apheresis. In blood donors, a higher number of blood donations within 2 and 5 years prior to HPC mobilization correlated significantly with successful donation within one leucocytapheresis (P = 0.014 and P = 0.024, respectively).

CONCLUSION

Multiple blood donations do not significantly influence the outcome of HPC collection in unrelated donors. Blood donors and non-donors have similar results of HPC collection, so there is no reason to favour either group.

Medical and ethical considerations on hematopoietic stem cells mobilization for healthy donors

Hematopoietic stem cell transplantation is a common procedure potentially beneficial to many individuals with cancer, hematological, or inherited disorders, and has highlighted the need of related or unrelated donors to perform allograft. Donation of hematopoietic stem cells, either through bone marrow harvest or peripheral blood stem cell collection, is well-established and widespread. Over the past two decades, the peripheral blood stem cell collection by aphaeresis has become the main source of hematopoietic stem cells for transplantation, due to faster engraftment and practicability and lower risk of relapse for high-risk patients. For peripheral blood stem cell donation, donors require mobilization of hematopoietic stem cells from bone marrow into the blood stream. This is performed by growth factors injections. This article is a review of reported applications of growth factors (original granulocyte colony stimulating factor and its biosimilars), for healthy donors' peripheral blood stem cell mobilization, in terms of toxicity, side effects, efficacy and follow-up. There is still an ethical dilemma for clinicians involved in allograft, because they expose healthy donors to drugs. It is important to dispel some of the critical concerns regarding their use in healthy volunteers, particularly because they receive no personal therapeutic benefit from this procedure.

Dose capping of plerixafor in patients weighing more than 100 kg at one vial led to successful mobilization outcomes and significant cost savings

BACKGROUND

Plerixafor is frequently used as an adjunct agent to improve mobilization of peripheral blood stem cells in many clinical settings. However, its high cost (>$8000 per single-use 24-mg vial) is a significant concern. The manufacturer-recommended dose is 0.24 mg/kg. Therefore, patients weighing more than 100 kg would require a second vial, thus doubling the drug cost per dose. We implemented a policy of capping the dose of plerixafor at 24 mg, or one vial, for patients weighing more than 100 kg. This retrospective study compares the mobilization of patients more than 100 kg who received capped doses, with historical control patients who received full, uncapped doses.

STUDY DESIGN AND METHODS

Consecutive, eligible patients weighing more than 100 kg who received capped (n = 47) and full doses of plerixafor (n = 40) were identified. Plerixafor was given up-front, as a rescue agent due to suboptimal mobilization, or during remobilization. Baseline characteristics and mobilization data were collected and compared.

RESULTS

Patients in the two groups showed comparable baseline characteristics. They collected similar total numbers of CD34+ cells/kg (median, 4.08 × 10⁶ vs. 3.36 × 10⁶ CD34+ cells/kg; p = 0.86) and achieved comparable collection success rates as defined by collecting more than 2.0 × 10⁶ CD34+ cells/kg (98% vs. 90%, p = 0.21). However, patients who received capped doses required only half of the number of vials of plerixafor (median, 3 vials vs. 6 vials; p < 0.0001).

CONCLUSION

Dose capping plerixafor at 24 mg for patients more than 100 kg is a cost-effective strategy, which achieved comparable mobilization outcomes and reduced the total number of vials of plerixafor used by half.

Hematopoietic progenitor cell mobilization is more robust in healthy African American compared to Caucasian donors and is not affected by the presence of sickle cell trait

BACKGROUND

Granulocyte-colony-stimulating factor (G-CSF)-stimulated hematopoietic progenitor cells (HPCs) collected by apheresis have become the predominant graft source for HPC transplantation in adults. Among healthy allogeneic donors, demographic characteristics (age, sex, body mass index [BMI]) and baseline hematologic counts affect HPC mobilization, leading to variability in CD34+ apheresis yields. Racial differences in HPC mobilization are less well characterized.

STUDY DESIGN AND METHODS

We retrospectively analyzed data from 1096 consecutive G-CSF-stimulated leukapheresis procedures in healthy allogeneic African American (AA) or Caucasian donors.

RESULTS

In a multivariate analysis, after adjusting for age, sex, BMI, baseline platelet and mononuclear cell counts, and daily G-CSF dose, peak CD34+ cell mobilization was significantly higher among AAs (n = 215) than Caucasians (n = 881; 123 ± 87 × 10(6) cells/L vs. 75 ± 47 × 10(6) cells/L; p < 0.0001). A ceiling effect was observed with increasing G-CSF dose (10 µg/kg/day vs. 16 µg/kg/day) in AAs (123 ± 88 × 10(6) cells/L vs. 123 ± 87 × 10(6) cells/L) but not in Caucasians (74 ± 46 × 10(6) cells/L vs. 93 ± 53 × 10(6) cells/L; p < 0.001). In AA donors, the presence of sickle cell trait (SCT; n = 41) did not affect CD34+ mobilization (peak CD34+ 123 ± 91 × 10(6) cells/L vs. 107 ± 72 × 10(6) cells/L, HbAS vs. HbAA; p = 0.34). Adverse events were minimal and similar across race.

CONCLUSIONS

AAs demonstrated significantly better CD34 mobilization responses to G-CSF than Caucasians. This was independent of other demographic and hematologic variables. Studying race-associated pharmacogenomics in relation to G-CSF may improve dosing strategies. Adverse event profile and CD34 mobilization were similar in AA donors with and without SCT. Our findings suggest that it would be safe to include healthy AA donors with SCT in unrelated donor registries.

Factors affecting hematopoietic stem cell mobilization and apheresis in allogeneic donors: The role of iron status

Infused CD34 cell count has a significant impact on transplant outcome. In this retrospective study, we aimed to analyze the impact of donor iron parameters on peripheral blood stem cell (PBSC) collection. A total of 303 related donors were included in the study. The mobilization regimen, recombinant G-CSF, was given for four consecutive days. A CD34⁺ cell count below 2×10⁶/kg was defined as mobilization failure which was demonstrated in 23 donors (7.6%). Mobilization failure was more frequent in female donors than male donors (13.7% vs 3.4%). Body mass index, mean corpuscular volume, hemoglobin and ferritin levels were found to be lower in donors with mobilization failure. Body mass index was significantly correlated with PBSC count on the 4th day of G-CSF. Body mass index, male gender, mean corpuscular volume and ferritin levels had significant impact on PBSC count. Although PBSC count was found to be similar between female and male donors, female gender was shown to have an adverse impact on PBSC collection, which may be attributed to lower body weight and concurrent iron deficiency.

Mobilization of allogeneic peripheral blood stem cell donors with intravenous plerixafor mobilizes a unique graft

A single subcutaneous (SC) injection of plerixafor results in rapid mobilization of hematopoietic progenitors, but fails to mobilize 33% of normal allogeneic sibling donors in 1 apheresis. We hypothesized that changing the route of administration of plerixafor from SC to IV may overcome the low stem cell yields and allow collection in 1 day. A phase 1 trial followed by a phase 2 efficacy trial was conducted in allogeneic sibling donors. The optimal dose of IV plerixafor was determined to be 0.32 mg/kg. The primary outcome of reducing the failure to collect ≥2 × 10⁶ CD34⁺/kg recipient weight in 1 apheresis collection to ≤10% was not reached. The failure rate was 34%. Studies evaluating the stem cell phenotype and gene expression revealed a novel plasmacytoid dendritic cell precursor preferentially mobilized by plerixafor with high interferon-α producing ability. The observed cytomegalovirus (CMV) viremia rate for patients at risk was low (15%), as were the rates of acute grade 2-4 graft-versus-host disease (GVHD) (21%). Day 100 treatment related mortality was low (3%). In conclusion, plerixafor results in rapid stem cell mobilization regardless of route of administration and resulted in novel cellular composition of the graft and favorable recipient outcomes. These trials were registered at clinicaltrials.gov as #NCT00241358 and #NCT00914849.

Factors associated with bone marrow stem cell yield for pediatric allogeneic stem cell transplantation: The impact of donor characteristics

The aim of this study was to investigate the effects of donor characteristics on CD34⁺ cell yield in BM harvest. Between April 2010 and November 2013, consecutive donors who underwent BM harvesting in our BM transplantation unit were retrospectively investigated. Donors were classified into two groups: those who donated BM without mobilization (steady-state BM donors) and those who received G-CSF for stem cell mobilization (G-CSF-primed BM donors). Donor characteristics (age, gender, race, body weight, BMI, and laboratory factors including donor's leukocyte, platelet, and monocyte) and their relationship with total nuclear cell and CD34⁺ cell numbers has been evaluated. A total of 64 healthy related donors (29 males/35 females, median age 11.2 years; 49 [76.6%] younger than 18 and 36 [56.3%] younger than 12 years) were included in the study. The median CD34⁺ cell yield in the harvest was 0.12×10⁶ /L (0.02-0.21) in SS-BM donors and 0.18×10⁶ /L (0.09-0.67) in GP-BM donors (P=.03). Median of CD34⁺ cell count given to recipients was 2.6×10⁶ /recipient body weight (1.3-19.3) in SS-BM yields and 3.8×10⁶ /recipient body weight (1.1-10.2) in GP-BM yields, respectively. Multiple regression analysis showed that donor height and pre-G-CSF platelet were the most important parameters to obtain a sufficient BM harvest. Our data suggest that the shorter donors and the donors with higher thrombocyte counts may offer more hematopoietic stem cell. The height and thrombocyte count of the donors should be taken into consideration before planning the targeted CD34⁺ cell count especially for pediatric donors.

The effect of age on peripheral stem cell mobilization in healthy donors, single center experience

PURPOSE

Peripheral stem cell transplantation is used as a life-saving therapeutic option in hematological malignancies. As previously established, most hematological malignancies are seen in the elderly population. Therefore, possible HLA-identical sibling donors of elderly patients are generally of an advanced age. In this study, we aimed to evaluate the effect of old age on stem cell mobilization and quality in older adult healthy sibling donors.

MATERIALS AND METHODS

Between 2006 and 2014, we evaluated 38 healthy donors aged ≥55 years. The granulocyte-colony stimulating factor (G-CSF) analogs were used at a dose of 5 µg/kg/day and administered subcutaneously twice a day for five days. CD34+ cells were estimated in the peripheral blood before collection of the apheresis product. The National Marrow Donor Program selects healthy unrelated donors if they are younger than 60 years. Therefore, we compared the product quality in donors over the age of 60 to that in donors aged 60 years or less.

RESULTS

We collected sufficient products from all the donors with one to three apheresis procedures. No serious complication was detected in all donors. Reaching the target CD34+ cell count in one day were detected in 83% of younger and 79% of older donors (P = NS). Collected CD34+ cells x10e6/recipient body weight (kg) was same and 5.1 in the groups (P = NS). There were no correlation between the donor age and these parameters.

CONCLUSION

Healthy donor apheresis in older adults can be performed effectively and possible donors should be evaluated regardless of their age. J. Clin. Apheresis 32:16-20, 2017. © 2016 Wiley Periodicals, Inc.

The impact of donor characteristics on the immune cell composition of second allografts in Chinese people

BACKGROUND

The association of the donor characteristics with the immune cell composition in second allografts remains poorly understood. In this study, we investigated retrospectively the effects of the donor characteristics on the immune cell composition in second allografts.

STUDY DESIGN AND METHODS

The immune cell composition in second allografts of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood harvests from 100 healthy donors (male, 47, female, 53; median age, 39 years old) who underwent a second-time donation were correlated with their donor characteristics.

RESULTS

The median counts of CD3(+) T cells, CD4(+) T cells, CD8(+) T cells, CD3(+) CD4(-) CD8(-) T cells and monocytes in allografts were 150·17 × 10(6) /kg, 82·57 × 10(6) /kg, 48·02 × 10(6) /kg and 24·97 × 10(6) /kg, respectively. Multivariate analysis showed that the number of lymphocytes and platelets pre-first collection of G-CSF mobilized blood (FM) was strongly associated with the number of total lymphocytes (for lymphocytes, P = 0·003; for platelets, P = 0·012), CD3(+) T cells (for lymphocytes, P = 0·009; for platelets, P = 0·004) and CD3(+) CD4(+) T cells (for lymphocytes, P = 0·035; for platelets, P = 0·004) in the second allograft. The donor's BMI was negatively related to the number of CD3(+) T cells (P = 0·022) and CD3(+) CD4(+) T cells (P = 0·026) in the second allograft. The donor weight was negatively associated with the number of CD3(+) CD4(-) CD8(-) T cells (P = 0·015) in the second allograft, while the pre-FM white blood cell count showed a positive correlation (P = 0·009).

CONCLUSION

The results demonstrate the impact of the donor characteristics, including pre-FM platelet count and lymphocyte count, donor BMI and weight, on the immune cell composition in the second allograft.

Circulating hematopoietic progenitors and CD34(+) cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

Background

Previous studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC) and CD34⁺ cell are positively correlated with CD34⁺ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34⁺ cells required for performing an efficient hematopoietic stem cell (HSC) harvest in lymphoma and myeloma patients have not been defined in our institution.

Patients and methods

Medical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×10⁶ CD34⁺ cells/kg and ≥5×10⁶ CD34⁺ cells/kg, respectively.

Results

The minimally required or optimal HSC yield obtained was not influenced by age (≥60 years), sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34⁺ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34⁺ cell) and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34⁺ cell). The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm³ for HPCs and 10/mm³ for CD34⁺ cells. Furthermore, the cell count cutoff for obtaining optimal HSC harvest was determined to be 60/mm³ for HPCs and 35/mm³ for CD34⁺ cells.

Conclusion

A total of 60/mm³ of HPCs and 35/mm³ of CD34⁺ cells in peripheral blood predicted optimal HSC harvest in lymphoma and myeloma patients.

Autologous peripheral blood stem cell mobilization following dose-adjusted cyclophosphamide, doxorubicin, vincristine, and prednisolone chemotherapy alone or in combination with rituximab in treating high-risk non-Hodgkin's lymphoma

Background

The regimen of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) is an efficient treatment of non-Hodgkin’s lymphoma (NHL). This study aimed to assess the efficacy and toxicity of dose-adjusted CHOP alone or in combination with rituximab (R-CHOP) by examining the stem cell mobilization in NHL patients. Factors affecting the collection of CD34⁺ cells were also explored.

Methods

Our retrospective study included 39 patients eligible for autologous stem cell transplantation: 14 patients who expressed CD20 and were financially eligible received R-CHOP for autologous peripheral blood stem cell (APBSC) mobilization; the remaining 25 patients received CHOP.

Results

The median CD34⁺ cell yield was 7.01 × 10⁶ cells/kg body weight (range 1.49–28.39 × 10⁶ cells/kg body weight), with only two patients failing to meet the target CD34⁺ cell harvest of ≥2.0 × 10⁶ cells/kg body weight. The median number of apheresis procedures per patient was 1 (range 1–3). The APBSC mobilization yield of the CHOP group appeared to be higher than that of the R-CHOP group (P = 0.005), whereas the success rate was similar between groups. R-CHOP elevated the complete response (CR) rate in B cell lymphoma patients as compared with CHOP (P = 0.01). No significant differences in toxicity or engraftment were observed between the two groups.

Conclusion

The present study demonstrated that dose-adjusted CHOP chemotherapy effectively mobilized APBSCs in NHL patients and that the addition of rituximab to dose-adjusted CHOP chemotherapy elevated the CR rate for patients with B-cell lymphoma.

Suitability Criteria for Adult Related Donors: A Consensus Statement from the Worldwide Network for Blood and Marrow Transplantation Standing Committee on Donor Issues

The number of allogeneic hematopoietic stem cell (HSC) transplants performed globally each year continues to increase. Advances in HLA typing, better supportive care, and administration of reduced-intensity conditioning regimens allow treatment of older patients with older sibling donors. Pretransplant donor assessment and testing are very important processes affecting the quality and safety of donation. For unrelated HSC donors detailed recommendations for health assessment have been published, allowing donation only if they are unrestrictedly healthy. Eligibility criteria for related donors are less strict and vary significantly between centers. In situations where a family donor does not meet the suitability criteria for unrelated donors, involved physicians often struggle with the decision whether the matched relative is suitable for donation or not. On behalf of the Worldwide Network for Blood and Marrow Transplantation Standing Committee on Donor Issues, we intended to develop a consensus document with recommendations for donor workup and final clearance of family donors who would not be able to serve as unrelated donors because of their age or pre-existing diseases. This article covers different topics intending to support decision-making, with the goal of minimizing medical risk to the donor and protection of the recipient from transmissible diseases.

Chronic wound repair and healing in older adults: current status and future research

Older adults are more likely to have chronic wounds than younger people, and the effect of chronic wounds on quality of life is particularly profound in this population. Wound healing slows with age, but the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The effect of age and accompanying multimorbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables; lack of standardization in data collection; and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this article, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify research questions to guide future study of age-associated changes in chronic wound healing.

Chronic wound repair and healing in older adults: current status and future research

The incidence of chronic wounds is increased among older adults, and the impact of chronic wounds on quality of life is particularly profound in this population. It is well established that wound healing slows with age. However, the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The impact of age and accompanying multi-morbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables, lack of standardization in data collection, and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this paper, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify key research questions to guide future study of age-associated changes in chronic wound healing.

Pegfilgrastim vs filgrastim in PBSC mobilization for autologous hematopoietic SCT: a systematic review and meta-analysis

Trial outcomes comparing cytokine agents for PBSC mobilization in autologous hematopoietic transplant patients have been controversial. We performed a systematic review and meta-analysis of evidence available on pegfilgrastim vs filgrastim in chemo-cytokine mobilization. Electronic literature searches of PubMed, EMBASE and CENTRAL identified nine articles eligible for qualitative analysis with one randomized controlled trial. Eight articles involving 719 patients were included in the meta-analysis. Results showed similar CD34+ cell collection yields for pegfilgrastim and filgrastim (SDM -0.08, 95% CI: -0.388 to 0.228). On comparison with filgrastim, pegfilgrastim showed a significantly earlier apheresis onset time (SDM: -0.512, 95% CI: -0.973 to -0.050) and reduction in required apheresis procedures (SDM -0.260, 95% CI: -0.466 to -0.054). Times to leukocyte (⩾1.0 × 10(9)/L) and platelet (⩾20 × 10(9)/L) recovery were similar between groups (SDM: 0.015, 95% CI: -0.41 to 0.44 and SDM: 0.309, 95% CI: -0.11 to 0.72, respectively). Both agents were well tolerated and mild bone pain was the most frequently reported adverse event. Pegfilgrastim may be a convenient alternative to filgrastim in PBSC mobilization for multiple myeloma and lymphoma patients, but further studies are required to clarify effects of cytokine dosage and previous cytotoxic exposure in specific subpopulations.

Plerixafor: what we still have to learn

Plerixafor, a hematopoietic stem cell mobilizer, is indicated in combination with G-CSF to mobilize hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin's lymphoma and multiple myeloma. Current evidence suggests that the addition of plerixafor with chemotherapy plus G-CSF is safe and effective in the large majority of the patients with low blood CD34(+) cell count after mobilization and/or poor yield after the first collection. Nevertheless, there are several questions strongly debated, and in this paper, we would like to identify areas of possible future use and development of the drug.

Factors determining pbsc mobilization efficiency and nonmobilization following ICE with or without rituximab (R-ICE) salvage therapy for refractory or relapsed lymphoma prior to autologous transplantation

ICE/R-ICE (ifosfamide, carboplatin, and etoposide without or with rituximab) chemotherapy followed by autologous stem cell transplantation is an established regimen in refractory/relapsed lymphoma. Few studies have addressed which factors are important in determining peripheral blood stem cell (PBSC) mobilization efficiency or nonmobilization following ICE/R-ICE. Between 2004 and 2013, 88 patients with refractory/relapsed lymphoma who received ICE/R-ICE salvage-chemotherapy prior to granulocyte colony stimulating factor (G-CSF) stimulated PBSC mobilization at a single center were identified. Mobilization efficiency was assessed by time from ICE/R-ICE to day of harvest, duration of G-CSF use, days to peripheral blood (PB) CD34(+) ≥15/µL, PB CD34(+) number on harvest day, CD34(+) yield and nonmobilization rate. Median PB CD34(+) at harvest were 54/μL (7-524); median days to first apheresis was 15 (11-30); median harvested total CD34(+) were 5.46 × 10(6) /kg (0.96-44.36); 71 patients (80.7%) successfully mobilized; 20 (22.7%) patients were poor mobilizers; 14 (15.9%) patients were considered nonmobilizers with maximal PB CD34(+) <7/µL and did not proceed to apheresis. Six of 20 poor mobilizers were apheresed with PB CD34(+) 7-12/µL, 50% were successfully harvested. No differences were found between ICE and R-ICE regimens. Impaired mobilization efficiency was associated with age, remission status, >1 line of induction chemotherapy, four cycles ICE/R-ICE and grade 4 neutropenia. Prior bone marrow (BM) involvement was associated with nonmobilization. The majority of patients can be successfully mobilized with ICE/R-ICE. Prior BM involvement is associated with high rates of nonmobilization following ICE/R-ICE. Such patients may benefit from novel mobilization agents and/or alternative salvage regimens to ICE/R-ICE.

Female donors and donors who are lighter than their recipient are less likely to meet the CD34+ cell dose requested for peripheral blood stem cell transplantation

BACKGROUND

It is of clinical relevance to recognize donors who are unlikely to meet the requested stem cell dose for transplantation, as this group may benefit from an alternative mobilization regimen. This study was performed to evaluate the frequency of unrelated donor peripheral blood stem cell (PBSC) collections that meet the target yield and the impact of donor factors on this.

STUDY DESIGN AND METHODS

All sequential PBSC collections facilitated by the national registry (n = 323) from January through December 2011 were analyzed. Donor factors analyzed included age, sex, weight, and presence of a central line.

RESULTS

In univariate analyses, we found that reaching the target yield was significantly associated with a higher donor weight (85.6 kg vs. 75.3 kg, p < 0.001), male donor sex (55% vs. 19%, p < 0.001), a positive difference in weight between donor and recipient (4.3 kg vs. -8 kg, p < 0.001), and a higher volume of blood processed (13.8 L vs. 11.9 L, p < 0.001). After stepwise binary logistic regression, sex (p < 0.001) and difference between donor and recipient weight (p < 0.005) remained significantly associated with target yield being met after 1 day of collection.

CONCLUSIONS

This study shows than women and donors who are lighter than their recipient have a decreased likelihood of meeting the transplant physician's requested dose. New strategies to improve mobilization in such donors are needed. These findings may also impact future donor recruitment strategies.

Older patients/older donors: choosing wisely

Two lingering problems regarding transplantation in older adults have been how to select patients appropriately and whether to use older sibling donors. Allogeneic hematopoietic cell transplantation (HCT) of older patients may result in long-term survival due to GVL, but the data remain observational and mostly restricted to those 50 to 69 years of age. Patients with excellent performance status and low comorbidity have the best long-term survival after HCT. Novel measures of health status such as self-report or performance-based functional measures allow “staging the age” and may inform candidacy for less robust patients. Older matched sibling donors should be preferred over matched unrelated donors (MUDs) because outcomes are equivalent to superior for matched sibling donors compared with MUD. However, MUDs also achieve acceptable outcomes and long-term disease control. An alternative donor can be considered based on institutional protocols and expertise. Very limited information is available in patients or related donors 70 years of age and older. Future efforts to more completely characterize patient health status before transplantation will allow better application of HCT in older adults.