Factors Associated with Opting Out of an Unrelated Hematopoietic Stem Cell Donor Registry: Differences and Similarities across Five Key Groups of Young Race/Ethnically Diverse Potential Donors in the United States

Young adults from underserved racial/ethnic groups are critically needed as unrelated hematopoietic stem cell (HSC) donors, yet they are more likely than other groups to opt out of donation after having matched a patient. Understanding which factors are most strongly associated with opting out among young underserved racial/ ethnic registered donors compared with their White counterparts will provide the basis for specific interventions to improve donor retention. We sought to determine the key, modifiable psychosocial, registry-related, and donation-related characteristics that are uniquely associated with opting out across 5 key racial/ethnic groups of young HSC donor registry members who had been contacted as a potential match for a patient. This study examines data from a large cross-sectional survey of young (age 18 to 30) registry members shortly after they preliminarily matched a patient (CT-stage) and continued toward or opted out of donation (CT-C and CT-NI), stratified by racial/ethnic group and sex. We assessed psychosocial, registry-related, and donation-related characteristics for all participants. We used chi-squared and F tests to assess differences between racial/ethnic groups. A separate logistic regression analysis for each racial/ethnic group was conducted to quantify adjusted associations between each variable and opting out. Then, we compared these associations across the racial/ethnic groups by evaluating the interaction effect between each variable and racial/ethnic group, with the same outcome (CT-C versus CT-NI) in question. Nine hundred thirty-five participants were surveyed, including 284 White, 165 Hispanic, 191 Black, 192 Asian/Pacific Islander, and 103 Multiracial/multiethnic participants. There were significant differences across racial/ethnic groups in values/goals, religious objections to donation, HSC-related medical mistrust, and parental involvement in donation decisions. Adjusted logistic regression subgroup analyses indicated that ambivalence was strongly associated with opting out across all racial/ethnic groups. Greater focus on intrinsic life goals (e.g., raising a family, becoming a community leader, influencing social values) was associated with opting out in the Multiracial/multiethnic, Hispanic, and Asian/Pacific Islander groups. Healthcare mistrust and insufficient registry contact was a significant factor for Hispanic participants. Protective factors against opting out included remembering joining the registry (Black participants), and parental support for donation decision (Asian/Pacific Islander participants). The performance of each logistic regression model was strong, with area-under-the curve ≥.88, CT-stage outcome classification accuracy ≥89%, and good fit between expected and observed opt-out probabilities. In the analysis across different racial/ethnic groups, the only significant interaction was race/ethnicity by whether more contact with the registry would have changed the decision at CT-stage; this variable was significant only for the Hispanic group. In the within-group analysis for Hispanic participants, the "more registry contact" variable was strongly associated with opting out (odds ratio 5.8, P = .03). Consistent with a growing body of HSC donor research, ambivalence was a key factor associated with opting-out for all racial/ethnic groups. Other key variables were differentially associated with opting-out depending on racial/ethnic group. Our study highlights key variables that registries should focus on as they develop targeted and tailored strategies to enhance commitment and reduce attrition of potential donors.

Three-Year Outcomes in Recipients of Mismatched Unrelated Bone Marrow Donor Transplants Using Post-Transplantation Cyclophosphamide: Follow-Up from a National Marrow Donor Program-Sponsored Prospective Clinical Trial

The use of post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis has resulted in reductions in GVHD and improved outcomes in allogeneic hematopoietic cell transplantation (HCT) using HLA-mismatched related donors. We report the 3-year outcomes of the first multicenter prospective clinical trial using PTCy in the setting of mismatched unrelated donor (MMUD) bone marrow HCT. The study enrolled 80 patients, treated with either myeloablative conditioning (MAC; n = 40) or reduced-intensity conditioning (RIC; n = 40), with the primary endpoint of 1-year overall survival (OS). The median follow-up for this study was 34 months (range, 12 to 46 months) in the RIC group and 36 months (range, 18 to 49 months) in the MAC group. Three-year OS and nonrelapse mortality were 70% and 15%, respectively, in the RIC group and 62% and 10% in the MAC group. No GVHD was reported after 1 year. The incidence of relapse was 29% in the RIC group and 51% in the MAC group. OS did not differ based on HLA match grade (63% in the 7/8 strata and 71% in the 4 to 6/8 strata). These encouraging outcomes, which were sustained for 3 years post-HCT, support the continued exploration of MMUD HCT using a PTCy platform. Important future areas to address include relapse reduction and furthering our understanding of optimal donor selection based on HLA and non-HLA factors.

Factors Associated with Opting Out of Donation among Registered Young Unrelated Hematopoietic Stem Cell Donors

Young adults enrolled in hematopoietic stem cell (HSC) donation registries, including the Be The Match registry in the United States, often opt out of the registry when a potential recipient is identified. This results in a limited supply from the most desirable allogeneic source of HSCs used in transplantation to treat serious health conditions. The differences in demographic, psychosocial, registry-related, and donation-related characteristics between those who continue to donation and those who opt out may elucidate the modifiable risk factors for attrition, but these characteristics have not been extensively studied in young donors up to age 30 years. Our goal was to study demographic, psychosocial, registry-related, and donation-related characteristics in a group of young HSC donor registry members who had recently been contacted about a potential recipient, to determine the key characteristics that differ between those who continued toward donation and those who opted out and to examine the extent of these differences. We conducted a cross-sectional survey in a random sample of young (age 18 to 30 years) current and former registry members, stratified by race/ethnicity and sex. Demographic, psychosocial (eg, life goals, HSC allocation mistrust), registry-related (eg context and motive for joining the registry), and donation-related (eg, ambivalence, religious objections to donation, knowledge about donation) characteristics were assessed. Chi-square and 2-sample t tests were used to examine differences between those who continued (CT-C group) and those who opted out (CT-NI group). Hierarchical logistic regression was used to estimate adjusted covariate effects on the odds of opting out. A total of 935 participants were surveyed. Donation-related knowledge was higher in the CT-C group than in the CT-NI group. HSC allocation mistrust, religious objections, and concerns about donation were higher in the CT-NI group. After adjusting for covariates in a logistic regression model, we found that having more intrinsic life goals, having more ambivalence, and talking with registry staff only once/twice were significantly associated with opting out of the registry. Ambivalence had the strongest association with opting out. In contrast, remembering joining the registry, believing that parents would support donation, and having medical concerns were significantly associated with continuing toward donation. This effect of medical concerns on donation was discovered only after adjusting for the related but distinct ambivalence variable, with the remaining effect of medical concerns relating to engagement with the donation process and information-seeking. The model had strong discriminative ability (area under the receiver operating characteristic curve = .92) and classification accuracy (86.6%). Our data indicate that among young adult members of a national HSC donor registry, ambivalence and limited contact with registry staff were more strongly associated with opting out of donation. Medical concerns were associated with continuing toward donation. Further studies are needed to confirm a causal link between medical concerns and continuing to donation among young donors. Our study suggests that these concerns might not be directly related to attrition, whereas other factors (eg, ambivalence, low donation-related knowledge) are associated with attrition and thus should be targeted for attrition reduction strategies.

National Marrow Donor Program-Sponsored Multicenter, Phase II Trial of HLA-Mismatched Unrelated Donor Bone Marrow Transplantation Using Post-Transplant Cyclophosphamide

PURPOSE

Hematopoietic cell transplantation (HCT) is curative for hematologic disorders, but outcomes are historically inferior when using HLA-mismatched donors. Despite unrelated donor registries listing > 38 million volunteers, 25%-80% of US patients lack an HLA-matched unrelated donor, with significant disparity across ethnic groups. We hypothesized that HCT with a mismatched unrelated donor (MMUD) using post-transplant cyclophosphamide (PTCy), a novel strategy successful in overcoming genetic disparity using mismatched related donors, would be feasible and increase access to HCT.

PATIENTS AND METHODS

We performed a prospective phase II study of MMUD bone marrow HCT with PTCy for patients with hematologic malignancies. The primary end point was 1-year overall survival (OS), hypothesized to be 65% or better. 80 patients enrolled at 11 US transplant centers (December 2016-March 2019). Following myeloablative or reduced-intensity conditioning-based HCT, patients received PTCy on days +3, +4, with sirolimus and mycophenolate mofetil starting on day +5. We compared outcomes to Center for International Blood and Marrow Transplant Research contemporary controls receiving PTCy.

RESULTS

Notably, 48% of patients enrolled were ethnic minorities. 39% of pairs were matched for 4-6 out of 8 HLA alleles. The primary end point was met, with 1-year OS of 76% (90% CI, 67.3 to 83.3) in the entire cohort, and 72% and 79% in the myeloablative and reduced-intensity conditioning strata, respectively. Secondary end points related to engraftment and graft-versus-host-disease were reached. Multivariate analysis comparing the study group with other mismatched HCT controls found no significant differences in OS.

CONCLUSION

Our prospective study demonstrates the feasibility and effectiveness of HCT with an MMUD in the setting of PTCy. Remarkably, nearly half of the study participants belonged to an ethnic minority population, suggesting this approach may significantly expand access to HCT.

Serious Adverse Events in Related Donors: A Report from the Related Donor Safe Study

The incidence and risk factors for severe adverse events (SAEs) in related donors (RD) of hematopoietic cell transplants is unknown. The Related Donor Safe study is a prospective observational cohort of 1680 RDs and represents an opportunity to examine characteristics of SAEs in RDs. In this cohort, we found that SAEs were reported in a total 12 (0.71%) RDs. Of these, 5 SAEs occurred in bone marrow donors (5/404, 1.24%), and 7 (7/1276, 0.55%) were in donors of peripheral blood stem cells. All of the SAEs were considered to be related (definite, probable, or possible) to the donation process. There were no donor fatalities. Of the 12 RDs who experienced an SAE, 10 were either overweight or obese. Five of the 12 RDs had predonation medical conditions that would have resulted in either possible or definite ineligibility for donation were they being assessed as unrelated donors. These SAE data will be useful in the counseling of prospective RDs before planned donation and may be helpful in identifying donors who should be considered medically unsuitable for donation.

Health-Related Quality-of-Life Comparison of Adult Related and Unrelated HSC Donors: An RDSafe Study

Multiple investigations have documented the health-related quality-of-life (HRQoL) and donation-related experiences of unrelated donors (URDs), but similar investigations of the related donor (RD) experience have been less common. The central goal of this study was to longitudinally examine and compare HRQoL of RD and URD hematopoietic stem cell (HSC) donors from predonation through 1 year postdonation. This prospective investigation included adult HSC donors ages 18 to 60 years who donated bone marrow or peripheral blood stem cells at one of 48 geographically diverse US transplant/donor centers and completed HRQoL interviews at predonation and 4 weeks and 1 year postdonation. At predonation, related donors were less ambivalent about donation (t = -3.30; P = .001), more satisfied with their decision to donate (t = 2.65; P = .009), and more likely to define themselves as donors (t = 2.94; P = .004) than were URDs. However, related donors were more concerned about the use of needles (odds ratio [OR] = 2.19; P = .012), about who would pay for the procedure (OR = 2.80; P = .011), and the possibility that they would feel responsible if the transplant failed (t = 2.31; P = .022). Shortly postdonation, related donors were more likely to report donation-related pain (t = 2.50; P = .013) and lightheadedness (OR = 3.63; P = .028). At 1 year postdonation, related donors were less likely to be fully recovered from donation (OR = 0.10; P = .010) and more likely to report a longer recovery period following donation (t = 2.57; P = .011), although this latter finding was primarily due to the percentage of related versus unrelated donors not fully recovered at 1 year postdonation (10% versus 1%). Taken together, these findings suggest that current related donor management practices may be sufficient in preparing related donors for the psychological aspects of donation but that there may be more to do in terms of calibrating the description of donation-related experiences and recovery time to the related donor group (i.e., descriptions of donation experiences based on unrelated donation may not provide best estimates of experience for this group).

Impact of autologous blood transfusion after bone marrow harvest on unrelated donor's health and outcome: a CIBMTR analysis

Pre-harvest autologous blood collection from bone marrow (BM) donors is performed to meet potential post-operative transfusion needs. This study examines the impact of autologous blood transfusion on BM donor's health and safety. The study included first-time unrelated BM donors from the United States whose BM harvest was facilitated by the National Marrow Donor Program (NMDP) centers between 2006 and 2017. Examination of 7024 BM donors revealed that 60% received at least one unit of autologous blood. The donors who received autologous blood were older, had lower hemoglobin pre-harvest, underwent longer duration of anesthesia, and higher volume BM harvest. Only donors who underwent high-volume BM harvest, defined as a BM harvest volume >27% of donor's blood volume, benefited from autologous transfusion. After a high-volume BM harvest, autologous blood transfusion was shown to decrease grade 2 to 4 collection-associated toxicities within 48 h of BM donation (p = 0.010) and shorten the time to donor-reported "complete" recovery from donation-associated symptoms (p < 0.001). Therefore, autologous transfusion could be avoided as support of marrow donation in the majority of unrelated BM donors and should be limited to cases where the planned BM harvest volume is expected to exceed 27% of donor's blood volume.

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.

Rapid Donor Identification Improves Survival in High-Risk First-Remission Patients With Acute Myeloid Leukemia

PURPOSE

Patients with acute myeloid leukemia with high-risk cytogenetics in first complete remission (CR1) achieve better outcomes if they undergo allogeneic hematopoietic cell transplantation (HCT) compared with consolidation chemotherapy alone. However, only approximately 40% of such patients typically proceed to HCT.

METHODS

We used a prospective organized approach to rapidly identify donors to improve the allogeneic HCT rate in adults with high-risk acute myeloid leukemia in CR1. Newly diagnosed patients had cytogenetics obtained at enrollment, and those with high-risk cytogenetics underwent expedited HLA typing and were encouraged to be referred for consultation with a transplantation team with the goal of conducting an allogeneic HCT in CR1.

RESULTS

Of 738 eligible patients (median age, 49 years; range, 18-60 years of age), 159 (22%) had high-risk cytogenetics and 107 of these patients (67%) achieved CR1. Seventy (65%) of the high-risk patients underwent transplantation in CR1 (P < .001 compared with the historical rate of 40%). Median time to HCT from CR1 was 77 days (range, 20-356 days). In landmark analysis, overall survival (OS) among patients who underwent transplantation was significantly better compared with that of patients who did not undergo transplantation (2-year OS, 48% v 35%, respectively [P = .031]). Median relapse-free survival after transplantation in the high-risk cohort who underwent transplantation in CR1 (n = 70) was 11.5 months (range, 4-47 months), and median OS after transplantation was 14 months (range, 4-44 months).

CONCLUSION

Early cytogenetic testing with an organized effort to identify a suitable allogeneic HCT donor led to a CR1 transplantation rate of 65% in the high-risk group, which, in turn, led to an improvement in OS when compared with the OS of patients who did not undergo transplantation.

Engraftment of rare, pathogenic donor hematopoietic mutations in unrelated hematopoietic stem cell transplantation

Clonal hematopoiesis is associated with various age-related morbidities. Error-corrected sequencing (ECS) of human blood samples, with a limit of detection of ≥0.0001, has demonstrated that nearly every healthy individual >50 years old harbors rare hematopoietic clones below the detection limit of standard high-throughput sequencing. If these rare mutations confer survival or proliferation advantages, then the clone(s) could expand after a selective pressure such as chemotherapy, radiotherapy, or chronic immunosuppression. Given these observations and the lack of quantitative data regarding clonal hematopoiesis in adolescents and young adults, who are more likely to serve as unrelated hematopoietic stem cell donors, we completed this pilot study to determine whether younger adults harbored hematopoietic clones with pathogenic mutations, how often those clones were transferred to recipients, and what happened to these clones over time after transplantation. We performed ECS on 125 blood and marrow samples from 25 matched unrelated donors and recipients. Clonal mutations, with a median variant allele frequency of 0.00247, were found in 11 donors (44%; median, 36 years old). Of the mutated clones, 84.2% of mutations were predicted to be molecularly pathogenic and 100% engrafted in recipients. Recipients also demonstrated de novo clonal expansion within the first 100 days after hematopoietic stem cell transplant (HSCT). Given this pilot demonstration that rare, pathogenic clonal mutations are far more prevalent in younger adults than previously appreciated, and they engraft in recipients and persist over time, larger studies with longer follow-up are necessary to correlate clonal engraftment with post-HSCT morbidity.

Higher Risks of Toxicity and Incomplete Recovery in 13- to 17-Year-Old Females after Marrow Donation: RDSafe Peds Results

Although donation of bone marrow (BM) or peripheral blood stem cells (PBSCs) from children to family members undergoing allogeneic transplantation are well-established procedures, studies detailing levels of pain, symptoms, and long-term recovery are lacking. To address this lack, we prospectively enrolled 294 donors age <18 years at 25 pediatric transplantation centers in North America, assessing them predonation, peridonation, and at 1 month, 6 months, and 1 year postdonation. We noted that 71% of children reported pain and 59% reported other symptoms peridonation, with resolution to 14% and 12% at 1 month postdonation. Both older age (age 13 to 17 years versus younger) and female sex were associated with higher levels of pain peridonation, with the highest rates in older females (57% with grade 2-4 pain and 17% with grade 3-4 pain). Multivariate analyses showed a 4-fold increase in risk for older females compared with males age <13 years (P <.001). At 1 year, 11% of 13- to 17-year-old females reported grade 2-4 pain, compared with 3% of males age 13 to 17 years, 0% of females age <13 years, and 1% of males age <13 years (P = .01). Males and females age 13 to 17 years failed to return to predonation pain levels at 1 year 22% and 23% of the time, respectively, compared with 3% and 10% in males and females age <13 years (P = .002). Our data show that females age 13 to 17 years are at increased risk of grade 2-4 pain at 1 year and >20% of females and males age 13 to 17 years do not return to baseline pain levels by 1 year after BM donation. Studies aimed at decreasing symptoms and improving recovery in older children are warranted.

Transplant center practices for psychosocial assessment and management of pediatric hematopoietic stem cell donors

Understanding the potential emotional and psychological risks of pediatric sibling HSC donation is an area of research that remains in its infancy. A cross-sectional survey was distributed electronically to directors at all CIBMTR and EBMT centers to describe current transplant center practices for obtaining assent, preparation for the physical/emotional experiences of donation, and monitoring the post-donation well-being of pediatric donors (<18 years of age). Respondents were 45/91 (49%) and 66/144 (46%) of CIBMTR and EBMT centers, respectively. Although 78% of centers reported having a mechanism in place to ensure donor free assent, centers also reported only limited assessment of psychosocial suitability to manage the emotional risks of donation. More than half of centers reported no psychosocial follow-up assessment post-donation. Few centers have policies in place to address donor psychological needs. Future investigations should include medical and psychosocial outcomes following full integration of comprehensive psychosocial screening and surveillance of pediatric donors.

Related peripheral blood stem cell donors experience more severe symptoms and less complete recovery at one year compared to unrelated donors

Unlike unrelated donor registries, transplant centers lack uniform approaches to related donor assessment and deferral. To test whether related donors are at increased risk for donation-related toxicities, we conducted a prospective observational trial of 11,942 related and unrelated donors aged 18-60 years. Bone marrow (BM) was collected at 37 transplant and 78 National Marrow Donor Program centers, and peripheral blood stem cells (PBSC) were collected at 42 transplant and 87 unrelated donor centers in North America. Possible presence of medical comorbidities was verified prior to donation, and standardized pain and toxicity measures were assessed pre-donation, peri-donation, and one year following. Multivariate analyses showed similar experiences for BM collection in related and unrelated donors; however, related stem cell donors had increased risk of moderate [odds ratios (ORs) 1.42; P<0.001] and severe (OR 8.91; P<0.001) pain and toxicities (OR 1.84; P<0.001) with collection. Related stem cell donors were at increased risk of persistent toxicities (OR 1.56; P=0.021) and non-recovery from pain (OR 1.42; P=0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors with more significant comorbidities were at especially high risk for grade 2-4 pain (OR 3.43; P<0.001) and non-recovery from toxicities (OR 3.71; P<0.001) at one year. Related donors reporting grade ≥2 pain had significant decreases in Health-Related Quality of Life (HR-QoL) scores at one month and one year post donation (P=0.004). In conclusion, related PBSC donors with comorbidities are at increased risk for pain, toxicity, and non-recovery at one year after donation. Risk profiles described in this study should be used for donor education, planning studies to improve the related donor experience, and decisions regarding donor deferral. Registered at clinicaltrials.gov identifier:00948636.

Effect of Aging and Predonation Comorbidities on the Related Peripheral Blood Stem Cell Donor Experience: Report from the Related Donor Safety Study

The development of reduced-intensity approaches for allogeneic hematopoietic cell transplantation has resulted in growing numbers of older related donors (RDs) of peripheral blood stem cells (PBSCs). The effects of age on donation efficacy, toxicity, and long-term recovery in RDs are poorly understood. To address this we analyzed hematologic variables, pain, donation-related symptoms, and recovery in 1211 PBSC RDs aged 18 to 79 enrolled in the Related Donor Safety Study. RDs aged > 60 had a lower median CD34+ level before apheresis compared with younger RDs (age > 60, 59 × 106/L; age 41 to 60, 81 × 106/L; age 18 to 40, 121 × 106/L; P < .001). This resulted in older donors undergoing more apheresis procedures (49% versus 30% ≥ 2 collections, P < .001) and higher collection volumes (52% versus 32% > 24 L, P < .001), leading to high percentages of donors aged > 60 with postcollection thrombocytopenia <50 × 109/L (26% and 57% after 2 and 3days of collection, respectively). RDs aged 18 to 40 had a higher risk of grades 2 to 4 pain and symptoms pericollection, but donors over age 40 had more persistent pain at 1, 6, and 12 months (odds ratio [OR], 1.7; P = 0.02) and a higher rate of nonrecovery to predonation levels (OR, 1.7; P = .01). Donors reporting comorbidities increased significantly with age, and those with comorbidities that would have led to deferral by National Marrow Donor Program unrelated donor standards had an increased risk for persistent grades 2 to 4 pain (OR, 2.41; P < .001) and failure to recover to predonation baseline for other symptoms (OR, 2.34; P = .004). This information should be used in counseling RDs regarding risk and can assist in developing practice approaches aimed at improving the RD experience for high-risk individuals.

The Concentration of Total Nucleated Cells in Harvested Bone Marrow for Transplantation Has Decreased over Time

Bone marrow (BM) is an essential source of hematopoietic stem cell grafts for many allogeneic hematopoietic cell transplant (HCT) recipients, including adult patients (for specific diseases and transplantation strategies) and the majority of pediatric recipient. However, since the advent of granulocyte colony-stimulating factor-mobilized peripheral blood stem cell (PBSC) grafts, there has been a significant decrease in the use of BM in HCT, thought to be due mainly to the increased logistical challenges in harvesting BM compared with PBSCs, as well as generally no significant survival advantage of BM over PBSCs. The decreased frequency of collection has the potential to impact the quality of BM harvests. In this study, we examined >15,000 BM donations collected at National Marrow Donor Program centers between 1994 and 2016 and found a significant decline in the quality of BM products, as defined by the concentration of total nucleated cells (TNCs). The mean TNC concentration in BM donations dropped from 21.8 × 10⁶ cells/mL in the earliest era (1994 to 1996) to 18.7 × 10⁶ cells/mL in the most recent era (2012 to 2016) (means ratio, .83; P < .001). This decline in BM quality was seen despite the selection of more donors perceived to be optimal (eg, younger and male). Multivariate regression analysis showed that higher-volume centers (performing >30 collections per era) had better-quality harvests with higher concentrations of TNCs collected. In conclusion, we have identified a significant decrease in the quality of BM collections over time, and lower-volume collection centers had poorer-quality harvests. In this analysis, we could not elucidate the direct cause for this finding, suggesting the need for further studies to investigate the key factors responsible and to explore the impact on transplant recipients.

Donor Experiences of Second Marrow or Peripheral Blood Stem Cell Collection Mirror the First, but CD34+ Yields Are Less

Little is known about the experiences of individuals donating peripheral blood stem cells (PBSCs) or marrow for a second time. To study this, unrelated donors making a second donation through the National Marrow Donor Program between 2004 and 2013 were evaluated. Experiences of second-time donors giving marrow (n = 118: first donation was PBSC in 76 and marrow in 42) were compared with those making only 1 marrow donation (n = 5829). Experiences of second-time donors giving PBSCs (n = 602) (first donation was PBSCs in 362; marrow in 240) were compared to first-time PBSC donors (n = 16,095). For donors giving a second PBSC or marrow donation there were no significant differences in maximum skeletal pain, maximum symptoms measured by an established modified toxicity criteria, and recovery time compared with those who donated only once. Notably, the yield of marrow nucleated cells and PBSC CD34⁺ cells with second donations was less. As previously noted with single first-time donations, female (PBSCs and marrow) and obese donors (PBSCs) had higher skeletal pain and/or toxicity with a second donation. PBSC donors who experienced high levels of pain or toxicity with the first donation also experienced high levels of these symptoms with their second donation and slower recovery times. In conclusion, for most donors second donation experiences were similar to first donation experiences, but CD34⁺ yields were less. Knowledge of the donor's first experience and stem cell yields may help centers decide whether second donations are appropriate and institute measures to improve donor experiences.

Health-Related Quality of Life among Pediatric Hematopoietic Stem Cell Donors

OBJECTIVES

To examine health-related quality of life (HRQoL) among sibling pediatric hematopoietic stem cell donors from predonation through 1 year postdonation, to compare donor-reported HRQoL scores with proxy-reports by parents/guardians and those of healthy norms, and to identify predonation factors (including donor age) potentially associated with postdonation HRQoL, to better understand the physical and psychosocial effects of pediatric hematopoietic stem cell donation.

STUDY DESIGN

A random sample of 105 pediatric donors from US centers and a parent/guardian were interviewed by telephone predonation and 4 weeks and 1 year postdonation. The interview included sociodemographic, psychosocial, and HRQoL items. A sample of healthy controls matched to donors by age, gender, and race/ethnicity was generated.

RESULTS

Key findings included (1) approximately 20% of donors at each time point had very poor HRQoL; (2) child self-reported HRQoL was significantly lower than parent proxy-reported HRQoL at all 3 time points and significantly lower than that of norms at predonation and 4 weeks postdonation; and (3) younger children were at particular risk of poor HRQoL.

CONCLUSIONS

Additional research to identify the specific sources of poorer HRQoL among at-risk donors (eg, the donation experience vs having a chronically ill sibling) and the reasons that parents may be overestimating HRQoL in their donor children is critical and should lead to interventions and policy changes that ensure positive experiences for these minor donors.

Voriconazole pharmacokinetics following HSCT: results from the BMT CTN 0101 trial

BACKGROUND

Voriconazole is a first-line agent for the prevention and treatment of a number of invasive fungal diseases. Relatively little is known about the relationship between drug exposure and the prevention of invasive fungal infections.

PATIENTS AND METHODS

A pharmacokinetic-pharmacodynamic substudy was performed as part of the BMT CTN 0101 trial, which was a randomized clinical trial comparing voriconazole with fluconazole for the prevention of invasive fungal infections in HSCT recipients. A previously described population pharmacokinetic model was used to calculate the maximum a posteriori Bayesian estimates for 187 patients. Drug exposure in each patient was quantified in terms of the average AUC and average trough concentrations. The relationship between drug exposure and the probability of breakthrough infection was investigated using logistic regression. AUC and trough concentrations in patients with and without breakthrough infection were compared.

RESULTS

Pharmacokinetic data from each patient were readily described using the maximum a posteriori Bayesian estimates. There were only five patients that had a breakthrough infection while receiving voriconazole in the first 100 days post-HSCT. For these patients, there was no statistically significant relationship between the average AUC or average trough concentration and the probability of breakthrough infection [OR (95% CI) 1.026 (0.956-1.102) and 1.108 (0.475-2.581), respectively]. P value for these estimates was 0.474 and 0.813, respectively.

CONCLUSIONS

Given the very small number of proven/probable infections, it was difficult to identify any differences in drug exposure in HSCT recipients with and without breakthrough fungal infections.

Recovery of Unrelated Donors of Peripheral Blood Stem Cells versus Recovery of Unrelated Donors of Bone Marrow: A Prespecified Analysis from the Phase III Blood and Marrow Transplant Clinical Trials Network Protocol 0201

We report a comparison of time to recovery, side effects, and change in blood counts from baseline to after donation from unrelated donors who participated in the Blood and Marrow Transplant Clinical Trials Network phase III randomized, multicenter trial (0201) in which donor-recipient pairs were randomized to either peripheral blood stem cell (PBSC) or bone marrow (BM) donation. Of the entire cohort, 262 donated PBSC and 264 donated BM; 372 (71%) donors were from domestic and 154 (29%) were from international centers (145 German and 9 Canadian). PBSC donors recovered in less time, with a median time to recovery of 1 week compared with 2.3 weeks for BM donors. The number of donors reporting full recovery was significantly greater for donors of PBSC than of BM at 1, 2, and 3 weeks and 3 months after donation. Multivariate analysis showed that PBSC donors were more likely to recover at any time after donation compared with BM donors (hazard ratio, 2.08; 95% confidence interval [CI], 1.73 to 2.50; P < .001). Other characteristics that significantly increased the likelihood of complete recovery were being an international donor and donation in more recent years. Donors of BM were more likely to report grades 2 to 4 skeletal pain, body symptoms, and fatigue at 1 week after donation. In logistic regression analysis of domestic donors only in which toxicities at peri-collection time points (day 5 filgrastim for PBSC donors and day 2 after collection of BM donors) could be analyzed, no variable was significantly associated with grades 2 to 4 skeletal pain, including product donated (BM versus PBSC; odds ratio, 1.13; 95% CI, .74 to 1.74; P = .556). Blood counts were affected by product donated, with greater mean change from baseline to after donation for white blood cells, neutrophils, mononuclear cells, and platelets in PBSC donors whereas BM donors experienced a greater mean change in hemoglobin. This analysis provided an enhanced understanding of donor events as product donated was independent of physician bias or donor preference.

The effect of donor characteristics on survival after unrelated donor transplantation for hematologic malignancy

There are >24 million registered adult donors, and the numbers of unrelated donor transplantations are increasing. The optimal strategy for prioritizing among comparably HLA-matched potential donors has not been established. Therefore, the objective of the current analyses was to study the association between donor characteristics (age, sex, parity, cytomegalovirus serostatus, HLA match, and blood group ABO match) and survival after transplantation for hematologic malignancy. The association of donor characteristics with transplantation outcomes was examined using either logistic or Cox regression models, adjusting for patient disease and transplantation characteristics associated with outcomes in 2 independent datasets: 1988 to 2006 (N = 6349; training cohort) and 2007 to 2011 (N = 4690; validation cohort). All donor-recipient pairs had allele-level HLA typing at HLA-A, -B, -C, and -DRB1, which is the current standard for selecting donors. Adjusting for patient disease and transplantation characteristics, survival was better after transplantation of grafts from young donors (aged 18-32 years) who were HLA matched to recipients (P < .001). These findings were validated for transplantations that occurred between 2007 and 2011. For every 10-year increment in donor age, there is a 5.5% increase in the hazard ratio for overall mortality. Increasing HLA disparity was also associated with worsening survival. Donor age and donor-recipient HLA match are important when selecting adult unrelated donors. Other donor characteristics such as sex, parity, and cytomegalovirus serostatus were not associated with survival. The effect of ABO matching on survival is modest and must be studied further before definitive recommendations can be offered.

Significant Improvements in the Practice Patterns of Adult Related Donor Care in US Transplantation Centers

Recent investigations have found a higher incidence of adverse events associated with hematopoietic cell donation in related donors (RDs) who have morbidities that if present in an unrelated donor (UD) would preclude donation. In the UD setting, regulatory standards ensure independent assessment of donors, one of several crucial measures to safeguard donor health and safety. A survey conducted by the Center for International Blood and Marrow Transplant Research (CIBMTR) Donor Health and Safety Working Committee in 2007 reported a potential conflict of interest in >70% of US centers, where physicians had simultaneous responsibility for RDs and their recipients. Consequently, several international organizations have endeavored to improve practice through regulations and consensus recommendations. We hypothesized that the changes in the 2012 Foundation for the Accreditation of Cellular Therapy and the Joint Accreditation Committee-International Society for Cellular Therapy and European Society for Blood and Marrow Transplantation standards resulting from the CIBMTR study would have significantly impacted practice. Accordingly, we conducted a follow-up survey of US transplantation centers to assess practice changes since 2007, and to investigate additional areas where RD care was predicted to differ from UD care. A total of 73 centers (53%), performing 79% of RD transplantations in the United States, responded. Significant improvements were observed since the earlier survey; 62% centers now ensure separation of RD and recipient care (P < .0001). This study identifies several areas where RD management does not meet international donor care standards, however. Particular concerns include counseling and assessment of donors before HLA typing, with 61% centers first disclosing donor HLA results to an individual other than the donor, the use of unlicensed mobilization agents, and the absence of long-term donor follow-up. Recommendations for improvement are made.

European Group for Blood and Marrow Transplantation Centers with FACT-JACIE Accreditation Have Significantly Better Compliance with Related Donor Care Standards

Previous studies have identified healthcare practices that may place undue pressure on related donors (RDs) of hematopoietic cell products and an increase in serious adverse events associated with morbidities in this population. As a result, specific requirements to safeguard RD health have been introduced to Foundation for the Accreditation of Cellular Therapy/The Joint Accreditation Committee ISCT and EBMT (FACT-JACIE) Standards, but the impact of accreditation on RD care has not previously been evaluated. A survey of transplant program directors of European Group for Blood and Marrow Transplantation member centers was conducted by the Donor Health and Safety Working Committee of the Center for International Blood and Marrow Transplant Research to test the hypothesis that RD care in FACT-JACIE accredited centers is more closely aligned with international consensus donor care recommendations than RD care delivered in centers without accreditation. Responses were received from 39% of 304 centers. Our results show that practice in accredited centers was much closer to recommended standards as compared with nonaccredited centers. Specifically, a higher percentage of accredited centers use eligibility criteria to assess RDs (93% versus 78%; P = .02), and a lower percentage have a single physician simultaneously responsible for an RD and their recipient (14% versus 35%; P = .008). In contrast, where regulatory standards do not exist, both accredited and nonaccredited centers fell short of accepted best practice. These results raise concerns that despite improvements in care, current practice can place undue pressure on donors and may increase the risk of donation-associated adverse events. We recommend measures to address these issues through enhancement of regulatory standards as well as national initiatives to standardize RD care.

Infections after Transplantation of Bone Marrow or Peripheral Blood Stem Cells from Unrelated Donors

Infection is a major complication of hematopoietic cell transplantation. Prolonged neutropenia and graft-versus-host disease are the 2 major complications with an associated risk for infection, and these complications differ according to the graft source. A phase 3, multicenter, randomized trial (Blood and Marrow Transplant Clinical Trials Network [BMT CTN] 0201) of transplantation of bone marrow (BM) versus peripheral blood stem cells (PBSC) from unrelated donors showed no significant differences in 2-year survival between these graft sources. In an effort to provide data regarding whether BM or PBSC could be used as a preferential graft source for transplantation, we report a detailed analysis of the infectious complications for 2 years after transplantation from the BMT CTN 0201 trial. A total of 499 patients in this study had full audits of infection data. A total of 1347 infection episodes of moderate or greater severity were documented in 384 (77%) patients; 201 of 249 (81%) of the evaluable patients had received a BM graft and 183 of 250 (73%) had received a PBSC graft. Of 1347 infection episodes, 373 were severe and 123 were life-threatening and/or fatal; 710 (53%) of these episodes occurred on the BM arm and 637 (47%) on the PBSC arm, resulting in a 2-year cumulative incidence 84.7% (95% confidence interval [CI], 79.6 to 89.8) for BM versus 79.7% (95% CI, 73.9 to 85.5) for PBSC, P = .013. The majority of these episodes, 810 (60%), were due to bacteria, with a 2-year cumulative incidence of 72.1% and 62.9% in BM versus PBSC recipients, respectively (P = .003). The cumulative incidence of bloodstream bacterial infections during the first 100 days was 44.8% (95% CI, 38.5 to 51.1) for BM versus 35.0% (95% CI, 28.9 to 41.1) for PBSC (P = .027). The total infection density (number of infection events/100 patient days at risk) was .67 for BM and .60 for PBSC. The overall infection density for bacterial infections was .4 in both arms; for viral infections, it was .2 in both arms; and for fungal/parasitic infections, it was .04 and .05 for BM and PBSC, respectively. The cumulative incidence of infection before engraftment was 47.9% (95% CI, 41.5 to 53.9) for BM versus 32.8% (95% CI, 27.1 to 38.7) for PBSC (P = .002), possibly related to quicker neutrophil engraftment using PBSC. Infections remain frequent after unrelated donor hematopoietic cell transplantation, particularly after BM grafts.

Recommendations for donor human leukocyte antigen assessment and matching for allogeneic stem cell transplantation: consensus opinion of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN)

The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) conducts large, multi-institutional clinical trials with the goal of improving the outcomes of hematopoietic cell transplantation (HCT) for patients with life-threatening disorders. Well-designed HCT trials benefit from standardized criteria for defining diagnoses, treatment plans, and graft source selection. In this perspective, we summarize evidence supporting criteria for the selection of related and unrelated adult volunteer progenitor cell donors or umbilical cord blood units. These standardized criteria for graft source selection have been adopted by the BMT CTN to enhance the interpretation of clinical findings within and among future clinical protocols.

Significant improvement in survival after unrelated donor hematopoietic cell transplantation in the recent era

Patients and physicians may defer unrelated donor hematopoietic cell transplantation (HCT) as curative therapy because of the mortality risk associated with the procedure. Therefore, it is important for physicians to know the current outcomes data when counseling potential candidates. To provide this information, we evaluated 15,059 unrelated donor hematopoietic cell transplant recipients between 2000 and 2009. We compared outcomes before and after 2005 for 4 cohorts: age <18 years with malignant diseases (n = 1920), ages 18 to 59 years with malignant diseases (n = 9575), ages ≥ 60 years with malignant diseases (n = 2194), and nonmalignant diseases (n = 1370). Three-year overall survival in 2005 to 2009 was significantly better in all 4 cohorts (<18 years: 55% versus 45%, 18 to 59 years: 42% versus 35%, ≥ 60 years: 35% versus 25%, nonmalignant diseases: 69% versus 60%; P < .001 for all comparisons). Multivariate analyses in leukemia patients receiving HLA 7/8 to 8/8-matched transplants showed significant reduction in overall and nonrelapse mortality in the first year after HCT among patients who underwent transplantation in 2005 to 2009; however, risks for relapse did not change over time. Significant survival improvements after unrelated donor HCT have occurred over the recent decade and can be partly explained by better patient selection (eg, HCT earlier in the disease course and lower disease risk), improved donor selection (eg, more precise allele-level matched unrelated donors) and changes in transplantation practices.

Race and ethnicity influences collection of granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells from unrelated donors, a Center for International Blood and Marrow Transplant Research analysis

Little information exists on the effect of race and ethnicity on collection of peripheral blood stem cells (PBSC) for allogeneic transplantation. We studied 10,776 donors from the National Marrow Donor Program who underwent PBSC collection from 2006 to 2012. Self-reported donor race/ethnic information included Caucasian, Hispanic, Black/African American (AA), Asian/Pacific Islander (API), and Native American (NA). All donors were mobilized with subcutaneous filgrastim at an approximate dose of 10 μg/kg/day for 5 days. Overall, AA donors had the highest median yields of mononuclear cells per liter and CD34(+) cells per liter of blood processed (3.1 × 10(9) and 44 × 10(6), respectively), whereas Caucasians had the lowest median yields at 2.8 × 10(9) and 33.7 × 10(6), respectively. Multivariate analysis of CD34(+) per liter mobilization yields using Caucasians as the comparator and controlling for age, gender, body mass index, and year of apheresis revealed increased yields in overweight and obese AA and API donors. In Hispanic donors, only male obese donors had higher CD34(+) per liter mobilization yields compared with Caucasian donors. No differences in CD34(+) per liter yields were seen between Caucasian and NA donors. Characterization of these differences may allow optimization of mobilization regimens to allow enhancement of mobilization yields without compromising donor safety.

Improved survival after transplantation of more donor plasmacytoid dendritic or naïve T cells from unrelated-donor marrow grafts: results from BMTCTN 0201

PURPOSE

To characterize relationships between specific immune cell subsets in bone marrow (BM) or granulocyte colony-stimulating factor-mobilized peripheral blood (PB) stem cells collected from unrelated donors and clinical outcomes of patients undergoing transplantation in BMTCTN 0201.

PATIENTS AND METHODS

Fresh aliquots of 161 BM and 147 PB stem-cell allografts from North American donors randomly assigned to donate BM or PB stem cells and numbers of transplanted cells were correlated with overall survival (OS), relapse, and graft-versus-host disease (GvHD).

RESULTS

Patients with evaluable grafts were similar to all BMTCTN 0201 patients. The numbers of plasmacytoid dendritic cells (pDCs) and naïve T cells (Tns) in BM allografts were independently associated with OS in multivariable analyses including recipient and donor characteristics, such as human leukocyte antigen mismatch, age, and use of antithymocyte globulin. BM recipients of > median number of pDCs, naïve CD8(+) T cells (CD8Tns), or naïve CD4(+) T cells (CD4Tns) had better 3-year OS (pDCs, 56% v 35%; P = .025; CD8Tns, 56% v 37%; P = .012; CD4Tns, 55% v 37%; P = .009). Transplantation of more BM Tns was associated with less grade 3 to 4 acute GvHD but similar rates of relapse. Transplantation of more BM pDCs was associated with fewer deaths resulting from GvHD or from graft rejection. Analysis of PB grafts did not identify a donor cell subset significantly associated with OS, relapse, or GvHD.

CONCLUSION

Donor immune cells in BM but not PB stem-cell grafts were associated with survival after unrelated-donor allogeneic hematopoietic stem-cell transplantation. The biologic activity of donor immune cells in allogeneic transplantation varied between graft sources. Donor grafts with more BM-derived Tns and pDCs favorably regulated post-transplantation immunity in allogeneic hematopoietic stem-cell transplantation.

Peripheral-blood stem cells versus bone marrow from unrelated donors

BACKGROUND

Randomized trials have shown that the transplantation of filgrastim-mobilized peripheral-blood stem cells from HLA-identical siblings accelerates engraftment but increases the risks of acute and chronic graft-versus-host disease (GVHD), as compared with the transplantation of bone marrow. Some studies have also shown that peripheral-blood stem cells are associated with a decreased rate of relapse and improved survival among recipients with high-risk leukemia.

METHODS

We conducted a phase 3, multicenter, randomized trial of transplantation of peripheral-blood stem cells versus bone marrow from unrelated donors to compare 2-year survival probabilities with the use of an intention-to-treat analysis. Between March 2004 and September 2009, we enrolled 551 patients at 48 centers. Patients were randomly assigned in a 1:1 ratio to peripheral-blood stem-cell or bone marrow transplantation, stratified according to transplantation center and disease risk. The median follow-up of surviving patients was 36 months (interquartile range, 30 to 37).

RESULTS

The overall survival rate at 2 years in the peripheral-blood group was 51% (95% confidence interval [CI], 45 to 57), as compared with 46% (95% CI, 40 to 52) in the bone marrow group (P=0.29), with an absolute difference of 5 percentage points (95% CI, -3 to 14). The overall incidence of graft failure in the peripheral-blood group was 3% (95% CI, 1 to 5), versus 9% (95% CI, 6 to 13) in the bone marrow group (P=0.002). The incidence of chronic GVHD at 2 years in the peripheral-blood group was 53% (95% CI, 45 to 61), as compared with 41% (95% CI, 34 to 48) in the bone marrow group (P=0.01). There were no significant between-group differences in the incidence of acute GVHD or relapse.

CONCLUSIONS

We did not detect significant survival differences between peripheral-blood stem-cell and bone marrow transplantation from unrelated donors. Exploratory analyses of secondary end points indicated that peripheral-blood stem cells may reduce the risk of graft failure, whereas bone marrow may reduce the risk of chronic GVHD. (Funded by the National Heart, Lung, and Blood Institute-National Cancer Institute and others; ClinicalTrials.gov number, NCT00075816.).

A perspective on the selection of unrelated donors and cord blood units for transplantation

Selection of a suitable graft for allogeneic hematopoietic stem cell transplantation involves consideration of both donor and recipient characteristics. Of primary importance is sufficient donor-recipient HLA matching to ensure engraftment and acceptable rates of GVHD. In this Perspective, the National Marrow Donor Program and the Center for International Blood and Marrow Transplant Research provide guidelines, based on large studies correlating graft characteristics with clinical transplantation outcomes, on appropriate typing strategies and matching criteria for unrelated adult donor and cord blood graft selection.

Fludarabine-based conditioning for marrow transplantation from unrelated donors in severe aplastic anemia: early results of a cyclophosphamide dose deescalation study show life-threatening adverse events at predefined cyclophosphamide dose levels

Excessive adverse events were encountered in a Phase I/II study of cyclophosphamide (CY) dose deescalation in a fludarabine-based conditioning regimen for bone marrow transplantation from unrelated donors in patients with severe aplastic anemia. All patients received fixed doses of antithymocyte globulin, fludarabine, and low-dose total body irradiation. The starting CY dose was 150 mg/kg, with deescalation to 100 mg/kg, 50 mg/kg, or 0 mg/kg. CY dose level 0 mg/kg was closed due to graft failure in 3 of 3 patients. CY dose level 150 mg/kg was closed due to excessive organ toxicity (n = 6) or viral pneumonia (n = 1), resulting in the death of 7 of 14 patients. CY dose levels 50 and 100 mg/kg remain open. Thus, CY at doses of 150 mg/kg in combination with total body irradiation (2 Gy), fludarabine (120 mg/m(2)), and antithymocyte globulin was associated with excessive organ toxicity.

Radiation disasters: role of the BMT team

Bone marrow transplant (BMT) teams do not generally consider themselves to be emergency responders. But the bone marrow is the most radiosensitive organ in the body, and early changes in peripheral blood counts remain the best indicator of major total-body radiation exposures. Following a mass casualty incident, such as that occasioned by a nuclear detonation, BMT teams should expect that they will be called upon for their expertise in managing severe myelosuppression. Numerous resources, including the Radiation Injury Treatment Network, are available to assist BMT teams in planning for such a role.

Practice patterns for evaluation, consent, and care of related donors and recipients at hematopoietic cell transplantation centers in the United States

Conflict of interest may arise when 1 physician serves 2 persons whose medical care is interdependent. In hematopoietic cell transplantation (HCT) from unrelated donors and in the setting of solid organ transplantation from living donors, the standard of care is for donors and recipients to be managed by separate physicians to provide unbiased care. However, the practice patterns of evaluation and care of related donors and recipients are not well described. A survey of HCT centers in the United States was conducted by the Donor Health and Safety Working Committee of the Center for International Blood and Marrow Transplant Research to determine the type of provider involved in medical clearance, informed consent, and medical management of hematopoietic cell collection and the relationship of that provider to the HC transplant recipient. The response rate was 40%. In greater than 70% of centers, transplantation physicians were involved or potentially involved in overlapping care of the HC transplant donor and the recipient. These patterns were similar between transplantation teams caring for adult or pediatric donors and recipients. Among responding centers, medical management of recipients and their related donors by the same provider is common, a practice that has the potential for conflict of interest.

Medical management of radiation victims in the United States

Many governmental and non-governmental agencies are involved in the planning for radiation events in the U.S. We will focus on medical management after mass casualty events, specifically the involvement of the Radiation Injury Treatment Network (RITN), a voluntary consortium of medical centers across the continental U.S. RITN and its partners have established standardized approaches for the evaluation and treatment of radiation victims, which are now available online. Efforts are underway to streamline these processes, provide training to healthcare practitioners around the country, and harmonize with similar efforts around the world.

Unrelated hematopoietic stem cell donors as research subjects

Requests for participation of unrelated stem cell donors in research transplant protocols are becoming more frequent. World Marrow Donor Association calls on donor registries to participate in research activities. Here, we discuss various implications of research participation and make some recommendations as how to make this possible.