Demand and usage of unrelated donor products for allogeneic haematopoietic cell transplantation during the COVID-19 pandemic: A Canadian Blood Services Stem Cell Registry analysis.

BACKGROUND AND OBJECTIVES: Understanding changes in the demand and usage of unrelated allogeneic haematopoietic cell transplantation (HCT) donors during the COVID-19 pandemic is needed to optimize pandemic preparedness of registry and donor collection services. The aim of this study was to understand the extent to which the pandemic has impacted the demand and usage of unrelated donors and cord blood units (CBUs) at Canadian Blood Services (CBS). MATERIALS AND METHODS: Data regarding stem cell donor interest and product usage for unrelated allogeneic HCT were retrieved from the database at CBS using de-identified anonymous information. RESULTS: Unrelated donor searches for Canadian patients remained unchanged by the pandemic, reflecting stable demand. The number of unrelated allogeneic transplants performed within Canada also remained stable, while the number of cord blood transplants increased, chiefly for paediatric patients. Requests for donor verification typing, a first signal of potential interest, increased from domestic centres during the first 6 months of the pandemic and decreased from international centres, before returning to baseline levels. The proportion of transplants for Canadian patients who used stem cell products procured from Canadian donors increased between 3 and 6 months after the start of the pandemic before returning to baseline and appears to be increasing again more than 1 year after the start of the pandemic. Use of CBUs for Canadian paediatric patients increased and remains elevated. CONCLUSION: Demand for unrelated adult HCT donors has remained stable despite the evolving pandemic with a transient and recurring increased interest and usage of domestic adult donors. Use of CBUs for paediatric patients has increased and remains elevated. Registries and donor collection centres should maintain the capacity to expand services for domestic donor collection during pandemics to offset threats to international donor usage.

Development and evaluation of checklists to support the recruitment of committed hematopoietic stem cell donors.

BACKGROUND: Checklists are memory recall tools used across healthcare to improve outcomes. Here, we describe the development and evaluation of checklists to support recruitment of committed allogeneic hematopoietic stem cell donors. STUDY DESIGN AND METHODS: Checklists were developed with the following objectives: (1) improve best-practice adherence; (2) reduce errors; and (3) support standardization at stem cell drives. Topics included: recruiting needed donors; securing informed consent; maintaining good-documentation practices; and supervising registration and tissue sample collection. Checklists were iteratively revised with input from stakeholders. We evaluated the checklists by examining recruitment outcomes and errors (i.e., preventing registrants from being listed as donors) pre- (11/2011-8/2016) and post- (9/2016-11/2019) implementation by the Canadian donor recruitment organization Stem Cell Club. Quantitative and qualitative methods were employed to analyze recruiters' perspectives on the checklists. RESULTS: The checklists supported recruitment of donors from needed demographic groups as Stem Cell Club expanded its recruitment effort from 4118 registrants (60% male, 58% non-European) pre-implementation to 10,621 (52% male, 56% non-European) post-implementation. Checklist implementation was associated with a marked reduction in errors (from 13.2% to 1.9%) and a three-fold increase in the match rate of recruited donors (from 0.024% to 0.075%). Qualitative and quantitative analysis of recruiter feedback supported that the checklists' objectives were realized from the recruiter perspective. DISCUSSION: We developed checklists to support donor recruitment and showed that their implementation was valued by recruiters and associated with both reduced errors and improved donor recruitment outcomes. The checklists are relevant to donor recruitment organizations worldwide.

Factors associated with registrant availability for unrelated adult donor hematopoietic stem cell donation: Analysis of the stem cell registry at Canadian Blood Services.

BACKGROUND: Greater use of unrelated donors to support hematopoietic cell transplantation can be hampered by unavailability of registrants when identified as potential candidates for donation. METHODS: Multivariate analysis was performed to identify donor factors associated with availability for verification of human leukocyte antigen typing (VT) needed before donor activation. All VT requests for registrants on the Canadian Blood Services Stem Cell Registry between 1 January and 31 December 2018 were reviewed (n = 1358). RESULTS: Potential donors identified by transplant centers were categorized as available at the time of VT but ineligible for medical or other reasons (n = 130 and excluded from further analysis), available (n = 622) or unavailable (n = 566) due to scheduling, loss of interest, and/or inability to contact. With multivariate analysis, registrants who previously donated blood, those recruited online or from blood donation clinics, and a shorter interval between registration and VT request were significantly correlated with increased donor availability. Donor sex and geographic location, however, displayed no correlation. CONCLUSION: Online registration and recruitment at whole blood donation centers should be enhanced to increase the availability of registrants at VT. More insight is needed to maintain registrant availability following community in-person recruitment events, especially if the interval between registration and activation is prolonged. Recruitment of male registrants who are well informed should not negatively impact availability.

Development and evaluation of stem cell collection procedure diagrams to support the education and recruitment of committed stem cell donors.

BACKGROUND: Diagrams which allow potential unrelated stem cell donors to visualize the stem cell collection process were hypothesized to support the recruitment and education of committed stem cell donors. STUDY DESIGN AND METHODS: A series of bone marrow and peripheral blood stem cell collection procedure diagrams were developed, featuring young adult male donors of varied ethnic backgrounds. Post-implementation, surveys were conducted to evaluate stakeholder perspective on the diagrams' utility. A quality improvement project was conducted at five stem cell drives from 2017 to 2018 at which recruiters did or did not show the diagrams to potential donors. Following the drives, registrants were invited to complete a survey exploring their experience, knowledge and attitude towards donation. RESULTS: The diagrams were implemented in Canada in 07/2016. Of 293 participating registrants (24·7% non-Caucasian males) recruited at five drives between 2017 and 2018, 76% (n = 197) were shown the diagrams. Participants who were shown the diagrams were significantly more likely to report that the recruiters appeared very knowledgeable (89% vs. 76%, P = 0·019) and to report improved self-reported knowledge of stem cell donation (P = 0·010) compared to participants not shown the diagram. Data are also shown demonstrating that stakeholders in donor recruitment used and valued the diagrams and that use of the diagrams was associated with improved donor recruitment outcomes in Canada. CONCLUSION: This report is the first evaluation of stem cell collection diagrams in the literature. The diagrams are relevant to donor registries, recruitment organizations and transplant centres worldwide, and their use may support efforts to educate and recruit committed, ethnically diverse donors.

Improved access to better HLA-matched hematopoietic cells for allogeneic transplant: analysis of donors and cord blood units selected for Canadian patients in 2018.

BACKGROUND: Patients undergoing hematopoietic cell transplantation (HCT) often require use of an unrelated donor or cord blood unit (CBU). An understanding of evolving practices in graft selection is needed for optimization of donor recruitment and cord blood collection. STUDY DESIGN AND METHODS: Each donor workup (WU) requested in 2018 involving a Canadian (CDN) patient and unique donor product or CBU was reviewed (n = 598). Degree of HLA match; product origin (domestic or international [INT]); and non-HLA factors including donor age, sex, cytomegalovirus (CMV), and ABO compatibility were analyzed for WUs that proceeded to transplant (n = 414). We also analyzed changes compared to a similar analysis performed in 2013. RESULTS: The majority of transplants used matched unrelated donors (MUDs; n = 323; 78%) and were most often young (≤35 years), male, INT donors (n = 136). The proportion of transplants involving MUDs, as opposed to mismatched unrelated donors or CBUs, increased by 12.4% compared with 2013. When young, male, CDN MUDs were identified in patient search reports but not selected, CMV mismatching and ABO incompatibility were most likely to have influenced the decision to use an INT MUD. Consistent with global trends, CBU transplants decreased compared to 2013; however, the degree of HLA matching improved significantly, and 27% of transplanted CBUs were procured from the Canadian Blood Services Cord Blood Bank. CONCLUSIONS: Access to MUDs and better HLA-matched CBUs by CDN patients has increased since 2013. Ongoing recruitment of young registrants and cord blood donors with diverse HLA haplotypes will support selection of donors with optimal non-HLA characteristics.

Effect of Donor Age and Donor Relatedness on Time to Allogeneic Hematopoietic Cell Transplantation in Acute Leukemia.

Relapse after allogeneic hematopoietic cell transplantation (HCT) for acute leukemia can be reduced when pursued early after first complete remission. The impact of donor age and donor relatedness on the time from diagnosis to transplant in patients with acute leukemia was examined to clarify the design of future prospective studies that can address optimal donor choice. Files of 100 consecutive patients undergoing transplantation for leukemia were reviewed. Recipients of related donors (RDs) and unrelated donors (UDs) were not significantly different in terms of recipient gender, age, underlying diagnosis, disease risk index, graft source, or donor HLA match. UDs were significantly younger than RDs (median age, 29 versus 51, P < .001). Multivariate linear regression revealed that when controlling for age of donor and recipient, the time from diagnosis to transplant was 35% longer with UDs compared with RDs (P = .018). No significant correlation was observed between donor and recipient age on length of time to transplant (P = .134 and P = .850, respectively), when controlling for other variables. The steps in UD procurement that contribute most to the longer time to transplant relate to activating the donor workup and scheduling the donor workup before cell collection. Understanding sources of delay in the transplant process will help transplant centers and UD registries reduce the time to transplant for patients with acute leukemia and will provide necessary insight for the design of prospective controlled studies that can address optimal donor choice.

Unrelated donor choices for allogeneic hematopoietic cell transplantation in Canada: an evaluation of factors influencing donor selection.

BACKGROUND: Utilization of unrelated donors and cord blood units (CBUs) for allogeneic hematopoietic cell transplantation continues to increase. Understanding the practices of donor selection by transplant centers is critical for unrelated donor registries and cord blood banks to optimize registry composition and inventory to meet patient need. STUDY DESIGN AND METHODS: Unrelated donor and CBU selection practices of Canadian transplant centers served by Canadian Blood Services' OneMatch Stem Cell & Marrow Network (OM) were reviewed, including HLA match level, locus of disparity, age, sex, and product choice (donor vs. CBU). RESULTS: HLA-matched donors within OM and/or international (INT) registries were preferentially investigated, underscoring the primary importance of HLA matching. In the case of HLA-mismatched donors, HLA-A disparities were most common while DRB1 mismatches were least common. Advanced age, sex, and lack of donor availability were the most frequent reasons that high-probability OM donors were overlooked in favor of INT donors. High-probability 10 of 10 HLA-matched female donors from OM were often avoided in favor of INT male donors. Use of female donors, however, increased in cases restricted to more HLA-disparate donor options. Caucasian patients were more likely to find 10 of 10 matched donors, whereas use of mismatched donors and CBUs were more prevalent among non-Caucasian patients. CONCLUSIONS: Recruitment and retention of young, male donors from diverse ethnic backgrounds may increase the usage of histocompatible OM donors for patients in need.

Risk of Exposure to Zika Virus and Impact on Cord Blood Banking and Adult Unrelated Donors in Hematopoietic Cell Transplantation: The Canadian Blood Services Experience.

Zika virus has emerged as a potential threat to the Canadian blood supply system. Stem cell donors within Canadian Blood Services' Cord Blood Bank (CBB) and OneMatch Stem Cell and Marrow Network (OM) now undergo screening measures designed to reduce the risk of Zika virus transmission. The impact these screening measures have on cord blood and unrelated adult stem cell donations is currently unknown. Among 146 donor workups initiated by OM between July 2016 and May 2017, 102 were completed and 44 workups were canceled. There were 17 potential donors (11.6%) with a risk of Zika virus exposure identified by the donor questionnaire (13 completed, 4 canceled workups). None of the workups involved a donor diagnosed with confirmed Zika virus within the past 6 months. Only 1 of the 44 canceled workups (and only 1 of 4 cases with a risk of Zika transmission) was canceled because of the risk of Zika transmission, and a backup donor was selected. Canadian Blood Services' CBB identified 25 of 875 cord blood units (2.9%) from women who donated their infants' cord blood and underwent screening that otherwise met the initial cell number thresholds for banking and had at least 1 risk factor for exposure to Zika virus. No women were diagnosed with Zika virus at any point of their pregnancy. All 25 units were discarded. Unrelated donors at OM have a higher incidence of a risk of exposure to Zika virus compared with cord blood donors. Only rarely did transplant centers cancel donor workups due to potential Zika virus exposure. The impact of screening for Zika virus exposure risk on cord blood banking was minor. Continued vigilance and surveillance is recommended.

Cryopreservation of adult unrelated donor products in hematopoietic cell transplantation: the OneMatch experience and systematic review of the literature.

BACKGROUND: The frequency of cryopreserving blood stem or progenitor products from unrelated donors is not known and the underlying reasons are poorly documented. Greater insight is needed to develop policies on cryopreservation that balance donor safety with patient needs. STUDY DESIGN AND METHODS: Cryopreservation requests between January 1, 2014, and May 31, 2016, at the OneMatch Stem Cell and Marrow Network at Canadian Blood Services were reviewed and a systematic review of the literature was performed. RESULTS: Thirty products of 719 (4.2%) unrelated donor collections facilitated by OneMatch were cryopreserved. Patient-related reasons were most common and included the need to delay transplant for continued antimicrobial treatment (six patients), patient too deconditioned to proceed with scheduled transplant (five patients), and/or need for more treatment for relapsed disease (three patients). Donor-related issues leading to cryopreservation requests were less common (five cases), mainly due to lack of donor availability after attempting to reschedule. Cryopreservation of a product that was never infused occurred infrequently (two cases, 7%). In our systematic review of the literature, 993 cases were identified in 32 published reports. Both patient-related and donor-related reasons were cited but not specifically reported, precluding quantitative insight regarding the relative frequency of causes. The impact of cryopreservation on hematopoietic engraftment appears negligible when compared to controls in a subset of studies; however, reporting of outcomes was inconsistent. CONCLUSION: Future studies with standard outcome measures are needed to clarify the impact of cryopreservation on engraftment and other transplant outcomes. International guidelines that consider the ethical framework surrounding requests for donor product cryopreservation are needed.