Impact of COVID-19 pandemic on global unrelated stem cell donations in 2020—Report from World Marrow Donor Association
The ongoing COVID-19 pandemic has an unprecedented impact on national health care systems including hematopoietic stem cell transplantation (HSCT). Early in the pandemic this prompted the Worldwide Network for Blood and Marrow Transplantation and The European Society for Blood and Marrow Transplantation to publish guidelines regarding the care of patients in need of an HSCT. As World Marrow Donor Association (WMDA) promotes global collaboration for the benefit of stem cell donors and transplant patients, we were interested in examining the impact of the COVID-19 pandemic on unrelated hematopoietic stem cell (HSC) donation numbers. WMDA activities include yearly recording the number and details of unrelated HSC donations performed globally and compiling into a Global Trends Report (GTR). We used the 2020 WMDA GTR to examine trends in unrelated HSC donations during the COVID-19 pandemic globally, per continent and per country/region by comparing it with the 2019 WMDA GTR.
HSC donations from unrelated donors (PBSC and BM) decreased by 3.5% (n = −707) from 20,330 in 2019 to 19,623 in 2020, compared to an average annual growth rate of +3.9% from 2015 to 2019. The slowest development in that period was in 2015 with a growth rate of +0.5%. A negative development has not been observed before. The 3.5% decrease is composed of a 29.0% (n = −1139) decrease for BM and a 2.6% (n = +428) increase for PBSC, resulting in a drop in the BM share of unrelated HSC donations from 19.3% in 2019 to 14.2% in 2020. The percentage of national use of HSC products (PBSC and BM) (i.e. products which did not cross a national border) increased from 51.2 to 53.5%. The share of HSC donations requiring intercontinental transport decreased from 24.6% in 2019 to 21.9% in 2020. The number of cord blood unit (CBU) shipments globally decreased by 3.5% (n = −101) from 2851 to 2750.
The decline in number of unrelated HSC donations in 2020 suggests an impact of the COVID-19 pandemic. Reasons could include disrupted courier utilisation due to travel restrictions, lower donor availability, slight changes in donor selection (related and haplo-identical donors vs. unrelated donors) and prioritisation of patients with acute diseases. The noticeable decrease in BM collections and intercontinental/cross-border shipments can be explained by logistically complex processes, and increased risk to the donor of being exposed to COVID-19 during an operative procedure. These observations are in line with published data in the early stages of the pandemic. Use of CBUs as a stem cell source was expected to increase given that the product is already available for shipping. However, on a global scale our data does not show increased use of CBU suggesting that clinical decision making about using CBU as a stem cell source did not change during the pandemic.
The success of handling this COVID-19 pandemic as a DR or CBB depended on many factors including: quality and size of the pre-pandemic unrelated donor repository/CBU inventory; having a solid network of collection and transplant centers in place with the ability to move patients and donors to hospitals in less affected regions; shifting towards donations from national donors; fast and adequate response to international transport challenges; cooperation with national/international authorities and collaboration with international colleagues.
The decrease in unrelated HSCT actually performed could be larger than our figures on HSC donations suggest, because at times during the pandemic a clear majority of all products were cryopreserved. This practice was relatively rare before the pandemic and it is reported by some DRs that a certain amount of these cryopreserved products are not transfused.
The emergence of new COVID-19 variants causing potential new waves and the drop in donor recruitment and CBU banking during 2020 (data not shown) could affect the donation rate in the coming years. However, from anecdotal reports by several DRs and CBBs we learned that levels of HSC donation returned to normal or increased in 2021. Therefore, the outlook for HSC donation and transplantation is positive, especially since organisations are now better equipped to deal with any COVID-19 related disturbance to their operations.
In conclusion, despite logistic and other challenges posed by the pandemic, global exchanges of HSC products continued and only decreased slightly. This is an extraordinary achievement by DRs, CBBs, collection/transplant centers, couriers and all willing unrelated donors, and is a testament to the importance of international collaborations facilitated through WMDA.
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