Serious Stem Cell Donation Events and Recipient Adverse Reactions Related to Severe Acute Respiratory Syndrome Coronavirus 2: Review of Reports to the World Marrow Donor Association.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has deeply impacted hematopoietic stem cell (HSC) donation and transplantation. Numerous changes in practice have been introduced, and monitoring the impact of these changes on donations and transplantations is of vital importance. As part of a global response to this pandemic, the World Marrow Donor Association (WMDA) asked that its member registries and cord blood banks submit SARS-CoV-2-related adverse events to the WMDA-operated Serious Product Events and Adverse Reactions (SPEAR) database. Here we review SARS-CoV-2-related SPEAR events that occurred in 2020. The WMDA SPEAR Committee reviewed reports submitted via an online tool. The Committee reviewed each report following the European Union definitions of a serious adverse event or reaction and determined the imputability and its impact. Reports submitted in 2020 were included in this analysis. A TOTAL OF: 74 such reports were received, and events were classified as donor-related (n = 41; 55.4%), recipient-related (n = 3; 4.1%), technical issues (n = 31; 41.8%), or transport-related issues (n = 4; 5.4%). Five cases appeared in multiple categories. The most frequently reported adverse events were of cells being unused. Many of these cases were caused by the uncoupling of the donation and transplantation consequent on the cryopreservation of products, as well as technical issues related to cell viability. Experience in some registries suggests that these issues have become less frequent as transplantation centers have become used to the changes in practice. Lessons learned include the importance of confirming recipient eligibility before the start of donor mobilization or collection and of minimizing the time between cell collection and transplantation. Transplantation centers should familiarize themselves with the expected cell losses when peripheral blood stem cell and bone marrow products are cryopreserved and should have validated viability assays in place for quality assurance. Reassuringly, there were no reports of donors becoming severely unwell because of G-CSF or transmission of SARS-CoV-2 to recipients and only 1 report of complete failure of transport of a donation.

Good Engraftment but Quality and Donor Concerns for Cryopreserved Hemopoietic Progenitor Cell Products Collected During the COVID-19 Pandemic.

Changes to donor availability, collection center capacity, and travel restrictions during the early phase of the COVID-19 pandemic led to routine cryopreservation of most unrelated donor products for hematopoietic transplantation prior to the recipient commencing the conditioning regimen. We investigated the effect of this change on unrelated donor product quality and clinical outcomes. Product information was requested from transplantation centers in Australia and New Zealand and clinical outcome data from the Australasian Bone Marrow Transplant Recipient Registry (ABMTRR). In total, 191 products were collected between April 1, 2021, and September 30, 2021, and most (74%) were from international collection centers. Median post-thaw CD34 recovery was 78% (range 25% to 176%) and median post-thaw CD34 viability was 87% (range 34% to 112%). Median time to neutrophil recovery was 17 days (interquartile range 10 to 24 days), and graft failure occurred in 6 patients (4%). These clinical outcomes were similar to those of "fresh" unrelated donor transplants reported to the ABMTRR in 2019. However, recipient transplantation centers reported problems with 29% of products in the form of damage during transit, low cell dose, inadequate labeling, missing representative samples, or missing documentation. These problems were critical in 7 cases (4%). At last follow-up, 22 products (12%) had not been infused. Routine cryopreservation of unrelated donor hemopoietic progenitor cell products has enabled safe continuation of allogeneic transplant services during the COVID-19 pandemic. However, practices for product tracing, documentation, and transportation can be optimized, and measures to reduce the incidence of unused unrelated donor product are required.

Variable CD34+ recovery of cryopreserved allogeneic HPC products: transplant implications during the COVID-19 pandemic.

Donor registries and transplantation societies recommend cryopreservation of unrelated donor hemopoietic progenitor cell (HPC) products before the recipient commences conditioning therapy to mitigate the donor and travel risks associated with the COVID-19 pandemic. However, little is known regarding the postthaw quality of such allogeneic products or the effect of precryopreservation storage and processing on these characteristics. We investigated the postthaw CD34+ cell recovery and viability of 305 allogeneic HPC products cryopreserved at 9 laboratories across Australia. Median postthaw CD34+ cell recovery was 76% and ranged from 6% to 122%. Longer transit time before cryopreservation, white cell count (WCC) during storage, and complex product manipulation before cryopreservation were independently associated with inferior postthaw CD34+ cell recovery. Longer precryopreservation transit time and WCC were also associated with inferior postthaw CD34+ cell viability. We conclude that although postthaw CD34+ cell recovery and viability of cryopreserved allogeneic HPC is generally acceptable, there is a significant risk of poor postthaw product quality, associated with prolonged storage time, higher WCC, and complex product manipulation precryopreservation. Awareness of expected postthaw recovery and practices that influence it will assist collection, processing, and transplant centers in optimizing outcomes for transplant recipients.

Development of pancytopenia with neutralizing antibodies to thrombopoietin after multicycle chemotherapy supported by megakaryocyte growth and development factor.

Clinical trials of thrombopoietin (TPO), the central regulator of megakaryocytopoiesis, have revealed few side effects associated with its use. We here report a case of pancytopenia associated with the development of neutralizing antibodies to TPO that occurred in a patient who had undergone multicycle chemotherapy with multiple cycles of subcutaneous administration of pegylated recombinant human megakaryocyte growth and development factor. Samples of the patient's bone marrow showed trilineage hypoplasia with absence of myeloid, erythroid, and megakaryocyte progenitor cells but with elevated endogenous levels of erythropoietin, granulocyte colony-stimulating factor, and stem-cell factor. To our knowledge, this is the first report of an aplastic anemia-like syndrome associated with neutralizing antibodies to TPO.