Eliza Wiercinska1, Vera Schlipfenbacher2, Gesine Bug2, Peter Bader3, Mareike Verbeek4, Erhard Seifried1,5, Halvard Bonig6,7,8. 1. German Red Cross Blood Service Baden-Württemberg-Hesse, Institute Frankfurt, Frankfurt a.M., Germany. 2. Center for Internal Medicine, Department of Medicine II: Hematology, Oncology, Hemostaseology, Rheumatology and Infectious Diseases, Goethe University, Frankfurt, Germany. 3. Center for Child Health, Dept. of Oncology, Immunology and Stem Cell Transplantation, Goethe University, Frankfurt, Germany. 4. Clinic for Internal Medicine III, Hematology and Oncology, Klinikum Rechts Der Isar, Technical University Munich, Munich, Germany. 5. Institute for Transfusion Medicine and Immunohematology, Goethe University, Haus 76, Sandhofstraße 1, 60528, Frankfurt, Germany. 6. German Red Cross Blood Service Baden-Württemberg-Hesse, Institute Frankfurt, Frankfurt a.M., Germany. h.boenig@blutspende.de. 7. Institute for Transfusion Medicine and Immunohematology, Goethe University, Haus 76, Sandhofstraße 1, 60528, Frankfurt, Germany. h.boenig@blutspende.de. 8. Dept. of Medicine/Division of Hematology, University of Washington, Seattle, WA, USA. h.boenig@blutspende.de.
Abstract
BACKGROUND: Because of limitations of transportation imposed by the COVID-19 pandemic, current recommendation calls for cryopreservation of allogeneic stem cell transplants before patient conditioning. A single cell therapy laboratory was selected to function as the central cryopreservation hub for all European registry donor transplants intended for the Australian-Pacific region. We examined properties of these transplants to ascertain how quality is maintained. METHODS: We analyzed 100 pandemic-related allogeneic mobilized blood-derived stem cell apheresis products generated at 30 collection sites throughout Europe, shipped to and cryopreserved at our center between April and November of 2020. Products were shipped in the cool, subsequently frozen with DMSO as cryoprotectant. Irrespective of origin, all products were frozen within the prescribed shelf-life of 72 h. RESULTS: Prior to cryopreservation, viable stem cell and leukocyte count according to the collection site and our reference laboratory were highly concordant (r2 = 0.96 and 0.93, respectively) and viability was > 90% in all instances. Median nominal post-thaw recovery of viable CD34+ cells was 42%. Weakly associated with poorer CD34+ cell recovery was higher leukocyte concentration, but not time lag between apheresis or addition of cryopreservant, respectively, and start of freezing. The correlation between pre- and post-thaw CD34+ cell dose was high (r2 = 0.85), hence predictable. Neutrophil and platelet engraftment were prompt with no evidence of dose dependency within the range of administered cell doses (1.31-15.56 × 106 CD34+ cells/kg). CONCLUSIONS: General cryopreservation of allogeneic stem cell transplants is feasible. While more than half of the CD34+ cell content is lost, the remaining stem cells ensure timely engraftment.
BACKGROUND: Because of limitations of transportation imposed by the COVID-19 pandemic, current recommendation calls for cryopreservation of allogeneic stem cell transplants before patient conditioning. A single cell therapy laboratory was selected to function as the central cryopreservation hub for all European registry donor transplants intended for the Australian-Pacific region. We examined properties of these transplants to ascertain how quality is maintained. METHODS: We analyzed 100 pandemic-related allogeneic mobilized blood-derived stem cell apheresis products generated at 30 collection sites throughout Europe, shipped to and cryopreserved at our center between April and November of 2020. Products were shipped in the cool, subsequently frozen with DMSO as cryoprotectant. Irrespective of origin, all products were frozen within the prescribed shelf-life of 72 h. RESULTS: Prior to cryopreservation, viable stem cell and leukocyte count according to the collection site and our reference laboratory were highly concordant (r2 = 0.96 and 0.93, respectively) and viability was > 90% in all instances. Median nominal post-thaw recovery of viable CD34+ cells was 42%. Weakly associated with poorer CD34+ cell recovery was higher leukocyte concentration, but not time lag between apheresis or addition of cryopreservant, respectively, and start of freezing. The correlation between pre- and post-thaw CD34+ cell dose was high (r2 = 0.85), hence predictable. Neutrophil and platelet engraftment were prompt with no evidence of dose dependency within the range of administered cell doses (1.31-15.56 × 106 CD34+ cells/kg). CONCLUSIONS: General cryopreservation of allogeneic stem cell transplants is feasible. While more than half of the CD34+ cell content is lost, the remaining stem cells ensure timely engraftment.
Authors: Andriyana K Bankova; Joseph Caveney; Bin Yao; Teresa L Ramos; Jan Bögeholz; Kartoosh Heydari; Nery Diaz; Marin L Jackson; Robert Lowsky; Janice Wes Brown; Laura Johnston; Andrew R Rezvani; Matthew J Frank; Lori Muffly; Wen-Kai Weng; Surbhi Sidana; Robert S Negrin; David B Miklos; Parveen Shiraz; Everett H Meyer; Judith A Shizuru; Sally Arai Journal: Transplant Cell Ther Date: 2022-01-15