The Viability of Hematopoietic Progenitor Cell Grafts after Cryopreservation Does Not Predict Delayed Engraftment in Allogeneic Hematopoietic Stem Cell Transplantation

Abstract

Abstract Objective Due to the COVID-19 pandemic, more peripheral blood stem cell (PBSC) allogeneic grafts are being frozen and infused thawed. Our objective was to study the influence of graft viability on engraftment outcome in patients treated with PBSCs. Methods Using trypan blue stain, we compared total nucleated cell (TNC) viability of both fresh and thawed grafts in allogeneic PBSCs. Results The viability of thawed PBSC grafts median was 74%, and fresh was 99.0%. The median number of CD34 + cells/kg infused thawed was 6.3 × 106/kg and median time to neutrophil and platelet engraftment was 17.5 and 20 days. Median number of CD34 + cells/kg infused fresh was 5.1 × 106/kg and median time to neutrophil and platelet engraftment was 18 and 19 days. There were no statistically significant differences in the time to engraftment between the 2 groups. Conclusion A low TNC viability of thawed PBSC grafts does not have an effect on time to neutrophil and platelet engraftment when more than 2.85 × 106 CD34 + cells/kg are infused.