Long-term stability of autologous peripheral blood stem cell products stored for up to 30 years.

Abstract

Following autologous stem cell transplantation, it is common for residual peripheral blood stem cell (PBSC) products to remain stored for potential subsequent use, particularly in conditions such as multiple myeloma. These products are routinely cryopreserved for future infusion, but extended storage occupies critical inventory space and raises questions about long-term stability. Data beyond 15 years of storage remain limited, hindering evidence-based decisions on inventory management and product disposition. We analyzed 23 autologous PBSC products cryopreserved for 15-30 years in vapor-phase nitrogen. CD34⁺ cell viability (vCD34⁺), clonogenic potential (ECLONE), and IL-3-induced STAT5 phosphorylation (%CD34⁺pSTAT5⁺) were evaluated post-thaw to assess trends in product quality over time. Total colony-forming unit (CFU) dose per product was also compared to institutional historical data (n = 2781). CD34⁺ cell viability remained consistently high across the cohort (mean 95.8 ± 2.8%) and showed a very modest but statistically significant increase with storage time (R² = 0.25, P = 0.0145), likely reflecting inter-sample variability. No significant association was observed between storage duration and either clonogenic potential (ECLONE, R² = 0.016, P = 0.567) or IL-3-pSTAT5 responsiveness (R² = 0.035, P = 0.390). Total CFU dose was comparable to that of historical samples, indicating preserved proliferative potential over time. Autologous PBSC products maintain high viability and functional properties after up to 30 years of cryogenic storage. These results support the long-term stability of cryopreserved PBSCs and provide evidence to inform rational inventory management and product retention policies in stem cell laboratories.