Uncontrolled‐rate freezing and storage at –80°C, with only3.5‐percent DMSO in cryoprotective solution for 109 autologous peripheral blood progenitor cell transplantations

BACKGROUND: Although controlled‐rate freezing and storage in liquid nitrogen are the standard procedure for peripheral blood progenitor cell (PBPC) cryopreserva‐tion, uncontrolled‐rate freezing and storage at –80°C have been reported. STUDY DESIGN AND METHODS: The prospective evaluation of 109 autologous PBPC transplantations after uncontrolled‐rate freezing and storage at –80°C of apheresis products is reported. The cryoprotectant solution contained final concentrations of 1‐percent human serum albumin, 2.5‐percent hydroxyethyl starch, and 3.5‐percent DMSO. RESULTS: With in vitro assays, the median recoveries of nucleated cells (NCs), CD34+ cells, CFU–GM, and BFU–E were 60.8 percent (range, 11.2‐107.1%), 79.6 percent (6.3‐158.1%), 35.6 percent (0.3‐149.5%), and 32.6 percent (1.7‐151.1%), respectively. The median length of storage was 7 weeks (range, 1‐98). The median cell dose, per kg of body weight, given to patients after the preparative regimen was 6.34 × 10 8 NCs (range, 0.02‐38.3), 3.77 × 10 6 CD34+ cells (0.23‐58.5), and 66.04 × 10 4 CFU–GM (1.38‐405.7). The median time to reach 0.5 × 10 9 granulocytes per L, 20 × 10 9 platelets per L, and 50 × 10 9 reticulocytes per L was 11 (range, 0‐37), 11 (0‐129), and 17 (0‐200) days, respectively. Hematopoietic reconstitution did not differ in patients undergoing myeloablative or nonmyeloablative conditioning regimens before transplantation. CONCLUSION: This simple and less expensive cryopreservation procedure can produce successful engraftment, comparable to that obtained with the standard storage procedure.