Long-term hematologic reconstitution and clinical evaluation of autologous peripheral blood stem cell transplantation after cryopreservation of cells with 5% and 10% dimethylsulfoxide at −80°C in a mechanical freezer

We report the long-term evaluation over 12 years of a simplified technique for stem-cell cryopreservation at −80°C without rate-controlled freezing and with 5% (n=251) or 10% (n=47) DMSO as the sole cryoprotectant. Platelet recovery was greater in the 5% DMSO group while long-term hematologic recovery did not differ. Factors influencing a faster hematologic recovery were infusion of more than 2.7×106/kg of CD34+ cells, 10% DMSO cryopreservation and G-CSF. We confirm that the procedure is feasible with a reduction in infusion-related toxicity from 60% using 5% DMSO. Differences in hematologic reconstitution were not clinically significant if a minimum of 1.5×106/kg CD34+-cells were infused.