Cryopreservation of human peripheral blood stem cells by-80℃non rate-controlled freezing method

Objective To investigate the cryopreservation of human peripheraI blood stern cells (PBSC)by-80℃non rate-controlled freezing method.Methods Forty-one samples of PBSC were obtained from 39 malignant tumor patients and 2 nornlal donors.PBSC in all malignant tumor patients were mobilized with special cherootherapy protocols combined with granulocyte colony-stimulating factor or granulocyte/monocyte colony-stimulating factor before collection.The obtained PBSC were mixed with same volume of cryoprotectant composed of 12 g/L hydroxyethyl starch,10% dimethylsulfoxide and 80 g/L human serunl albumin,and then eryopreserved in-80℃deep freeze refrigerator directly.Trypan blue viability and recovery rate of nucleated cells(NC),mononuclear cells(MNC),CD34+cells(CD34+),colony-forming unit-granulocyte macrophages (CFU-GM),burst forming unit-erythroid(BFU-E) were detected before and after cryopreservation in different periods.Results Having been cryopreserved from 1 month to 10 years in-80℃.there were no statistically significant differences in trypan blue viability,NC and MNC recovery rate(P>0.05).AIthough recovery rate of CD34+, CFU-M and BFU-E was decreased obviously after cryopreservation for 5-10 years(P＜0.05),10-year recovery rate was 89.6%,85.1%and 83.7%,respectively.Thirty-four patients subject to corresponding pretreatment were transfused with-80℃ cryopreserved PBSC which had been stored for 13 to 35 days(mean 19 days)and hematological reconstitution was obtained successfully in 11 to 27 days (mean 14.7 days).Conclusion -80℃non rate-controlled freezing method is suitable to human PBSC long-term cryopreservation with the cryoproteetant composed of 60 g/L hydroxyethyl starch,5%dimethylsulfoxide and 40 g/L human serum albumin,and its cryopreservation effect is ideal Key words: Cryopreservation; Peripheral blood stem cell transplantation