급속냉각법으로 -80℃에서 보존된 말초혈 조혈모세포이식을 받은 환자들의 임상경과.

초록

Background:Automated controlled-rate freezing by computer-assisted devices and subsequent storage in -196℃ is recognized as the standard freezing and cryopreservation method of peripheral blood stem cell transplantation (PBSCT). As an alternative, the more simple and economic cryopreservation method using -80℃ mechanical freezer without controlled-rate freezing has been introduced. We summarize our experiences involving the long-term follow-up data of the patients transplanted with autologous peripheral blood stem cells (PBSC) cryopreserved without controlled- rate freezer. Methods:Collected PBSCs were mixed with a cryoprotectant solution consisting of autologous plasma and 20% DMSO, then placed in a -80℃ freezer. The recovery rate of frozen-thawed mononuclear cells (MNC), CFU-GM colonies, and CD34^(+) cells were calculated, respectively. Engraftment time (neutrophil >500/μL, platelet >50,000/μL) and normal hemopoiesis (neutrophil >2,000/μL, platelet >100,000/μL) were evaluated. Results: Total number of cases was 24. Median duration of cryopreservation was 76 days. The mean recovery rate of MNC, CFU-GM colonies, and CD34^(+) cells was 93.4%, 78.4%, and 95.3%, respectively. The median engraftment time of neutrophil and platelet was 8 and 27 days, respectively. The median normal hemopoiesis time of neutrophil and platelet was 31 and 45 days, respectively. Nine are alive in a CR status. Seven in CR1 sustain normal hemopoiesis with the median duration of 35 months. Two patients, who achieved CR2 after salvage chemotherapy due to a leukemia relapse after PBSCT, maintained engraftment status for 24 and 28 months and one arrived at normal hemopoiesis. Conclusion:These results demonstrate that PBSCT using a -80℃ mechanical freezer without controlled-rate freezing leads to acceptable long-term engraftment stability.

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