title: Quality of umbilical cord blood CD34+ cells in a double-compartment freezing bag cryopreserved without a rate-controlled programmed freezer.
abstract: The aim of this study was to evaluate how a simple method of cryopreservation influences the quality of CD34+ cells in umbilical cord blood (UCB). The cells were dispensed into a double-compartment freezing bag, cryopreserved at -85 degrees C without a rate-controlled programmed freezer, and stored in the liquid phase of nitrogen. The viability of the CD34+ cells before freezing and after thawing was assessed by flow cytometry with 7-aminoactinomycin D and by colony-forming assays. Twenty UCB units cryopreserved for a median of 92 days were analyzed. Mean CD34+ cell viabilities before freezing were 99.8% +/- 0.4% and after thawing were 99.5% +/- 0.8% in large chambers, 99.6% +/- 0.5% in small chambers, and 99.4% +/- 0.6% in sample tubes. The mean values from colony-forming assays of the viable CD34+ cells before freezing were 30.7 +/- 6.8 (colony-forming units-granulocyte-macrophage [CFU-GM] per 100 viable CD34+ cells) and 68.5 +/- 14.8 (total CFUs per 100 viable CD34+ cells). The CFU-GM and total CFU values after thawing were, respectively, 32.7 +/- 9.0 and 66.0 +/- 13.4 in large chambers, 32.4 +/- 8.1 and 64.5 +/- 16.1 in small chambers, and 30.9 +/- 5.4 and 64.7 +/- 12.4 in sample tubes. The results of the colony-forming assays before freezing and after thawing were not significantly different. Our findings overall indicated that our simple method for the cryopreservation of UCB cells without a rate-controlled programmed freezer does not impair the clonogenic capacity of UCB progenitor cells. This cryopreservation method could provide cellular products adequate for hematopoietic stem cell transplantation.
authors.affiliation: Division of Blood Transfusion, Tohoku University Hospital, Sendai, Japan. minegisi@idac.tohoku.ac.jp
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Minegishi
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Itoh
authors.forename: Narumi
authors.initials: N
authors.lastname: Fukawa
authors.forename: Tamie
authors.initials: T
authors.lastname: Kitaura
authors.forename: Junko
authors.initials: J
authors.lastname: Miura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kudo
authors.forename: Ayuko
authors.initials: A
authors.lastname: Narita
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sato
authors.forename: Masakuni
authors.initials: M
authors.lastname: Suzuki
authors.forename: Takanori
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Wada
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takeyama
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tsuchiya
mesh_terms: D018952:Antigens, CD34; D002470:Cell Survival; D003114:Colony-Forming Units Assay; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods*; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D009584:Nitrogen; D013696:Temperature
chemical_list: D018952:Antigens, CD34; D009584:Nitrogen