title: Quality of functional haematopoietic stem/progenitor cells from cryopreserved human umbilical cord blood.
abstract: OBJECTIVE
  Transplantation of cryopreserved umbilical cord blood (UCB) can be used to treat a multitude of haematologic and immunological diseases. In this study, we examined the quality of UCB cryopreserved for 2 (group I), 4 (group II) and 6 (group III) years.
  
  
  METHODS
  The following parameters and procedures were used to test individual units of cryopreserved UCB: the number of total nucleated cells (TNC), cell viability, CFU-GM assay, T-cell activation in vitro and haematopoietic stem cell engraftment in NOD/SCID mice in vivo.
  
  
  RESULTS
  The TNC recovery rates for groups I, II and III were 106·2 ± 6·17%, 96·69 ± 6·39% and 100·38 ± 5·27%, respectively, and the mean percentages of viable cells after thawing were 86·88%, 86·38% and 87·43%. When TNC were plated at 5 × 10(3), the number of CFU-GM was 13·6 (group I), 13·8 (group II), 14·2 (group III) and 14·7 (fresh UCB). We confirmed that the huCD4(+) and huCD8(+) T cells within cryopreserved UCB are functionally responsive by assessment of activated huCD25(+) cells. Moreover, the percentage of huCD45(+) cells in the bone marrow was 4·32 ± 1·29% (group I), 4·48 ± 1·11% (group II), 4·40% ± 1·12% (group III) and 4·50% ± 0·66% (fresh UCB), and that in the peripheral blood was 14·69 ± 3·08% (group I), 15·24 ± 4·05% (group II), 15·74 ± 3·43% (group III) and 17·48 ± 3·74% (fresh UCB) in NOD/SCID mice infused with isolated huCD34(+) cells.
  
  
  CONCLUSIONS
  These results indicated that cryopreserved UCB units efficiently retrieve in functionally competent form and are suitable for transplantation.
authors: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: J-E
authors: JE
authors: Eom
authors: D S
authors: DS
authors: Kim
authors: M W
authors: MW
authors: Lee
authors: D-K
authors: DK
authors: Yu
authors: K S
authors: KS
authors: Jin
authors: S
authors: S
authors: Shin
authors: S H
authors: SH
authors: Lee
authors: K W
authors: KW
authors: Sung
authors: H H
authors: HH
authors: Koo
authors: K H
authors: KH
authors: Yoo
mesh_terms: D000818:Animals; D002470:Cell Survival; D015925:Cryopreservation; D005312:Fetal Blood / Q000166:cytology*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011786:Quality Control
keywords: blood processing; haematopoietic stem cell; progenitor cell; quality control; transplantation