Cryopreservation and Characterization of Umbilical Cord Blood / 대한수혈학회지

ABSTRACT

BACKGROUND: Umbilical cord blood (UCB) has been increasingly utilized for reconstituting hematopoiesis in a variety of congenital disorders and hematologic malignancies. In this report, we evaluated the maximum collection volume, the efficacy of red cell depletion, cell viability and phenotypic analysis before and after cryopreservation. METHODS: Forty units of UCB (17 from NSVD and 23 from cesarean section) were collected into blood donation bag with ACD-A. Red cells were depleted using 3% gelatin sedimentation or buffy coat separation. UCB units were cultured in methylcellulose media, and phenotypic analyses were performed with monoclonal antibodies for CD34, HLA-DR, CD38, CD13, CD33, c-kit, CD45/CD3, CD45/CD19, CD3/CD4, CD3/CD8. RESULTS: The mean volume of one unit of UCB was 109.2 +/- 32.5 mL and one unit contained 1.20 +/- 0.51x19(9) nucleated cells. Cell counts after red cell depletion by 3% gelatin sedimentation or buffy coat separation revealed recovery rates of 77.5 +/- 14.9% and 64.5 +/- 7.4%, respectively. Cell viabilities and the number of colony forming units - granulocyte and monocyte from fresh and cryopreserved UCB were were 98.1 +/- 1.6%, 88.7 +/- 4.8%, and 6.48 +/- 2.14x10(5), 7.35 +/- 0.65x10(5). The mean percentage of CD34+ cells was 1.02 +/- 1.6% and those of CD34+/HLA-DR+, CD34+/CD38+, CD34+/CD13+, CD34+/CD33+, CD34+/c-kit+ cells were 68.6%, 58.0%, 5.6%, 46.8%, and 29.8%, respectively. Lymphocyte subsets were composed of CD45+/CD3+ (59.0%), CD45+/CD19+ (13.8%), CD3+/CD4+ (42.7%), and CD3+/CD8+ cells (17.1%). There was no significant difference in phenotypic characteristics between fresh and cryopreserved UCB. CONCLUSION: We established the protocols for UCB collection, red cell depletion, cryopreservation, culture and phenotypic analyses. These results would be very useful for future UCB transplantation and preservation/storage.