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Assessment of cord blood hematopoietic cell parameters before and after cryopreservation
Author(s) -
Kurtz James,
Seetharaman Shalini,
Greco Nicholas,
Moroff Gary
Publication year - 2007
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2007.01327.x
Subject(s) - cryopreservation , andrology , cd34 , cord blood , haematopoiesis , biology , stem cell , leukapheresis , progenitor cell , microbiology and biotechnology , immunology , chemistry , medicine , embryo
BACKGROUND: The testing of cord blood (CB) progenitor and stem cell units for transplantation suitability involves enumeration of total nucleated cells before freezing. CD34+ cell counts may also be a means of determining suitability. Studies have been conducted to evaluate how specific storage conditions influence cell counts. STUDY DESIGN AND METHODS: CB units were processed by hydroxyethyl starch volume reduction. Cryopreserved‐thawed samples were diluted 1:3 without washing. CD34+ cells were measured with three commercially available assay methods. In specific studies, apoptosis‐indicating reagents were included. CB units were analyzed for nucleated cells, aldehyde dehydrogenase–containing cells, and progenitor colonies. RESULTS: CD34+ cell levels and nucleated cells were retained during storage in test tubes at 1 to 6°C for 3 days. Cryopreserved‐thawed samples showed a reduction in CD34+ cells relative to prefreeze levels with the largest decrease with the Stem‐Kit (Beckman Coulter) restricted gating procedure. Prefreeze samples contained minimal numbers of presumed apoptotic cells detected with 7‐aminoactinomycin D or SYTO16, but after cryopreservation‐thawing there was an increase. Nucleated cell levels determined with a hematology analyzer or flow cytometry were reduced after thawing. Cryopreservation‐thawing reduced the percentage of CD34+ cells positive for the presence of aldehyde dehydrogenase and the number of progenitor colonies. These differences were significant. CONCLUSION: These studies indicate that CD34+ cell counts were maintained when CB samples were stored at 1 to 6°C in test tubes for 3 days. Cryopreservation‐thawing resulted in changes in a number of parameters including the percentage of CD34+ cells that were aldehyde dehydrogenase + and the number of 7‐aminoactinomycin D + cells and SYTO16 low cells.