Association of CFU-Mk with total colony-forming units in thawed cord blood units.
OBJECTIVE
Cord blood unit (CBU) total colony-forming unit (CFU) count both pre-cryo and post-thaw has been shown to be associated with platelet (PLT) engraftment. Pre-cryo CBUs show good growth of megakaryocytic CFUs (CFU-Mk); however, CFU-Mk have rarely been studied in post-thaw CBUs.


METHODS
Nucleated cells (NCs) from post-thaw CB were cultured in a collagen-based assay designed to support growth of CFU-Mk. To ensure accurate counting two independent investigators evaluated four culture chambers per sample for CFU-Mk growth. Post-thaw CFU and other cellular characteristics of the CBUs were enumerated independently and compared to CFU-Mk.


RESULTS
The post-thaw CBU total CFU count varied from 0·47 to 4·20×10(6) colonies (median, 0·99×10(6)) and total CFU-Mk count from 0·11 to 0·70×10(6) colonies (median, 0·21×10(6)). Total CFU-Mk count was closely associated with total CFU count (Spearman's Rho=0·86, P=0·0072), haemoglobinized CFU (Rho=0·86, P=0·0072) and CFU-granulocyte/macrophage (CFU-GM; Rho=0·81; P=0·0154). Total CFU-Mk count also correlated with the post-thaw total CD34+ cell count (median, 2·55×10(6); range, 1·40-12·5×10(6); Rho=0·83; P=0·0154).


CONCLUSIONS
CFU-Mk growth was associated with total CFU, haemoglobinized CFU, CFU-GM and CD34+ cells in thawed CBUs. This study confirms the preservation of CFU-Mk potential after CB cryopreservation.
Department of Advanced Therapies and Product Development, Finnish Red Cross Blood Service, Helsinki, Finland. mikko.eskola@veripalvelu.fi
M
M
Eskola
A
A
Arvola
S
S
Juutistenaho
K
K
Aranko
R
R
Kekomäki
D001792:Blood Platelets / Q000187:drug effects; D001793:Blood Preservation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay / Q000379:methods*; D015925:Cryopreservation; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology* / Q000276:immunology