Association of CFU-Mk with total colony-forming units in thawed cord blood units.

BACKGROUND AND OBJECTIVES: 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. MATERIALS AND 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). CONCLUSION: 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.

Association of cord blood platelet count and volume with hemoglobin in healthy term infants.

OBJECTIVE: The aim of this study was to investigate relationships of cord blood cells in healthy term infants both from vaginal and Cesarean sections. STUDY DESIGN: The study sample comprised 167 consecutive cord blood collections accepted for processing in an accredited cord blood bank. The effect of varying anticoagulant-to-blood ratio was excluded by standardizing the cell concentrations to reflect the values in native blood. Statistical analysis included descriptive statistics, simple linear regression analysis, Mann-Whitney U-test, cumulative frequency plots and Smirnov two-sample test. RESULT: As expected, hemoglobin correlated with red blood cell concentration. Interestingly, mean platelet volume was associated with hemoglobin, red blood cell concentration and hematocrit. The platelet count was inversely associated with the parameters. CONCLUSION: The observed associations of cord blood hemoglobin with mean platelet volume and platelet count reflect the physiology of fetal hematopoiesis at term.

Prothrombin activation fragment 1 + 2 as a marker of coagulation activation in cord blood collection for banking.

There have been efforts to increase the quality of cord blood (CB) collections aimed at banking and transplantation. Yet, the effect of CB collection techniques on haemostatic activation is scarcely studied, despite the unique nature of the neonatal haemostatic system. The aim of this study was to explore coagulation system and platelet (PLT) activation during CB collection at a national CB bank. At three time points over a 9-year period (in 1998, 2000 and 2006), CB collections were assessed to evaluate the collection process during bank setup and changes in procedures. Thrombin generation and PLT activation were assessed with prothrombin activation fragment 1 + 2 (F1 + 2) and PLT factor 4 (PF4), respectively. The median F1 + 2 level was 2.8 nmol L(-1) in 1998 (n = 11), 0.7 nmol L(-1) in 2000 (n = 10) and 0.7 nmol L(-1) in 2006 (n = 6), the decrease being statistically significant (1998 vs 2000, P < 0.001; 1998 vs 2006, P = 0.01). The median PF4 level was 117 IU mL(-1) in 1998 and 104 IU mL(-1) in 2000. PF4 was not measured in 2006. The level of F1 + 2 correlated with that of PF4 (n = 21; Spearman's Rho = 0.59, P = 0.006). Haemostatic activation, assessed as a part of CB bank process control, decreased from the first to the subsequent sample series. F1 + 2 may be a candidate for quality control in CB banking; however, further studies are needed to optimise the analyses and to assess the effect of haemostatic activation on CB quality.