Factors associated with parameters of engraftment potential of umbilical cord blood.

BACKGROUND

Umbilical cord blood (UCB) is an acceptable source of hematopoietic cells for transplantation with success being associated with the nucleated cell count (NCC), CD34+ cells, and colony-forming unit-granulocyte-macrophage (CFU-GM) content infused. A total of 1033 UCB samples with neonatal and paternal characteristics that might influence hematopoietic content were examined.

STUDY DESIGN AND

METHODS

UCB samples were screened, processed, and reevaluated for the above cell counts. These parameters of engraftment potential were analyzed for associations with neonatal and parental characteristics.

RESULTS

Postprocessed NCCs (median, 6.53 x 10(8)+/- 2.80 x 10(8) SD; mean 7.30 x 10(8)), CD34+ counts (median, 2.02 x 10(6) +/- 2.20 x 10(6) SD; mean, 2.65 x 10(6); r = 0.66; p < 0.001), and CFU-GM content (median, 2.65 x 10(5) +/- 3.16 x 10(5) SD; mean, 3.54 x 10(5); r = 0.61; p < 0.001) all were strongly interrelated. Both initial volume (median, 77.5 +/- 26.2 mL SD; mean, 81.9 mL) and initial NCC (median, 9.75 x 10(8) +/- 4.88 x 10(8) SD; mean, 10.9 x 10(8)) correlated well with postprocessed NCC (r = 0.60; r = 0.90; p < 0.01), CD34+ count (r = 0.40; r = 0.63; p < 0.01), and CFU-GM content (r = 0.38; r = 0.59; p < 0.01), with a stronger relationship seen with initial NCC. Infant birth weight (specifically, >3000 g), but not sex, gestational age, or cytomegalovirus status correlated strongly with collection volume and UCB cell counts. Units from minority volunteers contained relatively smaller volumes and hematopoietic content.

CONCLUSION

UCB banks should emphasize selecting the heaviest infants and processing large-volume units with high NCCs to optimize hematopoietic potential. Minority recruitment should be encouraged with consideration given to inherent racial differences in cell counts. There does not appear to be a significant relationship between other neonatal and parental characteristics and that of engraftment potential.