Abstract: Objective: To investigate the angiogenic properties of cord blood endothelial progenitor cells (EPCs) in low birth weight(LBW) preterm infants. Methods: Venous umbilical cord blood was collected from 19 cases of full-term neonates with normal weight and 15 LBW neonates. The relative number of cord blood EPCs (CD34⁺/CD133⁺/VEGFR2⁺) from LBW preterm and full-term neonates was counted by ?ow cytometry. The angiogenic properties of cord blood EPCs were evaluated for the time for clone formation, clone forming ability and capacity to proliferate and formtubes in vitro. Results: There was no difference in the relative number of cord blood EPCs between LBW preterm and full-term neonates. Compared with EPCs of full-term neonates, the time for clone formation of EPCs was delayed in LBW, while clone forming ability and capacity to proliferate and form tubes were decreased. The expressions of VEGFR2 and VE-cadherin of EPCs in LBW were significantly reduced. Conclusions: Angiogenic properties of EPCs are impaired in LBW preterm infants, and this may be due to the decreased expression of VE-cadherin and VEGFR2.

Key words: Endothelial progenitor cells, Umbilical cord blood, Neonates