Circulating Endothelial Progenitor Cells in Preterm Infants with Bronchopulmonary Dysplasia

Rationale: The new form of bronchopulmonary dysplasia (BPD) is characterized by lung immaturity with disrupted alveolar and capillary development after extremely premature birth, but the mechanism of impaired lung vascular formation is still not completely understood.Objectives: We tested the hypothesis that reduced numbers of circulating endothelial progenitor cells at birth are associated with the development of BPD.Methods: We studied ninety-eight preterm infants with gestational age of less than 32 weeks or a birth weight less than 1,500 g. Endothelial colony-forming cells (ECFCs) were assessed by clonogenic analysis in infants for whom cord blood was available. The proportion of circulating endothelial and hematopoietic cells was measured by flow cytometry at birth, at 48 hours, and at 7 days of life.Measurements and Main Results: ECFCs in cord blood were lower in infants who later developed BPD (median [range]: 0.00 [0.00–0.48] vs. 2.00 [0.00–21.87]; P = 0.002). ECFCs decreased with decreasing gesta...