3: Umbilical Cord Blood Levels of Endothelial Progenitor Cells and Vascular Endothelial Growth Factor and Risk of Bronchopulmonary Dysplasia

Abstract

BACKGROUND: Bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, is currently considered a disease of abnormal vascular and alveolar growth. Mechanisms involved in impaired lung vascular development are poorly understood. Both endothelial progenitor cells (EPCs) and vascular endothelial growth factor (VEGF) are important factors in normal vascular development. OBJECTIVES: To test the hypothesis that in infants delivered at <32 weeks gestation, umbilical cord blood levels of EPCs and VEGF are lower in infants who develop BPD as compared to infants who do not develop the disease. DESIGN/METHODS: Umbilical venous cord blood samples were obtained within 30 minutes of birth. EPCs were measured using flow cytometry and were defined as cells expressing the surface markers CD-34, CD-133 and vascular endothelial (VE) cadherin with more mature endothelial cells defined as expressing CD-34 and VE cadherin. VEGF was measured using a quantitative sandwich enzyme linked immunoassay. BPD was defined as oxygen dependency at 36 weeks postmenstrual age. Exclusion criteria included chromosomal and congenital abnormalities. Mann-Whitney test was used for continuous variables and the χ2 or Fisher's exact test for dichotomous data. Multivariate logistic regression was performed to estimate the odds ratio (OR) for development of BPD. A P<0.05 was considered statistically significant. RESULTS: There was no effect of mode of delivery, chorioamnionitis or preeclampsia on EPC numbers. CONCLUSION: Levels of EPCs or VEGF at birth did not affect the risk of development of BPD in our group of premature infants. Further studies are needed before these cells and VEGF can be considered as biomarkers for prediction of BPD. (Table Presented).