Circulating endothelial progenitor cells in preterm infants with bronchopulmonary dysplasia.
BACKGROUND
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.


OBJECTIVE
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.


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 gestational age (r = 0.41; P = 0.02), but even at extremely low gestational ages, infants with higher numbers of ECFCs were protected from BPD. The endothelial and hematopoietic cell subsets studied by flow cytometry were comparable in infants with and without BPD and rapidly decreased after birth.


CONCLUSIONS
ECFCs are low at extremely low gestational ages and increase during gestation; extremely preterm infants who display lower numbers at birth have an increased risk of developing BPD. Our findings suggest that decreased ECFCs following extremely preterm birth may be associated with the risk for developing lung vascular immaturity characteristic of new BPD.
Borghesi
Alessandro
A
Neonatal Intensive Care Unit, Fondazione IRCCS Policlinico San Matteo, Piazzale Golgi n. 19, 27100 Pavia, Italy. alessandroborghesi@yahoo.it
Massa
Margherita
M
Campanelli
Rita
R
Bollani
Lina
L
Tzialla
Chryssoula
C
Figar
Tiziana A
TA
Ferrari
Giovanna
G
Bonetti
Elisa
E
Chiesa
Gaia
G
de Silvestri
Annalisa
A
Spinillo
Arsenio
A
Rosti
Vittorio
V
Stronati
Mauro
M
D018952:Antigens, CD34 / Q000097:blood; D001997:Bronchopulmonary Dysplasia / Q000097:blood / Q000473:pathology*; D042783:Endothelial Cells / Q000473:pathology*; D005260:Female; D005312:Fetal Blood; D005434:Flow Cytometry; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D019102:Infant, Very Low Birth Weight / Q000097:blood; D008297:Male; D012307:Risk Factors; D013234:Stem Cells / Q000473:pathology*
D018952:Antigens, CD34