RESUMEN
OBJECTIVE: Endothelial progenitor cells (EPCs) have been examined in numerous adult diseases and have been suggested as a cellular-based therapy. However, there are no reports describing EPCs being isolated from newborn peripheral blood. STUDY DESIGN: Endothelial colony-forming cells (ECFCs), a subtype of EPCs, were isolated from blood collected from 12 neonatal extracorporeal membrane oxygenation (ECMO) circuits. RESULT: ECFCs were isolated in all samples. We unexpectedly isolated a distinctly different colony of mesenchymal stem cells (MSCs) in seven samples. Both cell types expressed the expected endothelial or mesenchymal cell surface antigens. CONCLUSION: To our knowledge, this is the first report of ECFCs and MSCs isolated from peripheral blood of critically ill term newborns. Both cells types may be mobilized in response to critical illness or to the ECMO circuit. Further studies evaluating the role of stem cells in various newborn conditions are warranted.