A Paediatric Perspective on Stem Cells: Expression, Function and Clinical Relevance

In the last ten years, placenta, fetal membranes (i.e. amnion and chorion), and amniotic fluid have been extensively investigated as a potential non-controversial source of stem cells. They are usually discarded after delivery and are accessible during pregnancy through amniocentesis and chorionic villus sampling [1] Several populations of cells with multi-lineage differentiation potential and immunemodulatory properties have been isolated from the human placenta and fetal membranes; they have been classified by an international workshop [2] as human amniotic epithelial cells (hAECs) [3-8] human amniotic mesenchymal stromal cells (hAMSCs) [9,10] human chorionic mesenchymal stromal cells (hCMSCs) by Igura et al. and Anker et al., and human chorionic trophoblastic cells (hCTCs). In the amniotic fluid (AF), two main populations of stem cells have been isolated so far: