Cell Transplantation, July 29, 2009

Scientists at the Fondazione Poliambulanza-Instituto Ospelaliero in Brescia, Italy have used placental adult stem cells in the treatment of fibrotic lung diseases in laboratory animals.

Currently, conventional medicine offers no known treatment that can effectively halt or reverse the fibrotic process in diseases such as pulmonary fibrosis and other similar conditions that may be caused by exposure to radiation or chemical pathogens, and permanent damage to lung tissue is often the result, if not in fact complete pulmonary failure. Now, however, adult stem cells may offer the first actual therapy which not only stops the progression of these various diseases but which also repairs and regenerates damaged lung tissue.

Adult stem cells derived from the placenta are already known to be highly potent and have been shown in a number of studies to engraft naturally into solid organs such as the lungs. In particular, the mesenchymal stem cells (MSCs) that are derived from placental blood and tissue are "immune privileged", "universal donor" cells, meaning that they do not pose any risk of immune rejection, even when administered allogeneically (when the donor and recipient are not the same person). In fact, these MSCs are known to possess a number of anti-inflammatory, immunomodulatory properties which are also of significant benefit to the recipient.

As Dr. Ornella Parolini, lead author of the study, explains, "The potential application of fetal membrane-derived (placental, i.e.) cells as a therapeutic tool for disorders characterized by inflammation and fibrosis is supported in previous studies. In line with the hypothesis that cells derived from the amniotic membrane have immunomodulatory properties and have been used as an anti-inflammatory agent, we set out to evaluate the effects of fetal membrane-derived (placental) cell transplantation in chemically-treated mice." Using intraperitoneal, intratracheal and intravenous delivery of the cells, the researchers then observed a consistent and significant anti-fibrotic effect in the laboratory mice, in whom the fibrosis had been artificially induced via the administration of bleomycin - a glycopeptide antibiotic that is commonly used in the chemotherapeutic treatment of some types of cancer, but from which pulmonary fibrosis is known to be a common side effect. Although the adult stem cells did not reduce the severity of the inflammation in this particular animal model, nevertheless there was a marked reduction in infiltration by neutrophil granulocytes (white blood cells) after the stem cell transplantation, whether autologous (in which the donor and recipient are the same person) or allogeneic (in which the donor and recipient are not the same person).

As Dr. Parolini further adds, "It is worth noting that the presence of neutrophils is associated with poor prognosis for several lung diseases. However, the mechanism by which placenta-derived cells might affect infiltration by neutrophils is not known. Our findings suggest that (placenta-derived) cells may prove useful for cell therapy of fibrotic diseases in the future."

As the authors conclude in their paper, "Our findings constitute further evidence in support of the hypothesis that placenta-derived cells could be useful for clinical application, and warrant further studies toward the use of these cells for the repair of tissue damage associated with inflammatory and fibrotic degeneration."