The discarded placentas of newborn babies have been identified as a new and more plentiful source for harvesting stem cell by researchers from the Children's Hospital and Research Center, Oaklands, US. The more traditional stem cell source, blood from the umbilical cord, only contains enough stem cells for a transplantation to be useful on infants or children. Placentas contain far more stem cells and, when combined with blood from the umbilical cord, would mean that enough stem cell material could be safely extracted for adult transplantation to be viable. This could lead to treatments for a wide range of chronic blood-related illnesses such as sickle cell disease, thalassaemia and leukaemia. The findings will be published in the next issue of the journal Experimental Biology and Medicine.
Stem cells are unprogrammed cells that can transform into any other type of cell such as those that make up the brain, the heart or the blood. Since 1997, doctors from Oaklands have cured more than 100 children with chronic blood-related diseases by using stem cells from their sibling's umbilical cord blood. However, this success has never translated to a treatment for adults. 'There is simply not enough stem cells in one unit of cord blood to transplant an adult,' says Dr Frans Kuypers, who co-lead the study with Dr Vladimir Serikov. This is why they turned their attention to the placenta in this latest study, obtaining material from healthy women undergoing elective Caesarean sections.
'Yes, the stem cells are there; yes, they are viable; and yes, we can get them out,' declared Dr Kuypers, and 'there are many more than you will have in one unit of cord blood.' Up to five times as many, the study found. 'So that means that now you have cord blood and now you have placental derived cells, which are very similar,' explained Kuypers, adding: 'If you combine them, now you have enough to transplant to an adult.' Furthermore, the study has shown that the placenta stem cells may be even more 'primitive' than cord blood stem cells, meaning they are more versatile and the donor match does not have to be as exact as other sources such as bone marrow transplants.
The team's patent-pending method for harvesting the placental stem cells employs drugs normally used to extract stem cells from bone marrow. First the placenta is frozen after birth, and the drugs are used later, to avoid any harm to the baby or mother. The new method would make it possible for companies to collect, transport and store placentas in a central location. 'We're looking for a partnership with industry to get placenta-derived stem cells in large quantities to the clinic,' said Dr Kuypers, adding 'someday, we will be able to save a lot more kids and adults from these horrific blood disorders.'