Ethical and Safety Concerns of Cord Blood Stem Cells

The ethical controversy around human embryonic stem cells (hESCs) does not apply to cord blood-derived embryonic-like stem cells (CBEs) making them an attractive option for researchers and clinicians alike. There remains some considerable debate over the plasticity or potency of the stem cells derived from umbilical cord blood in comparison to adult stem cells and hESCs. Similarly, the concern over the potential for abnormal cell proliferation and tumor growth which is applied to hESCs may also need to be a consideration in CBE use. The risks of graft-versus-host disease do appear to be smaller for cord blood stem cells in comparison to more traditional transplant methods due, in part, to the relative immaturity of the immune cells in the cord blood.


A whole raft of research trials are currently recruiting which will look a the possibility of using cord blood from multiple umbilical cords to provide transplant material for a single patient. There is little understanding as yet regarding the safety or efficacy of such combination of stem cell sources and most transplant centers will only use blood taken from a single donor. The necessity of this ‘pooling’ of cord blood may be somewhat reduced given the newly found ability to culture the cord blood stem cells to treat a fully grown adult, although time constraints may be a factor which favors double cord blood infusion.

Stem cells harvested from umbilical cord blood (as well as from marrow, and peripheral blood) are injected intravenously into the patient after which they migrate to the patient’s own bone marrow. The stem cells then begin to grow and differentiate into new, normal blood cells and repopulate the patient’s system. New blood cells generally form within two to four weeks in the bone marrow, whereas stem cells in the bloodstream create new blood cells within just ten to twenty days. Cord blood appears to be a little slower to generate new blood cells than the stem cells already in the bloodstream which can leave a patient vulnerable to infection for a slightly longer period after they receive the transplant.

Continue Reading –> Cord Colitis Syndrome – A Danger of Cord Blood Transplants