May 12, 2010
Bone marrow and umbilical cord blood adult stem cell transplants are becoming more and more common, being used not just for cancer treatments but now for immune disorders, anemias, and genetic disorders. In 2006, there were over 50,000 transplants worldwide.
Now those transplants are getting easier, promising treatment of more patients and more conditions. Bone marrow transplants have been used successfully for several decades, as whole bone marrow and more recently by targeted use of the adult stem cells from bone marrow or umbilical cord blood. In the past, patients had their bone marrow adult stem cells collected and stored, then received high doses of chemotherapy drugs and/or radiation to kill cancer cells or rogue immune cells, followed by replacement of their stem cells to rebuild their system. It was definitely not an easy treatment. And for patients who don't use their own stem cells or don't have a perfectly-matched donor, there are additional risks from the donated graft itself, called Graft Versus Host Disease (GVHD), where the donated cells can attack the patient into whom they are injected.
More recently, doctors have been using milder doses of chemo and radiation, allowing better tolerance of the procedure. And techniques are being developed to minimize or eliminate potential GVHD.
For example, in December 2009, nine out of ten adults treated for sickle cell anemia with the gentler method had their sickle cell disease eliminated.
Dr. Suzanne Ildstad at the University of Louisville has devised a technique to minimize GVHD. One facet of Ildstad's new technique is the removal of immune cells that might cause GVHD from the bone marrow mix, and use of "facilitating cells", rare bone marrow adult stem cells that promote engraftment as well as tolerance of the grafted cells. The "conditioned" bone marrow adult stem cell transplant decreases the chance of GVHD and increases toleration of the graft in the patient, especially where there is not a complete match between donor and recipient. Using bone marrow adult stem cells along with transplant of other organs also has the possibility of making the organ transplant easier to accept.
Several clinical trials are ongoing to use these newer techniques with patients. One current trial combines transplant of "conditioned" bone marrow along with kidney transplantation; a second similar trial is recruiting patients for kidney transplants. Other trials are testing the technique for heart transplants, for sickle cell disease, and for multiple sclerosis.
Adult stem cells continue to save lives and improve health.