UVA joins National Marrow Donor Program giving greater access to cancer treatments by Ishaan Sachdeva | Jun 25 2014 | 06/25/14 10:11pm | Updated 10 hours ago
The Emily Couric Cancer Center of the University of Virginia Health System has expanded its access to bone marrow and hematopoietic stem cell transplant donors. Now designated as a National Marrow Donor Program (NMDP), the Health System will have access to the Be The Match Registry, the worlds largest and most diverse bone marrow registry. Implications of this change are significant for patients afflicted with blood cancers like leukemia who obtain treatment through the Health System.
Bone marrow, the soft, spongy tissue within bones like the sternum or the ilium of the pelvis, forms hematopoietic or blood-forming stem cells. These cells, unlike embryonic stem cells, differentiate only into types of blood cells- red blood cells, white blood cells or clotting platelets. Leukemia causes bone marrow to produce abnormal, leukemic white blood cells that divide uncontrollably, forming tumors that deprive cells of oxygen and reduce infection defense. One treatment method is autologous bone marrow transplant, in which patients receive stem cells from their healthy, non cancerous bone marrow.
The idea [of autologous transplants] is that you extract healthier bone marrow from the patient to have a source of stored, non-cancerous bone marrow. You can then treat the patient with higher doses of treatment than you can normally give because the most common limitation to treatment is that treatment will kill off healthy bone marrow you might have, said Thomas P. Loughran Jr., MD, the Universitys Cancer Center director.
Essentially, a patients healthy bone marrow is safeguarded outside their body while aggressive treatment is administered to kill cancerous marrow. Another form of treatment is allogeneic treatment, in which bone marrow is transplanted from a sibling or an unrelated donor.
In an allogeneic transplant, you are also transplanting in a new immune system. The new immune system comes in and recognizes the body as a foreign tissue and starts attacking that tissue. This causes a beneficial graft vs. leukemia effect where this new immune system attacks any residual leukemia, but may also cause a harmful graft versus host disease where normal tissue is also attacked, Loughran said.
The donor and recipient tissue interaction underscores the genetic component of bone marrow transplants from external donors. Despite the curative potential of a bone marrow transplant, a strong genetic match between donor and recipient is crucial to the utility of a transplant.
The ability of any donor to be successful is based on genetics. Its called HLA [human leukocyte antigen] typing. The HLA system has four genes called A, B, C and D, and it turns out that A, B and D are influential. We have half of our genes each from both parents, so we have six of these: 2 A, 2 B and 2 D. The best case is a six out of six match from a brother or sister, but the chances are only 1 in 4, said Loughran. The consequence of low genetic probabilities is a large pool of unrelated donors, like the Be The Match Registry. Through such services, patients have a greater chance of finding an unrelated donor who may provide a successful genetic match.
The coordinating center would identify the place where the donor is living and tell them they are potentially able to donate. In the past, the donor would have bone marrow directly extracted. Now it is almost always from the PBSCT [peripheral blood stem cell transplantation] procedure. The donor takes a growth factor that stimulates growth of the needed hematopoietic stem cells within their peripheral blood circulation. A catheter collects this blood and the stem cells are separated from the blood by a machine, and the blood is returned back to the donor. The collected stem cells are sent to the lab where they are purified and frozen, Loughran said.
Meanwhile, the patient in preparation for the transplant is given the highest dose of chemotherapy that can be tolerated. The donated stem cells are administered to the patient in a way similar to IV fluid.
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UVA Expands Cancer Treatment