For patients with hematological diseases (such as leukemia, aplastic anemia), an allogeneic stem cell transplant may be the only viable curative option. A patient undergoes round(s) of chemotherapy and radiation to drive down the cancerous cells to a level that is often non-detectable. Then, they are infused with healthy donor stem cells that will hopefully proliferate and replace the patient's immune system that was previously 'defective'.
Peripheral blood stem cell transplantation (PBSCT) technology is approximately 30 years old, and is currently used ~75% of allogeneic stem cell transplant cases. Prior to the collection of stem cells, the donor receives GCSF (Granulocyte Colony Stimulating Factor) doses over the course of a few days. This stimulates stem cell concentration to increase in the blood. The donor then undergoes a blood collection process called ‘apheresis’, which is an experience akin to giving a blood donation, except for a prolonged period of 4-6 hours. During this process, blood goes through a machine that filters the stem cells. The collected stem cells are then frozen until it is thawed and given to the patient.
Data from 2011 showed
adverse events occurred in 0.06% of donors who received GCSF. Also, long-term effects
of GCSF treatment are not currently known. These are some of the factors which raise ethical concerns and are topics of continued debate.
Amid these concerns, there are many who still choose to donate. The relatively non-invasive method of PBSCT may be instrumental to increase the number of donors. thereby increasing the number of patients who are cured of their hematological diseases.
Sources:
http://www.bloodjournal.org/content/117/24/6411?sso-checked=true
http://www.medicinenet.com/peripheral_blood_stem_cell_transplant/article.htm
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