The conditioning regimen for patients undergoing an allogenic stem cell transplant is a difficult experience, but is absolutely necessary to produce a favorable outcome. Remember, stem cells are the mother cells of all the cells in the blood, including immune cells (white blood cells). If donor cells were infused into an individual with a functioning immune system a battle would be waged by the recipient immune system on the donor stem cells. This battle would destroy the donor cells, preventing them from taking hold and curing the disease. The conditioning regimen destroys the recipient immune cells providing an easier path for the donor cells(1).
The conditioning regimen used varies by location and underlying condition being treated, but may include a combination of chemotherapy agents and total body irradiation (radiation therapy). Some centers use just chemotherapy, some use both chemotherapy and radiation. These therapies are especially deadly to the stem cells, damaging them so they can no longer produce many healthy cells. In general high amounts of chemotherapy and radiation in the conditioning program provide better remission rates(1). Again, the conditioning regimen prepares the body to receive the donor cells in a way that will ease their journey and their establishment within the bone marrow of the recipient.
Conditioning begins the week before transplant. The days before transplant are labeled "day minus 8", "day minus 7", "day minus 6: etc; transplant day is "day zero"; and the days following transplant are "day plus 1", "day plus 2", etc.
Print
Email Page
