Transplant using someone else’s cells. For some diseases, patients cannot use their own stem cells for a transplant. To have a chance at recovery, they need stem cells donated by someone else who is healthy. The cells may come from someone related to the patient or someone unrelated.
Transplant using the recipient’s own cells. For some diseases, doctors can remove stem cells from a patient and then put these cells back into the patient after he or she undergoes conditioning (receiving chemotherapy, radiation therapy or both). Patients having an autologous transplant do not need a donor; they are their own donor, in a sense.
A procedure designed to weaken or destroy tissues or cells that cause blood or immune-system diseases, and then to “reset” or replace those tissues or cells to restore healthy function.
Using high-potency drugs that target quickly dividing cells and destroy them. Some of the healthy cells (such as hair follicles, cells in the lining of the mouth and intestines, and normal bone-marrow stem cells) are also quickly dividing cells, so they are killed as well. Their destruction results in some of the side effects patients experience.
To treat blood or immune system diseases using a transplant, doctors first give the patient chemotherapy, radiation or both. This process is called conditioning.
Related to the formation of blood cells. Blood-forming stem cells are sometimes called hematopoietic cells.
A cancer that disrupts the normal development of blood cells. Inside most of your bones is a soft spongy material called bone marrow in which blood stem cells (immature blood cells) are produced. A blood stem cell becomes one of two types of stem cells: myeloid or lymphoid, each of which matures into different kinds of blood cells.
Mini-transplant or mixed-chimerism transplant
In patients who get low-dose conditioning before a transplant, engraftment means a new immune system develops alongside your remaining, but weakened, immune system. So for a time, you have a mixed immune system. The goal is for your new (transplanted) immune system to attack cancer cells that survived conditioning (called the graft-versus-tumor effect) and for the new immune system to eventually take over completely. This is called a mixed-chimerism transplant or a mini-transplant.