How is bone marrow obtained for transplantation?
The procedure for obtaining bone marrow is called "harvesting," and is similar for all three types of BMTs (Autologous, Syngeneic, and Allogeneic). The procedure is done under general or spinal anesthesia. A needle is inserted through a small cut into the bone marrow to draw the marrow out of the bone.
The harvested bone marrow is then processed to remove blood and bone fragments. Harvested bone marrow can be combined with a preservative and placed in a liquid nitrogen freezer to keep the stem cells alive until they are needed. This technique is known as cryopreservation. Stem cells may be cryopreserved for many years.
How are PBSCs obtained for transplantation?
A process called Apheresis or Leukapheresis is used to obtain peripheral blood stem cells for transplantation. For 4 or 5 days before Apheresis, the donor is given Inj G-CSF i.e Growth Factors subcutaneously to mobilize the stem cells from the bone marrow into the bloodstream. Apheresis requires insertion of a double lumen catheter into a large vein. The blood goes through a machine that removes the stem cells. The remaining blood is then returned to the donor and the collected cells are stored. Apheresis typically takes 4 to 5 hours to complete. The stem cells are then frozen, if required, until they are transplanted in to the patient.
How does the patient receive the bone marrow or PBSCs during the transplant?
Once the diseased cells have been destroyed by chemotherapy and /or Radiation, along with the bone marrow, it is time to proceed for the transplant. During this, the donated stem cells are infused into the recipient/ patient through a central venous catheter just like a regular blood transfusion. The process is usually short, taking only an hour or two, and usually uncomplicated.
What happens after the bone marrow or stem cells have been transplanted to the patient?
After entering the bloodstream, the transplanted cells travel to the bone marrow, where they begin to produce new white blood cells, red blood cells, and platelets in a process known as "engraftment." Engraftment usually occurs within about 2 to 4 weeks after transplantation, and is monitored by checking blood counts on a frequent basis. However, complete recovery of immune function takes much longer, up to several months for autologous transplant recipients and 1 to 2 years for patients receiving allogeneic transplants. Doctors evaluate the results of various blood tests to confirm that new blood cells are being produced and that the cancer has not returned.
Bone Marrow/Stem Cell Transplantation is a complex process and you need to maintain a positive attitude, stay determined of overcoming disease and becoming better. You need to take active part in the transplantation and keep doctors informed about physical and emotional state. By sharing concerns and being proactive, your doctors can help you more and ensure a successful transplantation.