Immediately after the transplant, patients usually remain in the hospital under close supervision. Patients are closely monitored until testing reveals adequate levels of white blood cells and platelets. Once the transplanted cells enter the patient’s bloodstream, they travel to the marrow and begin to produce new white blood cells, red blood cells and platelets. This process is known as engraftment, and it usually occurs two to four weeks after the transplant procedure. A physician can detect engraftment by regularly checking blood counts. Patients will also be monitored to ensure that:

• New bone marrow is functioning properly
• There are no signs of serious graft-versus-host disease
• The cancer has been controlled

Following a bone marrow transplant, it takes longer for a patient to experience complete recovery of immune function, which is the production and action of cells in fighting disease. Patients who receive an autologous transplant may need several months for this process to develop. Those patients who undergo allogeneic or syngeneic transplants may wait one to two years before experiencing full recovery of immune function.

After some allogeneic bone marrow transplants, such as for treating certain leukemias, a process known as the graft-versus-tumor (GVT) effect must occur for success.  The GVT effect develops when white blood cells from the donor recognize cancer cells remaining in the patient’s body and begin to attack them.

Physicians can use various blood tests to be sure that new blood cells are being produced and that the cancer has not returned. They also may use a needle to remove a small sample of bone marrow for examination under a microscope.  This is known as a bone marrow aspiration and it helps reveal how well the new bone marrow is working in the patient.