Monday, February, 13, 2012

Non-Hodgkin's Lymphoma - Transplantation

Table of Contents

Peripheral blood stem cell transplantation is easier to perform and is done more often than bone marrow transplantation. It also seems to be superior in terms of cost, quality of life, and the need for less supportive care.

Donor or Patient Cells. The marrow or blood stem cells can be taken from the patient (autologous) or from a matched donor (allogeneic):

  • In an autologous transplant, the marrow or blood cells used for replacement are taken from the patient. There is some danger, however, that these cells may contain tumor cells, and that the cancer can regrow. It is unclear if this approach improves survival compared to standard chemotherapy for newly diagnosed disease. However, it clearly has benefits in the treatment of some forms of relapsed non-Hodgkin's lymphomas. There is also a higher risk for leukemia. (This risk is lower in peripheral stem cells transplants than in bone marrow transplants.)
  • In an allogeneic transplant, bone marrow or stem cells are taken from a donor. Siblings are the best donors. Relapse rates can be very low with this approach, and cure may be possible in some cases. However, it is highly toxic and donor and recipient must be matched as closely as possible to avoid rejection by the immune system, a serious complication called graft-versus-host disease. Advances in techniques are reducing the toxicities associated with this approach. Older patients who cannot tolerate the preparatory treatment required for a standard allogeneic transplant may be able to receive a non-myeloblative transplant (“mini-transplant), which uses lower doses of chemotherapy and radiation.

The Blood Stem Cell Collection Procedure. With peripheral blood stem cell transplantation:

  • The donor is usually given a drug called granulocyte colony-stimulating factor, or G-CSF (filgrastim, lenograstim, pegfilgrastim) to stimulate stem cell growth.
  • The patient (or donor in an allogeneic procedure) then undergoes apheresis. With this process the blood is withdrawn from one of the patient's veins, then passes through a machine that filters out the white cells and platelets, which contain the stem cells. The blood is returned through another vein. The entire procedure takes 3 - 4 hours but needs to be repeated several times.
  • The stem cells are treated to remove contaminants and then are frozen to keep them alive until the patient is ready to receive them back.
Formed elements of blood
Blood transports oxygen and nutrients to body tissues, and returns waste and carbon dioxide. Blood also distributes nearly everything that is carried from one area in the body to another place within the body. For instance, blood helps transport hormones from the endocrine organs to their target organs. Blood also helps maintain body temperature. The protective functions of blood include clot formation and the prevention of infection.

The Transplantation Procedure

Review Date: 01/27/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)