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Hematopoietic Stem Cell Transplantation
Introduction
Hematopoietic progenitor (stem) cells are precursor cells that normally reside
primarily in the bone marrow. They have the ability to divide to produce other
stem cells or to develop into all the various blood cell lines - red cells,
neutrophils, lymphocytes, eosinophils, basophils, and platelets. Although these
cells were collected originally from the bone marrow, it is now possible to
stimulate the bone marrow to increase the number of stem it produces and spills
out into the peripheral circulation so that stem cells can be collected from
circulating blood.
There are two major types of stem cell/ bone marrow transplants based upon the
relationship of the donor to the recipient of the transplant.
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Autologous
- patient receives his own stem cells in transplant.
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Allogenic - Patient receives the stem cells form another person with
different levels of relatedness.
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Synergistic: Patient receives stem cells from identical twin
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Related: Patient receives stem cells from a closely matched relative
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Unrelated: Patient receives stem cells from a closely matched person where
there is no relation
Transplantation Process
The Stem Cell Transplantation process involves several steps:
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Mobilization
of stem cells from the bone marrow into the peripheral blood. This can be done
by administering low dose chemotherapy and growth factors e.g. G-CSF or
Neupogen. Allogenic donors, however, would be given only growth factors.
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Harvesting
the stem cells form the peripheral circulation 10 – 14 days after mobilization.
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Freezing (cryopreservation) the harvested stem cells
with DMSO(dimethyl sulphoxide) to protect them and storing at
–1960 °C.
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High Dose (Conditioning) Chemotherapy
is given to attempt to eradicate the malignancy with the highest doses of drugs
specific for that disease. At these levels, the drugs are toxic to the bone
marrow and destroy the patient’s ability to continue to produce the various
types of blood cells needed to sustain life.
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Stem Cell Transplant. 24 to 72 hours after
the high dose chemotherapy (dependent upon the particular drugs given), the
stem cells are thawed and immediately infused back into the patient. The goal
is to have these cells repopulate the bone marrow and once again begin to
produce the red cells, various white cells and platelets.
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The engraftment phase refers to the period during
which the new stem cells are getting established in the bone marrow. During
this time, the patient requires the support of red cells and platelet infusions
is at extreme risk of infection and is recovering from the other side effects
of the very high doses of chemotherapy.
Transplantation Centres
Kingston: Adult Autologous Stem Cell Transplant Program
The program was established in April 2004 to do Autologous stem cell
transplantation procedures on adults. The criteria for patients eligible for
this type of therapy are:
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Chemotherapy-responsive Multiple Myeloma
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Chemotherapy-responsive, relapsed diffuse, large B-cell Lymphoma
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Relapsed/ refractory Hodgkin’s Disease
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Non-cardiac AL Amyloidosis
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Testicular cancer (High risk factors)
For further information, please contact the Transplantation Physician,
Department of Haematology at Queen’s University or the Stem Cell Coordinator at
Kingston General Hospital, 549-6666 x 6627.
Ottawa
This program does both Autologous and Allogenic bone marrow and stem cell
transplantation on adults. For further information, please contact the Ottawa
Hospital Transplant Physician or the BMT Coordinator at (613) 737-8711
Princess Margaret Hospital
Program of Autologous and Allogenic stem cell and bone marrow transplantation
for adults. For more information, please contact Princess Margaret Hospital at
the switchboard at 416 946-2000
Centers for Pediatric Bone Marrow / Stem Cell Transplantation
Children are cared for at the Toronto Sick Children’s Hospital, or Ottawa
Children’s Hospital of Eastern Ontario (CHEO). For more information about
transplantation for pediatric patients click on Pediatric Oncology under
Special Populations.
References:
Ezzone,S. (ed) 2004. Hematopoietic Stem Cell Transplantation. A Manual for
Nursing Practice. Oncology Nursing Society, Pittsburgh.
Stewart, S. Autologous Stem Cell Transplants: A Handbook for Patients. Blood
& Marrow Transplant Information Network. (copy available in Cancer
Centre-SEO, Community Resource Centre Library for patients).
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