Stem Cell Apheresis

First, what are stem cell? Stem cells are(PBSC collection), the procedure is performed
immature cells that grow and divide into maturewith a medical device called a blood cell separator,
cells, almost any type of cell in the body. If wewhich uses a centrifuge to separate and collect
think of mature blood cells, stem cells can developmononuclear cells, including peripheral blood stem
into red blood cells, white blood cells, or platelets.cells, from the blood. Before a PBSC collection
The type of blood cell that a stem cell will developprocedure, the patient may receive a prescribed
into is determined by the specific needs of thedose of chemotherapy and/or other drugs called
patient's body, and through the stimulus of specialgrowth factors. A common growth factor is
substances called "growth factors." Stem cells canGranulocyte Colony-Stimulating Factor (G-CSF),
be collected from a number of sources, includingmanufactured by Amgen under the name
the peripheral blood (a PBSC collection), boneNeupogen®. These drugs will generally cause the
marrow via a bone marrow harvest, fat throughrelease of a large number of peripheral blood
a liposuction methodology, and umbilical cordstem cells into the blood stream. When the
recovery.physician determines the white blood cell count
In stem cell apheresis, a donor gives throughhas increased to a sufficient level, a series of
blood collection, but only stem cells rather thanPBSC collections will begin.
whole blood is collected. Prior to the donationThe medical staff will set the apheresis system to
procedure, the donor receives an injection of acollect a certain type of white blood cell called a
special type of protein, called a growth factor,mononuclear cell or MNC. The peripheral blood
which is used to stimulate the bone marrow tostem cells will be collected with these white blood
release stem cells into the bloodstream. Wholecells. It is impossible to collect only the peripheral
blood is drawn from the donor, and, in veryblood stem cells.Red blood cells and platelets will
simplistic terms, a machine that separates thebe mixed with the peripheral blood stem cell
blood into its components selectively removes theproduct. The latest technology allows blood cell
stem cells and returns the rest of the blood toseparators to accomplish all this in an automated,
the donor. Stem cell donors must be compatiblecontinuous and safe manner. Sterile tubing sets
with recipients by lymphocyte type (humanand needles in the system are used only once
leukocyte antigen, or HLA), a type of proteinand then discarded.
found on certain cells, rather than blood type.The procedure from the patient's viewpoint is
Stem cells are now used to treat people with asimple. Transfusion of the stem cells can either be
number of diseases including, leukemia, lymphoma,through a catheter, or insertion of a needle. Use
other cancers, neural diseases, spinal cord, andof a needle may cause some discomfort and
multiple sclerosis to name a few. Themay be somewhat uncomfortable for the patient
apheresis procedure described here is a majorgiven the duration of the procedure. Patients may
means of collecting stem cells for performingfeel some dizziness, cold or nausia during the
stem cell transplantation. The recipient's own stemprocedure. Afterward, they may feel tired.
cells can be obtained as described above, orHowever, there should be no lasting negative side
donated stem cells obtained from blood or othereffects. More than 25,000 PBSC procedures have
sources can be given to the patient as abeen conducted every year with veryfew
transplantation.problems. The procedure typically requires two to
Considering peripheral blood stem cell collectionfour hours.