Questions about Transplant
and Clinical Research
hematopoietic stem cells?
Hematopoietic stem cells are cells that reside in the bone marrow and
produce blood cells such as red blood cells, white blood cells and
platelets. There are several types of white blood cells including
granulocytes, lymphocytes and monocytes.
Hematopoietic cell transplantation means strictly spoken the infusion of stem cells into
a vene. The term transplantation is frequently used in broader context
to describe administration of high-dose or intermediate-high-dose
chemotherapy plus subsequent stem cell infusion. An ablative
transplant is a transplant in which the preparative regimen is so
aggressive that your bone marrow cannot recover without infusion of
stem cells. A non-myeloablative transplant is a transplants in which
the preparative regimen is more friendly and bone marrow recovery can
occur to a certain degree without infusion of stem cells.
How are stem
cells for transplantation collected?
Stem cells can be collected from the bone marrow or
from the blood by leukapheresis. During a harvest stem cells are
distracted from the bone marrow of the sacral bone. The procedure
occurs under (local) anesthesia. A bone marrow harvest contains stem cells and
mature blood cells. Stem cells are separated from the other cells in
the laboratory and are frozen for later use or prepared for infusion. A leukapheresis occurs
by use of an apheresis machine. The procedure can be compared to a
platelet donation procedure. A stem cell donor is connected to the machine and
stem cells are distracted from blood that passes through the machine.
Under normal circumstances few stem cells circulate in the blood. To
make stem cell donation efficient stem cells should be mobilized from
the bone marrow into the blood ; this may be done after chemotherapy
treatment while you receive growth factor for recovery of the bone
marrow if you donate your own cells (autologous), or during growth
factor alone if a family member or unrelated person donates cells to
Malignant diseases or cancer
Who can be
a stem cell donor?
Two major donor categories can be distinguished: autologous and
allogeneic. A patient donating his or her own stem cells for
reinfusion at a later stage is called an
autologous donor. A family member or unrelated person donating
stem cells for infusion in a patient after ablative or non-myeloablative
chemotherapy is called and allogeneic donor. Children and adults can
be autologous or allogeneic donors of stem cells collected by bone
marrow harvest or leukapheresis. About 25% of patients have a sibling
donor; for 40 to 50% of Caucasians a matched unrelated donor can be
found. Cord blood can be preserved for
autologous or allogeneic transplant purpose.
Which diseases can be
treated by stem cell transplantation?
There are several disease categories that can be treated by stem cell
Several malignant diseases can be treated by stem cell
transplantation. The response to transplantation depends among others
on the type of disease, the disease stage at transplant and prior
treatment for cancer. Transplants can be part of the initial treatment
or be administered at disease recurrence after initial other prior
treatment. The response of cancer to transplantation is in general
best early during the disease course, when cancer cells have not yet
become resistant to chemotherapy.
Genetic diseases may be treated by infusion of stem cells from a
healthy donor to restore the genetic defect to a percentage sufficient
for normal body function. Transplants early during the disease course
may prevent that irreversible damage of organs occurs as result from
the defect. Genetic diseases that may benefit from transplantation
include immune deficiency disorders, abnormalities of hemoglobulin,
and abnormalities or deficiencies of enzymes including diseases called
inborn errors of metabolism.
Bone marrow abnormalities
Bone marrow abnormalities such as aplasia or myelodysplasia may be
cured by adequate preparative treatment and infusion of allogeneic
hematopoietic stem cells to restore bone marrow capacity.
Autoimmune diseases may benefit from the therapeutic effect of
chemotherapy and from correction of disfunction of the immune system
by infusion of allogeneic immune competent cells.
What are the
side effects of transplantation?
Infusion of stem cells does in general induce little or no side
effects with appropriate prophylaxis and current procedures. Other
side effect of transplantation are induced by the preparative regimen
and by the fact whether the transplant is autologous or allogeneic.
Ask your doctor about side effects. The patient informed consent you receive when participating in a
study explains the side effects that may occur.
How can side
effects be reduced?
reduce side effects it is important that you are in good condition; at
younger age you tolerate the same treatment better than at older age.
It is a given fact that cannot be changed.
2) Myeloablative or high-dose chemotherapy induces more
side effects than non-myeloablative chemotherapy. Thus
non-myeloablative transplants are preferable above myeloablative
effective are reduced intensity conditioning transplants?
It is likely that reduced intensity conditioning transplants are as effective as
myeloablative transplants when the overall treatment is well planned
and the disease is in complete remission before start of the
non-myeloablative preparative regimen.
clinical study the same as a clinical trial?
Transplant Creations prefers to use the term study. Study and trial
are though both used. From terminology perspective, a
clinical study examines safety and efficacy of a
product or treatment strategy, a trial tries to evaluate safety and
participation in clinical studies involve?
Participation in a clinical study means that you participate in an
effort that enrolls patients and treats and evaluates according to the
treatment strategy defined in a protocol. A protocol defines standards
for treatment that will be applied to all patients treated according
to that protocol. The results of treatment per protocol can be
analyzed to determine the appropriateness of the treatment. When you
are treated per protocol you generally participate in a clinical
Participation in clinical studies does not mean more visits or tests
than standard in patient care. A study may require some
specific tests, but these can occur during standard visits. Evaluation
and visits are in Transplant Creations=
protocols reduced to these necessary for treatment and do not exceed
what should be the standard of care.
Top Site Map