When the immune system is
functioning well, it can identify and eradicate threats to human health.
When the hematopoietic (blood) system or the immune system fail to
function properly, various life-threatening diseases develop, or the
body is vulnerable to attack from without (bacteria, viruses) and within
(cancer, autoimmune diseases/disorders, and immune-deficiency
diseases). Transplantation of stem cells through myeloablative bone
marrow transplantation (BMT), reduced intensity conditioning (RIC) or
nonmyeloablative stem cell transplantation (NST) may be the only
treatment for such conditions. The purpose of these procedures is to
create a competent immune system in the patient, which will eradicate
the disease from which the patient suffers.
Each of these medical technologies (BMT, RIC, NST and dendritic cell vaccines) is described below.
|What are dendritic cell vaccines?
|Dendritic Cells: the Master Cells of the Immune System
immune system contains many different players, like an army. The army
has two large branches (the innate immune system, which includes natural
killer cells and others, and the adaptive immune system, which includes
T cells, B cells and the antibodies they produce, and others).
Dendritic cells are the master immune cells – the “General” of the
immune army – and are responsible for mobilizing the whole immune system
to attack pathogens and other threats, including malignant tumor cells.
A growing array of novel immune therapies are focused on the dendritic
cells – helping to activate them and educate them to mobilize the whole
immune system to attack a patient’s cancer cells.
|Dendritic Cell Vaccines: restoring the dendritic cells’ natural role
provides several types of dendritic cell vaccines. These are all
“therapeutic” vaccines, which patients take after they already have
cancer, rather than preventive vaccines. The vaccines are made from two
main ingredients: dendritic cells (master immune cells) plus antigens
(biomarkers) of the cancer being treated. The immune cells are obtained
through a blood draw, and may be the patient’s own cells or cells from a
healthy family member or other donor. The biomarkers are obtained from
the patient’s own tumor tissue if such tissue is available. If not, then
the biomarkers are obtained from a bank or library, or are produced
recombinantly. In cancer patients, the dendritic cells have become
impaired and are failing to mobilize the immune system to attack the
cancer effectively. Dendritic cell vaccines are designed to activate
dendritic cells so that they, in turn, can accomplish this mobilization
of the whole immune system.
vaccines are very simple to administer, generally requiring just an
intra-dermal injection under the skin, like a flu shot. Dendritic cell
vaccines are non-toxic, as confirmed in a very large and rapidly growing
scientific literature and in published reports on clinical trial
experience at many institutions in many locations, totaling nearly 2,000
|What are BMT, RIC, and NST?
|Stem Cells: the Foundation of the Blood and the Immune System
source of all the blood elements and the entire immune system (white
and red blood cells, platelets, lymphocytes, monocytes and the entire
reticulo-endothelial cells and more) is the stem cell.
|Types of Bone Marrow Transplants
may be autologous (from one's own healthy cells saved before they were
damaged, or saved by cryopreservation of cord blood post natally), or
allogeneic (from a family member (related) or from some other donor
(unrelated)). The kind appropriate for a particular patient is
determined by his/her physician based on the type of disease needing
treatment, disease status, the medical condition of the patient, and the
availability of a donor. Standard BMTs have a severe impact upon the
patient, as described below. CTCI’s Medical Director, Dr. Slavin, has
pioneered a far less toxic version of BMT, as also described below,
which can be provided to a much wider range of patients. One of CTCI’s
specialties is providing these milder BMTs.
described below, the more common and severe BMT procedure is used to
restore a patient's immune system after intense (lethal dose of)
chemotherapy directed at a serious cancer like leukemia has destroyed
the patient’s immune system. The milder version pioneered by Dr. Shimon
Slavin does not involve any lethal dose of chemotherapy. It is simply
directed at re-establishing an effective immune system by using a
donor's healthy immune cells to augment the patient's own immune system,
without the donor cells being rejected, to strengthen the patient's own
cancer defense response.
|Standard BMT Procedures
fully myeloablative bone marrow transplantation procedure must be
performed in a hospital under clean and isolated conditions since the
patient's own immune system is destroyed by the process, and the patient
has no natural defenses during the period it takes for the transplanted
stem cells to create new functioning white blood cells and the immune
system. This procedure is difficult for patients and can only be offered
to those who can withstand the rigors involved. Myeloablative BMT is
generally not offered to patients over age 60.
|"Mini Transplant" – A Milder Treatment
procedure was developed by Professor Shimon Slavin in the 1980s,
followed by clinical application of RIC and NST in the 1990s. The
nonmyeloablative stem cell transplant (NST) is much easier to tolerate
and can be performed on an outpatient basis with few side-effects for
the recipient. The procedure can be applied to elderly individuals with
no upper age limit and is also suitable for use for patients in less
than optimal clinical condition. In children and young adults, fertility
is retained. The transplant procedure is not associated with severe
side effects such as cataract formation and impairment of growth and
development in children. Tests before the procedure may take a number of
days, and tests to monitor the effectiveness of the procedure are
performed periodically over several months. However, side effects are
generally mild and hospitalization for them is infrequent.