Stem Cell Transplant
What Is a Blood and Marrow Stem Cell Transplant?
A blood and marrow stem cell transplant replaces a person's abnormal stem cells with healthy ones from another person (a donor). This procedure allows the recipient to get new stem cells that work properly.
Demystifying Stem Cells:
Stem cell or the 'basic cell' is a simple concept, based on the fact that all humans are made from a single cell. This cell gives rise to all body tissues and organs. However, it has been found that even in adult body, there are cells which can differentiate into any type of cell, and hence potentially can recreate any tissue! This is the premise of stem cell research. If we can find these cells and understand their controls, we can recreate and replace injured or lost tissues due to heart attack, stroke/ paralysis, diabetes, arthritis, liver or kidney damage, etc.
However, it is not as easy as it sounds. Till now, we have not be able to achieve the amount of control that we would like to have - when we inject stem cells into an area of the heart, we still can't predict whether they will grow into heart muscle cells or nerve cells or blood vessel wall cells or in what proportion. Thus, except for haematology, applications of stem cell research in all other diseases are still only in experimental stages.
Why are stem cells important?
Stem cells represent an exciting area in medicine because of their potential to regenerate and repair damaged tissue. Some current therapies, such as bone marrow transplantation, already make use of stem cells and their potential for regeneration of damaged tissues. Other therapies are under investigation that involves transplanting stem cells into a damaged body part and directing them to grow and differentiate into healthy tissue.
If the transplant is successful, the stem cells will migrate into the patient's bone marrow and begin producing new, healthy leukocytes to replace the abnormal cells.
New evidence suggests that bone marrow stem cells may be able to differentiate into cell types that make up tissues outside of the blood, such as liver and muscle. Scientists are exploring new uses for these stem cells that go beyond diseases of the blood.
Researchers are currently examining the use of stem cells to regenerate damaged or diseased tissue in many conditions: Heart disease, Parkinson’s disease, Spinal cord injury, Diabetes mellitus, Amyotrophic lateral sclerosis, Arthritis, Burns.
Collecting Stem Cells:
Stem cells are usually collected from the blood. You will have daily injections of a growth factor (G-CSF). This encourages the stem cells to move (mobilise) from the bone marrow into the blood. Once mobilised, the stem cells will be collected. This takes between 3-4 hours using a cell-separator machine. Stem cells may be collected a second time if not enough are collected at first.
a) Peripheral Blood Stem Cell Collection: Stem cells are generally collected using this method.
b) Bone Marrow Harvest: Stem cells can be collected directly from the bone marrow spaces, most often from the pelvic bones.
When and how are stem cells stored?
The stem cells may be held 1–2 days in the refrigerator or infused the day they are collected if all of the recipient’s conditioning treatment has been completed. If necessary, the stem cells can be frozen and stored for a long time. If the collected stem cells are to be frozen, some fluids and a chemical called DMSO must be added to protect the white blood cells during the freezing process. The cells are then transferred to special bags to be frozen, and are stored in liquid nitrogen freezers until needed.
Cost of this treatment is mainly related to the use of blood products, antibiotics/ antifungals etc, isolation unit, specially trained staff, chemotherapy/ immunosuppressive agents, investigations, stem cell collection and storage. The final figure usually features between five lakhs (for autologus) to10 lakhs (for allogeneic).
Source: Adapted from an article by Dr. Chirag A. Shah.