What Are Stem Cells Transplants?
Stem cell transplant is a cancer treatment in which the doctors treat severe blood related diseases using stem cell transplants. In the process of stem cell transplantation, high dose of chemotherapy is given to the patient. Chemotherapy has higher chances of killing all the cancer cells, but the major drawback of this process is that stem cells in the bone marrow also get destroyed. Earlier patients who needed a stem-cell transplant were in turn given bone marrow transplants because the stem cells were effectively collected from the bone marrow to replace the destroyed stem cells due to chemotherapy.
What Makes Stem Cells Transplant & Bone Marrow Transplant Crucial?
Blood marrow is an important or rather unique part of your bones, which makes blood cells. Marrow is a soft, spongy tissue which is found inside the bones. It contains within; cells known as hematopoietic cells. These hematopoietic cells have the capability to turn into other type of blood cells or healthier cells.
But when certain cancers or blood related diseases like leukemia, myeloma or blood cancer occurs, it prevents he hematopoietic cells from normal development. A stem cell transplant gives the patient new and healthy stem cells, which can produce healthy and newer blood cells.
Types of Stem Cells Transplant
There Are Two Types Of Stem Cell Transplant System:
Autologous Stem Cell Transplant: Doctors refer this type of stem cell transplant as AUTO or self transplant. This type of transplant system involves high dosage of chemotherapy. In Autologous Transplant, the patient gets his/her own stem cells after the cancer is treated. At first, the doctor extracts the healthy stem cells from the blood before starting chemotherapy and freezes them. Next, comes a powerful session of chemotherapy which might also include radiation therapy. After then, the health care system thaws the frozen stem cells and the doctor transplants the frozen stem cells back in the blood of the patient using a tube through the vein. It takes not more than 24 hours for the blood cells to actually reach the bone marrow and then multiply, grow and help the bone marrow in making healthy blood cells again.
Allogeneic Stem Cell Transplantation: This transplant system is also known by the name ALLO transplant system. In this, the patient is given stem cells of other person (donor) whose bone marrow exactly matches the patient’s. Unless the bone marrow matches, it is not possible for stem cells transplant. Human blood has certain type of proteins known as the human leukocyte antigens or HLA. The best matching protein will have the best matching protein system as possible. But the matching proteins can also create a very serious disease known as graft versus host disease or GVHD. In this disease, the healthy stem cells after the transplant attack your cells. Now, once you have found a donor, you will be given a session of chemotherapy which may or may not be accompanied by radiation therapy. Then the donor’s stem cells are transplanted to the patient through a tube. Moreover, the stem cells in the ALLO transplant system need not be frozen.
There are specifically two types of ALLO transplants. The best type depends upon the patient’s age, health and the type of disease being treated. They are:
- Ablative; which takes in use high dosage of chemotherapy.
- Reduced intensity in which mild dosages of chemotherapy is used.
Even if the health care system is not able to find the matching donor, then there are other options too. Research is in process to determine actually the best stem cell transplant which will work for different types of patients.
Umbilical Cord Transplant: This is an option to use when the there isn’t any type of donor match. Cancer centers around the globe use the cord blood to transplant the healthy stem cells to the patient.
Parent Child Transplant System or Haplotype Mismatched Transplant: Such type of transplant system is used much more commonly. The match in such transplant system is generally 50% and not 100%. The donor might be parent, child, brother or sister.
How Does The Stem Cell Transplant System Actually Work?
Below we discuss all the possible steps of AUTO and the ALLO transplant system. The health care team will do the steps in various orders but at times some steps would have to be taken in advance, like the collection of stem cells. Let’s take a look at the transplant system:
Steps in AUTO Transplant
Step 1: Collection of the Stem Cells
- The doctor in AUTO Transplant puts up a transplanting catheter in the vein for about 24 hours from which the stem cells are extracted or collected. The tube stays until the transplant process has completed.
- The patient is administered injections to specifically raise some white blood cells in the body. White blood cells help the body in fighting off infections.
- The health care provider collects the stem cells from the blood.
Time: 1-2 weeks
This is usually done in a hospital or clinic and there is no need for overnight stay in the hospital.
Step 2: AUTO Transplant Treatment
High doses of chemotherapy are given to the patient and very rarely radiation therapy is done.
Time: 5-10 days
This is usually done in hospitals or transplant centers. In stage until the stem cell transplant is done, the patient will have to stay for over 3 weeks in a hospital or if the center is located in the same city or nearby home, the patient can come every day.
Step 3: Retrieving the Stem Cells
Doctors call this system the “stem cell transfusion.” The health care system puts back or transplants the stem cells back in the blood using a transplant catheter.
Time: The exact time taken in this process, normally less than 30 minutes and you receive more than 1 infusion in the process.
Step 4: Recovery
This is perhaps the last phase in the stem cell transplant. In this stage, the patient is given certain drugs, antibiotics which boost the recovery process. You also get blood transfusion through the catheter if needed. The health care system would also look around for other side effects.
Time: The time taken for this process is usually 3 weeks. It’s done in hospital and you have the option of staying in the hospital or not.
Steps in Allogeneic Transplant
Step 1: Finding a Donor and Checking the Eligibility of the Donor
The donor needs to have HLA (Human Leukocyte Antigen) typing which is identical to the patient’s. After a suitable donor has been found the donor’s eligibility is checked to see if he/she is healthy to donate the stem cells to the patient.
Step 2: Stem Cell Donation
Patient undergoes chemotherapy session while the donor will be conditioned with neupogen which is an injection to boost the white blood cells in the body. The patient may also be given radiation therapy along with chemotherapy. While the chemotherapy is going on, the donor is also given injections to increase the WBC count for about 5 days so that stem cells can multiply.
Step 3: Stem Cells Transplantation
The stem cells are collected from the donor and transplanted to the patient the next day through your central line catheter. Patient can experience some side effects which include: fever, chills, wheezing and hives. The patient is monitored closely for all these side effects.
Step 4: Recovery After Stem Cell Transplant
After the transplantation has been done, patient may have some persistent side effects of chemotherapy and may also need blood and platelet transfusions. The transplant team closely monitors the patient following the weeks of transplant to check for transplant complications. Some of the potential complications of stem cell transplant include: infection, graft-versus-host disease, organ damage, relapse and lack of engraftment.