The following is for general information purposes only and is mainly based on transplants for CML. Information sources are listed at the bottom of this page.
A Bone Marrow Transplant (BMT), also known as a Stem Cell Transplant (SCT), is a complicated process that replaces the damaged and/or diseased stem cells in the patient’s bone marrow with healthy stem cells.
There are 2 main types of transplants:
Autologous Transplant – stem cells are collected from the patient and infused back into the patient’s blood stream.
Allogeneic Transplant – stem cells are collected from a related or unreleated or umbilical cord donor with matching, or close enough matching, blood (HLA) chemistry. The donor’s cells also replace the patient’s immune system, which can prevent the growth or proliferation of any remaining (in Kevin’s case) CML cells.
Days before the transplant, the patient is treated with cycles of high-dose chemotherapy and in some cases, radiation. They are also given a combination of other treatments including anti-nausea drugs, organ protection drugs, anti-seizure drugs, anti-rejection drugs, ATG (Anti-Thymocyte Globulin) immunosuppressant, steroids, anti-histamines, anti-viral drugs and anti-fungal drugs. This regimen is called “conditioning”. Conditioning is done for three main reasons:
1. To clean out and make room in the bone marrow for the transplanted stem cells.
2. To suppress the patient’s immune system to lessen the chance of graft rejection.
3. To hopefully destroy all of the diseased (cancer) cells anywhere in the patient’s body.
During the conditioning phase, the patient may experience common to severe side effects including, but not limited to, nausea, diarrhea, fatigue, mouth sores, bleeding, organ failure, etc… However, there are many drugs given to the patient to help manage and counteract these side effects.
Countdowns vary depending on the transplant patient’s circumstances. The first day of Conditioning marks the first day that the countdown starts leading up to “Day 0”, the day the patient receives his/her stem cells. Typically, the countdown period is 10 to 5 days. For example, if Conditioning is started on January 1st and transplant day is January 7th, January 1st would be “Day -6”, January 7th (transplant day) would be “Day 0” and January 8th would be “Day +1”. Day +100 is considered a transplant milestone, marking the end of the critical serious complication period, for the most part… but a patient is considered high risk for a number of complications for 1-2 years or longer.
On transplant day, the stem cells are infused into the patient’s bloodstream through a tube called a central venous catheter, a Hickman Line. This procedure is not painful and the patient is awake for it. The stem cells need to travel through the blood and find their way into the bone marrow. This process takes about 2-4 weeks. The hope is that the bone marrow will graft and start producing disease-free white blood cells, red blood cells and platelets that will replace the patient’s immune/blood system.
Day +1 to Engraftment
The patient blood cell counts continue to drop until they reach zero and the immune system is deleted. This process take about 7 days. During this time the patient is at HIGH RISK for infection, bleeding and other complications. The patient’s blood system is supported with blood transfusions until the donor cells start to engraft. The patient will also continue to experience side effects from the chemotherapy including, hair loss, mucositis, extreme fatigue, loss of appetite and taste, weight loss, severe diarrhea, infection, bleeding etc.
Engraftment can take approximately 2-4 weeks. During this time the patient is closely monitored by the transplant team for severe adverse reactions, complications, organ damage, rejection and Graft Verses Host Disease (GVHD). Daily blood counts are taken, more chemo is given, vitals are checked, drug doses are adjusted and blood transfusions are given if needed. A little bit a GVHD is good, as long as it attacks any remaining cancer cells.
Engraftment occurs once the donor cells have settle into their new home, replace the patient’s immune system and start producing healthy white blood cells, red blood cells and platelets. Even after this magic happens the patient is closely monitored for several months and possibly years. The patient is slowly weaned off of several drugs to make sure the donor and patient get along. +100 days is considered a milestone in the Bone Marrow Transplant process. It is the most critical time for serious complications. However, transplant patients MUST continue to be vigilant and cautious for a year or longer post transplant and understand that complications can happen at any stage post-transplant.
Transplants are extremely invasive procedures and they can result in severe complications including:
- Bleeding in the lungs, intestines, brain, and other areas of the body
- Clotting in the small veins of the liver
- Damage to the kidneys, liver, lungs, and heart
- Delayed growth in children who receive a bone marrow transplant
- Early menopause
- Graft failure, which means that the new cells do not settle into the body and start producing stem cells
- Graft-versus-host-disease, a condition in which the donor cells attack your own body
- Infections, which can be very serious
- Inflammation and soreness in the mouth, throat, esophagus, and stomach, called mucositis
- Extreme pain
- Stomach problems, including diarrhea, nausea, and vomiting
You can read more about BMT/SCTs by visiting the sources I have provided you with below or simply by googling your own information sources.