Doctor sheds light on stem cell transplant
MIRI: We have probably heard a lot about haemopoietic stem cell transplant and how it has become an option for blood-infused disease patients for survival.
But, how far do we understand haemopoietic stem cell transplant and what it can do?
Paediatric haematologist and oncologist of Sarawak General Hospital, Dr Ong Gek Bee, who was here recently shed light on stem cell transplant and why it is crucial to encourage more people to become stem cell donors.
“People are often confused between bone marrow stem cells transplant and haemopoietic stem cell transplantation. These two serve the same purpose as options for cure. However, they are completely different procedures,” she pointed out.
People are often confused between bone marrow stem cells transplant and haemopoietic stem cell transplantation. These two serve the same purpose as options for cure. However, they are completely different procedures.
What is haemopoietic stem cell transplant? When bone marrow, an important part of human body that produces blood cells has been destroyed due to disease, chemotherapy or radiation; healthy blood forming stem cell from donated bone marrow, peripheral blood or cord are transplanted into the patient to give back stem cells. Therefore, stem cell transplant is said to be the best possible treatment option, and for some patients, offers the only potential cure.
The transplant, she elaborated, involves putting healthy bloodforming cells from a donor into the patient’s bloodstream, where the stem cell begins to divide and grow and make healthy red blood cells, white blood cells and platelets.
“Depending on where the stem cells come from, this procedure may be called bone marrow transplant, peripheral blood stem cell transplant or cord blood transplant.”
Prior to the transplantation, patients will receive high doses and several rounds of chemotherapy to prepare their body for the transplant.
On the transplant day, the patient receives the donated cells in a process that is similar to getting blood or medicine through intravenous ( IV) catheter or tube.
After the transplant, the stem cells will begin to divide and grow and make healthy red blood cells, white blood cells and platelets. Usually, the whole process, called engraftment, takes about one to three months.
“The risk while waiting for the growth process is the patient is like a baby with defective immune system and is prone to infections,” said Dr Ong. Bone marrow stem cells vs peripheral blood stem cells Bone marrow donation, according to Dr Ong, is a method of collecting blood forming cells for bone marrow transplant. As it is a surgical procedure, needles are used to withdraw liquid marrow (where the body’s blood-forming cells are made) from both sides of the back of the pelvic bone.
“The procedure also involves the donor be given anaesthesia and therefore, no pain during the donation, and after that the donated liquid marrow will be infused into the patient for transplant,” she said, adding that the procedure would often terrify people who do not understand.
Peripheral blood stem cells ( PBSC) process, on the other hand, is a non-surgical procedure called apheresis to collect bloodforming cells for bone marrow transplants.
“The donation will take place at an experienced blood centre outpatient hospital facility that participates in PBSC collections – usually either in Kuala Lumpur or Sabah.
“For five days leading up to the PBSC donation, the donor will be given injections of a drug called ‘Neupogen’, a growth-factor drug
Dr Ong Gek Bee, paediatric haematologist and oncologist of Sarawak General Hospital
that causes the bone marrow to make and release a lot of stem cells into the blood.
“It is a little time- consuming as the donor would have to visit the hospital or clinic for four days in a row to receive injections which stimulate the production of stem cells and finally, on the fifth day, the donor will be connected to a cell-separator machine.”
The cell- separator machine is used to collect the stem cells from the blood through a vein in one arm, returning the blood into the donor’s body through a vein in the other arm.
“It is important to note that this procedure takes about four to five hours and may need to be repeated the following day.”
After that, she said, about 90 per cent of all PBSC donations are completed in one apheresis session whilst the remaining 10 per cent of the donations are completed in two apheresis sessions, which will take up to four or six hours each.
Between the two, peripheral blood stem cells (PBSC) procedure is said to be safer than bone marrow stem cells donation but PBSC is said to require more time than the latter. Side effects of bone marrow vs PBSC For bone marrow donation, donors are usually required to stay overnight after the marrow donation to make sure that they have recovered fully from the general anaesthesia.
The common side effects of marrow donation include back or hip pain, fatigue, throat pain, muscle pain, insomnia, headache, dizziness, loss of appetite and/or nausea which are often reported two days after the donation.
As for PBSC, Dr Ong said it is important for the donor to understand that the side effects may or may not occur to every donor.
“Some may experience headache or bone pain and muscle aches, similar to a cold or the flu, for several days due to Neupogen injections. Other common side effects are nausea, insomnia and tiredness.”
She explained that during the procedure some donors would probably experience tingling around the mouth, fingers and toes and mild muscle cramps and other common side effects include bruising at the needle site, chills and decrease in the blood platelet count.
“Rest assured that less than one per cent ( 0.6) of donors will experience any serious side effects,” she said. Why the need for haemopoietic stem donor? “Typically, I believe many have heard that it is ideal that healthy stem cells are donated by a close family member, such as siblings because there is a need to have a close match between tissue types. However, the brutal reality is that only around 30 per cent of patients will have a close relative with a matching tissue type.
“So, what about the remaining 70 per cent who do not have a matching donor in their family? It is during this time that their doctor will either turn to Malaysian or international registry for help to find an unrelated donor,” Dr Ong pointed out.
Malaysian Stem Cell Registry ( MSCR) which was set up in 2000 as a collaboration between the Institute of Medical Research, Ministry of Health and National Cancer Council Malaysia, plays a crucial role in registering stem cell volunteer donors, she added.
MSCR focuses on collecting database of volunteers in Malaysia who are willing to donate their blood stem cells to matching patients undergoing transplant.
“However, due to diversity of race and intermarriage especially in Sarawak, the probability of finding a matching donor is low. Therefore, the SCCS and MSCR stem cell donorship campaign that kicked off from Kuching to Miri is making the calls around Sarawak for more people to join the registry so that the patients have greater chance of finding a match.”
The ideal donor, she reiterated, is aged between 18 and 50 years who is free from any chronic disease or conditions such as Hepatitis B and Hepatitis C, HIV, heart attack or heart failure, kidney failure or disease or medical history of cancer including leukaemia.
Even if the registered volunteer is said to be suitable, he or she will still be given a full medical checkup before the actual donation and will still be rejected as donor if the doctor thinks that he or she is not suitable due to health concerns, said Dr Ong, stressing that it is important to become a responsible donor as it is a matter of saving another person’s life.