Blood disorders: When a bone marrow transplant is the solution
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Last week, a team of doctors from India carried out free check-ups for patients with sickle cell and blood disorders like leukemia, lymphoma and myeloma and blood cancer. This was at the bone marrow transplant consultation camp held at Legacy Clinics in Nyarugunga sector, Kicukiro District.
During the camp, the team provided consultation and educated patients and their families about treatment options, possible risks and cost implications for sickle cell anaemia, blood disorders and blood cancer patients.
The medics explained that for a successful bone marrow transplant procedure, identifying the right donor is the first step. The team also provided human leukocyte antigen (HLA) typing test kits to families and took samples from children and parents that will be sent to the USA for the high resolution testing.
The team disclosed that they had performed more than 300 pediatric transplants for sickle cell anemia and other various blood disorders for patients from across the globe, including Rwanda.
At the camp, more than 50 patients were checked and most of the problems identified included leukemia and sickle cell anaemia, with some of them requiring a transplant.
The camp also intended to create awareness among the population about the available treatment options for different kinds of blood disorders in India.
Dr Tharcise Ngambe, a pediatrician at King Faisal Hospital, says Rwanda currently doesn’t offer bone marrow transplants and that for the patients who need such treatment, they are sent to other countries among them India.
What’s bone marrow transplant?
According to Dr Vikas Dua, a senior consultant in pediatric haemato-oncology immunology, bone marrow transplant (also called stem cell transplant) is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells.
“The bone marrow is the soft, fatty tissue inside your bones which produces blood cells. Stem cells are immature cells in the bone marrow that give rise to the different blood cells,” he says.
Dua explains that a bone marrow transplant procedure involves transplanting blood stem cells, which travel to the bone marrow where they produce new blood cells and promote growth of new marrow, which in turn gives a normal and healthy life to the patient.
Bone marrow transplants, Dua says, have been successfully used for the treatment and cure of a variety of blood cancers, immune system diseases and blood diseases like sickle cell anemia, thalassemia, myeloma, lymphoma, leukemia and many others for years.
How does a bone marrow transplant work?
In a person with sickle cell disease, the bone marrow produces red blood cells that contain hemoglobin S, which leads to complications of sickle cell disease.
“To prepare for a bone marrow transplant, a procedure called chemotherapy is used to weaken or destroy the patient’s own bone marrow, stem cells, and infection fighting system. This is done so the patient does not reject the new blood cells coming from the donor,” Dua says.
He further explains that the patient’s bone marrow is then replaced with blood-forming stem cells from a donor who does not have sickle cell disease. This can be a donor with normal hemoglobin or a sickle cell trait. The actual transplant is given like a blood transfusion through an intravenous (IV) tube.
The new bone marrow then produces red blood cells that are healthy since they do not contain a lot of hemoglobin S.
Who can be a donor?
First of all, two major requirements must be met for a transplant to proceed.
The first one, Dr Dushyant Magu, another specialist from India, says is to identify the person who is the best donor and that the human leukocyte antigen test or blood tests will determine who the best match is.
Secondly, he notes that after the best donor is chosen, both the donor and the patient must have pre-transplant evaluations of the heart, lungs and kidney, among others.
According to Magu, there are three main types of stem cell donors.
The first is match related. He says here is where a family member, especially a sibling or parent who has the same bone marrow type is the ideal donor. This is because these close family members are matched through a special test called human leukocyte antigen test.
Another category, Magu says is known as matched unrelated. He points out that here, volunteers who have the same bone marrow type as the patient can also qualify as donors.
“Usually these types of donations are matched through national organisations or registries that match donors and patients who have the same type of bone marrow,” he says.
However, there is also a third type of donor known as haploidentical, which, according to Magu remains the only option for saving the patient who doesn’t have a matching donor.
He explains that this is normally with half-matched family members, usually a mother or father. Magu adds that, stem cells can be obtained from the donor’s bone marrow or peripheral blood (blood in the veins). Or in some cases, stem cells are collected from the umbilical cord at the time of birth.
Magu says bone marrow (stem cell) transplant is the only treatment available today that can cure sickle cell disease.
Risks associated with bone marrow transplant
One of the main risks associated with transplant, Dua says is infections.
He explains that chemotherapy lowers the white blood cell count, which puts the patient at a high risk for infections that can be caused by bacteria, fungi or viruses.
To prevent this, Dua says medication is given to fight these germs and prevent secondary infections. Infections that do not respond to the treatment can lead to death in 5 to 10 per cent of patients, he says.
Another risk Dua says is graft-versus-host disease (GVHD). He explains that this reaction occurs when the immune cells of the donor sense that cells of the patient are different and attack them.
“This can be a serious side-effect of transplant,” he says, adding that GVHD occurs in up to 10 per cent of patients who undergo matched related types of transplants, and that incidence can be higher in transplants using other donors.
Dua notes that this condition can be acute (occurring less than 100 days after the transplant) or chronic (occurring more than 100 days after transplant). It may cause damage to the skin, liver and the intestinal tract of the patient.
In order to prevent this, Muga says drugs are given to prevent or limit GVHD. These drugs increase the patient’s risk of infection. However, GVHD that does not respond to treatment can lead to organ damage or even death.
Nutrition problem is another risk. Dua says the stomach and intestines are sensitive to chemotherapy. “Nausea, vomiting, mouth sores, diarrhoea, and loss of appetite may occur. Typically, food must be given through the veins until patients are able to eat,” he says.
Graft failure is also another risk associated with bone marrow transplant, and according to Muga, there is about a 10 per cent risk that the new bone marrow from a matched family member will fail to work.
Dua says the chance of graft failure is higher with other types of donors. This means that the patient will not be able to make any white blood cells, red blood cells, or platelets.
“Typically, the transplant would need to be repeated. If there are no more donor cells, stem cells collected from the patient before the transplant can be given back to the patient. This restores the patient’s original bone marrow, which means the sickle cell disease comes back,” he adds.
Further, Dua also points out that infertility is a risk associated to the transplant procedure. “Most patients who receive a transplant will not be able to have their own children in the future. This is one possible side effect of drugs used while preparing for the transplant; however, there have been patients who were able to conceive children after having a transplant,” he says.