SA needs black stem cell donors
Patients who require a transplant are most likely to find a match among those from the same ethnic background. But the donor registries do not reflect the country’s diversity. By
In August, mother of three Phindile Mokwebo (33) was diagnosed with acquired severe aplastic anaemia. This rare, serious blood disorder is caused by a failure of the bone marrow to produce blood cells, and it can be treated with a stem cell transplant.
When a matching stem cell donor could not be found among Mokwebo’s siblings, an unrelated donor was sought through a bone marrow donor registry. To date, no match has been found.
“It has been a very daunting experience,” says Mokwebo. “When people are getting tested, you have this hope in your heart that maybe they will match, and I’ll get these stem cells and life will go on. Because I constantly feel like my life is at a standstill.”
Mokwebo is a teacher of Grade 11 and 12 English, but she has not been able to return to work since her diagnosis. Even leaving the house is a risk to her health.
“I stay at home all the time. The only time I go out is when I have my weekly check-in at the hospital for my blood top-up and my platelets top-up, or when I have to go and see the doctor,” she says.
Mokwebo’s situation is not unique. Patients of African descent have a mere 19% chance of finding a match for a stem cell transplant, according to DKMS Africa, an organisation that recruits stem cell donors.
There are currently 37,811 donors on the DKMS registry. As of March this year, the donor pool was 75.8% white, 8.4% coloured, 8.7% black, 6.8% Asian/Indian and 0.4% unspecified.
The South African Bone Marrow Registry (SABMR), founded in 1991, has more than 78,000 registered donors. Of these, 67% are white, 7.8% are coloured, 10% are black, 9.9% are Asian/Indian and 5.2% are listed as “other/unknown”.
The process of transferring stem cells from a healthy donor to a recipient is known as allogeneic stem cell transplantation. It is used in cases where transplants are required to treat blood cancers, blood disorders or metabolic disorders – conditions that cannot be cured by a patient’s own stem cells.
“Every 72 minutes, someone is diagnosed with blood cancer in South Africa. What that means is I, you, a friend, a colleague may well be one of those people,” says Tumi Sole, a lawyer, social activist and founder of #CountryDuty.
Sole recently partnered with DKMS Africa to raise awareness of the need for greater diversity among local stem cell donors.
“Only 0.04% of South Africans are registered blood stem cell donors, so there’s a lot of work that we as South Africans need to do,” he says.
Many factors can make a person unwilling to donate, including cultural barriers and a lack of understanding of the process behind donation, according to Dr Justin du Toit, bone marrow transplant director at the Wits Donald Gordon Medical Centre.
Donation can be done without putting the donor at physical or financial risk, emphasises Sole. The process usually takes only a few hours at a medical centre.
“There is so much information-sharing that needs to go on,” says Sole. “Views and misconceptions and myths – those need to be challenged.”
⬤
⬤
Becoming a donor
Sole says there are no costs involved in registering as a donor with DKMS Africa. Should a donor be confirmed as a match with a patient, the organisation will cover all costs involved in donation, including travel, meals and accommodation. Similarly, the SABMR covers all costs involved in the process of donating.
Registration with both DKMS Africa and the SABMR involves filling in an application form, and the administration of a buccal swab that will be used to determine a potential donor’s human leukocyte antigen (HLA) characteristics.
HLAs are proteins or markers found on most cells in your body, according to DKMS Africa. A person’s immune system uses these markers to recognise which cells belong to the body and which do not. A match in HLA typing between a donor and patient provides the best chance of the patient’s body accepting the donated cells.
According to the DKMS donor handbook, actual donation involves the following steps: A preliminary medical assessment at the hospital that will carry out your donation;
A daily granulocyte-colony stimulating factor (G-CSF) injection for four consecutive days before the donation. G-CSF is a naturally
Left: People of African descent have a 19% chance of finding a matching donor. Photo: Lizwi Ncaluka/Supplied occurring growth factor that encourages your stem cells to move from your bone marrow to your blood;
A further single injection of G-CSF on the morning of donation;
A peripheral stem cell collection procedure, which usually involves blood being removed from a vein in one arm and passed through a machine that collects the blood stem cells, after which the remaining blood components are returned to the body through a vein in the other arm; and
A short monitoring period after donation to ensure the donor is physically stable. Kim Patton (21), a stem cell donor registered with DKMS Africa, says the process of donating stem cells is not as intensive as some people might assume.
“It doesn’t actually take a lot – it didn’t take a lot out of me to just register and actually donate,” says Patton.
“I was kind of nervous about the whole process, but for me, I just thought I could actually save this person’s life. And I mean, if I were to need [a stem cell transplant] one day, I would also [hope] there would be kind-hearted people out there who would be able, if they are matched, to save me.”
⬤
⬤
⬤
Finding a donor
The ideal donor for a person requiring an allogeneic stem cell transplant is a sibling because they are most likely to have matching HLA typing, says professor Alan Davidson, head of the department of haematology and oncology at the Red Cross War Memorial Children’s Hospital.
“[There is a] one in four chance that a sibling is a match. Getting those cells from another person that you don’t know from [bone marrow] registries… the chances of somebody matching are much lower. But then again, there are a lot more people, and it depends on the size of the registry.”
If a sibling is not a match for a patient, the next step involves searching local registries such as the SABMR or DKMS Africa. But owing to the limited number of black and coloured donors on these registries, black and coloured patients are less likely to find a match than their white counterparts.
“Your probability of finding a match will improve as you increase the number of donors over time. If more people of different ethnicities start becoming donors, the chances of getting a donor is going to become higher,” says Du Toit.
When a local donor cannot be found, local registries can also be used as an access point for larger international registries, says Davidson. “The difficulty, historically, has been the funding side. There’s gradually more availability of international donors, but from a sustainability point of view, that’s not really what we want to do. What we want to do is to recruit more local donors. Genetically, it’s still more likely to get somebody who’s a match if they live in the next town than if they live on the next continent.”
Another option for someone needing a stem cell transplant is haploidentical transplantation, or a “half-matched transplant”, according to Du Toit. It involves using a family member with half-matched HLA typing as a donor. “If we get stuck, we should do haploidentical transplants, and it is doable in the public sector,” says Du Toit.
However, this is riskier and can result in chronic health complications, according to Davidson.
Owing to the limited number of black and coloured donors on these registries, black and coloured patients are less likely to find a match than their white
counterparts