Finding matching donors

How is blood stem cell donation different to blood donation?

Donating blood stem cells is similar to giving blood in 90% of cases. However, whether a donor and a patient in need of a blood stem cell transplant are a suitable match is decided on the basis of their human leukocyte antigen (HLA) type (tissue type), rather than on the basis of their blood type.

When you register as a potential blood stem cell donor, you complete a cheek swab which is then analysed at our lab to establish your tissue type. If your tissue type matches that of someone in need, we will be in contact as soon as possible – you could end up saving someone’s life!

There are two methods of donating blood stem cells.

What are HLA characteristics?

As a potential blood stem cell donor, your tissue type will be matched using human leukocyte antigen (HLA) typing. HLA are proteins or markers found on all cells in your body. These proteins are used by your immune system to recognise which cells belong in your body and which cells do not. If these proteins do not match, the patient’s body would reject the given stem cells of the donor. A close match means that the patient’s immune system would recognise your blood system as its own.

With more than 20,000 known characteristics that can occur in millions of combinations, finding a match is extremely rare. Approximately two thirds of patients who need a transplant do not have a suitable donor within their family and rely on the register to find an unrelated donor. In these cases, the patient’s doctor will search for an unrelated donor. To be considered a match, the patient and donor must have at least 8 out of 10 tissue characteristics in common, but ideally should have 10. The rarity of having matching HLA tissue-type characteristics is the reason finding matching donors is so difficult.

What happens if no matching donor can be found?

If no matching donor is found for a patient, their consultant will try to help the patient through other forms of treatment. Typical treatments are (but are not limited to) chemotherapy and radiation therapy, although this will vary depending on the patient’s specific needs. For many patients however, a blood stem cell donation may be their only hope of survival.