TME 23: Why is it difficult to find a match for Bone marrow donor?

Why Finding a Bone Marrow Donor is Like Finding a Needle in a Haystack

For people with serious blood diseases like leukemia or lymphoma, a bone marrow transplant can be a lifeline. This procedure involves replacing their damaged bone marrow (the spongy stuff inside our bones that makes blood cells) with healthy marrow from a donor. The catch? Finding that perfect donor match is incredibly difficult.

Blood stem cell - AI generated

The Matchmaking Game of Medicine

Imagine our cells have tiny identification tags called HLAs. Think of them like super-specific barcodes. Your immune system uses these "barcodes" to figure out which cells are yours and which are foreign invaders. For a successful bone marrow transplant, we need a donor whose HLA barcodes closely resemble the patient's. A mismatch can cause the patient's body to reject the new marrow, leading to serious complications.

HLA testing and finding a match is one of the most crucial steps in Bone Marrow transplant

It's All in the Family... Or Maybe Not

The trouble is, we inherit our HLA types from our parents – a mix-and-match process like shuffling a deck of cards. Siblings have the highest chance of being a close match, but even then, it's only about a 25% chance. The further you go on the family tree, the less likely you are to find a suitable match.

You must understand that HLA has small small variations within themselves. The higher the match, the higher the acceptance rate. The sample of donors is buccal swabs. The cheek cells contain our genetic material and it is a painless and easy 5-minute procedure to obtain. These samples are processed at an HLA laboratory to know what HLA combination this donor has. The combination is then compared with the patient's HLA combination to ascertain a match.

HLA match is very difficult to obtain in patient and donor

Ethnicity Plays a Big Role

To make things even trickier, certain HLA "barcodes" are more common within specific ethnic groups. A patient's best chance of finding a donor often lies with someone who shares a similar ethnic background. This highlights why having diverse bone marrow registries is critical.

The Search for the Perfect Match

Organizations like "Be The Match", "DKMS", and "Datri" maintain massive registries of potential donors. When a patient needs a transplant, doctors search these registries, hoping for a close match. Unfortunately, even with these extensive lists, sometimes the perfect match isn't found. This can be especially difficult for patients from ethnic groups with fewer registered donors.

Sometimes, perfect match donors can be found in another country in a completely unexpected individual.

What happens if we transplant without a match?

Even if there is a slight mismatch we will go for a transplant if we cannot find a full match. Because the patient might die without a transplant. Transplanting without an HLA match has a higher chance of graft rejection or failure.

Bone Marrow Registries: Connecting Patients and Donors

Bone marrow registries are like giant databases of potential donors. Organizations maintain these registries, collecting information on the HLA types of volunteers. When a patient needs a transplant, doctors search these registries, hoping for a close match. Unfortunately, even with these extensive lists, sometimes the perfect match isn't found. This can be especially difficult for patients from ethnic groups with fewer registered donors.

What happens if a match is not found?

Without a matching HLA bone marrow donor, the patient might die due to the progress of the disease.

How You Can Make a Difference

• Become a Potential Hero: Joining a bone marrow registry is a simple way to make a huge impact. If you're healthy and between the ages of 18-40, you might be eligible. Organizations like "Be The Match" will send you a kit to collect a sample and add you to the registry.

• Spread Awareness: The more people understand the importance of bone marrow donation, the greater the chance of finding matches! Encourage your friends, family, and community to join registries or support the cause.

The Power of a Match

Finding a bone marrow donor might seem like searching for a needle in a haystack, but it's worth the effort. A transplant can be a complex medical procedure, but it offers many patients their best shot at overcoming life-threatening diseases. By choosing to become a potential donor, you could be the key to someone's second chance at life.

Click here to read more about bone marrow donation.