The evolving tech behind bone marrow transplants

Advances in technology and international cooperation have improved the chance of finding stem cell donors for blood cancer patients, and ultimately saved lives. As we celebrate World Marrow Donor Day this September, we look at how far the evolving technology has taken us in only two decades.

More lives saved

One of the biggest changes the bone marrow donor sector has seen has been with the donations themselves. In the beginning, the only way to extract bone marrow stem cells was from the hip. However, it’s a relatively inefficient method and requires an anaesthetic, says the Australian Bone Marrow Donor Registry’s Medical Director Dr Hung Yang. Now, 90 percent of donations in Australia involve peripheral blood stem cells (PBSC) being extracted via the bloodstream. It’s a non-invasive procedure that’s carried out in a hospital and is like a long blood donation.

Prior to the donation, the donor has a course of hormones to stimulate the production of stem cells and push them into the peripheral blood. The donation is then collected using a cell separator machine that extracts the bone marrow stem cells from the bloodstream, returning the rest of the blood back to the donor. On average, it’s a four-hour procedure that’s pain-free and many donors are surprised at how easy the process is.

South Australian donor Paris Boin, 24, recalls a positive experience.

“Everyone in that department was very cheerful and laughing…” she says of the hospital she attended. “I had a nurse come in who made sure that I was entertained, made sure that I had enough snacks and enough drinks…”

As a result of such a big change to the way people donate, becoming involved has never been easier and more Australians are stepping up to save lives.

Match making

With better technology also comes better matching. Decades ago, the success rate for blood transplants was limited by our evolving ability to genetically match the HLA (human leucocyte antigen) tissue type of donors and patients. The development of DNA testing and particularly “next generation sequencing” over the last 20 years has completely changed the game for both patients and donors.

In the beginning, HLA testing of blood cancer sufferers and donors relied on a procedure called serology testing, which uses antibodies in blood. But that method was both complicated and inaccurate. The introduction of DNA testing was an important step in improving accuracy, but it was next-generation DNA sequencing technology that provided the real quantum leap because it allowed doctors to test HLA in incredible detail and more efficiently.

For you and me, this means that matching is more reliable and testing streamlined. “It’s allowed us to be much more accurate and it’s a cheaper technology so we can test more people for the same money,” says Dr Yang.

These advances also meant that doctors could use non-blood samples to determine DNA. Oral samples – saliva or a cheek swab – became an option. This not only made the testing process much more accessible for people with busy lifestyles, but also less intimidating for those who dislike needles. For the registry, it simplified donor recruitment, allowing them to introduce Strength to Give as a “mail order” programme.

Bringing the world together

Improved technology has made testing around the world more in tune. Prior to next-generation DNA testing, HLA testing methods varied greatly with some labs still using serology while others had moved to DNA testing. For this reason the World Marrow Donor Association (WMDA) introduced a mandatory check called “confirmatory typing”, also known as verification typing, which is where the patient’s own lab is given a sample, to confirm the HLA match.

The standard use of next-generation DNA testing has virtually eliminated those discrepancies, but confirmatory typing remains an important step for verifying donor identity and checking for administrative errors because so many donations come from a country that’s not the patient’s home.

“The huge variation in HLA types means that it can be very difficult to find a genetic match for a patient who needs a transplant.  Being able to access donors from other countries can make all the difference. But all that relies on the interconnected network of world-wide registries being able to cooperate in using technology to register more donors, match more patients and collect more donations” says Dr Yang.