Going beyond A, B and O: Thermo Fisher unveils DNA test for the rarest blood types

Thermo Fisher Scientific has put forward a DNA-based test it says can offer much more precise identification of blood and its potential compatibility—going much further than the traditional positive and negative blood types of A, B, AB and O.

Currently available for research use only, the company said its genetic approach could help support the development of cost-effective diagnostics for screening blood donations and matching them to the proper patients in need, including those with extremely rare blood types.

When a person receives incompatible blood through a transfusion or a transplant, the immune system can develop antibodies that trigger severe or potentially fatal reactions to future doses—with that risk increasing for patients who receive frequent transfusions, such as people undergoing chemotherapy or treatments for certain blood disorders.

In sickle cell disease, for example, the company estimates that the rate of immune system reactions to the presence of new red blood cells can range from 18% to as high as 65%. At the same time, shortages in blood donations can make finding exact matches even more difficult.

The Axiom BloodGenomiX Array covers more than 40 genes and 260 antigens across 38 blood group systems in a single assay, as well as tissue and platelet types, and can be run on Thermo Fisher’s automated, high-throughput Applied Biosystems hardware.

The test was developed in collaboration with the Blood Transfusion Genomics Consortium, which includes several national and international blood banks and transplant centers alongside Thermo Fisher, toward a goal of making comprehensive blood typing the new standard of care.

“Adoption of DNA-based blood typing will pave the way for large-scale genomics research and the future establishment of international standards to improve the safety and efficacy of blood transfusion for millions of patients,” consortium chair Willem Ouwehand, M.D., Ph.D., professor of experimental hematology at the University of Cambridge and NHS Blood and Transplant, said in a statement.

According to Thermo Fisher, a validation study employed 14,000 diverse DNA samples from the national blood services of Australia, Canada, England, Finland, the Netherlands, South Africa and the New York Blood Center. The array showed a 99.89% level of concordance with the participants’ blood group antigen types.

A blood type is considered rare if it lacks the antigens found in 99% of other people, while ultra-rare types reach 99.99%. According to Thermo Fisher, the rarest blood type known—dubbed Rh-null, or “golden blood” for its universal compatibility—has only been identified in fewer than 50 people in the world.