Blood donors genotyped on large scale for first time in major step towards personalised, precision-matched transfusion

Tens of thousands of blood donors have had their blood types DNA tested in a UK first, in a groundbreaking step towards personalised, precision-matched blood.

Blood bags being processed As a part of the STRIDES National Institute for Health and Care Research (NIHR) BioResource study, NHS Blood and Transplant (NHSBT) has carefully DNA tested, (genotyped), 77,000 blood donors, enabling the NHS to precision match blood from donor to recipient in the future, reducing transfusion-related side effects and reducing the risk of reactions from transfusions.

It is the first time that blood groups have been DNA tested on this scale in the UK and could mark the beginning of a significant change in how blood is matched.

How this study will help

The DNA testing is done by NHSBT's Molecular Diagnostics scientists, who investigate blood profiles, and it has already confirmed dozens of donors have rare blood types. The total is expected to rise to several hundred, once all the data has been analysed. The donor blood can be frozen and stored should it be needed in the future for somebody with the same rare blood types – or should they need to receive it back themselves.

Blood matching is vital due to the complexity of blood groups. There are 362 known blood types. People can develop antibodies against blood types their body recognises as foreign.

By precision matching the blood taken from a donor to the intended recipient, the recipient can avoid severe transfusion reactions, in which the donor blood is destroyed by the recipient, which can occur when the body sees the donor red blood cells as foreign and rejects them.

Precision matching significantly reduces the chances of the recipient's immune system seeing the donated cells as foreign. Reactions are a particular risk in those who regularly receive blood, such as those with sickle cell disorder and transfusion dependant thalassaemia, who often go on to develop antibodies, in response to donor cells.

This work is one of several NHSBT programmes to genotype significant numbers of donors and patients and is the first step towards large scale precision matching, which will take many years to be widely implemented. Over time, blood for patients that require repeated transfusions will be sourced from donors who have been matched for an increasing number of blood groups.

The wider STRIDES study, carried out by the NIHR Blood and Transplant Research Unit in Donor Health and Behaviour, was created to improve donor experience and to establish the STRIDES NIHR BioResource. Donors were recruited for STRIDES by NHSBT donor teams during regular donation sessions. The genotyping of 77,000 NIHR STRIDES BioResource donors has been carried out by NHSBT and funded by the NIHR BioResource, partly to support future medical and health-related studies and to also assist NHSBT in more precisely matching.

Statements

Statement from Dr Gail Miflin

Dr Gail Miflin, Chief Medical Officer at NHS Blood and Transplant, says:

"At NHS Blood and Transplant, we are always working to improve patient experience and health outcomes, through an extensive programme of research and development, including the STRIDES study. Taking these 77,000 donors and testing their blood to such a precise level has been an incredible undertaking and will work to significantly change the way we issue blood – especially to those patients at higher risk of transfusion related reactions.

"We will be able to match to an increasing number of blood groups, ensuring that patients have blood that is most similar to their own and reducing the risk of any reactions. It is an example of just how we are driving innovation which can radically improve patient outcomes."

Statement from Kate Downes

Kate Downes, Genomics Programme Director at NHS Blood and Transplant, said:

"Having the ability to genotype 77,000 donors as a part of the NIHR STRIDES BioResource study is extremely significant – this inventory of blood will enhance our capacity to find units with rare blood groups for difficult to match patients as well as provide better matched units for patients who have an increased risk of transfusion reactions, aiding us in our mission to save and improve even more lives.

"As an organisation, NHSBT is focused on investing in research and development and driving innovations that could radically improve patient outcomes and our partnership with the NIHR BioResource is a strong example of that. This genotyping is a first major step towards rolling out precision matched blood more widely, which would be a landmark change in how blood is matched."

Statement from Dr Nathalie Kingston

Dr Nathalie Kingston, NIHR BioResource Director, added:

"Volunteers in the NIHR STRIDES BioResource are already making a significant contribution to research and we are proud to support this work through our partnership with NHSBT.

"There is huge potential to improve blood matching, particularly important for those with inherited anaemias like sickle cell disorder and thalassaemia, or those with rare blood groups, through this work. This complements our Improving Black Health Outcomes (IBHO) BioResource which initially focuses on those living with sickle cell disorder, many of whom require regular blood transfusions."

Statements from rare blood donors

Ryan Wilkinson, 33, a Civil Servant from Essex.

Ryan discovered he has a rare Lu(a+b-) blood type as a part of the study – a subtype only 0.2% of the population has. He said:

"It was amazing to find out that I had such a rare blood type. When I initially signed up to the STRIDES study, I didn’t think that anything would come of it, but it seems so, so worth it now. I was so surprised when I got the letter explaining the results of my blood testing and have now joined an international register of people with rare blood types like mine.

"It's so valuable to know that my blood could now be used in a more targeted way and have a greater impact on somebody's life when they need it most."

Dave Sale, 66, a retired serviceman from Market Drayton, Shropshire.

Dave has been a blood donor since the age of 18 and has recently discovered he has a rare Co(a-) blood subtype, found in up to 0.5% of the population. He said:

"I was very surprised to discover that I have such a rare blood type and find it quite incredible that there are so few who have it, it's extraordinary! It is very reassuring to know that NHS Blood and Transplant are carrying out this type of work, so that my blood may be able to help somebody else directly – or perhaps even myself, if I were ever so unfortunate."

Jamie Mullen, 30, from London.

Jamie discovered he has a rare Yt(a-) blood subtype – found in 0.3% of the population - after he agreed to be a part of the STRIDES study at a regular blood donation appointment. He said:

"I've always donated blood because I wanted to help other people. Finding out that I've got a rare blood type has given me even more reason to find the time to donate blood, knowing that could be integral in somebody’s care. It's interesting to learn about the progress being made in matching blood to individuals even more closely and I look forward to seeing how this could impact future patient care."

The STRIDES NIHR BioResource study looked at 77,000 donors and 52 antigens within 16 different blood group systems – Colton, Cromer, Diego, Dombrock, Duffy, Kidd, Kell, Knops, Lutheran, LW, MNS, P1PK, RH, Scianna and YT. The study will now go on to confirm the blood groups in at least 20,000 donors who have been identified as having either rare blood groups or combinations of different blood groups, which will provide the best matches for patients who require regular transfusions. Once completed, this confirmatory testing will allow matched units to be issued to patients.