The breakthrough could prove “transformative” for patients with rare blood disorders.

The team suspects the ‘made-to-order’ blood may last longer than regular transfusions and carry less risk of rejection for those who have built up an immunity to all blood types.

Hope across the globe

An end may be in sight for those whose life revolves around endless blood transfusions as researchers say they have successfully completed the world’s first infusion of lab-grown red blood cells to humans. Scientists grew the blood cells from stem cells provided by donors that the group then transfused into participants as part of the RESTORE trial. The investigation, headed by the UK’s National Health Service (NHS), is run by a multi-institutional team.

The scientists will investigate how well these made-to-order cells survive in the body compared to a traditional donor transfusion containing cells from different people. To test this, each volunteer will receive one transfusion containing standard cells and, four months later, one with lab-grown cells.

Usually, transfusions containing cells of varying ages last roughly 120 days – conversely, the manufactured cells are all fresh and ‘genetically uniform,’ so they should last longer and be received better by the patient’s immune system.

All this means that the technique could reduce the frequency of transfusions for people who regularly need blood. Consequently, patients could also avoid the complications of high-volume transfusions, such as developing antibodies that target certain blood types and ‘iron overload’ – where too much iron accumulates in the body, damaging organs.

Chief Investigator Professor Cedric Ghevaert, Professor and Consultant Haematologist at the University of Cambridge, said: “We hope our lab grown red blood cells will last longer than those that come from blood donors. If our trial, the first such in the world, is successful, it will mean that patients who currently require regular long-term blood transfusions will need fewer transfusions in future, helping transform their care.”

The genetics

According to the American Red Cross website, blood type is passed genetically from your parents. But not all blood is alike. Presently, eight common blood types exist and many rare ones, with a staggering 43 blood types officially classified (and more expected).

Red blood cells carry markers on their surface called antigens that determine one’s blood type. To give you an idea of the hereditary blood pool’s enormity: more than 600 known antigens are currently swirling around in the human race, with certain blood types only found in specific racial and ethnic groups.

For example, Duffy-negative and U-negative blood groups are unique to African Americans: people with these blood types and sickle cell disease rely solely on blood donors from the Black community when they need a transfusion.

Therefore, when there is a phenotypical match, patients are at a lower risk of complications from transfusion therapy. For this reason, increasing the number of blood donors from all ethnic and racial groups is still extremely important. However, the use of made-to-order blood could put an end to the complications caused by the use of ‘undiversified’ blood transfusions. 

“This research offers real hope for those difficult to transfuse sickle cell patients who have developed antibodies against most donor blood types,” said John James OBE, CEO of the Sickle Cell Society.

And cautions, “However, we should remember that the NHS still needs 250 blood donations every day to treat people with sickle cell and the figure is rising. The need for normal blood donations to provide the vast majority of blood transfusions will remain.” And that “We strongly encourage people with African and Caribbean heritage to keep registering as blood donors and start giving blood regularly.”

The methodology

At the start of the trial, the researchers separated stem cells from the blood of donors recruited from the NHS Blood and Transplant (NHSBT) database. The stem cells they targeted were ‘hematopoietic,’ meaning they can only mature or ‘differentiate’ into red blood cells, white blood cells, or platelets. 

After this, the team placed the matured cells in a nutrient solution for 18-21 days, where they multiplied and developed into more mature cells. According to the Guardian, the group says that roughly 24 liters of nutrient solution produce one to two tablespoons (15-30 ml) of red blood cells.

A tracer was then attached to the cells, enabling the scientists to detect them in the volunteer’s blood samples up to six months after the initial transfusion.

They state that two people have received the new red cells so far, with no untoward side effects reported.

In the next stage of the trials, a minimum of ten participants will receive two mini transfusions containing 5-10 ml of blood at least four months apart. Both will again consist of one standard donation and one of the laboratory-made cells to see which batch lasts longer in the body.

What now

In an official statement, the scientists state: “Further trials are needed before clinical use, but this research marks a significant step in using lab grown red blood cells to improve treatment for patients with rare blood types or people with complex transfusion needs.”

Dr. Farrukh Shah, Medical Director for the NHSBT, said: “Patients who need regular or intermittent blood transfusions may [as a] result develop antibodies against minor blood groups.”

He explains that this makes it harder to use standard blood transfusions without potentially risking the patient’s life and concludes, “The need for normal blood donations to provide the vast majority of blood will remain. But the potential for this work to benefit hard to transfuse patients is very significant.”