Lab-grown red blood cells used for mini transfusion by Cambridge researchers in trial that could transform treatments

Two people have been given a transfusion using red blood cells grown in a laboratory in a world-first trial involving Cambridge researchers.

If it proves safe and effective, manufactured red blood cells could revolutionise treatments for patients with blood disorders such as sickle cell and those with rare blood types, for whom finding appropriate matches is difficult.

Chief investigator Professor Cedric Ghevaert, professor in transfusion medicine and consultant haematologist at the University of Cambridge and NHS Blood and Transplant, 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 manufactured blood cells were grown from stem cells from donors and transfused into volunteers in the RESTORE randomised controlled clinical trial, which involves a number of partners.

Prof Ashley Toye, professor of cell biology at the University of Bristol and director of the NIHR Blood and Transplant Unit in red cell products, said: “This challenging and exciting trial is a huge stepping stone for manufacturing blood from stem cells. This is the first-time lab grown blood from an allogeneic donor has been transfused and we are excited to see how well the cells perform at the end of the clinical trial.”

When patients receive a standard donation, they receive red blood cells of varying ages. But the lab grown cells are all fresh, so should perform better and potentially last longer, which would mean fewer transfusions for patients who regularly need blood. This would reduce the risk of iron overload from frequent transfusions, which can lead to serious complications.

While the trial is a step towards making lab grown red blood cells available in future as a clinical product, for the foreseeable future manufactured cells can only be used for a very small number of patients with very complex needs, meaning blood donations remain critically important.

Co-chief investigator Dr Rebecca Cardigan, head of component development NHS Blood and Transplant and affiliated lecturer at the University of Cambridge, said: “It’s really fantastic that we are now able to grow enough red cells to medical grade to allow this trial to commence. We are really looking forward to seeing the results and whether they perform better than standard red cells.”

No untoward effects have yet been reported in the two healthy volunteers involved in the NIHR BioResource who were given the lab grown red cells. The amount of lab grown cells being infused in the trial ranges from around 5ml to 10ml - one to two teaspoons.

To grow them, stem cells were separated from blood donated to the trial then used to grow red blood cells at a laboratory at NHS Blood and Transplant’s Advanced Therapies Unit in Bristol.

At least 10 participants will receive two mini transfusions a minimum of four months apart, one of standard donated red cells and one of lab grown red cells, to find out if the young red blood cells made in the laboratory last longer than cells made in the body.

Further trials will be needed before any clinical use.

John James, chief executive of the Sickle Cell Society, said: “This research offers real hope for those difficult to transfuse sickle cell patients who have developed antibodies against most donor blood types. 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. We strongly encourage people with African and Caribbean heritage to keep registering as blood donors and start giving blood regularly.”

Dr Farrukh Shah, medical director of transfusion for NHS Blood and Transplant, said: “Patients who need regular or intermittent blood transfusions may result develop antibodies against minor blood groups which makes it harder to find donor blood which can be transfused without the risk of a potentially life-threatening reaction. This world leading research lays the groundwork for the manufacture of red blood cells that can safely be used to transfuse people with disorders like sickle cell. 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.”

The trial is a joint research initiative by NHS Blood and Transplant and the University of Bristol, working with the University of Cambridge, Guy’s and St Thomas’ NHS Foundation Trust, NIHR Cambridge Clinical Research Facility, and Cambridge University Hospitals NHS Foundation Trust. It is part-funded by a National Institute for Health and Care Research (NIHR) grant.