Lab-grown blood cells transfused into two patients in a world-first clinical trial

The single-cell randomized trial called RESTORE (Recovery and survival of stem cell-originated red cells), a joint initiative between the NHS Blood and Transplant (NHSBT) and teams in Bristol, Cambridge, and London, was intended to compensate for the shortage of rare blood group types. For such patients suffering from blood diseases, the NHS Blood and Transplant was unable to meet the transfusion requirements. Now, with new blood cells being grown from human blood stem cells in the lab, the "novel" transfusion product for patients who need regular transfusions throughout their life is truly a lifesaver.

"This challenging and exciting trial is a huge stepping stone for manufacturing blood from stem cells," Ashley Toye, co-chief investigator and professor of Cell Biology at the University of Bristol and Director of the NIHR Blood and Transplant Unit in red cell products, said in a statement. "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."

How is the blood grown?

First, the donors were recruited from NHSBT's blood donor base. The selected donors donated a pint of blood, from which flexible stem cells that can become red blood cells are fished out using magnetic beads. These special stem cells are grown in large numbers in labs, eventually "guided" to become red blood cells, reported BBC News. 

Around half a million stem cells can result in 50 billion red blood cells. The latter is then filtered down to 15 billion red blood cells - the entire process takes three weeks, according to the publication. 

Eventually, the amount of lab-grown cells being infused is around 0.16-0.33 ounces (5-10mls) - about one to two teaspoons. 

The trial then compares the lab-grown cells' longevity with infusions of standard red blood cells from the same donor. The team expects the lab-grown cells to perform better as they are newly minted.

Also, if the manufactured cells are seen to last longer in the body, patients who require blood regularly will not even require transfusions as often. This will go a long way in reducing the "iron overload" from frequent blood transfusions.

The patients are hale and healthy, with no side effects

The two people who have been transfused with lab-grown red cells are reported to be healthy, with no untoward side effects. 

A minimum of ten participants will receive two mini transfusions at least four months apart, one of the standard donated red cells and one of the 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," said the release.

Though the trial is a solid step towards the possibility of lab-grown red cells as a clinical product, manufactured cells can only be used for a tiny segment of patients dealing with complex transfusion needs.

"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," said John James OBE, chief executive of the Sickle Cell Society.