In a world-first clinical trial, red blood cells that were grown in a laboratory have been transfused into two people.
It’s a major step toward lab-grown cells being used in blood transfusions – instead of blood from donors.
Who would benefit? The initial focus is on people with blood disorders such as sickle cell and rare blood types.
Firstly, by creating blood in the lab they’ll circumvent the problem of finding enough well-matched blood from the donor pool.
Secondly, lab-grown cells are effectively “fresh” when used in a transfusion, and will remain viable longer than donated blood.
How long do red cells live for?
Red blood cells are viable for about four months and then need to be replaced.
Whole blood taken from a donor contains a mix of young and old red blood cells, whereas the lab-grown blood is all freshly made so should last the full four months.
The UK researchers expect these fresh cells to perform better than a regular transfusion.
Plus, if manufactured cells last longer in the body, it’s thought that patients with blood conditions won’t need transfusions as often.
The big benefit is a reduction in iron overload from frequent blood transfusions that can lead to scarring of the liver and other complications.
The clinical trial
Known as the RESTORE trial, the research is a joint effort by NHS Blood and Transplant, University of Bristol, University of Cambridge and others.
The process starts with a bag of donated whole blood, about 470ml.
Using magnetic bead technology, pluripotent stem cells are filtered out. These are the stem cells that can be cultivated into any type of cells in the body: In this case, red blood cells.
As it goes with stem cell therapies, the pluripotent cells are grown in large numbers in the lab, and then manipulated into becoming red blood cells, a process that takes about three weeks.
According to a BBC report, an initial pool of about half a million stem cells blooms to 50 billion red blood cells.
Out of this pool, about 15 billion red blood cells “at the right stage of development to transplant” are filtered out.
The human factor
Two people were transfused with a small amount of lab-grown cells, about 5ml to10ml – or one to two teaspoons.
According to a statement from the University of Cambridge: “They were closely monitored and no untoward side effects were reported. They are well and healthy.
“The identities of participants infused so far are not currently being released, to help keep the trial ‘blinded’.”
A minimum of 10 participants will receive two mini-transfusions at least four months apart, one of standard donated red cells and one of lab-grown red cells.
This is to confirm that the laboratory cells last longer than those in the body.
These are early days and further trials are needed before clinical use.
Dr Farrukh Shah, Medical Director of Transfusion for NHS Blood and Transplant, said: “Patients who need regular or intermittent blood transfusions may [as a] 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.”
