Blood that has been grown in a laboratory has been put into people in a world-first clinical trial, UK researchers say.
Tiny amounts - equivalent to a couple of spoonfuls - are being tested to see how it performs inside the body.
The bulk of blood transfusions will always rely on people regularly rolling up their sleeve to donate.
But the ultimate goal is to manufacture vital, but ultra-rare, blood groups that are hard to get hold of.
These are necessary for people who depend on regular blood transfusions for conditions such as sickle cell anaemia.
the blood is not a precise match then the body starts to reject it and
the treatment fails. This level of tissue-matching goes beyond the
well-known A, B, AB and O blood groups.
Ashley Toye, from the University of Bristol, said some groups were
"really, really rare" and there "might only be 10 people in the country"
able to donate.
the moment, there are only three units of the "Bombay" blood group -
first identified in India - in stock across the whole of the UK.
research project combines teams in Bristol, Cambridge, London and at
NHS Blood and Transplant. It focuses on the red blood cells that carry
oxygen from the lungs to the rest of the body.
This is how it works:
process takes about three weeks and an initial pool of around half a
million stem cells results in 50 billion red blood cells.
These are filtered down to get around 15 billion red blood cells that are at the right stage of development to transplant.
want to make as much blood as possible in the future, so the vision in
my head is a room full of machines producing it continually from a
normal blood donation," Prof Toye told me.
first two people have taken part in the trial, which aims to test the
blood in at least 10 healthy volunteers. They will get two donations of
5-10mls at least four months apart - one of normal blood and one of
blood has been tagged with a radioactive substance, often used in
medical procedures, so scientists can see how long it lasts in the body.
It is hoped the lab-grown blood will be more potent than normal.
blood cells normally last for around 120 days before they need to be
replaced. A typical blood donation contains a mix of young and old red
blood cells, whereas the lab-grown blood is all freshly made so should
last the full 120 days. The researchers suspect this could allow both
smaller and less frequent donations in the future.
However, there are considerable financial and technological challenges.
average blood donation costs the NHS around £130. Growing blood will
cost vastly more, although the team will not say how much.
challenge is the harvested stem cells eventually exhaust themselves,
which limits the amount of blood that be grown. It will take more
research to produce the volumes that would be needed clinically.
Farrukh Shah, the medical director of transfusion at NHS Blood and
Transplant, said: "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 potential for this work to benefit hard to transfuse patients is very significant."
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