People receive blood created in a laboratory in an unprecedented test

Volunteers received transfusions of laboratory-created blood in the world’s first clinical trial of its kind, carried out by UK researchers.

Small amounts are being tested to see how laboratory blood behaves within the body.

The purpose of this test is not to replace blood donations entirely — most blood transfusions will always rely on voluntary donors. The goal of the experiment is to manufacture blood for ultra-rare blood groups, which are difficult to obtain from donors.

This is the case for patients who rely on regular blood transfusions for conditions such as sickle cell anemia.

If the blood doesn’t exactly match, the body starts to reject it, and the treatment doesn’t work. This level of tissue compatibility goes beyond the known blood groups A, B, AB and O.

Professor Ashley Toye of the University of Bristol in the UK says some groups are “very, very rare” – and “there may only be 10 people in the country” able to donate.

There are currently just three units of the “Bombay” blood group – first identified in India – in stock across the UK, for example.

How is blood created?

The research project is led by teams from Bristol, Cambridge, London and from NHS Blood and Transplant, the UK public health system. It focuses on the red blood cells that carry oxygen from the lungs to the rest of the body.

That’s how it works:

• The test starts with a normal donation of about 470 ml of blood;
• Magnetic spheres are used to “fish” flexible stem cells that are capable of becoming a red blood cell;
• These stem cells are encouraged to grow in large numbers in laboratories;
• Then they are directed to become red blood cells.

The process takes about three weeks and an initial reserve of about half a million stem cells results in 50 billion red blood cells.

These are then filtered to obtain about 15 billion red blood cells that are at the right stage of development for transplantation.

“We want to produce as much blood as possible in the future, so I see in my head a room full of machines continuously producing from a normal blood donation,” says Toye.

Two people have already participated in the trial, which aims to test blood on at least 10 healthy volunteers. They will receive two transfusions of 5 to 10 ml at least four months apart — one of normal blood and one of laboratory-created blood.

The blood has been labeled with a radioactive substance, often used in medical procedures, so scientists can see how long it lasts in the body.

Lab-grown blood is expected to be more potent than normal.

Red blood cells typically last about 120 days before they need to be replaced. A typical blood donation contains a mixture of young and old red blood cells, while lab-grown blood is freshly made, so it should last the full 120 days.

The researchers suspect this could allow for smaller and less frequent donations in the future.

There are, however, considerable financial and technological challenges.

Regular blood donation costs the NHS around £130. Cultivating blood will cost a lot more, though the team doesn’t say how much.

Another challenge is that the harvested stem cells end up being exhausted, which limits the amount of blood to be produced. More research will be needed to produce the volumes that would be needed clinically.

“This world-leading research lays the groundwork for manufacturing red blood cells that can be safely used to transfuse people with disorders such as sickle cell anemia,” says Farrukh Shah, medical director of transfusion for NHS Blood and Transplant.

“The potential of this study to benefit patients with transfusion difficulties is very significant.”

This text was originally published here.