Scientists Begin Trials for Transfusions of Lab-Grown Blood Cells

Blood transfusions are an important way to replace lost blood, often saving lives in the worst possible circumstances. But not everyone can get the procedure. Some patients with rare blood group types don’t meet the requirements. But what if they could use blood grown in a lab?

The National Health Service (NHS) in the U.K. announced on Monday that it has started a clinical trial where researchers will be administering laboratory-grown red blood cells to patients. Notably, this is the first time ever that red blood cells grown in a lab will be given to another person as part of a blood transfusion trial. 

The study––called the RESTORE trial––is a joint research initiative between the NHS Blood and Transplant (NHSBT) and the University of Bristol,  as well as various researchers at the University of Cambridge. 

In a YouTube video from NHS, University of Bristol researcher Ash Toye explains that RESTORE is a clinical trial set up to assess whether lab-grown red blood cells are similar, or possibly even better, than a donor’s own blood cells produced inside the body. 

“We’re hoping that because they’re so freshly made and ready to go that they’ll be better. If that’s true, then this will be a world first because effectively we’ve taken a cell produced in the donor and we’ve put them into a volunteer who is not related to the donor and they’ve been matched,” he said.

Now, these cells are not just cooked up in a lab from scratch. They’re red blood cells grown from human blood stem cells, specifically CD34+ cells isolated from adult donor blood. (Donors were recruited from NHSBT’s blood donor base).  Using stem cells allows researchers to pretty much conjure up whatever type of blood cell type they need, with the hope that it won’t be rejected by the body. 

As Toye explained in a follow-up email with Motherboard, laboratory-made blood has been transfused before through autologous transfusion, in which researchers utilized stem cells from a donor and then put the lab-grown red cells back into the person. But this is the first time it’s been transferred to another person, a process known as allogeneic transfusion. 

“Most blood donation is allogenic—and the trial we are doing is also allogenic, i.e the cells come from a donor and then we put them into another person and see how they perform vs. the donors own red cells they produced in the body (that get given first or second dependent on the randomisation in the clinical trial),” he wrote.

Toye also explained that the trial builds on preclinical work published in 2017, where researchers compared stem-derived cells in a mouse model versus donated blood. (Toye notes that it is difficult to study in mice as the mice destroy the human cells because they don’t recognize them). 

The group has already transfused mini doses into two recipients with lab-grown red blood cells, but the rest of the trial will continue over the next few months. According to the press release, the study will recruit a minimum of 10 participants, who will receive two mini-transfusions at least four months apart (one of the standard donated red cells and one of lab-grown red cells). Further trials will be necessary before this method is implemented on a wide scale. 

However, if the manufactured red blood cells do indeed outlast the standard ones, this could have implications for individuals with blood disorders, rare blood types, or complex transfusion needs. 

“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,”  Dr Farrukh Shah, Medical Director of Transfusion for NHS Blood and Transplant, said in a statement provided by a NHS spokesperson. “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.”