The NHS first proposed this trial in 2015 (see BioNews 808). Now, using red blood cells derived from stem cells, the transfusion was performed on volunteers in the ongoing RESTORE clinical trial (a joint initiative between the NHS and the University of Bristol). Currently, two people have been transfused with the cells, with no adverse side effects reported.
Professor Ashley Toye of the University of Bristol and director of the National Institute for Health and Care Research Blood and Transplant Unit in red cell products, explained: 'this challenging and exciting trial is a huge stepping stone for manufacturing blood from stem cells. 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.'
The process of creating these cells takes around three weeks. First, stem cells are extracted from a normal donation of blood. These stem cells are then guided into growing and becoming red blood cells.
The trial is planned for a minimum of ten healthy participants, who will receive two transfusions of five-ten mls of blood at least four months apart. One of lab-grown blood cells and one of standard red blood cells from the same donation of blood. This will allow for a comparison of whether the lab cells last longer.
The trial team expects the lab-grown cells to perform better and last longer than a standard transfusion of donated red blood cells, as they are all 'fresh', in comparison to donated blood, which would contain cells of all ages. This could mean patients would not require transfusions as often, reducing the risk of iron overload (which can occur after frequent transfusions).
If the trial is successful, proving safe and effective, this discovery could revolutionise treatments for blood disorders. Patients with disorders such as sickle cell disease may require up to 12 units of blood transfused every four to six weeks. Yet, it is often difficult to find a good blood match from a donor. Manufacturing red blood cells from stem cells means it becomes possible to create transfusions that match these ultra-rare blood groups.
John James OBE, chief executive of the Sickle Cell Society, who is not involved in the trial, stated: 'this research offers real hope for those difficult to transfuse sickle cell patients who have developed antibodies against most donor blood types.'
The challenge of this new discovery is that it is an expensive process. On average, blood donation costs the NHS around £130, and although the team is not currently willing to disclose the costs, growing red blood cells is expected to cost more.
Furthermore, the team believes that lab-grown cells will only be used for a very small number of patients with very complex transfusions needs, and that donors will continue to be required to provide the vast majority of blood for transfusions.