More than 90 million red blood cell transfusions are carried out worldwide every year and the transfusion services are faced with increased pressure to meet demand.
As such, there is a need to find an alternative source of blood cells to alleviate the burden of meeting this demand and to ensure sufficient blood supplies.
While demand in developed countries is increasing – with people living longer and greater prevalence of disease – there is also a major shortage of available blood products in developing countries. The World Health Organisation estimates that less than one per cent of the population– the minimum donation rate – donate blood in Africa, South and Central America.
Lack of effective screening is also believed to account for eight infections per 1,000 units transfused in sub-Saharan Africa. Furthermore, there is a continuing need to maintain vigilance over emerging diseases that might threaten blood supplies.
As well as addressing the above challenges of supply and transfusion-transmitted infection, cultured red blood cells might offer a more efficient product.
They could benefit patients who need regular transfusions, such as those suffering from a chronic anaemic conditions such as beta thalassaemia or sickle cell anaemia. These patients have to undergo frequent transfusions and this puts them at risk of iron loading – when iron builds up in their bodies – which can lead to organ damage.
Cultured red blood cells may reduce this risk, because the cells would be fresher, younger and better-matched than those in donated blood. This means they would survive in the body for longer, resulting in less frequent transfusions and therefore reduce the build-up of toxic iron.
There is also a challenge to address alloimmunisation in these patients, whose bodies start to produce antibodies that attack antigens found in donated blood. This could be addressed with an alternative source of red cells.
A new source of red blood cells would thus not only increase blood supplies, but could also ensure immune compatibility with recipients, prevent the transmission of infection and reduce iron loading.