
Lab-grown Blood Given To People in World-First Clinical Trial (bbc.com) 24
If 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. Prof 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. At the moment, there are only three units of the "Bombay" blood group -- first identified in India -- in stock across the whole of the UK.