Scientists convert a kidney from blood type A to universal type O and implant it in a brain-dead recipient

In a step toward increasing access to donor organs, scientists have converted a blood-type-A kidney to blood type O and then transplanted it into a brain-dead person. Humans have four major blood groups — A, B, AB and O — and the immune system of a person with one blood type may react against another type. For example, a transplant candidate with type O blood can only receive a type-O donor kidney, but someone with A, B or AB blood type can also receive a type O kidney. The team transplanted the ECO kidney into the recipient, who carried a high quantity of anti-A antibodies. Immune responses to the new kidney appeared on day three, which is when the ECO kidney began creating new A antigens.