Surgeons in the U.S. have successfully transplanted a pig kidney into a human for the first time without it triggering a rejection by the recipient’s immune system, Reuters reports.
The procedure involved the use of a pig whose genes had been altered so that its tissues no longer contained a molecule known to trigger almost immediate rejection.
Dr Robert Montgomery, who led the study, theorised with his team that knocking out the pig gene for a carbohydrate that triggers rejection — a sugar molecule, or glycan, called alpha-gal — would prevent the issue.
To do this, a pig embryo with one gene modified was implanted inside a surrogate sow by United Therapeutics Corp’s Revivicor unit.
The sow then delivered a piglet with a modified immune system more compatible with humans.
Once an adult, the pig also had surgery to attach its thymus to its kidney. The thymus is a small gland near the top of the lungs, which produces white blood cells.
Transplanting the pig thymus along with its kidney is aimed at reducing a person’s long-term immune response to the foreign kidney.
Surgeons then attached the organ to the human recipient’s thigh, giving researchers access to it.
In theory, the patient’s thymus would then be removed.
