A new paper details how genetically modified pig hearts transplanted into baboons could support life and function for up to 195 days. In this new breakthrough attempt, the team has replaced the baboon hearts with the pig hearts. The baboons who were receiving the hearts were given medications to stop the pig hearts within them from expanding and also medications to bring down their blood pressures to the levels seen commonly in pigs.
Front view of the pig donor heart (left) and the heart of a baboon from the study (right). He wrote, "Heart failure in the United States is expected to reach more than eight million by 2030, and many of these people will die while waiting for a donor organ". They could keep the baboons alive for an average of 57 days maximum with the pig hearts.
"Although the potential benefits are considerable, the use of xenotransplantation raises concerns regarding the potential infection of recipients with both recognized and unrecognized infectious agents and the possible subsequent transmission to their close contacts and into the general human population", the US Food and Drug Administration says. The hearts were genetically modified to express a human gene called CD46 and thrombomodulin, a membrane protein.
The authors of the "landmark" study refined the procedure with three successive groups of primates - with 16 baboons involved in the study in total.
They achieved successful long-term transplantation in the final group by keeping the hearts oxygenated during the transplant process. They preserved the donor hearts in cold storage at 8C (46.4F) immersed in fluids which contained hormones, red blood cells, nutrients and oxygen which moved in and out of the organ.
He said: 'The publication by Professor Bruno Reichart's group in Munich is a significant landmark in progress towards transplantation into humans of pig hearts, for the treatment of end stage heart disease.
Four of the five baboons in the final group remained healthy for at least 90 days (when the experiment was terminated), including one that was in good health after 195 days. The researchers made a decision to extend the study and found that the last two recipients in the group survived in good general condition for 195 and 182 days, respectively.
One of the ideas scientists have proposed is the use of the organ of another species.
This study could pave the way for xenotransplantation of pig organs into humans who are in need of organ transplantation.
But the study has provided two technical advances in science, Murry said.
Barry Fuller, professor in surgical science and low temperature medicine, of UCL and Royal Free London NHS Foundation Trust Transplantation Services, said: "The possibility to use animal organs for transplantation to overcome organ shortages has been discussed for decades, but has never become a reality because the human body aggressively rejects animal organ transplants because of multiple and strong immune reactions".
Pig hearts could soon be tested in humans after scientists passed an important milestone when transplanting the organs into primates.