Xenotransplantation is defined as the procedure of transplanting or
grafting tissues or organs between members of distinct species. With the
arrival of animal cloning techniques, the method of nuclear transmission
was able to produce alpha 1,3-galactosyltransferase-knockout (Gal-KO)
pigs in several institutes across the world, specifically in Japan,
during the onset of 21st century. The controversy of the risks of PERV
has slowly decreased, due to the fact that there are no cases of PERV
infections noted in humans. In addition, a huge clinical wave for islet
allotransplantation regained the interest of xenotransplantation,
particularly porcine islet transplantation and few exceptions. Clinical
trials have been carried out in several countries till date, including
Mexico, China, Sweden, USA (Inventory of Human Xenotransplantation
Practices - IXA and HUG in association with World Health Organization).
Furthermore, a novel clinical trial was authorized by the government,
and continued the porcine islet transplantation research in New Zealand
two years ago.