Two scientists from Quebec, Marie-Josée Hébert and Mélanie Dieudé, “have just discovered why the human body sometimes rejects transplanted organs”. After a long period of research dating back to the 1990s, they have proven that “signals sent by the transplanted organs can trigger attack from the recipient’s body”. Blocking these signals would reduce the frequency of rejection, which currently affects one in ten transplants.
Why does the recipient’s immune system sometimes view the transplanted organ as an intruder and attack it? “The organ sends a message to the body to say: please note, I am damaged”, explained Mélanie Dieudé, research associate at the Montreal Hospital Research Centre (CRCHUM). These signals are transmitted by vesicles originating from damaged cells in the transplanted organ. In fact, the transplanted organ “invariably sustains damage when it is harvested, handled and stored outside the body. This damage is even more significant if the organs are harvested from a deceased donor”. Scientists believe that “the immune system is already on alert even before the transplant is carried out. If the transplanted organ is slightly damaged and also secretes vesicles – it’s the perfect storm!”.
The discovery of these signals paves the way for new treatment options to prevent graft rejections. One molecule, bortezomib, already tested in mice, is currently being studied.
La presse.ca, Philippe Mercure (18/03/2017)
Photo: Pixabay / DR