Promising breakthrough for transplant patients

(Press-News.org) This press release is available in French.

A team led by Dr. Marie-Josée Hébert from the University of Montreal Hospital* Research Centre (CRCHUM) has discovered a new cause of organ rejection in some kidney transplant patients. Her team has identified a new class of antibodies – anti-LG3 – which when activated lead to severe rejection episodes associated with a high rate of organ loss. This discovery, which holds promise for organ recipients, was published in the online version of the American Journal of Transplantation.

Rejection is one of the major obstacles to organ transplantation. For the most part, it occurs when the recipient's immune system recognizes the transplanted organ as a foreign body that must be eliminated. However, even when there is a good donor-recipient immunologic match, the recipient's immune system can attack the transplanted organ's blood vessels. Called acute vascular rejection, this phenomenon often leads to a high rate of graft loss.

Hébert's team has characterized anti-LG3, an antibody that some patients produce to attack LG3, a protein that plays an important role in vascular repair and regeneration. "In these patients, the secretion of LG3 by the new kidney stimulates the activity of these antibodies which attack and injure the blood vessels of the transplanted organ. The net effect is that the normal healing process of the transplanted organ is hindered, if not interrupted, leading to impaired kidney function and even loss," explains Dr. Hébert.

By identifying the heightened presence of anti-LG3 antibodies in patients prior to transplantation, researchers will be able to predict the development of severe rejection episodes. "These results are quite exciting," notes Hébert, "and suggest that new therapies aimed at eliminating LG3 antibodies prior to transplantation could reduce organ rejection or limit its severity."

Given that LG3 is present in all blood vessels and thus in all transplanted organs, Hébert's results could also explain rejection of other types of transplanted organ, such as the heart, lung and pancreas.

### About Dr. Hébert Dr. Marie-Josée Hébert is a transplant nephrologist at CHUM and a researcher with the CRCHUM's Infection, Immunity and Inflammation research axis. She is also the Shire Chair in Nephrology Transplantation and Renal Regeneration, a professor in the Faculty of Medicine and Director of the Organ Transplant Program at the University of Montreal*. Her research is funded by the Kidney Foundation of Canada, Canada Foundation for Innovation, the Fonds de recherche du Québec – Santé, and the Canadian Institutes for Health Research.

About the CRCHUM The University of Montreal Hospital* Research Centre (CRCHUM) improves the health of adults through a high-quality academic research continuum which, by improving our understanding of etiological and pathogenic mechanisms, fosters the development, implementation and assessment of new preventive, diagnostic and therapeutic strategies. The CRCHUM provides a training environment to ensure the development of new generations of researchers committed to research excellence.

*The University of Montreal Hospital and the University of Montreal and are known officially as Centre hospitalier de l'Université de Montréal and Université de Montréal, respectively.

Source: Communication Division
Centre hospitalier de l'Université de Montréal (CHUM)

For information: Lucie Dufresne
Communication Advisor
Centre hospitalier de l'Université de Montréal (CHUM)
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