Transplant: Unlocking the secrets of the immune system

One of the biggest barriers to long-term success in solid organ transplant is the body’s own immune response. The transplanted organ is seen as a foreign object and the immune system goes into attack mode, trying to kill the invader. To control this, patients need to take immune-suppression drugs for the rest of their lives. But there are two significant problems with this cocktail of toxic pharmaceuticals: life threatening side effects from prolonged use and life threatening infections and illnesses because the dampened immune system can’t fight back.

Addison has had two hospitalizations since her transplant, both to fight infections. In October 2012, she contracted pneumocystis pneumonia, a rare disease which only affects immune-compromised patients. During the inital onset of the AIDS epidemic, a positive PCP test is what often led doctors to ultimately diagnose AIDS. The fungus which causes PCP is everywhere and all of us are probably carriers, but healthy people don’t get sick. PCP used to prove deadly for many transplant patients, but early detection and better management of antibiotics has changed that. We were in the hospital for a month, with three weeks of IV antibiotics.

Long term, cancer is a very real threat for transplant patients. According to the Canadian Cancer Society, post-transplant lymphoproliferative disorder (PTLD) behaves like an aggressive lymphoma, occurring in about 1-2% of transplant patients. It is almost always linked to a virus, so patients are routinely tested for the presence of this virus.

Dr. Sandy Feng at the University of California San Francisco has been leading a ground-breaking study, weaning pediatric liver patients off their anti-rejection drugs. Some of her young patients have been completely drug-free for years, effectively turning their transplants into cures. All of them have had live liver donations from their parents. But Dr. Feng is expanding her research to see if there are other transplant patients who potentially don’t need to be immune-suppressed.

In Vancouver at the Child and Family Research Institute, Megan Levings is focused on the T-regulatory cells. These cells are the “police chiefs” of the body’s defense force. The Tregs are the ones who mount a major battle when an organ is transplanted, and if unchecked ultimately results in acute rejection. Levings is hoping to find a way to turn off that specific response using cell therapy, but also maintaining the body’s defenses against other invaders. This is called “tolerance” and would mean no more need for immune-suppressants, which would also effectively achieve a cure.

One of the Canadian National Transplant Research Program’s six core projects focuses on immunology and transplantation tolerance.

Elaine and Aaron have launched The Addison Fund to fund transplant research.  100% of all donations will go directly to research.  

WATCH: Part I – Transplant: The Search for the Cure