By Mary Elizabeth Dallas
"This study shows that the liver transplant itself regulates the host's immune responses. Compared to the other organs, the liver is immunologically a very active organ, so it is capable of regulating the immune responses against itself," explained study author Dr. Timucin Taner, a transplant surgeon at the Mayo Clinic in Rochester, Minn.
Scientists have known for decades that people who've had a liver transplant need less medication to suppress their immune system and prevent their body from rejecting the organ they received. This is true even if they receive other organs along with a new liver, the study authors explained.
To explore this phenomenon further, the researchers compared blood samples from organ recipients one year after their surgery. There were 61 patients who had undergone kidney transplants, 31 who got liver transplants, and 28 patients who underwent both a kidney and a liver transplant.
The study showed those who received both organs or just a liver had fewer immune cells that respond to foreign invaders than those who only received a new kidney.
And although the liver transplant patients' response to the donated organs was weaker, their immune systems remained strong against other foreign substances.
In a Mayo Clinic news release, the researchers said more research is needed to determine exactly how the liver alters the body's immune response.
They noted that if doctors could mimic this response in other types of transplants, organ recipients would be less reliant on anti-rejection medications, which increase the risk for infection, cancer and other health issues.
The findings were published recently in the journal Kidney International.