Hepatitis C Infection May Have 'Silver Lining' for Transplant Patients
Infected people who need new organ might have less need for immune-suppressing drugs, study finds
By Dennis Thompson
WEDNESDAY, June 25, 2014 (HealthDay News) -- The liver-damaging hepatitis C virus may come with an unexpected benefit for patients who need a liver transplant due to the infection, a new European study reports.
The virus appears to restrain a dangerous immune system response that can otherwise cause the body to reject the new liver, according to findings published June 25 in Science Translational Medicine.
This effect allowed about half of a small group of liver transplant patients to stop taking drugs that suppress their immune system, said lead author Felix Bohne, a postdoctoral fellow with the Institute of Virology at the Technical University of Munich Hemholtz Center Munich, Germany.
"It is always a hard thing to translate results from clinical studies into the everyday treatment of patients, but our study clearly shows that hepatitis C-infected liver recipients can discontinue the immunosuppressive medication," Bohne said.
Hepatitis Foundation International (HFI) called the research "encouraging news for people who may need a liver transplant."
"This is exciting research that shows the hepatitis virus changes the immune system in such a way to protect these liver transplants from being rejected by the body," said Dr. Gregory Pappas, medical director for HFI. "This is good news for many of HFI's constituents and those who will need a liver transplant and/or who have been infected with hepatitis C."
Doctors must typically use immunosuppressive drugs to help a body accept a new organ, but these medications often do more harm than good for hepatitis C patients who receive a new liver, experts say.
In background information supplied with the study, the researchers explained that because the immune system is suppressed by medications, hepatitis C actually flourishes after a transplant, causing rapid damage to the new liver.
However, if the immune-suppressing drugs are not given, hepatitis C appears to help a liver recipient accept the new organ -- even better than immunosuppressive medications would.
All this is due to a common viral trick that hepatitis C uses to avoid getting spotted by the immune system. According to the new study, the virus "rewires" immune cells to reduce their function -- essentially performing the immune-squelching work that immunosuppressive drugs do.
"This is part of the virus' immune evasion strategy and can be observed in a part of patients developing chronic hepatitis C," Bohne said.
The result is an environment in which immune response is blunted against the replacement liver because hepatitis C has taught the body to ignore the new organ.
In a study of 34 people with hepatitis C who received a new liver, Bohne and his colleagues found that 17 were able to stop taking their immunosuppressive medications without suffering organ rejection.
Might the same process occur with other infectious viruses? Bohne is doubtful. He said that while other viruses can suppress the immune response, few focus their efforts on one organ the way that hepatitis C focuses on the liver.