Hepatitis C infection decreases likelihood of rejection after liver transplant

A group of European researchers found that liver-destroying hepatitis C virus infection may have the unexpected benefit of lowering the chance that a new, transplanted liver will be rejected by the patient’s immune system.

by John Tyburski

Copyright © Daily Digest News, KPR Media, LLC. All rights reserved.

First published at Daily Digest News on June 26, 2014

In a rather odd case of “the disease is also the cure.” Hepatitis C virus (HCV) infection may serve as the primary cause of liver injury in a patient and yet may suppress the patient’s immune system in a specific way that lowers the risk of the patient rejecting a transplanted new liver. According to a report published on Wednesday in the journal Science Translational Medicine, Spanish researchers conducting a small clinical trial to study liver transplant tolerance in patients with HCV found that about half of the study subjects were able to go off drugs that prevent organ rejection.

“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,” said Dr. Felix Bohne, lead author of the study.

Patients who receive organ transplants normally must take medications that suppress their immune systems so that they do not reject the new organ. The reason organs are rejected is because they have come from other individuals who donated them. Each person’s immune system has a strong ability to discriminate between “self” and “foreign.” Tissue from a donor is matched according to blood type, but rejection is still a likely outcome without the immunosuppressing drugs.

Prior research in animal models has suggested that HCV infection may exert a suppressing effect on the immune system and lower the chances that the animals will reject transplanted livers. Observations in patients show also that administration of immunosuppressing drugs in HCV patients who received a transplant allows HCV to flourish, resulting in accelerated injury to the new liver tissue. The finding that at least some HCV-infected patients do better without immunosuppression is encouraging.

“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 Hepatitis Foundation International. “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.” Pappas was not involved in the study.

The report presents the reason why HCV lowers liver transplant rejection risk as relating to the mechanism that HCV has to hide from the immune system. The result is immune system cells that do not function at maximal capacity.

“This is part of the virus’ immune evasion strategy and can be observed in a part of patients developing chronic hepatitis C,” Bohne said.