Review
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World J Gastroenterol. May 14, 2012; 18(18): 2172-2179
Published online May 14, 2012. doi: 10.3748/wjg.v18.i18.2172
Enhanced apoptosis in post-liver transplant hepatitis C: Effects of virus and immunosuppressants
Eu Jin Lim, Ruth Chin, Peter W Angus, Joseph Torresi
Eu Jin Lim, Peter W Angus, Liver Transplant Unit, Austin Hospital, Heidelberg, Victoria 3084, Australia
Eu Jin Lim, Peter W Angus, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
Ruth Chin, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
Joseph Torresi, Department of Infectious Diseases, Austin Hospital, Heidelberg, Victoria 3084, Australia
Joseph Torresi, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
Author contributions: Lim EJ performed the literature review, analyzed and interpreted the data, drafted the manuscript, and approved the final version; Chin R, Angus PW, Torresi J critically reviewed the manuscript, assisted with the design of the paper, made corrections and revisions, and approved the final version.
Correspondence to: Dr. Eu Jin Lim, MBBS (Hons), FRACP, Liver Transplant Unit, Austin Hospital, 145 Studley Road, Heidelberg, Victoria 3084, Australia. ejlim@rocketmail.com
Telephone: +61-3-94965000 Fax: +61-3-94963487
Received: January 24, 2012
Revised: March 29, 2012
Accepted: April 9, 2012
Published online: May 14, 2012
Abstract

Hepatitis C (HCV)-infected patients have a poorer survival post-liver transplantation compared to patients transplanted for other indications, since HCV recurrence post-transplant is universal and commonly follows an aggressive course. There is increasing evidence that in the non-transplant setting, induction of hepatocyte apoptosis is one of the main mechanisms by which HCV drives liver inflammation and fibrosis, and that HCV proteins directly promote apoptosis. Recent studies have shown that post-liver transplant, there is a link between high levels of HCV replication, enhanced hepatocyte apoptosis and the subsequent development of rapidly progressive liver fibrosis. Although the responsible mechanisms remain unclear, it is likely that immunosuppressive drugs play an important role. It is well known that immunosuppressants impair immune control of HCV, thereby allowing increased viral replication. However there is also evidence that immunosuppressants may directly induce apoptosis and this may be facilitated by the presence of high levels of HCV replication. Thus HCV and immunosuppressants may synergistically interact to further enhance apoptosis and drive more rapid fibrosis. These findings suggest that modulation of apoptosis within the liver either by changing immunosuppressive therapy or the use of apoptosis inhibitors may help prevent fibrosis progression in patients with post-transplant HCV disease.

Keywords: Hepatitis C, Liver transplantation, Apoptosis, Immunosuppressive agents, transforming growth factor-β