Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Hepatitis C recurs rapidly after liver transplant


Extrahepatic sites may account for some viral replication

When a diseased liver is removed from a patient with Hepatitis C (HCV), serum viral levels plummet. However, after receiving a healthy liver transplant, virus levels rebound and can surpass pre-transplant levels within a few days, according to a new study published in the February 2006 issue of Liver Transplantation, the official journal of the American Association for the Study of Liver Diseases (AASLD) and the International Liver Transplantation Society (ILTS). The journal is published on behalf of the societies by John Wiley & Sons, Inc. and is available online via Wiley InterScience.

Hepatitis C is the number one reason for liver transplantation, however, the virus always recurs in the new liver. Since mathematical models have been useful in the study of the viral dynamics of HIV and hepatitis B, researchers, led by Kimberly A. Powers and Ruy M. Ribeiro of the Los Alamos National Laboratory in New Mexico, sought to use a mathematical model to quantify the liver reinfection dynamics of HCV.

The researchers, in collaboration with a surgical team lead by John McHutchison now at Duke University Medical Center, followed six HCV-infected patients who received cadaveric liver transplants. They collected blood samples before, during and after transplantation to assess changing levels of HCV RNA which was measured using reverse transcription polymerase chain reaction assay. They then plugged the data into a mathematical model, correcting for fluid balance, and analyzed the results using linear regression.

"In most patients," the authors report, "HCV RNA levels decreased rapidly during and after transplantation and subsequently began to increase – reaching above pre-transplant levels in all but one patient – within a few days of the procedure." They found that when the diseased liver was removed, virus levels dropped with an average half-life of 48 minutes. After the new liver was implanted, they found that virus levels continued to drop for up to 23 hours, then began to rise, doubling every 2 days.

Notably, in three patients, the virus levels plateaued before rising, suggesting, say the authors "that a non-hepatic source supplied virions and balanced their intrinsic clearance." The authors estimate, however, that non-hepatic sources can only account for 4 percent of total viral production. Ninety-six percent of it occurs in the liver.

The patterns of viremia decline and increase seen in this study are consistent with previous studies, although this study indicates a much faster virion half-life than previously suggested. The findings also support the notion that HCV can replicate rapidly in the post-transplant immunosuppressed patient, leading the authors to suggest that early antiviral therapy may delay or prevent reinfection.

The study was limited by the small number of patients and the single compartment model, which did not separately account for liver and extrahepatic sites of viral replication. "Nevertheless," report the authors, "the rapid HCV RNA decline in the anhepatic phase, followed by the postoperative increase observed in several patients…suggest that the liver is the primary site of viral replication, with at most small contributions from extrahepatic sites."

In conclusion, the authors write, "Continued work towards elucidating extrahepatic replication, the time-course of reinfection, the effects of immunosuppressive therapy, and the relationships among viremia, infection and liver damage will be beneficial in optimizing treatment for HCV patients undergoing liver transplantation."

David Greenberg | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>