Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hepatitis C recurs rapidly after liver transplant

03.02.2006


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:
http://www.interscience.wiley.com/journal/livertransplantation

More articles from Health and Medicine:

nachricht Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>