Experts are warning that hepatitis C (HCV) can return rather quickly following a liver transplant. That’s even after the transplant itself helped significantly reduce viral levels. The findings are reported in the February issue of the journal Liver Transplantation.1
The viral rebound, say the researchers from the Los Alamos National Laboratory in New Mexico, can occur within a few days.
A Primary Transplant Cause
Hepatitis C is the primary reason for liver transplantation. Yet the virus always recurs in the new liver, doctors have found.
In this study, chief investigators Kimberly Powers and Ruy Ribeiro sought to use special mathematical calculations to determine the odds, and quantity, of liver reinfection after a transplant.
For their research, the Los Alamos team in conjunction with the a surgical team from Duke University Medical Center, followed six HCV-infected patients who received livers from cadavers. The researchers collected blood samples before, during and after transplantation to evaluate blood levels of the virus in these patients. The information was then plugged into the mathematical model used in the study to calculate future varying viral loads following the transplant procedures.
“In most patients, HCV RNA [genetic evidence of the virus’ presence] 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,” wrote the medical research team.
Viral Rebound
They found that when the diseased liver was removed, viral load dropped. But after the new liver was implanted, virus levels continued to drop for up to 23 hours, then began to rise, doubling every two days.
The investigators noted that in three patients, vial load plateaued before rising, suggesting that some source other than the liver was responsible for helping the virus maintain certain levels. However, they were quick to add that these non-liver-based sources accounted for only about four percent of total viral production. The rest occurs directly in the liver.
The patterns of viral load decrease followed by increases are consistent with previous study findings. The findings also suggest that HCV can replicate (make copies of itself) rapidly in the post-transplant patient taking immunosuppression therapy, typically given to prevent liver rejection. This may mean that early antiviral therapy may help delay or even prevent reinection, the study authors wrote.
This study, the researchers pointed out, was limited by the small number of patients, making it difficult to suggest that the findings were similar to what would occur in the overall population of liver transplant patients with hepatitis. The study also didn’t take into account the sources of viral replication, whether liver- or non-liver-based.
“Nevertheless, the rapid HCV RNA decline … 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,” Powers, Ribeiro, and their colleagues concluded.
1. Powers KA, Riberio RM, Patel K et al. Kinetics of hepatitis C virus reinfection after liver transplantation. Liver Transpl 2006 Jan 30;12(2):207-16 [Epub ahead of print].
John Martin is a long-time health journalist and an editor for CuraScript. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
