Management of hepatitis B is a challenge for physicians and patients due to an incomplete understanding of the disease course, complex treatment indications, and the lack of large studies focusing on important health outcomes. To examine these issues, the NIH convened an independent, impartial panel this week to weigh the available evidence on the management of hepatitis B.
While more than 95 percent of U.S. children are routinely vaccinated for hepatitis B, the vaccine does not protect individuals already infected with the virus. In unprotected individuals, acute infection with the hepatitis B virus is usually resolved by the body's immune system and does not cause long-term problems. The transition from acute to chronic infection appears to occur when the immune system does not effectively destroy and clear virus-infected cells.
A number of antiviral therapies approved by the U.S. Food and Drug Administration are available for use in fighting chronic hepatitis B infection including interferons and nucleos(t)ides. "We know that these therapies have positive effects on indicators such as viral load, but further controlled trials are needed to substantiate that these agents prevent disease progression to liver failure, cancer, or death," explained panel chair Dr. Michael F. Sorrell, Professor of Medicine at the University of Nebraska Medical Center.
To address this gap in the evidence, the panel recommended several avenues for future research. Among these, they gave top priority to large andomized studies, including placebo-controlled trials, testing single drug and combination therapies' effects on liver failure, cancer, and death. The panel also proposed representative prospective cohort studies to define the natural history of the disease to optimize management across diverse patient subgroups. This would also help decide which patients are most in need of immediate therapy and which could be carefully followed without drug therapy.
The panel is encouraged by the National Institute of Diabetes and Digestive and Kidney Disorders' plans to launch the Hepatitis B Clinical Research Network to promote translational research on this challenging condition. It is anticipated that the recommendations in the consensus statement will inform the consortium's research agenda.
The panel identified elevated hepatitis B DNA blood levels and elevated levels of ALT (alanine aminotransferase, a liver enzyme) as the most important indicators for progression to cirrhosis and liver cancer (hepatocellular carcinoma). Older age, male sex, family history of liver cancer, coinfection with hepatitis C or HIV, and elevated blood levels of hepatitis B DNA were also found to be key predictors.
The panel recommends routine hepatitis B screening for newly arrived immigrants from countries where hepatitis B prevalence is greater than two percent. These practices are intended to facilitate access to care for infected individuals and their families and to provide valuable data on disease prevalence, not to exclude immigrants in any way.
The panel recommends therapy for certain patients, including those with acute liver failure and complications from cirrhosis. However, immediate therapy is not indicated for patients with inactive forms of the disease.
The panel's complete consensus statement will be available later today at http://consensus.nih.gov. The conference was sponsored by the NIH Office of Medical Applications of Research (OMAR) and the National Institute of Diabetes and Digestive and Kidney Diseases, along with other NIH and Department of Health and Human Services components. This conference was conducted under the NIH Consensus Development Program, which convenes conferences to assess the available scientific evidence and develop objective statements on controversial medical issues.
Source: NIH/National Institutes of Health, Office of Disease Prevention
The conference artwork is a stylized representation of the hepatitis B virus (Dane particle) amongst surface antigen filaments and spheres found in the blood of chronically infected patients. The bottom image represents the hepatitis B virus genome, a circular, partially double-stranded DNA molecule. Emanating from the central genome are the various RNA transcripts.
(Photo Credit: The artwork was designed by Bryan Ewsichek and Ethan Tyler of NIH Medical Arts and is in the public domain. No permission is needed to use the image.)