Written by David Bernstein Friday, 05 February 2010 00:00
At the start of this new decade, liver disease continues to be major source of morbidity and mortality both at home and around the world. We expect a significant rise in the incidence of viral hepatitis and other infectious diseases following the devastating earthquake in Haiti. Hepatitis B is one of those conditions. During the last decade, our ability to recognize, understand and treat hepatitis B has improved exponentially. From the first approved therapies in the mid-1990s through today, we have seen several new potent agents become available to treat this potentially serious infection. Chronic hepatitis B affects an estimated 300 million to 400 million people worldwide and about 1 million to 2 million people Americans. It is more common in Asian-Americans and Native Americans than Caucasians and African-Americans. Chronic hepatitis B is characterized in the blood by a positive hepatitis B surface antigen and the presence of hepatitis B virus in the blood and it is usually asymptomatic. People suffering from this virus have an increased chance of developing cirrhosis, liver cancer and needing a liver transplantation due to liver failure. In the United States, sexual contact is the most common means of disease transmission, although this condition may be passed along via contact from any bodily fluid. It is for this reason that all close contacts of chronic hepatitis B patients need to be vaccinated against hepatitis B to prevent its spread.
Therapy is available for people chronically infected with hepatitis B. Luckily, therapy is not indicated for all patients as the majority of patients will not develop significant progressive disease. A medical professional must determine who is an appropriate candidate for treatment as treatments may be costly and in many cases, are indefinite. Hepatitis B is not a curable disease at this point and therefore the goal of therapy is to slow or prevent the progression of disease. Many of the current therapies have been shown to improve underlying liver histology but not necessarily lessen the risk of developing liver cancer. Hopefully newer therapies which are in the pipeline will be able to meet these objectives. The treatments of hepatitis B are for the most part oral agents without side effects. These treatments, however, require absolute compliance as starting and then stopping medications can lead to life-threatening recurrence of disease.
Currently, the two most commonly used oral agents are entecavir and tenofovir. Both of these agents are well tolerated and have minimal side effects. The main concern when using these agents is that they may induce the development of mutations and thus allow for the development of resistant strains of hepatitis B. So far, the risk of resistance with these medications has been low. While we currently apply single-drug therapy for the treatment of chronic hepatitis B, most hepatologists believe that future treatment regimens will consist of multiple combinations of medications similar to the way the human immunodeficiency virus is treated as this should further decrease the incidence of mutations. I think that the upcoming decade will be very exciting in our ability to better understand and control the hepatitis B virus.
While these therapies all offer promise that we can control this common and deadly disease, the best mode of prevention is avoiding risk factors and ensuring that all people who are not previously exposed to hepatitis B receive appropriate vaccination.
(Disclaimer: The views and opinions represented are those of the author and meant for informative purposes only. For your specific questions, consult your physician.)