Year : 2007 | Volume
: 4 | Issue : 1 | Page : 7--11
Hepatitis B viral infection: Emerging issues
Shivaram Prasad Singh, Yogesh Kumar Chawla
Gastroenterology, SCB Medical College, Cuttack-753 007 Orissa, India
Shivaram Prasad Singh
Gastroenterology, SCB Medical College, Cuttack-753 007 Orissa
|How to cite this article:|
Singh SP, Chawla YK. Hepatitis B viral infection: Emerging issues.Hep B Annual 2007;4:7-11
|How to cite this URL:|
Singh SP, Chawla YK. Hepatitis B viral infection: Emerging issues. Hep B Annual [serial online] 2007 [cited 2021 Dec 7 ];4:7-11
Available from: https://www.hepatitisbannual.org/text.asp?2007/4/1/7/45085
Despite the availability of an effective vaccine against hepatitis B virus for over two decades, this infection continues to be a major health problem across the globe. Over 350 million people are estimated to be harboring the infection globally. Research on hepatitis B virus infection over the last few decades has added considerably to our understanding of its replication, pathology, natural history, diagnosis and treatment; ongoing research on this topic continues to throw up new knowledge that helps to understand and control this infection. The present issue of Hepatitis B Annual is the result of our endeavor to present to our readers authoritative reviews on issues related to hepatitis B viral infection not touched upon in the previous issues of the journal. However, since it was observed that the article on Hepatitis B in pregnancy in the first volume of the journal was one of the most sought after article, it was decided to publish another review on this important aspect in the current issue. Besides, this issue also introduces a new section "Hepatitis B: News from the Research World", which the journal intends to continue on a regular basis in all subsequent issues.
In the review on hepatitis B virus and pregnancy, Dr. Silvia Sookoian attempts to answer some key questions regarding hepatitis B infection during pregnancy, in order to provide healthcare professionals with updated information in this field, with special emphasis on the main risk factors associated with vertical transmission of HBV in pregnant women chronically infected with hepatitis B virus, the influence of pregnancy on HBV viral load and the effect of pregnancy on the clinical course of chronic hepatitis B. Lastly, Dr. Sookoian has also provided recommendations to decrease vertical transmission rates of chronic viral hepatitis.
In the new section "Hepatitis B: News from the Research World" Dr. P. Piramanayagam and Dr. G. Choudhuri have selected 7 seminal articles from over 10,000 articles published in 2007 on hepatitis B viral infection which they believe enhance our understanding of the basic nature of this infection, throw new light on the natural history of this infection, and help us to treat patients with chronic infection better. The authors have added succinct comments after the abstracts of these landmark articles to highlight why they wish to share the research information with the readers.
The majority of the hepatitis B virus infected population resides in the developing world, especially in Asia, Africa and Latin America. Because of the high cost of hepatitis B medications, herbs - also termed 'complementary and alternative therapies' - are widely used for treatment of chronic hepatitis B in developing countries. The large repertoire of herbal compounds has shown potential in developing new ways to combat many diseases. At present, alternative or traditional medical resources are used by more than 80% of the population in developing countries, and by an increasing number of people in other parts of the globe too. The role of the 'complementary and alternative therapies' in the treatment of chronic hepatitis B is being extensively explored, and the results appear promising. Herbals are active not only in inhibiting HBV secretion but also in building up immunity against viruses. After studying the anti-HBV mechanism of herbs, scientists have been encouraged to find that novel anti-HBV drugs target viral secretion, whereas nucleoside analogs target viral polymerase. In the article "Complementary and alternative therapies in the treatment of chronic hepatitis B" by Dr. Jia-Ming Chang and Dr. Kai-Ling Huang, information on complementary and alternative anti-HBV therapies published in scientific peer-reviewed journals are reviewed and discussed.
HBV infection is a common cause of acute viral hepatitis (AVH) in India, being responsible for 14 to 30% of cases. HBV infection can cause severe AVH, which can progress to acute liver failure. Besides, occult HBV infection may be the etiology of acute liver failure (ALF) in varying numbers of patients depending upon the geography - from 0-4% in Europe to up to 50% in Japan. Thus it becomes important to find out if any available therapy can play a role in preventing the progression of AVH-B to severe hepatitis and ALF. In the review on management of severe acute hepatitis B, Prof. Rakesh Tandon and Dr. Sudeep Khanna appraise the immune response in acute hepatitis B, and the role of HBV genotypes in development of severe acute HBV related hepatitis, besides discussing the definition of severe acute hepatitis B and the current role of available antivirals, especially lamivudine, in the clinical setting of severe acute hepatitis B.
Drug resistance to antivirals has emerged as a major challenge in the management of chronic hepatitis B. Drug resistance is now considered as a natural response to the selective pressure of the antiviral drug, and depends on the viral mutation frequency, intrinsic mutability of the antiviral target site and the magnitude and rate of virus replication. The emergence of resistance to antiviral agents for the treatment of chronic HBV can be associated with exacerbation of hepatitis, hepatic decompensation, reduced HBeAg seroconversion, and worsening of liver disease. The article on clinical relevance of HBV drug resistance by Prof. Premashis Kar and Dr. Rajib Kishore Hazam reviews the molecular mechanism, identification and monitoring, and the management of drug resistance. The authors discuss how the knowledge of in vitro cross-resistance profiles between different nucleos(t)ides provides the rationale for selecting second-line agents for patients who developed drug resistance, and the necessity of careful selection of a first-line agent to avoid the occurrence of resistance and the development of cross resistance to other agents. They have also stressed the need for judicious use of nucleos(t)ide analog therapy for prevention of antiviral-resistance, and the importance of administering the most potent drug with the lowest rate of genotypic resistance with reinforcement of compliance.
Serologic and nucleic acid testing are critical to disease prevention and treatment objectives. Serologic assays for HBV are the mainstay diagnostic tools for HBV infection. However, the advent of molecular biology-based techniques has added a new dimension to the diagnosis and treatment of patients with chronic HBV infection. Information from such testing helps determine patients' infectivity and immune status, appropriate monitoring strategies, and the efficacy of treatment, as well as providing data that contributes to a better understanding of the natural history and epidemiology of the disease. The article "HBV Serology: use and interpretation" by me and Dr. Sunil Shah reviews the clinical use of serologic and nucleic acid tests as diagnostic markers and as markers of disease activity. The article also discusses certain clinically relevant problems like HBV serology in certain special situations including chronic renal failure, HIV co-infection and in healthcare workers which are of utmost importance.
There is an interesting short review on hepatitis B vaccine induced HBsAg positivity. This review highlights the fact that hepatitis B vaccine can induce transient hepatitis B surface antigen positivity not only in adult hemodialysis patients but also in normal adults and children. As a result hepatitis B vaccinees may be mistaken for confirmed HBV carrier and may be permanently disqualified as blood donors. The article emphasizes that caution should be exercised when interpreting HBsAg seropositivity within 4 weeks of HBV immunization, and recommends that blood donors should not donate blood in this early postvaccination period and that renal dialysis patients should not be screened for hepatitis B surface antigen for at least 21 to 28 days after hepatitis B vaccination. These guidelines could prevent individuals in the early postinoculation period from being erroneously labeled as having hepatitis B viral infection.
Dr. Mamun-Al-Mahtab and his colleagues from Bangladesh have penned the review on non-invasive markers of hepatic fibrosis in Chronic Hepatitis B. Assessment of fibrosis is very important in chronic hepatitis B for a number of reasons including decision making regarding treatment and predicting prognosis. Although, liver biopsy is considered the gold standard for assessing liver histology, in view of the fact that liver biopsy has significant limitations, there is a constant need for developing non-invasive alternatives to biopsy to assess hepatic fibrosis. The review discusses several alternatives to liver biopsy for assessing hepatic fibrosis, and concludes that despite the fact that much has been done, we still have a long way to go before we can finally say farewell to liver biopsy.
In "Management Overview of Chronic Hepatitis B with established therapies", Dr Deepak Narayan Amarapurkar discusses the currently available options for the treatment of chronic hepatitis B virus (HBV) infection including standard and pegylated interferon alfa and the four oral antiviral agents (lamivudine, adefovir, entecavir, and telbivudine). Dr. Amarapurkar highlights the importance of "road map strategy" which proposes a schedule for monitoring and defines clinically meaningful on-treatment responses to help optimize patient management.
We sincerely hope that the reviews in this issue of the journal would shed light on selected difficult and challenging problems related to management of Hepatitis B viral infection, and assist and guide students, researchers and physicians especially from the developing countries in the management of these problems.