Natural history and disease progression in Chinese chronic hepatitis B patients in immune-tolerant phase

Hepatitis B virus genotype C is associated with more severe liver fibrosis than genotype B

BACKGROUND & AIMS

Histologic analyses of liver fibrosis have been limited by small sample sizes and the predominance of samples from patients with active hepatitis.

METHODS

We performed a prospective study of transient elastography in treatment-naive patients with chronic hepatitis B, to investigate the relationship between hepatitis B virus (HBV) genotype and liver fibrosis. A validated liver stiffness measurement algorithm was used to define insignificant fibrosis and advanced fibrosis.

RESULTS

Of 1106 patients, 711 (64%) were older than age 40, 370 (34%) had positive test results for hepatitis B e antigen (HBeAg), and 386 (35%) had increased serum levels of alanine aminotransferase. Of the patients, 524 (49%) had genotype B and 582 (51%) had genotype C HBV infection. Patients with genotype C infection had insignificant fibrosis less often (42% vs 55%; P < .0001) and advanced fibrosis more often (25% vs 19%; P = .015) than those infected with genotype B HBV. The difference in the severity of liver fibrosis between the 2 HBV genotypes was most marked among patients older than age 40 and those who tested negative for HBeAg. The mean age of patients infected by genotype C was greater than that of patients infected by genotype B HBV (41 vs 36 y). Among patients who were older than age 40 and tested negative for HBeAg, those with genotype C infection had higher levels of HBV DNA and alanine aminotransferase than those with genotype B HBV.

CONCLUSIONS

Genotype C HBV was associated with more severe liver fibrosis than genotype B HBV, probably because of delayed HBeAg seroconversion and prolonged active disease.

[A 23-year-old asymptomatic HBsAg positive woman]

This paper discusses the case of a young 23-year-old asymptomatic HBsAg woman, diagnosed in the immune-tolerance phase of HBV infection. The monitoring shows the loss of tolerance and eventually the transition to the inactive carrier state. Management strategies are discussed for each phase according to the recent EASL guidelines.

Implication of normal liver enzymes in liver disease

Chronic liver disease is usually asymptomatic until its late stages and also significant hepatic necroinflammation and fibrosis may be present in persistently normal ALT levels HBV, HCV carriers or similarly, in patients with nonalcoholic fatty liver disease. Given the large number of persons in the general population which may harbor a clinically significant liver disease behind the screen of normal alanine aminotransferase, more attention should be devoted to future research for alternative noninvasive markers of liver damage.

Antiviral therapy of chronic hepatitis B: opportunities and challenges in Asia

Asia comprises more than 40 countries encompassing a wide geographic area with a very large population. Many of these countries have low-income economies together with high endemicity of chronic hepatitis B virus (HBV) infection, which is usually acquired perinatally or during early childhood. The well elucidated natural history of chronic HBV infection, together with the extensive research and the longest experience in the use of therapeutic agents in Asia have provided a great opportunity for Asian patients to benefit from recent advancements. However, treatment of chronic HBV infection is a complex task that requires individualized assessment, thus representing a great challenge for general physicians. The inherent problems of the drugs currently available, together with a lack of awareness of the disease among patients, government, and healthcare practitioners are obstacles to proper management of HBV. The most critical challenge and obstacle is the high cost of medical care and antiviral drugs. Lack of adequate reimbursement for treatment and diagnostic testing makes adherence to treatment guidelines impossible. Hence lamivudine is still widely used in Asia. To address these challenges, the ongoing awareness campaigns, active screening programs, educational activities are needed but must be enhanced. Cost-cutting measures and international support are essential to improve the difficult situation in this part of the world.

[Natural history and clinical manifestations of chronic hepatitis B virus]

Hepatitis B virus (HBV) infection is a serious public health problem worldwide. In the last few decades, major advances have been achieved that have contributed to greater understanding of the natural history and clinical manifestations of this infection. The fluctuation between viral replication and the host's immune response has implications in the pathogenesis and progression of the hepatic lesion. In immunocompetent adults, most HBV infections resolve spontaneously in contrast with progression to chronic infection in most infants. Patients with chronic hepatitis due to HBV or chronic hepatitis B can present at four phases: 1) the immune tolerance phase, 2) HBeAg-positive chronic hepatitis B, 3) inactive HBsAg carrier state, and 4) HBeAg-negative chronic hepatitis. HBeAg-positive or -negative chronic hepatitis can progress to cirrhosis, liver failure and hepatocellular carcinoma. Progression to these complications is more frequent in HBeAg-negative forms, associated with mutations that affect the pre-core region and maintain active viral replication. Risk factors are HBV-DNA positive serum levels, an increase in serum transaminase levels and some genotypes. These factors highlight the need to evaluate and monitor all HBV carriers to identify those who could benefit from early antiviral treatment, thus avoiding progression to more advanced forms of liver disease. These measures could improve prevention and treatment of hepatitis B.

HBeAg seroconversion as an important end point in the treatment of chronic hepatitis B

During the natural history of chronic hepatitis B virus (HBV) infection, the loss of serum hepatitis B e antigen (HBeAg) and the development of anti-HBe antibodies (HBeAg seroconversion) mark a transition from the immune-active phase of disease to the inactive carrier state. This review examines the evidence from natural history and cohort studies on the relationship between HBeAg seroconversion and disease progression. The role of HBeAg seroconversion as an important milestone in the management of HBeAg-positive patients with chronic hepatitis B (CHB), as well as the advantages and disadvantages of administering a finite course of therapy for HBeAg-positive CHB, is also discussed. The evidence from natural history and cohort studies indicates that spontaneous or treatment-induced HBeAg seroconversion is associated with lower rates of disease progression to cirrhosis and hepatocellular carcinoma, a potential of hepatitis B surface antigen seroconversion, and improved survival rates. Updated guidelines developed by major liver associations recommend stopping oral therapy for HBeAg-positive patients who achieve sustained HBeAg seroconversion with polymerase chain reaction-undetectable HBV-DNA on two separate occasions for 6 or more months apart, taking into consideration the individual's clinical and virologic response to therapy, as well as the severity of liver disease. Thus, early induction of HBeAg seroconversion with interferon-based therapy or oral nucleos(t)ide analogues has important clinical and socioeconomic implications for the management of CHB.

Indications for therapy in hepatitis B

Increased treatment options that are more efficacious and safe and new knowledge on the natural history of chronic hepatitis B virus (HBV) infection have expanded the indications for therapy in hepatitis B. The question is no longer "Who should be treated?" but "When should treatment be initiated?" Treatment is clearly indicated in patients with life-threatening liver disease (acute liver failure, decompensated cirrhosis, or severe hepatitis flare) and in those with compensated cirrhosis and high levels of serum HBV DNA. For patients with precirrhotic liver disease, treatment indications should be based on clinical, biochemical, or histological evidence of liver disease, such as elevated alanine aminotransferase (ALT) levels, abnormal histology, and high levels of serum HBV DNA. The cutoff for ALT and HBV DNA values are constantly being revised and should be set at a lower level for older patients who may have been infected for a longer period of time. High serum HBV DNA levels persisting for a few decades are associated with increased risk of clinical outcomes, but there is insufficient data to support the initiation of treatment based on high serum HBV DNA alone, particularly in young patients, those with persistently normal ALT levels, and those with a single high HBV DNA level. The decision to initiate treatment at the time of assessment or to defer treatment should take into consideration other factors such as desire to start a family, occupational requirement, family history of hepatocellular carcinoma, access to care and insurance coverage, and commitment to long-term treatment and medication compliance. All patients who are not initiated on treatment should continue to be monitored so treatment can be started if and when the indication arises.

Liver biopsy findings in chronic hepatitis B

Liver biopsy plays a central role in treatment algorithms in patients with hepatitis B and remains the gold standard for evaluating hepatic pathology. The pathology of hepatitis B is diverse and reflects the natural history of infection. An acute hepatitic pattern with lobular disarray is seen in acute infection, during acute flares of disease, and with acute hepatitis D superinfection. In chronic hepatitis B, inflammation is less pronounced in the immune-tolerant phase and is prominent during immune-mediated viral clearance. Active inflammation appears to be the driving force for development of fibrosis. Inflammatory grades and fibrosis stage are assigned as is done for hepatitis C. Although current management guidelines recommend liver biopsies only in select patients based on age, viral levels, and hepatitis B e antigen status, these clinical and biochemical parameters do not show consistent correlations with liver histology. Liver biopsy also helps identify preneoplastic lesions including large cell and small cell change. Unlike in other causes of chronic hepatitis, immunostains are widely used and can help determine the phase of infection. Liver biopsies can also identify additional pathology that may contribute to liver disease such as steatohepatitis, iron overload, autoimmune hepatitis, and drug-induced injury. Thus, liver biopsy can play an important role in staging and grading chronic hepatitis B and should be more widely used in assessing the need for therapy.

The natural history of chronic hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection has a complicated course. Three phases are identified: an immune tolerant phase with high HBV DNA and normal alanine aminotransferase (ALT) levels associated with minimal liver disease; an immune active phase with high HBV DNA and elevated ALT levels with active liver inflammation; and an inactive phase with HBV DNA levels < 2000 IU/mL and normal ALT levels with minimal inflammation and fibrosis on liver biopsy. Affected persons can move progressively from one phase to the next and may revert backward. The primary adverse outcomes of chronic HBV infection are hepatocellular carcinoma (HCC) and cirrhosis. Published natural history studies were reviewed and ranked by the strength of evidence regarding the study design. Factors with the highest evidence of risk for development of HCC or cirrhosis from population-based prospective cohort studies include male sex, family history of HCC, HBV DNA level above 2000 IU/mL in persons above age 40, HBV genotypes C and F, and basal core promoter mutation. Those with the next highest level of evidence include aflatoxin exposure, and heavy alcohol and tobacco use. Improved methods to identify persons at highest risk of developing HCC or cirrhosis are needed to allow intervention earlier with antiviral therapy in appropriate patients. Future studies should include prospective follow-up of established population-based cohorts as well as new cohorts recruited from multiple centers stratified by HBV genotypes/subgenotypes and clinical phase to determine the incidence of the various HBV phases, HCC, and cirrhosis. Also, nested case-control studies assessing immunological and host genetic factors among persons with active and inactive disease phases, HCC, and cirrhosis could be conducted using these types of cohorts.

Evaluation of the patient with hepatitis B

The initial evaluation of a patient with hepatitis B virus infection should attempt to assess the disease activity and stage in the context of the known natural history of this infection and to properly assess the needs for treatment and surveillance. In addition to a medical history and focused physical examination, the initial evaluation usually requires serological, biochemical, and virological tests to confirm the diagnosis as well as an imaging study to establish a baseline for future monitoring. A liver biopsy is generally not needed but can provide useful information on prognosis, need for surveillance for hepatocellular carcinoma (HCC), and whether to recommend therapy. Follow-up monitoring is aimed at determining disease progression, development of complications, and reassessing the need for treatment. Monitoring frequency should be determined based on the activity and stage of disease. Initiation of screening for HCC should be based on age, race, sex, family history, and stage and duration of disease. The current recommended method of screening and surveillance for HCC is by ultrasonography and alpha-fetoprotein measurements every 6-12 months. Prospective studies are needed to evaluate the role of longitudinal application of noninvasive assays of fibrosis, such as serum fibrosis markers and transient elastography. Better biomarkers and imaging modalities are needed for early detection of HCC. Finally, studies are needed to better refine the indications and to balance the risks and benefits of antiviral therapy.

A review of the natural history of chronic hepatitis B in the era of transient elastography

Understanding the natural history of chronic hepatitis B is important in order to predict the prognosis, to stratify the risk of hepatocellular carcinoma and to select appropriate candidates for antiviral treatment. Liver fibrosis is the pathogenic process that leads to liver cirrhosis. The study of liver fibrosis in the past has largely been hampered by the invasive nature of a liver biopsy. Most liver biopsy series represent biased populations with more active disease. Transient elastography is a reliable and non-invasive measurement of liver fibrosis that allows the study of liver fibrosis among patients without clinical indication for liver biopsy. Large studies using transient elastography in patients with predominantly normal alanine aminotransferase levels have been reported recently. The different roles of patient age, hepatitis B virus DNA and alanine aminotransferase levels in the risk stratification for advanced liver fibrosis have been defined in hepatitis B e antigen-positive and hepatitis B e antigen-negative chronic hepatitis B patients. The relationship between metabolic syndrome and chronic hepatitis B is also explored. In this review, new insights from studies using transient elastography on the natural history of chronic hepatitis B with special focus on liver fibrosis will be summarized and discussed.

Hepatitis B virus infection

Since the introduction of the hepatitis B vaccine and other preventive measures, the worldwide prevalence of hepatitis B infection has fallen. However, chronic infection remains a challenging global health problem, with more than 350 million people chronically infected and at risk of hepatic decompensation, cirrhosis, and hepatocellular carcinoma. An improved understanding of hepatitis B virology, immunology, and the natural course of chronic infection, has identified hepatitis B virus replication as the key driver of immune-mediated liver injury and disease progression. The approval of potent oral antiviral agents has revolutionised hepatitis B treatment since 1998. Conventional and pegylated interferon alfa and nucleoside and nucleotide analogues are widely authorised treatments, and monotherapy with these drugs greatly suppresses virus replication, reduces hepatitis activity, and halts disease progression. However, hepatitis B virus is rarely eliminated, and drug resistance is a major drawback during long term therapy. The development of new drugs and strategies is needed to improve treatment outcomes.

DNA-guided hepatitis B treatment, viral load is essential, but not sufficient

Hepatitis B virus (HBV) infection is a global public health problem that concerns 350 million people worldwide. Individuals with chronic hepatitis B (CHB) are at increased risk of developing liver cirrhosis, hepatic de-compensation and hepatocellular carcinoma. To maintain undetectable viral load reduces chronic infection complications. There is no treatment that eradicates HBV infection. Current drugs are expensive, are associated with adverse events, and are of limited efficacy. Current guidelines try to standardize the clinical practice. Nevertheless, controversy remains about management of asymptomatic patients with CHB who are hepatitis B e antigen (HBeAg)-positive with normal alanine aminotransferase, and what is the cut-off value of viral load to distinguish HBeAg-negative CHB patients and inactive carriers. We discuss in detail why DNA level alone is not sufficient to begin treatment of CHB.

Natural history of chronic hepatitis B virus infection and long-term outcome under treatment

Chronic hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, the hepatocytes and the immune system of the patient. Perinatally or early childhood-acquired chronic HBV infection has a long 'immune tolerant phase', when patients are young, and HBeAg seropositive with a high viral load but with no significant liver disease. Persistent or episodic liver injuries during the 'immune clearance phase' may lead to decompensation, fibrosis progression or cirrhosis development in some patients, but may eventually lead to HBV-DNA seroclearance with HBeAg seroconversion and entry into the 'inactive phase' with remission. Hepatitis may relapse, because of reactivation of HBV with precore or basal core promptor mutations, and develop 'HBeAg-negative chronic hepatitis', in some patients. In contrast, HBsAg seroclearance may occur in those with sustained remission. During the course, HBV replication is the key driver of disease progression including development of cirrhosis and hepatocellular carcinoma (HCC). Among the currently available anti-HBV drugs, the most extensive and longest experience has been gained with conventional interferon (IFN)-alpha and lamivudine. A finite course of IFN therapy has long-term benefit in achieving a cumulative response, increasing HBsAg seroclearance and reducing cirrhosis and/or HCC. Maintained virological response to lamivudine therapy has a similar long-term benefit in reducing disease progression. Pegylated IFN and newer nucleos(t)ide analogues may have even better long-term outcomes because of better therapeutic efficacy and/or a low risk of drug resistances. The treatment outcomes are still far from satisfactory. The development of safe and affordable anti-HBV agents/strategies is needed to further improve outcomes.

A treatment algorithm for the management of chronic hepatitis B virus infection in the United States: 2008 update

Chronic HBV infection is an important public health problem worldwide and in the United States. A treatment algorithm for the management of this disease, published previously by a panel of U.S. hepatologists, has been revised on the basis of new developments in the understanding of the disorder, the availability of more sensitive molecular diagnostic tests, and the licensure of new therapies. In addition, a better understanding of the advantages and disadvantages of new treatments has led to the development of strategies for reducing the rate of resistance associated with oral agents and optimizing treatment outcomes. This updated algorithm was based primarily on available evidence by using a systematic review of the literature. Where data were lacking, the panel relied on clinical experience and consensus expert opinion. The primary aim of antiviral therapy is durable suppression of serum HBV DNA to low or undetectable levels. Assays can now detect serum HBV DNA at levels as low as 10 IU/mL and should be used to establish a baseline level, monitor response to antiviral therapy, and survey for the development of drug resistance. Interferon alfa-2b, lamivudine, adefovir, entecavir, peginterferon alfa-2a, telbivudine, and tenofovir are approved as initial therapy for chronic hepatitis B and have certain advantages and disadvantages. Although all of these agents can be used in selected patients, the preferred first-line treatment choices are entecavir, peginterferon alfa-2a, and tenofovir. Issues for consideration for therapy include efficacy, safety, rate of resistance, method of administration, and cost.

New paradigms for the treatment of chronic hepatitis B

The main goals of chronic hepatitis B treatment should be the long-term suppression of viral replication to minimize disease progression and the risk for the development of hepatocellular carcinoma. Treatment end-points, depending on surrogate markers alone, in particular hepatitis B e-antigen seroconversion, may not be ideal for patients who acquire the disease early in life. Currently-available drugs include interferons and oral nucleoside/nucleotide analogs. Although interferon therapy provides a finite treatment period, a significant proportion of patients may not respond, and long-term outcome is inconclusive. Long-term efficacy has been demonstrated for both lamivudine and adefovir. However, prolonged nucleoside/nucleotide analog therapy is associated with the emergence of drug-resistant mutations. Therefore, nucleoside/nucleotide analogs with a high genetic barrier and potent antiviral activity, such as entecavir, should be used to reduce the chance of developing drug-resistant mutations. Drugs with a low genetic barrier, including lamivudine and telbivudine, should be used in conjunction with early testing for antiviral response. This can predict favorable outcomes in the long term. The early detection of drug-resistant mutations should prompt clinicians to either add or switch to another agent with a different drug-resistance profile. There are currently no treatment models in the use of combination or sequential therapy in treatment-naïve patients. To date, long-term treatment appears to be the most effective option. Despite recent advances made with better understanding on the natural history of chronic hepatitis B infection and with newer antiviral drugs available, challenges remain with respect to treatment criteria, treatment end-points, and duration of treatment.

Diagnosis of hepatitis B virus infection through serological and virological markers

Hepatitis B virus (HBV) infection is an important health problem and the major cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) worldwide. The natural history of chronic HBV infection can be divided into four dynamic phases in HBV carriers who acquire the virus early in life. Diagnosis of HBV infection is usually through serological and virological markers. Hepatitis B surface antigen (HBsAg) is the hallmark of HBV infection and is the first serological marker to appear in acute hepatitis B, and persistence of HBsAg for more than 6 months suggests chronic HBV infection. Hepatitis B e antigen (HBeAg) usually indicates active HBV replication and risk of transmission of infection. Recently, occult HBV infection is recognized as the absence of circulating HBsAg in individuals positive for serum or tissue HBV DNA, irrespective of other HBV serological markers. Meanwhile, monitoring the serum HBV DNA level is valuable for assessing liver disease activity, differentiating other etiologies of hepatitis activity in HBV carriers, predicting risk of HCC development or liver-related mortality, deciding to administer antiviral therapy, determination of the response to antiviral treatment, predicting the risk of developing drug resistance, and detecting the emergence of drug-resistant mutants. On the other hand, HBV genotype C, basal core promoter mutant and pre-S deletion mutant are reported to be associated with increased risk of HCC development. The roles of quantitative HBV serology and intrahepatic HBV covalently closed circular (ccc)DNA deserve further studies. In conclusion, it is particularly important for physicians to screen for HBV infection in HBV-endemic areas and to monitor liver disease progression in HBV carriers by using both serological and virological markers, so that effective treatment can be initiated early before the development of advanced liver disease.

Hepatitis B: reflections on the current approach to antiviral therapy

This article summarizes the current state of antiviral therapy of hepatitis B with special attention given to areas that remain controversial or poorly defined. Strict adherence to liver association practice guidelines may result in missed opportunities to treat patients with significant underlying liver disease. In particular, recommended ALT thresholds may not appropriately reflect disease activity or degree of fibrosis. There is growing evidence that an alternative treatment paradigm for preventing late-stage disease complications may be indicated in highly viremic patients with early life exposure to hepatitis B. Pegylated interferon therapy is often a better choice for young to middle-aged patients with genotype A and B because of the higher rate of HBeAg seroconversion and a greater chance for HBsAg seroconversion in both HBeAg-positive and -negative patients as compared to nucleoside analogs. Nucleoside analog monotherapy is the current standard of care for many patients. However, long-term monotherapy results in resistance to a variable degree and sequential monotherapy may result in multi-drug resistant virus. Which patients would specifically benefit from early combination therapy also remains poorly defined. The rapidity and robustness of the suppression of HBV DNA while on a nucleoside analog should be monitored relatively early during treatment because it affects treatment outcome and the rate of resistance. While great progress has been made in treating hepatitis B, many important issues require further study.

[Natural history of chronic hepatitis B]

An estimated 350 million people worldwide are chronically infected with hepatitis B virus (HBV). Three phases of chronic hepatitis B virus infection is are recognized: the immune tolerant phase (HBeAg-positive, high levels of serum HBV-DNA, normal ALT, and no evidence of active liver diseases), the immune clearance phase or chronic hepatitis phase (HBeAg-positive, high levels of serum HBV-DNA, elevated ALT, and active liver disease ), and the inactive carrier state or asymptomatic phase (HBsAg-positive in serum without HBeAg, HBV-DNA levels than < 10(5) copies/mL, and normal ALT levels). Chronic hepatitis B is classified into 2 major forms: HBeAg-positive disease (wild-type HBV) and HBeAg negative disease (pre-core/core promoter HBV variant). Both forms can lead to liver cirrhosis, hepatic decompensation and liver cancer. The purpose of this article is to review the principal aspects of natural history of chronic hepatitis B.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon alpha2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included.

Significant prevalence of histologic disease in patients with chronic hepatitis B and mildly elevated serum alanine aminotransferase levels

BACKGROUND & AIMS

Serum ALT remains the most accessible test available to clinicians for monitoring chronic hepatitis B virus infection, but appropriate action when ALT levels are only mildly elevated is ambiguous in standard guidelines.

METHODS

A retrospective study was conducted to investigate the prevalence of significant histology in a patient population with mildly elevated serum ALT levels. A total of 193 consecutive patients were selected and divided into 2 groups according to HBeAg status. Patients were further divided into cohorts on the basis of their highest ALT elevation during follow-up and whether it was 1-1.5 times the upper limit of normal (ULN), 1.5-2 times the ULN, or greater than twice the ULN. The ULN that was used is 30 U/L for men and 19 U/L for women.

RESULTS

In all cohorts there was a substantial fraction of patients with histologic disease as evaluated by liver biopsy. HBeAg-negative patients were older, had lower viral load, and had a higher prevalence of disease. After adjustments for age, HBeAg status and HBV DNA viral load were not predictors of significant histology. Age >35 years, male gender, and increasing ALT levels were predictors for significant histology on multivariate analysis.

CONCLUSIONS

A substantial proportion of patients with mildly elevated ALT levels have significant histologic disease. The prevalence increased with the higher ALT levels and age.

Update on viral hepatitis: 2007

PURPOSE OF REVIEW

This is a concise review of recent developments in the field of viral hepatitis, based on publications between December 2006 and November 2007.

RECENT FINDINGS

Hepatitis A vaccine has similar efficacy to immune globulin as postexposure prophylaxis. Entecavir is a potent antiviral agent with a low rate of drug resistance in nucleoside-naïve chronic hepatitis B patients but it is not as effective in lamivudine-refractory patients. A combination of adefovir and lamivudine is preferred to adefovir monotherapy for lamivudine-refractory hepatitis B patients. Two orally administered hepatitis C protease inhibitors, telaprevir and boceprevir, were shown to have antiviral activity in hepatitis C genotype 1 patients. A 16-week course of pegylated interferon and ribavirin resulted in a lower rate of sustained virologic response compared with the standard 24-week course. Patients with hepatitis C-related cirrhosis who achieved sustained virologic response to antiviral therapy remain at risk for hepatocellular carcinoma. A novel recombinant hepatitis E vaccine was shown to be safe and effective in preventing infection.

SUMMARY

Advances have been made in the prevention of hepatitis A and hepatitis E. It is likely that specifically targeted antiviral therapies for hepatitis C will be available in the next few years.

Changes in viral load and HBsAg and HBeAg status with age in HBV chronic carriers in The Gambia

Background

Little is known about changes in hepatitis B viral load (HBV DNA) in relation to age in Africa. The aim of this study is to determine the natural course of HBV chronic infection, particularly in relation to sequential changes in serum HBV DNA levels and hepatitis B surface (HBsAg) antigen/hepatitis e antigen (HBeAg) status by age.

Methods

The study was conducted on 190 HBV chronic carriers, aged 1–19 years who were followed for 19 years. 160, 99 and 123 were traced at 5, 9 and 19 years later. All available samples were tested for HBsAg and HBeAg, whilst 170, 61, 63 and 81 were tested for HBV DNA at the baseline, and at 5, 9 and 19 years following recruitment.

Results

In general HBeAg which correlated with high levels of HBV DNA was lost at a much faster rate than HBsAg. 86% of the carriers who were recruited at the age of 1–4 yrs lost HBeAg by the age of 19 years compared to 30% who lost HBsAg. HBeAg negative carriers had serum HBV DNA levels of < 10⁵ copies per mL, HBV DNA positivity declined from 100% in 1–4 yrs old carriers at recruitment to 62.5%,60% and 88% at 5, 9 and 19 years respectively following recruitment.

Conclusion

After 19 years of follow up, the majority of HBV surface antigen carriers had lost HBeAg positivity and had low levels of viral replication. However small proportions (10–20%) retained HBeAg and continue to have high levels of viral replication.

Natural history of chronic hepatitis B: special emphasis on disease progression and prognostic factors

The natural history of chronic hepatitis B virus (HBV) infection and disease is complex and highly variable. We review the natural history of chronic hepatitis B with emphasis on the rates of disease progression and factors influencing the course of the liver disease. Chronic hepatitis B is characterized by an early replicative phase (HBeAg positive chronic hepatitis) and a late low or non-replication phase with HBeAg seroconversion and liver disease remission (inactive carrier state). Most patients become inactive carriers after spontaneous HBeAg seroconversion with good prognosis, but progression to HBeAg negative chronic hepatitis due to HBV variants not expressing HBeAg occurs at a rate of 1-3 per 100 person years following HBeAg seroconversion. The incidence of cirrhosis appears to be about 2-fold higher in HBeAg negative compared to HBeAg positive chronic hepatitis. In the cirrhotic patient the 5-year cumulative risk of developing hepatocellular carcinoma is 17% in East Asia and 10% in the Western Europe and the United States and the 5-year liver related death rate is 15% in Europe and 14% in East Asia. There is a growing understanding of viral, host and environmental factors influencing disease progression, which ultimately could improve the management of chronic hepatitis B.

Role of viral factors in the natural course and therapy of chronic hepatitis B

Hepatitis B virus (HBV) infection is a global health problem that causes a wide spectrum of liver disease, including acute or fulminant hepatitis, inactive carrier state, chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The pathogenesis of hepatocyte damage associated with HBV is mainly through immune-mediated mechanisms. On the basis of the virus and host interactions, the natural history of HBV carriers who are infected in early life can be divided into four dynamic phases. The frequency, extent, and severity of hepatitis flares or acute exacerbation in the second immune clearance and/or fourth reactivation phase predict liver disease progression in HBV carriers. In the past decade, hepatitis B viral factors including serum HBV DNA level, genotype, and naturally occurring mutants predictive of clinical outcomes have been identified. The higher the serum HBV DNA level after the immune clearance phase, the higher the incidence of adverse outcomes over time. In addition, high viral load, genotype C, basal core promoter mutation, and pre-S deletion correlate with increased risk of cirrhosis and HCC development. As to the treatment of chronic hepatitis B, patients with high HBV DNA level and genotype C or D infection are shown to have a worse response to interferon therapy. In conclusion, serum HBV DNA level, genotype, and naturally occurring mutants are identified to influence liver disease progression and therapy of chronic hepatitis B. More investigations are needed to clarify the molecular mechanisms of the viral factors involved in the pathogenesis of each stage of liver disease and the response to antiviral treatments.