Fulminant hepatic failure in acute hepatitis C: increased risk in chronic carriers of hepatitis B virus

Viral etiologies of acute liver failure

Acute liver failure (ALF) is a rare cause of liver-related mortality worldwide, with an estimated annual global incidence of more than one million cases. While drug-induced liver injury, including acetaminophen toxicity, is the leading cause of ALF in the Western world, viral infections remain a significant cause of ALF and the most common cause in many developing nations. Given the high mortality rates associated with ALF, healthcare providers should be aware of the broad range of viral infections that have been implicated to enable early diagnosis, rapid treatment initiation when possible, and optimal management, which may include liver transplantation. This review aims to provide a summary of viral causes of ALF, diagnostic approaches, treatment options, and expected outcomes.

Elucidating the distinct contributions of miR-122 in the HCV life cycle reveals insights into virion assembly

Efficient hepatitis C virus (HCV) RNA accumulation is dependent upon interactions with the human liver-specific microRNA, miR-122. MiR-122 has at least three roles in the HCV life cycle: it acts as an RNA chaperone, or 'riboswitch', allowing formation of the viral internal ribosomal entry site; it provides genome stability; and promotes viral translation. However, the relative contribution of each role in HCV RNA accumulation remains unclear. Herein, we used point mutations, mutant miRNAs, and HCV luciferase reporter RNAs to isolate each of the roles and evaluate their contribution to the overall impact of miR-122 in the HCV life cycle. Our results suggest that the riboswitch has a minimal contribution in isolation, while genome stability and translational promotion have similar contributions in the establishment phase of infection. However, in the maintenance phase, translational promotion becomes the dominant role. Additionally, we found that an alternative conformation of the 5' untranslated region, termed SLIIalt, is important for efficient virion assembly. Taken together, we have clarified the overall importance of each of the established roles of miR-122 in the HCV life cycle and provided insight into the regulation of the balance between viral RNAs in the translating/replicating pool and those engaged in virion assembly.

Impaired anti-HBV vaccine response in non-cirrhotic chronic HCV is not overcome by double dose regimen: randomized control trial

INTRODUCTION AND OBJECTIVES

Some studies suggest chronic HCV infection diminishes responses to the anti-HBV vaccine. We evaluated the efficacy of double versus standard dose HBV vaccination among HCV patients without cirrhosis.

PATIENTS AND METHODS

141 adults with untreated chronic HCV were randomized to HBV vaccination with double dose (40μg) or standard dose (20μg) at 0, 1 and 6 months; 70 healthy HCV-negative patients given standard dose served as controls. Vaccine response was defined by anti-HBs ≥10 mIU/mL.

RESULTS

128 patients (60 double, 68 standard doses) completed the study. Patients were of median age 52 years, 61% female, 60% fibrosis <2 of 4, and 76% genotype 1 with median 6-log _{10 IU}/mL HCV RNA. Overall seroprotection rate was 76.7% (95% CI: 65-87) in the 40μg versus 73.5% (95% CI: 63-84) in the 20μg dose HCV-positive groups (p =0.68) and 91.2% (95%CI:84-99) in HCV-negative controls (p =0.011 and 0.003, respectively). In multivariate logistic regression, vaccine dose (double vs. standard dose) was not associated with vaccine response (OR=0.63, p =0.33). Of 32 HCV-infected patients who were non-responders to 3- doses, 25 received the fourth dose of vaccine. The fourth dose seroconversion rate for the 40μg and 20μg groups were 45.5% and 21.4%, respectively.

CONCLUSIONS

In HCV-infected patients without cirrhosis, impaired responses to HBV vaccination cannot be overcome by the use of double dose HBV vaccination, but adding a fourth dose of vaccine for non-responders may be an effective strategy. Other adjuvant measures are needed to enhance seroconversion rates in these patients.

TRIAL REGISTER

U 1111-1264-2343 (www.ensaiosclinicos.gov.br).

From hepatitis A to E: A critical review of viral hepatitis

Viral infections affecting the liver have had an important impact on humanity, as they have led to significant morbidity and mortality in patients with acute and chronic infections. Once an unknown etiology, the discovery of the viral agents triggered interest of the scientific community to establish the pathogenesis and diagnostic modalities to identify the affected population. With the rapid scientific and technological advances in the last centuries, controlling and even curing the infections became a possibility, with a large focus on preventive medicine through vaccination. Hence, a comprehensive understanding of hepatitis A, B, C, D and E is required by primary care physicians and gastroenterologists to provide care to these patients. The review article describes the epidemiology, pathogenesis, clinical presentation, diagnostic tools and current medication regimens, with a focus on upcoming treatment options and the role of liver transplantation.

Precipitants of Acute-on-Chronic Liver Failure: An Opportunity for Preventative Measures to Improve Outcomes

Acute-on-chronic liver failure (ACLF) is a feared complication that can develop at any stage of chronic liver disease. The incidence of ACLF is increasing, leading to a significant burden to both the affected individual and health care systems. To date, our understanding of ACLF suggests that it may be initiated by precipitants such as systemic infection, alcohol use, or viral hepatitis. The prevalence of these vary significantly by geography and underlying liver disease, and these precipitants have a varying impact on patient prognosis. Herein, we present a review of our current understanding of the precipitants of ACLF, including gaps in current data and opportunities for meaningful intervention and areas of future research.

Liver Fibrosis Markers Improve Prediction of Outcome in Non-Acetaminophen-Associated Acute Liver Failure

A prognostic system for acute liver failure (ALF) with a higher predictive value is urgently needed. The role of extracellular matrix (ECM) remodeling in ALF has not been fully elucidated. We hypothesized that serologic fibrosis markers, which reflect ECM remodeling, are predictive of ALF outcome at first presentation. This observational study included 110 patients with acute liver dysfunction, of which 73 had non-acetaminophen-associated ALF (NAA-ALF). We evaluated serum levels of hyaluronic acid, 7S domain of type IV collagen (4COL7S), and Wisteria floribunda agglutinin-positive Mac-2-binding protein at first presentation to a tertiary center. Serologic fibrosis markers were significantly higher in NAA-ALF compared with acute hepatitis. Elevated hyaluronic acid and 4COL7S levels at first presentation correlated significantly with worse clinical outcomes. 4COL7S, along with age, ammonia, and the Model for End-Stage Liver Disease (MELD) score, was a significant prognostic factor in multivariate analysis; 4COL7S correlated significantly with coagulopathy, decreased hepatic synthetic functions, advanced hepatic encephalopathy, and liver atrophy and also predicted 180-day transplant-free survival. Cox regression models incorporating 4COL7S with the MELD system had profoundly improved predictive values that significantly surpassed the MELD system alone. Conclusion: Elevation of serologic fibrosis markers reflecting ECM remodeling in NAA-ALF predicted a worse clinical outcome. Incorporation of 4COL7S at first presentation to a transplant center improves the specificity while retaining the sensitivity of the MELD system. External validation of a fibrosis marker as part of a clinical prediction tool in ALF warrants further investigation.

Bacterial Infections

Bacterial infections are the most significant infectious source of morbidity and mortality in cirrhotic patients. Bacteria infections result is both acute decompensation in chronic liver disease and mortality in patients with decompensated cirrhosis. Spontaneous bacterial peritonitis (SBP), bacteremia, pneumonia, urinary tract infections (UTI) and skin and soft tissue infection (SSTI) are the most significant sources of infection in cirrhosis. Bacterial infections can precipitate renal failure and worsening hepatic encephalopathy, and patients with sepsis and liver disease have higher rates of acute respiratory distress syndrome (ARDS) and coagulopathy.

Hepatitis B reactivation during or after direct acting antiviral therapy - implication for susceptible individuals

INTRODUCTION

The FDA issued a warning following 24 cases of HBV reactivation during DAA therapy for HCV, including individuals with inactive, occult and past HBV infection. Clinical presentations ranged from asymptomatic fluctuations in HBV DNA to fulminant hepatic failure, liver transplantation and death. The mechanism is unknown. Areas covered: HCV/HBV coinfection is common, particularly in regions endemic for HBV. HCV and HBV utilize host factors to support replication; both viruses evade/impair host immunity. Clinical presentations of HBV reactivation during DAAs are summarized. Other causes of HBV reactivation are revisited and recent data regarding HBV reactivation are presented. Expert opinion: HBV reactivation during DAAs for HCV occurs, with life-threatening consequences in some individuals. The risk of HBV reactivation is observed in all HBV stages. The rapid removal of HCV likely alters and liberates host-viral ± viral-viral interactions that lead to increased HBV replication. As immune reconstitution occurs with HCV removal, host recognition of HBV DNA likely ensues followed by vigorous host immune responses leading to liver injury (HBV flare). These cases highlight the importance of HBV testing prior to initiating DAA therapy, the need for close monitoring of HBV during therapy and timely administration of anti-HBV therapy to prevent serious sequelae.

Toxicant-Induced Hepatic Injury

The sudden failure of a previously healthy and functioning liver is a dramatic and devastating event. Acute liver failure is the common final pathway of a multitude of conditions and insults, all of which result in massive hepatic necrosis or loss of normal hepatic function. The ensuing multiorgan system failure frequently has a fatal outcome, with mortality rates in most series ranging from approximately 55% to 95% [1]. Acute liver failure (ALF, previously often referred to as fulminant hepatic failure (FHF)) knows no age boundaries, with many cases occurring in those younger than 30 years. Short of excellent intensive care unit (ICU) support and liver transplantation in selected cases, few viable treatment options are available. Over the past few decades, however, survival has been improved by anticipation, recognition, and early treatment of associated complications, as well as the application of prognostic criteria for early identification of patients requiring liver transplantation (along with improvement in the techniques and science of transplantation itself). The etiology of ALF varies from country to country and the incidence change over time. Paracetamol (acetaminophen) has now replaced viral hepatitis as the leading cause of ALF [2]. In a study from London including 310 patients with ALF in the period 1994–2004, 42% of the cases were caused by paracetamol [3], whereas this was only the cause in 2% of 267 patients in Spain from 1992 to 2000 [4]. However, less than 10% of all liver transplants are performed in patients with ALF [5, 6].

Hepatitis B Virus Infection and Liver Decompensation

The goal in patients with immune active hepatitis B virus (HBV) infection is to significantly suppress viral replication and prevent progression of fibrosis to cirrhosis and liver decompensation and decrease the incidence of hepatocellular carcinoma. This is achievable by the highly active antivirals, entecavir and tenofovir, which are considered first-line therapy in most patients with immune active hepatitis C virus and after liver transplantation to prevent HBV recurrence. Patients with decompensated cirrhosis should be referred for liver transplantation and treated with first-line antivirals as early as possible, with the goal of achieving complete viral suppression in the shortest time possible.

The Natural History of Hepatit is C Viral Infection: Clinical Evaluation and Monitoring

Hepatitis C virus (HCV) infection is one of the most common causes of chronic liver disease in the world and represents a substantial burden on global health systems and individual patient wellbeing. Routine screening for HCV in certain high-risk populations is appropriate. HCV can cause both an acute and chronic hepatitis, and manifests as a variety of hepatic and extrahepatic symptoms, largely influenced by a combination of host and viral factors. It can be difficult to predict clinical outcomes in individual cases. In those who suffer a chronic infection, progression to cirrhosis carries the risk of decompensation and hepatocellular carcinoma. The natural history of HCV infection and our understanding of risk factors that are predictive of disease progression are discussed.

Outcome of Hepatitis B Virus Infection After Living-Donor Liver Transplant: A Single-center Experience Over 20 Years

OBJECTIVES

Despite living-donor liver transplant being a life-saving therapy for patients with hepatitis B virus with or without hepatocellular carcinoma, outcomes for patients with these diseases are worse. Hepatitis B virus recurrence or relapse of hepatocellular carcinoma can result in subsequent graft loss or patient death. In this study, we discuss the postoperative outcomes of patients with hepatitis B virus infection after living-donor liver transplant.

MATERIALS AND METHODS

We retrospectively analyzed 125 patients with hepatitis B virus-related end-stage liver disease, comparing results with 1228 control patients who had other pathologies, including hepatitis C virus, combined hepatitis B virus and hepatitis C virus, and neither virus.

RESULTS

Survival rates of patients with hepatitis B virus did not differ from the control groups (P > .05). Patients with concurrent hepatitis B virus and hepatocellular carcinoma were significantly older (P < .0001), had critical status (P < .0001), had chronic underlying pathology (P = .001), lower graft-to-recipient body weight ratio (P = .047), needed more intraoperative plasma transfusion, and experienced more rejection episodes than those without hepatocellular carcinoma. Of interest, in 5 patients who had hepatitis B virus recurrence after living-donor liver transplant, Model for End-Stage Liver Disease score was significantly higher than those who did not have recurrence (P = .015). In addition, 2 patients had hepatocellular carcinoma recurrence in the form of peritoneal metastasis, with both patients having high preoperative alpha-fetoprotein levels.

CONCLUSIONS

Our study provides details on long-term outcomes of patients with hepatitis B virus infection who had undergone living-donor liver transplant. Based on our results, we suggest that prolonged antiviral prophylactic therapy in the form of hepatitis B immunoglobulin with either lamivudine or entecavir be considered for patients who associated with risk factors to prevent postoperative recurrence.

Fulminant hepatic failure (FHF) due to acute hepatitis C

Acute hepatitis C (HCV) infection has been identified as an important cause of fulminant hepatic failure (FHF), characterized by rapid deterioration of liver function from massive hepatic necrosis leading to encephalopathy and multi-organ failure. We admitted a female patient at Shalamar Hospital with jaundice, fever, encephalopathy and coagulopathy of short duration with no history of any comorbidity. Her hepatitis viral screen revealed positive anti HCV. Her viral loads were also high. A diagnosis of FHF due to acute HCV infection was made. Patient was treated conservatively and improved gradually. In summary, acute HCV can cause FHF and should be ruled out in patients with FHF of unknown cause in an endemic country for HCV like Pakistan.

Nationwide longitudinal analysis of acute liver failure in taiwan

Acute liver failure (ALF) is uncommon but fatal. Current management is based mostly on clinical experience. We aimed to investigate the incidence, etiology, outcomes, and prognostic factors of ALF in Taiwan. Patients with the admission diagnosis of ALF between January 2005 and September 2007 were identified from the Longitudinal Health Insurance Database of Taiwan. ALF was further confirmed by disease severity based on laboratory orders, prescriptions, and duration of hospital stay, and acute onset without prior liver disease. Prognostic factors were identified using Cox regression analysis. During the study period, 218 eligible cases were identified from 28,078 potential eligible ALF patients. The incidence was 80.2 per million person-years in average and increased with age. The mean age was 57.9 ± 17.1 years and median survival was 171 days. The most common etiologies were viral (45.4%, mainly hepatitis B virus) and followed by alcohol/toxin (33.0%). Independent prognostic factors included alcohol consumption (hazard ratio, HR, 1.67 [1.01-2.77]), malignancy (HR 2.90 [1.92-4.37]), frequency of checkups per week for total bilirubin (HR 1.57 [1.40-1.76]), sepsis (HR 1.85 [1.20-2.85]), and the use of hemodialysis/hemofiltration (HR 2.12 [1.15-3.9]) and proton pump inhibitor (HR 0.94 [0.90-0.98]). Among the 130 patients who survived ≥90 days, 66 (50.8%) were complicated by liver cirrhosis. Eight (3.7%) were referred for liver transplantation evaluation, but only 1 received transplantation and survived. ALF in Taiwan is mainly due to viral infection. Patients with malignancy and alcohol exposure have worst prognosis. The use of proton pump inhibitor is associated with improved survival. Half of the ALF survivors have liver cirrhosis.

Fulminant viral hepatitis

Acute liver failure (ALF) is a condition wherein the previously healthy liver rapidly deteriorates, resulting in jaundice, encephalopathy, and coagulopathy. There are approximately 2000 cases per year of ALF in the United States. Viral causes (fulminant viral hepatitis [FVH]) are the predominant cause of ALF in developing countries. Given the ease of spread of viral hepatitis and the high morbidity and mortality associated with ALF, a systematic approach to the diagnosis and treatment of FVH is required. In this review, the authors describe the viral causes of ALF and review the intensive care unit management of patients with FVH.

Management of acute hepatitis B and reactivation of hepatitis B

The natural course of hepatitis B virus infection and the resulting hepatic injury is determined by the degree of virus replication and the intensity of host immune response. Upon exposure to hepatitis B virus (HBV), individuals with a vigorous and broad immune response develop acute self-limited infection, which may result in acute hepatitis. However, with stringent testing for HBV and universal precautions, acute HBV is rather rare. Reactivation of HBV most often presents as acute hepatitis B (AVH-B) and clinically, it is difficult to differentiate AVH-B from reactivation of chronic hepatitis B (CHB) and it requires a high index of suspicion. In the presence of high HBV DNA (>2 × 10(4) IU/ml) underlying liver disease should be investigated by liver biopsy, endoscopy and/or imaging. The degree of liver failure often depends on the severity of acute insult and the stage of underlying chronic liver disease. Mutations in the HBV genome, immunosuppressive therapy and viral or drug induced injury are common causes of reactivation. As most patients with AVH-B resolve the infection spontaneously, antiviral therapy is not indicated in them. However, the use of a potent oral nucleoside(tide) analogue is necessary as soon as possible in patients with CHB reactivation. Liver transplantation should be considered in patients who develop liver failure secondary to severe acute exacerbation. If this is not feasible, supportive therapy with the addition of granulocyte colony stimulating factor (GCSF) therapy could be beneficial.

Antiviral treatment of hepatitis B virus and hepatitis C virus co-infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are among the most common causes of advanced chronic liver disease worldwide. HBV/HCV co-infection is not uncommon with an estimated 7-20 million individuals affected worldwide. Patients with HBV/HCV co-infection have an increased risk of cirrhosis, hepatocellular carcinoma (HCC), and even death. The pathophysiology of HBV/HCV co-infection is complex, as different patterns of virological dominance may occur, which can even fluctuate over time. Recently, combination of pegylated interferon (PEG-IFN) plus ribavirin has been explored in HBV/HCV-coinfected patients who are positive for HCV-RNA. In this paper, we summarize the epidemiology, viral interaction and clinical features of HBV/HCV co-infection and the available treatment options. Detailed serological and virological evaluations are required for HBV/HCV-co-infected patients before initiation of antiviral therapy. At present, PEG-IFN-a plus ribavirin should be the treatment of choice in patients with dominant HCV replication. However, HBV rebound may occur after elimination of HCV, and thus close monitoring for both viruses is recommended even for patients with initially suppressed HBV DNA.

Influence of occult hepatitis B virus infection in chronic hepatitis C outcomes

Persistence of hepatitis B virus-DNA in the sera, peripheral blood mononuclear cells or in the liver of hepatitis B surface antigen (HBsAg)-negative patients with or without serological markers of previous exposure (antibodies to HBsAg and/or to HB-core antigen) defines the entity called occult hepatitis B infection (OBI). Co-infection with hepatitis B and hepatitis C viruses is frequent in highly endemic areas. While this co-infection increases the risk of liver disease progression, development of cirrhosis and hepatocellular carcinoma and also increases the rate of therapeutic failure to interferon-based treatments than either virus alone, a potentially negative effect of OBI on clinical outcomes and of therapeutic response to current antiviral regimes of patients with chronic hepatitis C remains inconclusive.

Natural history of chronic hepatitis B

In this article, the 4 phases of chronic HBV infection are reviewed and the factors that are associated with disease progression and the development of hepatocellular carcinoma (HCC) and cirrhosis are discussed. Also discussed is what is known to date about how to identify persons at the highest risk of developing HCC and/or cirrhosis. Finally, ways in which the natural history can be altered by hepatitis B vaccination and identification, close monitoring, and appropriate treatment of chronically infected individuals are reviewed.

Treatment of HBV/HCV coinfection

IMPORTANCE OF THE FIELD

Hepatitis B (HBV) and hepatitis C (HCV) virus infections are among the most common causes of advanced chronic liver disease worldwide. HBV/HCV coinfection is not uncommon with an estimated 7 - 20 million individuals affected worldwide. Patients with HBV/HCV coinfection have an increased risk for cirrhosis, hepatocellular carcinoma (HCC) and even death.

AREAS COVERED IN THIS REVIEW

The pathophysiology of HBV/HCV coinfection is complex, as different patterns of virological dominance may occur, which can even fluctuate over time. Recently, combination of pegylated interferon (PEG-IFN) plus ribavirin has been explored in HBV/HCV coinfected patients who are positive for HCV-RNA. HBV polymerase inhibitors may be indicated if HBV-DNA concentrations are above 2000 IU/ml. In this review, we summarize the epidemiology, viral interaction, its clinical features and the available treatment options.

WHAT THE READER WILL GAIN

Insights into viral interaction of HBV/HCV coinfection and treatment individualization strategies are provided in the review.

TAKE HOME MESSAGE

Detailed serological and virological evaluations are required for HBV/HCV coinfected patients before initiation of antiviral therapy. At present, PEG-IFN-alpha plus ribavirin should be the treatment of choice in patients with dominant HCV replication. However, HBV rebound may occur after elimination of HCV, and thus close monitoring for both viruses is recommended even for patients with initially suppressed HBV-DNA.

Hepatitis C comorbidities affecting the course and response to therapy

Several studies have demonstrated that the outcome of chronic hepatitis C (CHC) infection is profoundly influenced by a variety of comorbidities. Many of these comorbidities have a significant influence on the response to antiviral therapy. These comorbidities negatively affect the course and outcome of liver disease, often reducing the chance of achieving a sustained virological response with PEGylated interferon and ribavirin treatments. Comorbidities affecting response to antiviral therapy reduce compliance and adherence to inadequate doses of therapy. The most important comorbidities affecting the course of CHC include hepatitis B virus coinfection, metabolic syndrome, and intestinal bacterial overgrowth. Comorbidities affecting the course and response to therapy include schistosomiasis, iron overload, alcohol abuse, and excessive smoking. Comorbidities affecting response to antiviral therapy include depression, anemia, cardiovascular disease, and renal failure.

Acute hepatitis C: prevention and treatment

HCV can cause acute or chronic hepatitis and is a health problem all over the world. It is one of the leading causes of cirrhosis and hepatocellular carcinoma, and is a common indication for liver transplantation. Unrecognized patients with HCV infection may transmit the virus to uninfected people. The acute form of the disease leads to chronic hepatitis in the majority of cases. Since the success rate of treatment given in the chronic phase is much lower than that given in the acute phase, recognizing acute hepatitis is critical. Although HCV is less prevalent since 1990s in the Western world after improved blood-donor screening programs, needle-exchange facilities and education among intravenous drug users, it is still endemic in some regions, including African countries, Egypt, Taiwan, China and Japan. Acute HCV infection may be a challenge for the clinician; since it is often asymptomatic, detection and diagnosis are usually difficult. After an incubation period of 7 weeks (2-12 weeks), only a minority of patients (10-15%) report symptoms. The spontaneous clearance of the virus is more frequent primarily during the first 3 months of clinical onset of the disease, but may occur anytime during the 6 months of acute infection. This spontaneous resolution seems to be more frequent in symptomatic cases. Viremia persisting more than 6 months is accepted as chronic infection. The virus is transmitted more frequently through infected blood or body fluids. Detection of antibodies against HCV is not a reliable method of diagnosing acute HCV infection since the appearance of antibodies against HCV can be delayed in up to 30% of patients at the onset of symptoms. Thus, the diagnosis of acute hepatitis C relies on the qualitative detection of HCV RNA, which may appear as early as 1-2 weeks after exposure quickly followed by highly elevated alanine aminotransferase. After a follow-up period of 8-12 weeks for allowing spontaneous resolution, treatment should be initiated. Pegylated interferon monotherapy for 24 weeks seems effective, and the therapy can be individualized according to the characteristics of the patient.

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.

HBV superinfection in HCV chronic carriers: a disease that is frequently severe but associated with the eradication of HCV

The impact of hepatitis B virus (HBV) superinfection in hepatitis C virus (HCV) chronic carriers was evaluated in a long-term follow-up study on 29 chronic anti-HCV carriers with acute hepatitis B (AVH-B) (Case group BC) and 29 anti-HCV negative patients with AVH-B (Control group B), pair-matched for age (+/-5 years), sex, and risk factors for the acquisition of HBV infection. Patients in Case group BC and those in Control group B showed similar initial HBV viral load and a similar trend of becoming negative for HBV-DNA. AVH-B showed a severe course more frequently in Case group BC than in Control group B (34.5% versus 6.9%, P < 0.05). Of the 28 patients in Case group BC alive at the end of the acute illness (one death from liver failure), 24 were followed up for 2-6 years, median 5 years: 22 patients became HBsAg-negative and two progressed to HBsAg-positive chronic hepatitis. HCV-RNA was undetectable in all patients during AVH-B; in the 24 patients with a long-term follow-up, HCV-RNA was detected in seven (29.2%) after 1 year, in 14 (58.3%) after 2 years, and in 18 (75%) after 3-6 years. The six patients who eradicated chronic HCV infection, compared with 18 showing reactivation of HCV replication, had higher values of aspartate aminotransferase and alanine aminotransferase and a higher prevalence of cases with severe AVH-B (83.3% versus 22.2%, P < 0.05).

CONCLUSIONS

Although it can be life-threatening, HBV superinfection in HCV chronic carriers may lead to clearance of chronic HCV infection, especially in patients with severe AVH-B.

Nimesulide associated fulminant hepatic failure

PURPOSE

It is controversial whether the non-steroidal inflammatory drug nimesulide is associated with severe hepatotoxicity. Our objective was to determine whether nimesulide is associated with fulminant hepatic failure.

METHODS

Retrospective cohort study in the Irish national liver transplant unit. All patients who received a liver transplant for fulminant hepatic failure of unknown cause, between January 1994 and March 2007, were evaluated. New medications started within 6 months prior to transplant were identified. Likelihood of association assessed using the Naranjo and Roussel UCLAF Causality Assessment Method (RUCAM) scoring systems.

RESULTS

Thirty-two patients with sero-negative, non-paracetamol fulminant hepatic failure, who received an emergency liver transplant, were identified. Nimesulide had been started within 6 months in 6 patients. Five of the six were middle aged females. Nimesulide was assessed as probably associated with liver injury in all six cases.

CONCLUSIONS

Nimesulide was associated with fulminant hepatic failure requiring liver transplant in 6/32 cases of unknown origin. This association requires further investigation.

Trastuzumab-Induced Hepatotoxicity

Objective:

To report a case of probable trastuzumab-induced hepatotoxicity.

Case Summary:

A 54-yoar-old African American woman presented with locally advanced right-sided breast cancer that was found to be strongly positive for human epidermal growth factor receptor 2 (HER2) by fluorescence in situ hybridization. She was treated with neoadjuvant chemotherapy with 4 cycles of dose-dense doxorubicin and cyclophosphamide. Laboratory test results, including liver function tests (LFTs), were normal at that time. Therapy consisting of weekly doses of paditaxel 80 mg/m2 and a loading dose of trastuzumab 4 mg/kg for the first week and 2 mg/kg weekly thereafter was started. Alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels began to increase after the initial dose; the levels were significantly elevated after the fifth cycle. Paclitaxel was withheld, and trastuzumab was continued, as there were no prior reported cases of trastuzumab-induced hepatotoxicity at that time. Other possible etiologies for the elevated enzyme levels, including metastasis to the liver, were excluded. The patient continued to receive trastuzumab for a total of 8 weeks; it was discontinued at that time because enzyme levels continued to increase. When trastuzumab was discontinued, enzyme levels returned to normal. Subsequently, surgical resection of the cancer was performed. The patient's lymph nodes wore found to be involved and, because of the high risk of disease recurrence, she was re-challenged with trastuzumab, LFTs showed enzyme levels rising again and trastuzumab was discontinued after 2 cycles, with subsequent normalization of the levels. She was then treated with weekly paclitaxel and her LFT values continued to be in the near-normal range.

Discussion:

There were no comorbidities in this patient and, on initiation of trastuzumab, her liver enzyme levels were normal. The levels became elevated after initiation of trastuzumab, normalized after its discontinuation, and increased upon rechallenge. According to a validated drug-induced hepatotoxicity scale, trastuzumab was the probable cause of hepatotoxicity in this patient.

Conclusions:

Livor enzyme levels must be closely monitored in patients receiving trastuzumab. To our knowledge, this is the first report of trastuzumab-induced hepatotoxicity requiring discontinuation of the drug.

Hepatitis E virus as an etiology of acute exacerbation of previously unrecognized asymptomatic patients with hepatitis B virus-related chronic liver disease

BACKGROUND AND AIM

Hepatitis E virus (HEV) has recently been implicated in episodes of acute decompensation in patients having underlying chronic liver disease (CLD) of varying etiology. However, HEV as a cause of acute exacerbation of previously asymptomatic and unrecognized hepatitis B virus (HBV)-infected patients is less well described. The aim of the present study was to investigate the etiology of acute exacerbation of previously asymptomatic and unrecognized HBV-infected patients and to evaluate the relative role of HEV. We also investigated the effect of superinfection on the clinical spectrum of underlying HBV infection.

METHODS

Forty-three patients presented with the following were retrospectively analyzed: (i) clinical features suggestive of acute hepatitis; (ii) with hepatitis B surface antigen (HBsAg) (+); (iii) IgM hepatitis B core antibody (IgM anti-HBc) (-); (iv) no previous history of liver disease; (v) no features suggestive of CLD at presentation; (vi) HBsAg remaining (+) for at least 12 months on follow up; and (vii) having a follow-up biopsy during the convalescent phase showing evidence of chronic hepatitis B.

RESULTS

Of the 43 patients, 21 were hepatitis e antigen (HBeAg) (+) (Gr.1) and 22 HBeAg (-) (Gr.2) at presentation. In Gr.1, only two (9.5%) had superinfection (both with hepatitis A virus), whereas in Gr.2, 11 (50%) had superinfection (27.3% hepatitis E, 13.6% hepatitis A and 9.1% both) (P = 0.007). In Gr.1, the remaining 19 (90.5%) patients had spontaneous exacerbation (immune clearance with spontaneous seroconversion) whereas in Gr.2, the remaining 11 (50%) had spontaneous exacerbation (due to reactivation). Overall, HEV superinfection contributed to 20% of acute exacerbation episodes and, in particular, 36% of episodes in initially HBeAg (-) patients. Time to alanine aminotransferase normalization was longer in patients with superinfection (n = 13) as compared to spontaneous exacerbation (n = 30) (median [range] 36 [8-48]vs 16 [6-36] weeks, P = 0.001). During convalescence, there was no significant difference between histological activity index score (median [range] 8 [4-11]vs 8 [4-16] weeks, P = 0.629) and fibrosis scores (median [range] 3.5 [1-4]vs 2 [1-4] weeks, P = 0.099] on liver biopsy after recovery among patients with acute exacerbation due to superinfection and spontaneous exacerbation.

CONCLUSIONS

Acute exacerbations in HBeAg (+) patients are most often due to spontaneous viral activation, while in HBeAg (-) patients, superinfection with non-B hepatitis viruses and spontaneous viral activation are equally common. HEV is an important cause of acute exacerbation in previously asymptomatic and unrecognized patients with HBV-related CLD.

Acute liver failure: Summary of a workshop

Acute liver failure (ALF) is a rare but challenging clinical syndrome with multiple causes; a specific etiology cannot be identified in 15% of adult and 50% of pediatric cases. The course of ALF is variable and the mortality rate is high. Liver transplantation is the only therapy of proven benefit, but the rapidity of progression and the variable course of ALF limit its use. Currently in the United States, spontaneous survival occurs in approximately 45%, liver transplantation in 25%, and death without transplantation in 30% of adults with ALF. Higher rates of spontaneous recovery (56%) and transplantation (31%) with lower rates of death (13%) occur in children. The outcome of ALF varies by etiology, favorable prognoses being found with acetaminophen overdose, hepatitis A, and ischemia (approximately 60% spontaneous survival), and poor prognoses with drug-induced ALF, hepatitis B, and indeterminate cases (approximately 25% spontaneous survival). Excellent intensive care is critical in management of patients with ALF. Nonspecific therapies are of unproven benefit. Future possible therapeutic approaches include N-acetylcysteine, hypothermia, liver assist devices, and hepatocyte transplantation. Advances in stem cell research may allow provision of cells for bioartificial liver support. ALF presents many challenging opportunities in both clinical and basic research.

Hepatitis B virus/hepatitis C virus coinfection: epidemiology, clinical features, viral interactions and treatment

Because of the shared modes of transmission, hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection is not uncommon in highly endemic areas and among subjects with a high risk of parenteral infections. The worldwide prevalence of HBV/HCV coinfection is unknown and might be underestimated with the phenomenon of silent (occult) HBV infection. HCV superinfection in patients with chronic HBV infection was the most common clinical features of coinfection in Asia-Pacific countries. Further, most, but not all, clinical observations suggested that interference between the two viruses was more frequently characterized by an inhibition of HBV replication exerted by HCV. However, longitudinal follow-up studies have demonstrated that the virological patterns in coinfection cases are widely divergent and have dynamic profiles over time. As compared with monoinfected patients, HBV/HCV coinfected persons tend to have more severe liver injury, a higher probability of liver cirrhosis and hepatic decompensation, and a higher incidence of hepatocellular carcinoma. Detailed serological and virological evaluations are required for coinfected patients before initiation of antiviral therapy. Previous studies demonstrated that HBV/HCV coinfected patients responded poorly to interferon (IFN) monotherapy. Currently, for patients with dominant HCV infection and low level HBV viremia (<10(4) IU/mL), IFN or pegylated IFN plus ribavirin can achieve comparable sustained virus response as expected with HCV monoinfection. However, phenomenon of reciprocal viral interference can happen, and resultant "flare" of hepatitis activity may cause liver function deterioration. For coinfected patients with dually-active HBV/HCV, the optimal regimen for therapy remains unclear although adding oral nucleos(t)ide analogs to pegylated IFN and ribavirin seems a reasonable empiric option.

Prevention of viral hepatitis in HIV co-infection

Co-infection of HIV-positive patients with hepatitis viruses worsens the long-term prognosis and this is summative for each new infection in any individual. Vaccination against hepatitis A or B may be effective but response rates are reduced in HIV infected patients. Improvement in response can be induced through extra doses, higher doses and HAART-induced increase in the CD4 count. Hepatitis B and C may also be prevented through counselling about safer sex, particularly condom use. In intravenous drug users, harm reduction, counselling and the use of needle/syringe exchange schemes may be helpful.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) dual infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. Because the two hepatotropic viruses share same modes of transmission, coinfection with the two viruses is not uncommon, especially in areas with a high prevalence of HBV infection and among people at high risk for parenteral infection. Patients with dual HBV and HCV infection have more severe liver disease, and are at an increased risk for progression to hepatocellular carcinoma (HCC). Treatment of viral hepatitis due to dual HBV/HCV infection represents a challenge.

Hepatitis C virus superinfection in hepatitis B virus chronic carriers: a reciprocal viral interaction and a variable clinical course

BACKGROUND

The virological and clinical impact of hepatitis C virus (HCV) superinfection in chronic hepatitis B virus (HBV) carriers has been poorly characterized.

OBJECTIVE

To evaluate the viral interaction, clinical presentation and course of the disease in four HBsAg/HBV-DNA positive chronic hepatitis patients who developed acute HCV infection.

STUDY DESIGN

To evaluate clinical, virological and laboratory data for at least 6 months from the onset of acute HCV infection in patients with chronic HBV infection.

RESULTS

Three patients with acute HCV infection had a normal clinical course, but the remaining patient had severe disease with ascites and a marked decrease in prothrombin activity. In all cases, plasma HBV-DNA, which had been detectable prior to the HCV infection, was no longer detectable when the acute HCV infection occurred. The inhibition exerted by HCV on HBV-DNA persisted throughout the follow-up period in three patients, but was temporary in the one patient who experienced an acute exacerbation of chronic HBV infection. HCV-RNA became persistently undetectable in two patients and reduced to low levels in the other two.

CONCLUSIONS

Acute HCV infection in the four HBV chronic carriers was characterized by a reciprocal inhibition of HBV-HCV genomes and, in one case, by a severe course of disease.

Fulminant hepatic failure in children and adolescents in Northern Brazil

The histological findings of fulminant hepatic failure were correlated to the demographic, clinical, biochemical and virological features in children and adolescents, native to the Amazonas State in Northern Brazil. 96.2% had evidence of infection by primary hepatotrophic viruses. Histological analysis revealed three distinct patterns of fulminant hepatic failure.

Case fatality rate of acute viral hepatitis in Italy: 1995-2000. An update

BACKGROUND

Fulminant hepatic failure is the most serious complication of viral hepatitis. Although this event occurs rarely, it may be fatal.

AIMS

To evaluate the case fatality rate (several deaths divided by number of cases x 100) for each viral hepatitis type in Italy from 1995 to 2000.

PATIENTS

Acute hepatitis cases identified by the surveillance system for acute viral hepatitis, which covers approximately 58% of the Italian population.

RESULTS

Twenty-five deaths (0.1%) occurred among the 18 460 acute viral hepatitis cases observed from 1995 to 2000, a rate threefold lower than the 0.3% reported during the period 1985-1994. The highest case fatality rate (0.4%) was seen for acute hepatitis B (18 deaths among 4257 cases). Only one death (0.01%) occurred among the 11 063 acute hepatitis A cases and two deaths (0.1%) among the 1536 acute hepatitis C cases. No deaths were observed among the 309 acute hepatitis A cases superimposed on chronic HBsAg carriers and the 166 superimposed on chronic HCV carriers. Intravenous drug use (22.2% of cases) and other parenteral exposures (22.2% of cases) were the most frequent non-mutually exclusive sources of infection reported by subjects who died of acute hepatitis B.

CONCLUSIONS

Analysis of surveillance system data from 1995 to 2000 indicates that, in Italy, deaths due to acute viral hepatitis are rare, but most commonly observed with acute hepatitis B. There is no evidence that acute hepatitis A may be fatal in chronic HBsAg or HCV carriers. The overall better survival rate may probably reflect improvements in the treatment of fulminant hepatitis in the last few years in Italy.

[Epidemiological study of the hepatitis C virus in our population and vaccine coverage]

OBJECTIVE

Epidemiological study of patients with chronic hepatitis C and its serological status in relation to the hepatitis A (HA) and B (HB) viruses.

DESIGN

Descriptive cross-sectional study.

SETTING

Two urban health centres. Participants. 291 patients with chronic hepatitis C.

MAIN MEASUREMENTS

VARIABLES

age, sex, year and reason for diagnosis, personal histories, alcohol intake, serological status of the HA and HB viruses and HIV, and initial level of transaminases.

RESULTS

Mean age, 55 +/- 16. Sex, 52% women. Prevalence, 0.98%. Reason for diagnosis, 41% health study, 15% study of hepatic pathology, 18% study of other pathologies. Personal histories, surgical intervention, 37.5%; intravenous drug users, 21.4%; transfusion, 14%; high-risk sexual conduct, 2.4%; health material used more than once, 2.4%; family member HC positive, 1.4%; no personal history recorded, 26.5%. Alcoholism, 17.9%. Mean transaminases: AST, 79.7 +/- 100 (9-920); ALT, 114.8 +/- 160 (6-1640). HB serological status: natural immunity, 22%; chronic, 9%; vaccine immunity, 3%; negative, 44%; not recorded, 21%. HA serological status: natural immunity, 2%; vaccine immunity, 2.5%; negative, 9%; not recorded, 87%. HIV-positive: 4.5%.

CONCLUSIONS

Prevalence was below the expected level. Knowledge of serological status needs to be improved, especially for HA. The degree of vaccine coverage in these patients for HA and HB should be increased.

Acute hepatitis B and C virus coinfection: a virological and clinical study of 3 cases

We report the virological interaction in, clinical presentation of, and course of disease observed in 3 male injection drug users with acute hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection. In all 3 cases, HBV infection presented first and quickly resolved. Diagnosis of acute HBV/HCV coinfection requires a long follow-up period with careful observation.

HBV superinfection in hepatitis C virus chronic carriers, viral interaction, and clinical course

We enrolled 44 patients with hepatitis B virus (HBV) acute infection, 21 anti-hepatitis C virus (HCV)-positive for at least 1 year (case BC group), 20 anti-HCV-negative (control B group), and 3 with HBV/HCV acute concurrent infection. For each case BC, a subject with chronic HCV infection alone was selected (control C group). At the first observation, 85.7% of patients in case BC group and 85% of those in control B group were HBV-DNA-positive (polymerase chain reaction [PCR]), with a similar trend towards a decrease and negativization in about 20 days; in the case BC group, seroconversion to antibody to hepatitis B e antigen (anti-HBe) was more rapid. HCV-RNA (PCR) was undetectable in all case BC patients but 1, who shortly became negative, whereas 85.7% of subjects in control C group were positive (P <.001). Severe acute hepatitis was more frequent in the case BC group than in the control B group (28.6% vs. 0%, P <.05). Of the 14 patients in the case BC group and of the 16 in the control B group followed up for more than 6 months, 1 in the first and 1 in the second group became hepatitis B surface angiten (HBsAg) chronic carriers. Of the 13 patients in case BC group who recovered, 1 cleared both anti-HCV and HCV-RNA, 6 became HCV-RNA-positive, and 6 remained HCV-RNA-negative. In patients with HBV/HCV acute concurrent infection, HBV-DNA became undetectable in 15 days, and HCV-RNA and anti-HCV became positive at days 30 and 45, respectively; these patients developed HCV-RNA-positive chronic hepatitis. In conclusion, HBV superinfection in chronic HCV carriers has a severe clinical course and strongly and persistently depresses HCV.

Sexually acquired hepatitis

OBJECTIVES

To assess current knowledge of sexually transmitted viral hepatitis in relation to epidemiology, clinical presentation, management, and diagnosis with particular reference to resource-poor settings.

METHOD

A search of published literature identified through Medline from 1966 to October 2001, the Cochrane Library, and reference lists taken from each article obtained. Textword and MeSH searches for hepatitis A, B, C, D, E, G, delta, GB virus, GBV-C, and TT virus were linked to searches under the textword terms sex$, prevent$, and MeSH subheadings, microbiology, complications, drug therapy, therapy, diagnosis, epidemiology, transmission, and prevention and control.

CONCLUSIONS

In heterosexual relationships, hepatitis B is readily transmitted sexually and hepatitis C and D less so, with no evidence for sexual transmission of hepatitis A. Hepatitis types A-D are all transmissible sexually in male homosexual relationships under certain conditions. In resource-poor countries sexual transmission is generally only a significant route of transmission for hepatitis B.

Acute hepatitis C virus (HCV) infection in chronic carriers of hepatitis B virus (HBV): the impact of underlying active HBV replication on persistence of HCV infection and antibody responses to HCV

BACKGROUND AND AIMS

The aim of this study was to assess whether underlying chronic hepatitis B virus (HBV) infection interferes with persistence of hepatitis C virus (HCV) infection and humoral immune responses to HCV in acute HCV infection.

METHODS

Serial sera from 12 patients with acute HCV infection (group A) and 12 hepatitis B surface antigen (HBsAg) carriers with acute HCV infection (seven anti-hepatitis B e antigen (anti-HBe) positive (group B1) and five hepatitis B e antigen (HBeAg) positive (group B2)) were tested for HCV RNA by polymerase chain reaction, and anti-HCV by third generation enzyme immunoassay and confirmatory assay. Serial serum samples from HBsAg carriers were also tested for HBeAg, anti-HBe, and HBV DNA by hybridisation assay.

RESULTS

Persistent HCV viraemia for more than six months was significantly more frequent in groups A (83%) and B1 (86%) than in group B2 (0%). Anti-HCV was detected in 100% and 86% of group A and group B1 one month after onset while only one group B2 patient was transiently anti-HCV positive 1-2 months after onset. Of the latter, three had anti-core 1 less than two months after onset while no patient responded to other HCV antigens. Overall, of six HBsAg carriers with acute self limiting HCV infection, only one had transient anti-HCV and three had transient anti-core 1. HBV DNA became undetectable transiently in four and persistently in one group B2 patient.

CONCLUSION

The presence of active HBV replication can inhibit the persistence of HCV infection and antibody responses to HCV. Acute HCV infection in HBsAg carriers with active HBV replication usually presents transient HCV viraemia with poor antibody responses to HCV.

Occult hepatitis B virus infection and its clinical implications

Occult hepatitis B virus (HBV) infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg). Serum HBV level is usually less than 104 copies/mL in these patients. Diagnosis of occult HBV infection requires sensitive HBV-DNA PCR assay. Several possibilities have been hypothesized as the mechanisms of occult HBV infection. These include: (i) mutations of HBV-DNA sequence; (ii) integration of HBV-DNA into host's chromosomes; (iii) infection of peripheral blood mononuclear cells by HBV; (iv) formation of HBV-containing immune complex; (v) altered host immune response; and (vi) interference of HBV by other viruses. The precise prevalence of occult HBV infection remains to be defined. The clinical implications of occult HBV infection involve different clinical aspects. First of all, occult HBV infection harbours potential risk of HBV transmission through blood transfusion, haemodialysis, and organ transplantation. Second, it may serve as the cause of cryptogenic liver disease, contribute to acute exacerbation of chronic hepatitis B, or even fulminant hepatitis. Third, it is associated with development of hepatocellular carcinoma. Fourth, it may affect disease progression and treatment response of chronic hepatitis C. Most of the previous studies utilized retrospective observation without control groups, and lacked direct association of occult HBV infection with specific pathological changes and disease progression. Highly sensitive, quantitative, and functional molecular analyses of HBV, combined with a well-designed prospective clinical assessment will provide the best approach for the future study of occult HBV infection.

SEN virus: response to interferon alfa and influence on the severity and treatment response of coexistent hepatitis C

The SEN virus (SENV) is a recently identified single-stranded, circular DNA virus. A strong association between 2 SENV variants (SENV-D and SENV-H) and transfusion-associated non-A-to-E hepatitis has been reported. To clarify the effect of SENV infection on coexisting chronic hepatitis C and the effect of interferon alfa (IFN-alpha) therapy on SENV replication, SENV DNA was quantitated by polymerase chain reaction in serum samples from 186 patients with chronic hepatitis C. Thirty-nine of 186 (21%) patients with chronic hepatitis C were positive for SENV DNA. There were no differences in the clinical, virologic and histologic features between patients with and without SENV infection. Eighteen of 102 patients with chronic hepatitis C who received IFN-alpha were positive for SENV DNA. The sustained response rate for hepatitis C virus (HCV) clearance after IFN-alpha treatment did not differ significantly between patients with SENV (28%) and without SENV infection (39%). SENV DNA levels decreased during therapy in 15 of 16 patients, and 11 of the 16 patients (69%) had a sustained loss of SENV DNA in response to IFN-alpha. In coinfected patients, SENV responses to IFN-alpha were significantly better in those who failed to clear HCV RNA than in those who lost HCV RNA (P =.013). In conclusion, SENV infection was frequently found in patients with chronic hepatitis C. SENV infection had no apparent influence on the severity of HCV-related liver disease or the HCV response to IFN-alpha. SENV was sensitive to IFN-alpha therapy and the majority of patients had a sustained virologic response.

Acute flares in chronic hepatitis B: the natural and unnatural history of an immunologically mediated liver disease

Acute flares in chronic hepatitis B are common and may be caused by a number of identifiable and potentially treatable factors. The common link for many of these exacerbation episodes is a change in the immunologic response to hepatitis B virus (HBV), and this may have no identifiable cause or be triggered by an increase in viral replication or genotypic change. It is important to keep in mind the clinical situations in which patients are at increased risk of reactivated infection and secondary exacerbations. Reactivation is frequently induced by medical treatments such as cancer chemotherapy, antirejection drugs used in organ transplantation, and corticosteroids. The immunologic flares that often result from sudden withdrawal of these medications can be life-threatening unless recognized and treated promptly with antivirals, and there is increasing experience that preemptive antiviral treatment can diminish their occurrence and improve the outcome. The experience with lamivudine and other nucleoside analogues has increased our understanding of the molecular events behind hepatitis flares that occur when chronic hepatitis B is treated with drugs that potently inhibit HBV DNA polymerase. However, not all flares are explainable by events related to HBV infection alone. Depending on the population studied, as many as 20%-30% of flares may be caused by infection with other hepatotropic viruses, and this situation may inhibit HBV replication. Proper understanding of the etiology and effective treatment of acute flares in chronic hepatitis B requires an appreciation of high-risk clinical situations, assessment of HBV replication status, and testing for other viruses when appropriate.

Natural history of chronic hepatitis B virus infection in adults with emphasis on the occurrence of cirrhosis and hepatocellular carcinoma

The natural course of perinatally acquired hepatitis B virus (HBV) infection has three phases. In the first 'immune tolerance phase', patients are HBeAg positive and have high serum levels of HBV DNA, but have no symptoms, normal ALT levels and minimal histological activity. The second 'immune clearance phase' usually occurs between 15 and 35 years of age, during which HBV replication declines, accompanied by increased serum ALT levels and inflammatory activity in the liver; HBeAg to anti-HBe seroconversion is then observed, frequently preceded by a flare of the ALT level. The average rate of spontaneous HBeAg seroconversion is 10% per year. In the third 'low-replicative phase', serum HBsAg persists, but HBeAg is no longer detectable and HBV DNA can only be detected by PCR assay. During this phase, patients are usually asymptomatic and liver disease is inactive; some patients, however, may progress to cirrhosis and hepatocellular carcinoma (HCC). The ultimate outcome of chronic HBV infection appears to depend on the duration and severity of liver injury during the immune clearance phase. About 2.1% of patients with chronic type B hepatitis develop cirrhosis each year. Patients who have a severe acute exacerbation complicated by subacute hepatic failure or who have recurrent episodes of acute exacerbations with bridging hepatic necrosis are more likely to develop cirrhosis. A significant proportion of those with HBsAg eventually develop HCC; they have a 100-fold increased risk of HCC relative to those without. The development of HCC, however, is closely related to the severity of the underlying liver disease. The annual incidence of HCC is only 0.1% in asymptomatic HBsAg individual, 1% in patients with chronic hepatitis B, but increases to 3-10% in patients with cirrhosis. Some anti-HBe-positive patients continue to have active liver disease and they should be tested for HBV DNA by hybridization assay to determine whether the disease results from replicative precore mutant HBV infection or other causes of liver disease, such as superinfection with HCV and HDV. A substantial number of apparently healthy HBV-infected individuals are first recognized when they present with episodes of acute hepatitis. About 30% of these cases could be attributed to other hepatotropic virus superinfection. Acute viral hepatitis in patients with concurrent HBV infection is associated with an increased risk of fulminant hepatic failure. Finally, HBsAg disappears from serum in about 1% of patients each year. HCV superinfection can enhance the termination of HBsAg positivity. HCV, however, replaces HBV as the dominant cause of chronic viral hepatitis. The outcome of HBV-infected persons with 'spontaneous' seroclearance of HBsAg is usually favourable, though progress to cirrhosis and HCC is still possible.