Natural history and prognosis of hepatitis B

Introduction to chronic hepatitis B infection

Chronic hepatitis B virus (HBV) infection affects over 350 million people worldwide and over 1 million die annually of HBV-related chronic liver disease. Although many individuals eventually achieve a state of nonreplicative infection, the prolonged immunologic response to infection leads to the development of cirrhosis, liver failure, or hepatocellular carcinoma (HCC) in up to 40% of patients. In endemic areas, where carrier rates are >5%, most individuals are infected perinatally, by vertical transmission, or in early childhood. In the United States, where prevalence is low except in particular areas and populations (e.g., Alaskan natives, immigrants from highly endemic areas), transmission is generally horizontal, percutaneous, or via sexual contact in adulthood. A variety of host (age at infection, gender, immune status); viral (viral load, genotype, mutation); and external (concurrent viral infections, alcohol consumption, chemotherapy) factors influence disease progression. Several variables (age at infection, gender, ethnicity, immune status) also influence the risk of chronic infection. Perinatal transmission, the most common mode of infection worldwide, can be reduced by appropriate prophylaxis (vaccination of the infant at birth together with hepatitis B immune globulin); anti-viral therapy in late pregnancy may also be beneficial. Five drugs are now FDA-approved for the treatment of HBV (interferon, lamivudine, adefovir, entecavir, and peginterferon alfa-2a), and suppressive anti-viral therapy improves the natural history of HBV. Patients with decompensated cirrhosis or HCC are highly likely to die unless they successfully undergo liver transplantation. While novel anti-viral drugs have improved the management of cirrhosis, strategies to prevent and treat HCC remain inadequate.

Natural history of chronic hepatitis B virus infection: what we knew in 1981 and what we know in 2005

Remarkable progress has been made in our understanding of the natural history of chronic hepatitis B virus (HBV) infection in the past 25 years. Availability of sensitive HBV DNA assays and application of sophisticated immunological techniques led to the recognition that HBV replication persists throughout the course of chronic HBV infection, and host immune response plays a pivotal role in HBV-related liver disease. Knowledge of the HBV genome organization and replication cycle led to the unraveling of HBV genotypes and molecular variants, which contribute to the heterogeneity in outcome of chronic HBV infection. The natural course of chronic HBV infection is now perceived as consisting of 4 phases: immune tolerance, immune clearance [hepatitis B e antigen (HBeAg)-positive chronic hepatitis], inactive carrier state, and reactivation (HBeAg-negative chronic hepatitis B). Understanding the dynamic nature of chronic HBV infection is crucial in the management of HBV carriers and underscores the need for long-term monitoring. Accumulating evidence indicates that antiviral therapy can prevent progression of HBV-related liver disease, particularly among patients with sustained response. Newer antiviral therapies with improved efficacy and decreased risk of resistance may lead to a complete revision of the chapter on the natural history of chronic HBV infection on the occasion of the golden jubilee of Hepatology.

Low HBV-DNA levels in end-stage renal disease patients with HBeAg-negative chronic hepatitis B

In end-stage renal disease patients treated by hemodialysis with HBeAg-negative chronic hepatitis B virus (HBV) infection, the evaluation of the presence of viral replication is essential in the assessment for renal transplantation. Data on HBV viral load, prevalence of precore mutations, as well as the influence of HCV coinfection on HBV-DNA levels in this group of patients is scarce. The aim of this study was to determine the HBV viral load in HBsAg-positive/HBeAg-negative hemodialysis patients; to compare HBV-DNA levels between isolated HBV infection carriers and HBV-HCV coinfected patients, and to evaluate the prevalence of precore mutations in these patients. Fifty hemodialysis patients with chronic HBeAg-negative HBV infection were studied. Viral load was determined by PCR (Amplicor HBV Monitor-Roche). The detection of precore mutations was made by sequencing. Of a total of 50 patients, 76% were male, with a mean age of 44 +/- 11 years. Anti-HCV was positive in 56% of patients. HBV-DNA was undetectable in 58% of patients; 24% had HBV-DNA <10,000 copies/ml, 12% between 10,000-100,000 copies/ml, and only 6% had HBV-DNA >100,000 copies/ml. There was no difference in the viral load of patients infected only by HBV and HBV-HCV co-infected patients (P = 0.96). Precore mutations were detected in only 8% of cases. In conclusion, hemodialysis patients with HBeAg-negative HBV infection had a low viral load. Precore mutations were infrequent and the presence of anti-HCV has not influenced the levels of HBV-DNA.

Alternative peptide-fusion proteins generated by out-of-frame mutations, just upstream ORFs or elongations in mutants of human hepatitis B viruses

By various means including out-of-frame mutations, just upstream ORFs and elongations, additional peptide fusions could be generated by mutants of Human Hepatitis B Virus (HBV). Numerous frameshift mutations inducing long alternative open reading frames have been evidenced in all HBV genes. Interestingly, these mutants are frequently detected in severe liver diseases, but seldom in asymptomatic carriers. The high level of conservation of some of these sequences in spite of the fact that they could be generated by different types of mutations, as their presence in mutants found on various continents, suggest that these mutations could play a role. These mutants could combine two advantages, that related to the loss of a part of a wild-type protein and that related to the putative advantage conferred by the additional sequences. In addition, in numerous Asian genomes (more than 300 to date) pre-X or pre-pre-S regions were found just upstream to, respectively, the X and the pre-S1 genes. These two regions are translated with their respective genes in frame and recent studies have evidenced the transactivating role of the corresponding proteins. With some exceptions, these regions are genotype- and serotype-specific (C/adr). In addition, these mutants have been found principally in patients with severe hepatitis diseases, for example, hepatocarcinoma in more than one third of the cases. As additional sequences generated by HBV variants may be relevant for viral life cycle, persistence and pathogenesis, further investigations are necessary to give a clearer picture of the subject.

Fibrinogen-like protein 2 fibroleukin expression and its correlation with disease progression in murine hepatitis virus type 3-induced fulminant hepatitis and in patients with severe viral hepatitis B

AIM

To evaluate the expression of fibrinogen-like protein 2 (fgl2) and its correlation with disease progression in both mice and patients with severe viral hepatitis.

METHODS

Balb/cJ or A/J mice were infected intraperitoneally (ip) with 100 PFU of murine hepatitis virus type 3 (MHV-3), liver and serum were harvested at 24, 48, and 72 h post infection for further use. Liver tissues were obtained from 23 patients with severe acute chronic (AOC) hepatitis B and 13 patients with mild chronic hepatitis B. Fourteen patients with mild chronic hepatitis B with cirrhosis and 4 liver donors served as normal controls. In addition, peripheral blood mononuclear cells (PBMC) were isolated from 30 patients (unpaired) with severe AOC hepatitis B and 10 healthy volunteers as controls. Procoagulant activity representing functional prothrombinase activity in PBMC and white blood cells was also assayed. A polyclonal antibody against fgl2 was used to detect the expression of both mouse and human fgl2 protein in liver samples as well as in PBMC by immunohistochemistry staining in a separate set of studies. Alanine aminotransferase (ALT) and total bilirubin (TBil) in serum were measured to assess the severity of liver injury.

RESULTS

Histological changes were found in liver sections 12-24 h post MHV-3 infection in Balb/cJ mice. In association with changes in liver histology, marked elevations in serum ALT and TBil were observed. Mouse fgl2 (mfgl2) protein was detected in the endothelium of intrahepatic veins and hepatic sinusoids within the liver 24 h after MHV-3 infection. Liver tissues from the patients with severe AOC hepatitis B had classical pathological features of acute necroinflammation. Human fgl2 (hfgl2) was detected in 21 of 23 patients (91.30%) with severe AOC hepatitis B, while only 1 of 13 patients (7.69%) with mild chronic hepatitis B and cirrhosis had hfgl2 mRNA or protein expression. Twenty-eight of thirty patients (93.33%) with severe AOC hepatitis B and 1 of 10 with mild chronic hepatitis B had detectable hfgl2 expression in PBMC. No hfgl2 expression was found either in the liver tissue or in the PBMC from normal donors. There was a positive correlation between hfgl2 expression and the severity of the liver disease as indicated by the levels of TBil. PCA significantly increased in PBMC in patients with severe AOC hepatitis B.

CONCLUSION

The molecular and cellular results reported here in both mice and patients with severe viral hepatitis suggest that virus-induced hfgl2 prothrombinase/fibroleukin expression and the coagulation activity associated with the encoded fgl2 protein play a pivotal role in initiating severe hepatitis. The measurement of hfgl2/fibroleukin expression in PBMC may serve as a useful marker to monitor the severity of AOC hepatitis B and a target for therapeutic intervention.

Evaluation of liver tissue by polymerase chain reaction for hepatitis B virus in patients with negative viremia

AIM: To assess the clinical significance of Hepatitis B virus (HBV) DNA localization in the liver tissue of patients with positive HBsAg and negative viremia.

METHODS: HBV virological parameters of 33 HBsAg positive chronic hepatitis patients, including seromarkers and HBV DNA amplification in both sera and liver biopsies, were evaluated.

RESULTS: Ten patients had negative viremia and positive HBV DNA in their liver biopsies. Most of them had HBeAg-negative/HBeAb-positive chronic hepatitis. Their liver biochemical and histopathological profiles were different from the viremic patients. Their disease pattern was designated as “hepatitis B in situ”.

CONCLUSION: Hepatitis B in situ is a consequential entity which can be missed in clinical practice. It is a new clinical pattern of chronic HBV infection that considers HBV in liver biopsy and adds a new indication for antiviral therapy.

Systematic review: treatment of chronic hepatitis B virus infection by pegylated interferon

BACKGROUND

Pegylated interferon-alpha has been shown to be more efficacious than conventional interferon in treating chronic hepatitis C. The use of peginterferon in chronic hepatitis B virus infection with positive hepatitis B e antigen has also been tested in a number of trials since 2003.

AIM

To systematically summarize and compare the results of these studies.

METHODS

Four studies were identified from PubMed, Medline and reference lists. Data from the trials were extracted and analysed. Where appropriate, combined odds ratio of different trials was calculated. Safety data including serious adverse events and emergence of drug-resistant mutants were recorded.

RESULTS

Three of the four trials contained predominantly Asian patients. Peginterferon is found to be superior to lamivudine monotherapy and induced sustained biochemical and virological responses in about one-thirds of patients after 12 months of therapy. Coadministration of lamivudine did not result in improvement in viral suppression. Peginterferon appears to reduce the emergence of YMDD mutation in the combination treatment groups. It was well tolerated with serious adverse events reported in <10% of patients in most trials.

CONCLUSIONS

Peginterferon-alpha treatment of at least 6 months should be considered as one of the first-line therapeutic options for hepatitis B virus infection.

Long-term hepatic consequences of chemotherapy-related HBV reactivation in lymphoma patients

AIM: To investigate the long-term consequences of chemotherapy-related HBV reactivation in patients with lymphoma.

METHODS: This study was based on the database of published prospective study evaluating HBV reactivation in HBV lymphoma patients during chemotherapy. Deteriorated liver reserve (DLR) was defined as development of either one of the following conditions during follow-up: (1) newly onset parenchyma liver disease, splenomegaly or ascites without evidence of lymphoma involvement; (2) decrease of the ratio (albumin/globulin ratio) to less than 0.8 or increase of the ratio of INR of prothrombin time to larger than 1.2 without evidence of malnutrition or infection. Liver cirrhosis was diagnosed by imaging studies.

RESULTS: A total of 49 patients were included. The median follow-up was 6.2 years (range, 3.9-8.1 years). There were 31 patients with and 18 patients without HBV reactivation. Although there was no difference of overall survival (OS) and chemotherapy response rate between the two groups, DLR developed more frequently in patients with HBV reactivation (48.4% vs 16.7%; P = 0.0342). Among the HBV reactivators, HBV genotype C was associated with a higher risk of developing DLR (P = 0.0768) and liver cirrhosis (P = 0.003). Four of five patients with sustained high titer of HBV DNA and two of three patients with multiple HBV reactivation developed DLR. Further, patients with a sustained high titer of HBV DNA had the shortest OS among the HBV reactivators (P = 0.0000). No patients in the non-HBV reactivation group developed hepatic failure or liver cirrhosis.

CONCLUSION: Chemotherapy-related HBV reactivation is associated with the long-term effect of deterioration of hepatic function.

How to predict HCC development in patients with chronic B viral liver disease?

Hepatocellular carcinoma (HCC) is one of the major malignant diseases in Asia. Although no randomized controlled studies have demonstrated decreased mortalities, screening for HCC has become an accepted procedure in the high-risk population. Since the incidence of HCC is strikingly different according to geographical distribution of risk factors, especially chronic hepatitis B virus (HBV) infection, a surveillance strategy in high endemic areas should be established according to national conditions. Chronic necro-inflammation by persistent HBV infection per se can progress to cirrhosis and the occurrence of HCC. As in other chronic liver diseases, the more risk factors the chronic B viral patients have, the higher occurrence of HCC was shown. Based on the risk factors of 4,339 Korean patients, the individual prediction model (IPM) was made by the calculation of relative weighs of risk factors and a self-exploited screening program for HCC was established accordingly. US screening at 6-month intervals was beneficial for the early detection of HCC, especially in the high-risk group, and prolonged survival. The usefulness of a tailored screening program with IPM for HCC was prospectively confirmed. The effective screening system for diagnosis of HCC limited to patients with chronic hepatitis B might be necessitated in high endemic area.

Change of intrahepatic T and B lymphocyte contents in immune tolerant phase of patients with chronic hepatitis B virus infection

AIM: To investigate the characteristics of intrahepatic CD3⁺, CD4⁺, CD8⁺ T lymphocytes and B cells in immune tolerant phase of patients with chronic hepatitis B virus infection, and to explore the relationship between intrahepatic immune competent cells and the status of immune tolerance in chronic HBV infection.

METHODS: Sixteen liver biopsies were selected from patients with HBV infection in immune tolerant phase for the immunohistochemical detection of T lymphocyte subsets, B lymphocytes and expression of HBsAg and HbcAg. Six normal liver biopsies and 17 liver biopsies of patients in immuneactive phase were employed to serve as control respectively.

RESULTS: CD3⁺, CD4⁺, CD8⁺ T lymphocyte subsets in the liver biopsies of patients in immune tolerant phase were all significantly increased as compared with those in the normal control (t = 4.504, 8.272, 4.742, all P<0.01), but significantly decreased as compared with those in biopsies of patients in immuneactive phase (t = 7.079, 6.866, 6.316, all P<0.01). The ratio of CD4/CD8 in portal tract was lower in immune tolerant phase than in immuneactive phase (t = 3.46, P<0.01), but it was not markedly different from that in the normal control. The number of intrahepatic B cells in immune phase was decreased statistically as compared with that in immuneactive phase (t = 4.76, P<0.01), but were almost the same as that in normal control (P>0.05). The rate of HBcAg expression in hepatocytes of patients at immune tolerant phase was significantly higher than that of patients at immuneactive phase (t = 8.76, P<0.01).

CONCLUSION: T and B lymphocytes may play important roles in the clearance of HBV as well as in liver inflammation and injury during chronic HBV infection. The fewer T and B lymphocyte infiltrations are associated with the status of immune tolerance.

Determinants for the occurrence of acute exacerbation of hepatitis B virus infection in Chinese patients after HBeAg seroclearance

This study was performed to determine the factors for predicting the occurrence of acute exacerbation of hepatitis B virus infection in HBeAg-negative patients. Two hundred and sixteen patients with known times of HBeAg seroclearance were recruited. Liver biochemistry and virologic markers were monitored. Precore and core promoter mutations were determined by a line probe assay. The median age at HBeAg seroclearance was 34.5 years. The median follow-up duration was 26.4 months. Fifty-six (27.9%) patients had acute exacerbations. By Cox regression analysis, male gender, older age, and core promoter mutations at the time of HBeAg seroclearance were independently associated with the occurrence of acute exacerbation after HBeAg seroclearance (P = 0.025, 0.018, and 0.001, respectively). Fourteen (7.0%) patients had HBeAg seroreversion within a median follow-up period of 11.6 months after HBeAg seroclearance. By Cox regression analysis, older age at HBeAg seroclearance was independently associated with the chance of HBeAg seroreversion (P = 0.01). We concluded that male patients with core promoter mutations and delayed HBeAg seroclearance had a higher cumulative chance of acute exacerbation in the HBeAg-negative phase. Patients with delayed HBeAg seroclearance had a higher frequency of HBeAg seroreversion.

Immunology of hepatitis B virus and hepatitis C virus infection

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.

Epidemiology of hepatocellular carcinoma

Year 2000 estimates of the incidence of cancer indicate that primary liver cancer remains the fifth most common malignancy in men and the eighth in women. The number of new cases has been predicted as 564,000, corresponding to 398,000 in men and 166,000 in women. The geographic areas at highest risk are located in Eastern Asia, Middle Africa, and some countries of Western Africa. Changes in incidence among migrant populations underline the predominant role of environmental factors in the etiology of primary liver cancer. In high-risk countries, the early cases of primary liver cancer occur already at ages 20 and above, underlying the impact of viral exposures early in life. In countries at low risk, primary liver cancer is rare before the 50s, translating the impact of late exposures with moderate risks and long latency intervals. Sex ratios are typically between 2 and 4. The incidence of primary liver cancer is increasing in several developed countries including the United States, and the increase will likely continue for several decades. The trend has a dominant cohort effect related to exposures to hepatitis B and C viruses. The variability of primary liver cancer incidence is largely explained by the distribution and the natural history of the hepatitis B and C viruses. The attributable risk estimates for the combined effects of these infections account for well over 80% of liver cancer cases worldwide. Primary liver cancer is the first human cancer largely amenable to prevention using hepatitis B virus vaccines and screening of blood and blood products for hepatitis B and C viruses.

HBV-DNA Suppression and Disease Course in HBV Cirrhosis Patients on Long-Term Lamivudine Therapy

In hepatitis B virus (HBV) cirrhosis patients on long-term lamivudine (LAM), the relationships between HBV suppression, development of viral resistance and disease outcome are unclear. We analysed the dynamic of serum HBV-DNA and its relationship with the clinical course of 59 patients (52 males, mean age 51.4 ±8.4 years, 12 HBeAg positive and 47 HBeAg negative, and 57 genotype D and two genotype A) with cirrhosis (45 in Child-Turcotte-Pugh class A) and high levels of serum HBV-DNA (median 14.7x107 genomes/ml) treated with LAM [median (range): 44 (15–78) months]. A total of 50 patients (84.7%) achieved a virological response (serum HBV-DNA negative by PCR) during the first 6 months of therapy, and nine (13.3%) achieved a reduction in viral load of >3 log10. Mutations in the YMDD motif of HBV polymerase were documented in 26 patients [median (range) 18: (7–42) months]. At the time of the emergence of mutants, 22 patients had HBV-DNA <105 genomes/ml and normal alanine aminotransferase (ALT) levels. The appearance of virological resistance was followed by an increase of HBV-DNA to ≥105 genomes/ml and of ALT values in 19 out of 26 patients [median (range): 8 (3–19) months]. Event-free survival was significantly longer ( P=0.001) in patients who maintained virological suppression than in those who did not have a complete virological response or suffered a breakthrough. Patients with advanced cirrhosis were more likely to develop liver failure after the emergence of YMDD mutants. The risk of development of hepatocellular carcinoma in patients with compensated cirrhosis and YMDD mutations was maintained, regardless of HBV-DNA serum levels.

Profound and maintained HBV-DNA suppression correlates with a better outcome. Early identification of LAM resistance mutations allows switching to other antivirals before liver decompensation or hepatocellular carcinoma development.

Hepatitis B virus genotypes and precore mutations in Scottish blood donors

BACKGROUND AND OBJECTIVES

This study was carried out to determine the frequency of hepatitis B virus (HBV) core promoter variants (nucleotide positions 1762, 1764) and precore variants (nucleotide position 1896) in hepatitis B surface antigen (HBsAg)-positive Scottish blood donors. HBV genotypes present in this population were also identified.

MATERIALS AND METHODS

A total of 85 HBsAg-positive blood donor samples were included in the study. Of these, 79 were polymerase chain reaction (PCR) positive and had sequence and mutation information. They were divided into two groups: group 1 (23 individuals) were hepatitis B e antigen (HBeAg)-positive and negative for antibody to HBe (anti-HBe); and group 2 (56 individuals) were HBeAg negative and positive for anti-HBe. A line probe assay was used to detect mutations, and a comparison was made by using direct sequence analysis. A different line probe assay was used to identify HBV genotype.

RESULTS

The frequencies of mutations in group 1 were 22% each for mutations 1762, 1764 and 1896, increasing to 26%, 35% and 55% in group 2, respectively. By contrast, direct sequence analysis failed to identify 70% of wild-type/mutant mixes. The prevalence of viral genotypes was 41% for genotype A, 12% for genotype B, 5% for genotype C, 30% for genotype D and 12% for mixed-genotype infections. Precore mutations were seen in 10%, 88%, 25% and 74% of genotypes A, B, C and D, respectively.

CONCLUSIONS

The results indicate that core promoter and/or precore mutants may be under-reported. The combination of HBV PCR and line probe assays is useful for supplementing HBV serological tests. Non-Caucasian genotypes are present in the UK blood-donating population and will therefore affect the demographics of HBV infection.

Long-term clinical and histological outcomes in patients with spontaneous hepatitis B surface antigen seroclearance

BACKGROUND/AIMS

During the natural course of hepatitis B virus (HBV) infection, the long-term clinical and histological outcomes following spontaneous hepatitis B surface antigen (HBsAg) seroclearance remain unclear.

METHODS

Between 1984 and 2003, 49 (9.5%) out of 432 inactive HBsAg carriers had no detectable level of circulating HBsAg. Fifteen of 49 patients had undergone paired peritoneoscopic liver biopsies.

RESULTS

During a mean follow-up period of 19.6 months after HBsAg seroclearance, 5 of 49 (10.2%) patients were noted to have HCC. Liver cirrhosis (P=0.040), a history of perinatal infection (P=0.005) and long-standing duration (at least 30 years) of HBsAg positivity (P=0.002) were associated with a significantly higher risk of developing HCC. Despite HBsAg seroclearance, HBV DNA was detected in the liver tissues from all 15 patients who underwent paired liver biopsies. Necroinflammation was significantly ameliorated (P<0.0001). On the other hand, amelioration of the fibrosis score did not reach a statistically significant level (P=0.072). Interestingly, aggravation of liver fibrosis was evident in 2 patients (13.3%) including one who had rapidly progressed to overt cirrhosis.

CONCLUSIONS

In patients with spontaneous HBsAg seroclearance, necroinflammation was markedly improved and liver fibrosis was unchanged or regressed despite occult HBV infection. However, HCC developed in a minority of cases.

Strong association between genotype F and hepatitis B virus (HBV) e antigen-negative variants among HBV-infected argentinean blood donors

A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in hepatitis B virus (HBV)-infected individuals carrying HBV e antigen (HBeAg)-negative variants. Although distinct core promoter and precore mutations distributed according to geographical locality and viral genotype have been reported, epidemiological data from South America are still scarce. The prevalences of HBV genotypes and core promoter and precore polymorphisms in 75 HBeAg-negative Argentinean blood donors were surveyed. The observed frequencies of HBV genotypes were 64.0% for genotype F, 17.3% each for genotypes A and D, and 1.3% for genotype C. Genotype F strains were widely distributed and significantly more prevalent in the northern region of the country (P < 0.001). An overall high proportion of a stop codon mutation (UAG) at precore codon 28 (66.7%) was observed. Wild-type codon 28 (UGG) was present in 29.3% of the samples, and the remaining 4.0% of samples had mixed variants. The combination of A at nucleotide (nt) 1762 and G at nt 1764 of the core promoter was found in 58.7% of the samples. The variant profiles--T at nt 1762 and A at nt 1764 or A at nt 1762 and A at nt 1764--were detected in 28.0 and 1.3% of the samples, respectively. The observed core promoter polymorphisms could not be related to the ratio of HBeAg to anti-HBeAg antibody, HBV genotype, or precore codon 28 status. Nevertheless, a clear association of genotype F and a precore stop codon mutation was found (P < 0.05). In conclusion, HBV genotype F and mutant codon 28 strains predominated and were strongly associated in a geographically broad Argentinean blood donor population.

A Practical Approach to Management of Chronic Hepatitis B

Chronic hepatitis B (CHB) is one of the important public health problems worldwide. Major advances have been made in the treatment of CHB during the past several years. This article systemically reviews advances in the application of HBV DNA quantitation and three approved drugs for HBV treatment, and presents an updated and practical clinical approach to managing CHB. Highly sensitive PCR-based quantitation of HBV DNA makes it possible to precisely determine pre-treatment HBV load and monitor HBV DNA response during treatment. HBV DNA level, HBeAg status, degree of hepatic histological activity and fibrosis, and serum transaminases are the most important parameters in determining indication, regimen, and duration of HBV treatment. Although interferon alfa-2b, lamivudine, and adefovir are all approved as initial HBV treatment, understanding the advantages and advantages of each agent is important in choosing the best treatment for each individual patient with CHB.

Primary liver cancer: worldwide incidence and trends

Estimates from the year 2000 indicate that liver cancer remains the fifth most common malignancy in men and the eighth in women worldwide. The number of new cases is estimated to be 564,000 per year, including 398,000 in men and 166,000 in women. In high-risk countries, liver cancer can arise before the age of 20 years, whereas, in countries at low risk, liver cancer is rare before the age of 50 years. Rates of liver cancer in men are typically 2 to 4 times higher than in women. The incidence of primary liver cancer is increasing in several developed countries, including the United States, and the increase will likely continue for some decades. The trend is a result of a cohort effect related to infection with hepatitis B and C viruses, the incidence of which peaked in the 1950s to 1980s. In selected areas of some developing countries, the incidence of primary liver cancer has decreased, possibly as a result of the introduction of hepatitis B virus vaccine. The geographic variability in incidence of primary liver cancer is largely explained by the distribution and the natural history of the hepatitis B and C viruses. The attributable risk estimates for the combined effects of these infections account for well over 80% of liver cancer cases worldwide. Primary liver cancer is the first human cancer largely amenable to prevention using hepatitis B virus vaccines and screening of blood and blood products for hepatitis B and C viruses.

Antiviral therapy in patients with chronic hepatitis B and cirrhosis

Chronic hepatitis B virus infection (HBV) may result in significant morbidity, including cirrhosis, end-stage liver disease, and hepatocellular carcinoma. The management of chronic HBV cirrhosis is advancing rapidly. Current treatment options for patients with HBV-related cirrhosis include interferon-alpha (IFN-alpha), lamivudine and adefovir dipivoxil. IFN-a is used less commonly today because of its toxicity, difficulty with administration, and the availability of safer drugs. Lamivudine, an oral nucleoside analog, has proven to be at least as effective, and is safer, than IFN-a in the treatment of HBV-related cirrhosis. It is plagued by the development of resistant viral mutants, however. The newest oral nucleotide analog, adefovir dipivoxil, has shown excellent efficacy in treatment-naïve and lamivudine-resistant HBV patients and has lower rates of resistance in the short-term.

Tumor necrosis factor and its potential role in insulin resistance and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic pathology that resembles alcohol-induced fatty liver disease(AFLD), but which develops in individuals who are not heavy drinkers. In people, NAFLD is associated strongly with obesity,insulin resistance, and dysmetabolic syndrome, but the exact mechanisms that promote liver disease in this clinical context remain poorly understood. The proinflammatory cytokine, funor necrosis factor alpha is known to be a key mediator of AFLD. This article discusses clinical and experimental evidence that tumor necrosis factor plays a role in the pathogenesis of insulin resistance syndromes, including nonalcoholic fatty syndromes, including nonalcoholic fatty liver disease.

N/A

N/A

Viral infection and antiviral therapy in the neonatal intensive care unit

Viral diseases are leading causes of mortality and morbidity among infants requiring care in the neonatal intensive care unit (NICU), with ongoing discoveries of new viral pathology likely to add to the burdens posed. Many viral diseases in NICU infants are undiagnosed or appreciated only late in the course because of subtle or asymptomatic presentation, confusion with bacterial disease, and failure to consider viral disease. We present an overview of viral disease in NICU infants, with emphasis on pharmacologic agents currently employed for prophylaxis and treatment of such diseases. Advances in molecular biology and popular demand to develop antiviral agents for viral diseases (eg, human immunodeficiency virus) offer great promise for the future.

CD14+ cell dysfunction in patients with chronic active hepatitis B

AIM: To study the functional states of CD14⁺ cells in peripheral blood mononuclear cell (PBMCs) by analyzing the expression of early active antigen, production of pro-inflammatory cytokines and phagocytosis with flow cytometry (FCM).

METHODS: PBMCs were isolated from 11 patients with chronic active hepatitis B and 10 healthy blood donors, and 4-color flow cytometry and gate setting techniques were applied. The percentage of CD14⁺ cells and level of CD14 antigen were tested by FCM, after gate setting with CD14, side scatter (SSC) and activation-linked surface antigen (CD69) expression rate, percentage of TNF-α producing cells, level of intro-cellular TNF-α, the percentage of phagocytes and the ability of phagocytosis were investigated.

RESULTS: The SSC mean value of CD14⁺ cell of HBV patients was higher than that of health control (P < 0.01); There were no difference between two testing groups on the percentage of CD14⁺ cells and level of CD14 antigen, however the level of CD14 antigen was positively associated with the percentage of CD14⁺ cells. CD14/69 double expression rate was significantly higher than that of control group (P < 0.01); No difference was observed on CD14/TNF-α double stain cells between testing groups; In comparison with control group, the level of cellular TNF-α in HBV group was higher (P < 0.05). In control group, the percentage of TNF-α producing cells were correlated with SSC value and number of phagocytes that expressed CD14/69. There was no difference in phagocytes that expressed CD14/69 in two groups. As compared with the control group, there was more phagocytostic CD14⁺ cells in HBV group (P < 0.01), but the mean phagocytosis amount was significantly lower in this group (P < 0.05), and the number of phagocyte was negatively correlated with the level of CD14 antigen; while the SSC value and number of TNF-αproducing cells were negatively correlated with level of CD14 antigen.

CONCLUSION: CD14⁺ cells in PBMCs from chronic active hepatitis B patients are over activated in a dysfunction stage.

Specific mutations of hepatitis B virus in plasma predict liver cancer development

A major risk factor for hepatocellular carcinoma (HCC) is hepatitis B virus (HBV), whose pathogenesis is exacerbated by the acquisition of mutations that accelerate carcinogenesis. We examined, with mass spectrometry, the temporality of an HBV 1762(T)/1764(A) double mutation in plasma and tumors. Initial studies found that 52 of 70 (74.3%) tumors from patients residing in Qidong, People's Republic of China, contained this HBV mutation. Paired plasma samples were available for six of the tumor specimens; four tumors had the HBV 1762(T)/1764(A) mutation, whereas three of the paired plasma samples were also positive. The potential predictive value of this biomarker was explored by using stored plasma samples from a study of 120 residents of Qidong who had been monitored for aflatoxin exposure and HBV infection. After 10 years of passive follow-up, there were six cases of major liver disease including HCC (four cases), hepatitis (one case), and cirrhosis (one case). All six cases had detectable levels of the HBV 1762(T)/1764(A) mutation up to 8 years before diagnosis. Finally, 15 liver cancers were selected from a prospective cohort of 1,638 high-risk individuals in Qidong on the basis of available plasma samples spanning the years before and after diagnosis. The HBV 1762(T)/1764(A) mutation was detected in 8 of the 15 cases (53.3%) before cancer. The persistence of detection of this mutation was statistically significant (P = 0.022, two-tailed). We therefore found that a prediagnosis biomarker of specific HBV mutations can be measured in plasma and suggest this marker for use as an intermediate endpoint in prevention and intervention trials.

Primary care physicians' approach to diagnosis and treatment of hepatitis B and hepatitis C patients

Background

Infections caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) are considered to be important health problems worldwide. The purpose of this study was to measure the general practitioners (GPs)' basic knowledge on HBV and HCV risk factors in determining their practice about this subject.

Methods

A cross-sectional type questionnaire survey was carried out at all of 32 primary healthcare centers (PHCCs) in Samsun, Turkey, between March 1 and April 31, 2002. The questionnaires were sent to 160 GPs and 129 (80.6%) of them answered the questionnaires. Knowledge, role responsibility, self-efficacy and attitudes and beliefs regarding to viral hepatitis B and hepatitis C were asked.

Results

Most of the GPs had adequate knowledge about transmission of HBV and HCV and also about risk factors for transmission of viruses. Most of the GPs (83.7%) were aware of recommendations for approach to a baby, born from HBsAg positive mother. They have limited facilities in diagnosis of viral hepatitis. Of the participants, 108 (83.7%) expressed that they could not diagnose HBV infections and 126 (97.7%) of them stated that they could not make the diagnoses of HCV infection in their local healthcare centers. The knowledge about treatment of chronic viral hepatitis B (21.8%) and C patients (17.8%) with elevated ALT is not sufficient.

Conclusion

GPs' knowledge about risks of viral hepatitis was adequate in this study. They were not able to diagnose and follow up of these infections at PHCCs because of limited knowledge about chronic viral hepatitis and diagnostic facilities. GPs should be informed about current advice in diagnosis and treatment of chronic of HBV and HCV infections.

Construction of the vector that harbors self-restricted system for hepatitis B virus clearance in gene therapy

AIM

To construct the vector that harbors self-restricted system for clearing hepatitis B virus, eliminating infected hepatic cells and inhibiting hepatitis B recurrence in gene therapy.

METHODS

After amplifying hepatitis C virus (HCV) internal ribosome entry sites (IRES) by reverse-transcription PCR (RT-PCR), the products were cloned into pcDNA3. A biscistronic vector was obtained. A part of sequence in HBV anti-surface gene and part of sequence in HCV core gene were cloned into the vector before IRES site in turn and thymidine kinase (TK) was also cloned into it following the IRES site. After determination by PCR and sequencing, we acquired the vector containing HBV anti-S, HCV-C gene, HCV IRES and thymidine kinase gene, which was named the vector pcDNA3-SCITK. The vectors were separately transfected into HepG2 cells and 2.2.15 cells and all the media contained ganciclovir.

RESULTS

The novel vector was transfected into 2.2.15 and hepG2 cells, the expressed protein could destroy the former, but had no effect on HepG2 cells if all the media contained ganciclovir. Apoptosis cells in the former accounted for 15 per cent of all cells by fluorescence (FACS) detection. There was obvious difference between the two types of cells (the later was only 6 per cent).

CONCLUSION

The function of genes that pcDNA3-SCITK carried with self-restricted system could be ego-controlled, and it might be used as gene therapy vector for HBV clearance if taking HBV S gene as target gene and TK gene as objective gene.