Hepatitis B virus genotype B is associated with earlier HBeAg seroconversion compared with hepatitis B virus genotype C

Functional and clinical significance of hepatitis D virus genotype II infection

Hepatitis D virus (HDV) infection is one of the important etiologies of fulminant hepatitis and may aggravate the clinical course of chronic HBV infection to cirrhosis and liver failure. HDV was classified into three genotypes. Recent molecular phylogenetic analysis of HDV suggests at least seven major clades. The genotype I HDV is widely spread, genotype II is found in East Asia and genotype III HDV is prevalent in South America. The genomic size is 1682-1685 nucleotides (nt) for genotype II, and 1676 nt for genotype IV (IIb). The divergence in HDV nucleic acid sequences between genotype II and other genotypes varies from 13.8% to 35.3%. The divergences in the HDAg-coding region may range from 17.8% to 29.8% between genotype II and other genotypes. There is no genotypic or size restriction on the interactions of either the small or the large hepatitis delta antigens (HDAgs) between genotypes I and II, and there is also no genotypic incompatibility during co-package of HDAgs of different genotypes into virus like particles. There appears no apparent universal genotypic restriction of the transactivation of genotype I HDV RNA replication by small HDAg of genotype II. In contrast, there appears more genotypic restriction for genotype I small HDAgs to transactivate genotype II HDV RNA replication. Of the functional domains of HDAg, the 19 amino acids at the carboxyl-end of the large HDAg show the greatest divergences (70%-80%) between genotypes I and II. The viral packaging efficiencies of genotype I HDV isolates are usually higher than those of genotype II. The 19 amino acids at the carboxyl-end seem to be the most important determinant for viral packaging efficiencies. The editing efficiencies of the genotype I HDV are also higher than those of the genotype II. Genotype II HDV infection is relatively less frequently associated with fulminant hepatitis at the acute stage and less unfavorable outcomes [cirrhosis or hepatocellular carcinoma (HCC)] at the chronic stage as compared to genotype I. It appears that the clinical manifestations and outcomes of patients with genotype IV (IIb) HDV infection are more like those of patients with genotype II HDV infection. Persistent replication of HBV or HDV was associated with higher adverse outcomes (cirrhosis, HCC or mortality) compared to those who cleared both viruses from the sera. HBV of the genotype C is also a significant factor associated with adverse outcomes (cirrhosis, HCC or mortality) in patients with chronic hepatitis D in addition to genotype I HDV and age. However, most patients with chronic HDV infection have low or undetectable hepatitis B virus DNA levels. During longitudinal follow-up, genotype I HDV is the most important determinant associated with survival.

Hepatitis B virus genotypes, precore and core promoter variants among predominantly Asian patients with chronic HBV infection in a Canadian center

BACKGROUND AND AIMS

The epidemiology of hepatitis B virus (HBV) infection in North America may be changing as a result of immigration from endemic countries. The purpose of this study was to determine the prevalence of HBV genotypes, precore (PC) and core promoter (CP) variants, and the proportion of patients meeting treatment criteria for HBV.

METHODS

A cross-sectional study of consecutive HBV patients attending a Canadian tertiary liver center was conducted. HBV DNA was quantified by polymerase chain reaction assay. HBV genotypes and variants were determined using a line probe assay.

RESULTS

Two hundred and seventy-two patients were enrolled; 200 were not receiving treatment at enrollment, of whom 116 were men and 84 women with a mean age 42+/-14 years. Among this group, 177 (88%) patients were Asian and 19 (10%) were Caucasian and 69 (35%) patients were hepatitis B e antigen (HBeAg) positive. Genotypes B and C were found in 42% and 50% untreated patients, respectively; while CP and PC were detected in 52% and 43% patients, respectively. Approximately 20% patients not receiving treatment (29% HBeAg positive, 14% HBeAg negative) met AASLD guidelines for antiviral therapy. If lower cutoff values for alanine aminotransferase and HBV DNA levels were used, 49% patients would qualify for treatment.

CONCLUSIONS

The vast majority of patients at a Canadian tertiary referral center were Asian. Virological and clinical characteristics of these patients reflect their country of origin. Our findings highlight the need to monitor the changing patterns of HBV infection in countries with large immigrant populations.

A unique amino acid substitution, T126I, in human genotype C of hepatitis B virus S gene and its possible influence on antigenic structural change

Amino acid substitutions in the S gene of hepatitis B virus (HBV), especially in the 'a' determinant region, have been suggested to affect the antigenicity of the virus and the clinical outcome of the infected patient. However, no convincing evidence has been presented for this hypothesis, partly because the 3D structure of the S protein has not been determined. Comparative analysis of viral genes offers an approach to testing this hypothesis, as it may reveal signals of natural selection and provide insights into the functional significance of the observed amino acid substitutions. In this study, we analyze HBV S gene sequences obtained from 24 patients infected with HBV genotypes B or C, together with 16 representative viral strains of HBV genotypes A-F retrieved from GenBank. We use phylogenetic methods to infer evolutionary changes among HBV genotypes and to identify amino acid residues potentially under positive selective pressure. Furthermore, we employ the fragment assembly method to predict structural changes in the S protein. The results showed that an amino acid substitution within the 'a' determinant, T126I, was unique to genotype C, may affect the antigenicity of the HBsAg, and may result in poorer clinical outcomes of patients infected with genotype C viral strains. We suggest that an integrated approach of evolutionary comparison and structural prediction is useful in generating hypotheses for further laboratory validation.

Phylogenetic, virological, and clinical characteristics of genotype C hepatitis B virus with TCC at codon 15 of the precore region

Hepatitis B virus (HBV) with T-1856 of the precore region is always associated with C-1858 (i.e., TCC at nucleotides 1856 to 1858), and it is reported only in genotype C HBV isolates. We aimed to investigate the phylogenetic, virological, and clinical characteristics of HBV isolates bearing TCC at nucleotides 1856 to 1858. We have previously reported on the presence of two major subgroups in genotype C HBV, namely, HBV genotype Cs (Southeast Asia) and HBV genotype Ce (Far East). We have designed a novel 5' nuclease technology based on the nucleotide polymorphism (C or A) at nucleotide 2733 to differentiate the two genotype C HBV subgroups. The mutations at the basal core promoter and precore regions were analyzed by direct sequencing. Among 214 genotype C HBV-infected patients, 31% had TCC, 37% had CCC, 3% had CTC, and 29% had CCT at nucleotides 1856 to 1858. All except one HBV strain with TCC at nucleotides 1856 to 1858 belonged to subgroup Cs, which has been reported only in Hong Kong; Guangzhou, China; and Vietnam. HBV with TCC at nucleotides 1856 to 1858 was associated with the G1898A mutation (64%). Patients infected with HBV harboring TCC had more liver cirrhosis than those infected with HBV harboring CCC (18% versus 5%; P = 0.008), and more of the patients infected with HBV harboring TCC were positive for HBeAg (58% versus 36%; P = 0.01) and had higher median alanine aminotransferase levels (65 IU/liter versus 49 IU/liter; P = 0.006); but similar proportions of patients infected with HBV harboring TCC and those infected with HBV harboring CCT had liver cirrhosis (18% versus 13%; P = 0.43). In summary, we report that HBV with TCC at nucleotides 1856 to 1858 of the precore region might represent a specific HBV strain associated with more aggressive liver disease than other genotype C HBV strains.

Impact of the hepatitis B virus genotype and genotype mixtures on the course of liver disease in Vietnam

Eight genotypes (A-H) of hepatitis B virus (HBV) have been identified. However, the impact of different genotypes on the clinical course of hepatitis B infection remains controversial. We investigated the frequency and clinical outcome of HBV genotypes and genotype mixtures in HBV-infected patients from Vietnam, Europe, and Africa. In addition, we analyzed the effects of genotype mixtures on alterations in in vitro viral replication. In Asian patients, seven genotypes (A-G) were detected, with A, C, and D predominating. In European and African patients, only genotypes A, C, D, and G were identified. Genotype mixtures were more frequently encountered in African than in Asian (P = .01) and European patients (P = .06). In Asian patients, the predominant genotype mixtures included A/C and C/D, compared to C/D in European and A/D in African patients. Genotype A was more frequent in asymptomatic compared with symptomatic patients (P < .0001). Genotype C was more frequent in patients with hepatocellular carcinoma (HCC; P = .02). Genotype mixtures were more frequently encountered in patients with chronic hepatitis in comparison to patients with acute hepatitis B (P = .015), liver cirrhosis (P = .013), and HCC (P = .002). Viral loads in patients infected with genotype mixtures were significantly higher in comparison to patients with a single genotype (P = .019). Genotype mixtures were also associated with increased in vitro HBV replication. In conclusion, infection with mixtures of HBV genotypes is frequent in Asia, Africa, and Europe. Differences in the replication-phenotype of single genotypes compared to genotype-mixtures suggest that co-infection with different HBV-genotypes is associated with altered pathogenesis and clinical outcome.

Sequential accumulation of the basal core promoter and the precore mutations in the progression of hepatitis B virus-related chronic liver disease

OBJECTIVES

Despite the pathogenic role of the basal core promoter (BCP) and the precore mutations in chronic hepatitis B virus (HBV) infection, their role in the progression of liver disease is still controversial. We analyzed whether the accumulation of these mutations might enhance the progression of HBV-related chronic liver disease.

METHODS

Forty consecutive patients at each clinical status were analyzed. Clinical statuses were as follows: HBeAg-positive asymptomatic carrier (HBeAg(+) ASC) (defined as HBeAg(+), anti-HBe(-), HBV-DNA(+) by hybridization, normal ALT); inactive HBsAg carrier; chronic hepatitis B; liver cirrhosis. The genotype and the BCP/precore regions were determined by PCR using genotype specific primers and direct sequencing, respectively.

RESULTS

All patients except one were infected with genotype C. The A to T mutation at nucleotide 1762 and/or G to A mutation at nucleotide 1764 were found in 30% in HBeAg(+) ASC, 65.7% in inactive HBsAg carrier, 95% in chronic hepatitis B, and 90% in liver cirrhosis (p < 0.001). The prevalence of the G to A mutation at nucleotide 1896 was 5% in HBeAg(+) ASC, 22.5% in inactive HBsAg carrier, 32.5% in chronic hepatitis B, and 50% in liver cirrhosis, respectively (p < 0.001). The T to C/A mutation at nucleotide 1753 in the BCP and G to A mutation at nucleotide 1899 in the precore were more frequent in liver cirrhosis than in the other clinical statuses (p < 0.05).

CONCLUSION

Sequential accumulation of mutations in the BCP/precore has an important role in the progression of HBV-related liver disease.

Clinical Significance of the Genotype and Core Promoter/Pre-Core Mutations in Hepatitis B Virus Carriers

It has been shown that clinical and virological characteristics vary among hepatitis B virus (HBV) genotypes. In this study, we measured the virus level, disease severity, and presence or absence of core promoter (CP)/pre-core (PC) mutations in 241 HBV carriers, and investigated the clinical significance of measuring the HBV genotype. In genotype C HBV carriers, the proportion of hepatitis B e antigen (HBeAg)-positive patients was significantly higher than that in genotype B HBV carriers (0 vs. 34.4%, p < 0.05), and the virus level was higher (4.9 vs. 4.05 LGE/ml). In the genotype B HBV carriers, the incidence of PC mutation was significantly higher (69 vs. 34%, p < 0.05). In the genotype C HBV carriers, the incidence of CP mutation was significantly higher (13 vs. 78%, p < 0.05). We compared patients with the wild (W)/mutant (M) pattern in the CP/PC regions to those with the M/W pattern in the CP/PC regions among the genotype C HBV carriers. Both the proportion of HBeAg-positive patients (65.8 vs. 15.4%, p < 0.05) and the alanine aminotransferase (ALT) level (48 vs. 21.5 IU, p < 0.05) were higher in the patients with the M/W pattern in the CP/PC regions, and the disease severity was deteriorated. In conclusion, genotype B HBV may more frequently induce HBe seroconversion via PC mutation compared to genotype C HBV. Among the genotype C HBV carriers, hepatitis activity and the deterioration of the disease severity were significantly inhibited in the group in which PC mutation initially occurred, in comparison to the group in which CP mutation initially occurred.

Evaluation of 10 commercial diagnostic kits for in vitro expressed hepatitis B virus (HBV) surface antigens encoded by HBV of genotypes A to H

Genetic variability of the hepatitis B virus (HBV) constitutes one of the major challenges for diagnosis of HBV infection. It is plausible that amino acid substitutions in the "a" determinant of the HBV surface antigen (HBsAg) that affect antigenic sites, whether originating from genetic diversity or from mutations in the HBV strain itself, will affect the sensitivity of some diagnostic kits. In fact, recent studies have indicated that some diagnostic kits had false negative results with particular HBsAg mutants. There have been, however, few substantial studies evaluating sensitivities of diagnostic kits to the HBsAg encoded by different HBV genotypes. Our recent study found that 10 diagnostic kits available in Japan were able to detect HBsAg irrespective of whether it originated from HBV genotypes A, B or C, with the latter two genotypes being the dominant species in East Asia. In this study, we extended our previous efforts by assessing the ability of diagnostic kits to detect recombinant HBsAg derived from HBV genotypes A to H. Our results demonstrated that 9 out of 10 diagnostic kits evaluated were able to detect as low as 0.2 International Units (IU)/ml HBsAg, irrespective of HBV genotype. The genotypic differences in the HBV family thus appear to have little impact on the sensitivity of currently available HBsAg diagnostic kits.

Hepatitis B virus genotypes and G1896A precore mutation in 486 Spanish patients with acute and chronic HBV infection

This study aims to determine the prevalence of hepatitis B virus (HBV) genotypes (A-F) and their association with the G1896A precore mutation in 486 patients positive for HBV surface antigen. Genotypes were determined by RFLP and precore mutation by real-time PCR. Genotypes D (48.1%) and A (39.5%) were the most common, followed by F (4.1%) and B, C and E (<1%). The A to D ratio (A:D) was 1.4 in HBeAg+ chronic hepatitis B (CHB), 0.6 in HBeAg- CHB and 1.4 in HBeAg- inactive carriers. Distribution of these genotypes was different between HBeAg+ CHB and HBeAg- CHB (P = 0.02), and between HBeAg- CHB and HBeAg- inactive carriers (P = 0.009). Genotype A was the most prevalent in HBeAg+ CHB with elevated alanine aminotransferase (ALT) (68.6%) and genotype D in HBeAg+ CHB with fluctuating ALT (60.7%). There was a difference in genotype prevalence between chronic and acute infection (P = 0.03). The precore mutant correlated with high levels of HBV-DNA in genotype d HBeAg- CHB. Genotype D is not as highly prevalent in Spanish patients as would be expected in a Mediterranean area. The unequal prevalence of genotypes between acute and chronic infection suggests that genotype A is associated with a higher tendency to cause chronic infection.

Association of core promoter/precore mutations and viral load in e antigen-negative chronic hepatitis B patients

Apart from core promoter A1762T/G1764A and precore G1896A mutations, other hepatitis B virus (HBV) mutants are detected in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). The aim of this study was to determine the effects of those mutants on clinical manifestation and viral loads of genotypes B and C HBV. Seventy-nine HBeAg-negative CHB patients with hepatitis flare were enrolled in this study and their HBV precore/core region were sequenced. Serial biochemical profiles and viral loads were assessed and compared. Fifty-three patients (67%) were infected by genotype B HBV and 26 (33%) were infected by genotype C HBV. The clinical manifestation and HBV viral loads were comparable between the two groups. However, genotype B was significantly associated with precore G1896A mutation (92.5%), and more mutations within nucleotide 1809-1817 were detected in patients infected by genotype B as compared with those infected by genotype C (18.9%vs 3.8%). Most of the cases had mutations at the -2, -3 or -5 position from the precore AUG initiation codon. Triple core promoter mutations T1753C/A1762T/G1764A [corrected] appeared to be linked to genotype C rather than genotype B HBV (19.2%vs 1.9%; P = 0.013). In multivariate analysis, the presence of either triple core promoter 1753/1762/1764 mutation or nucleotide 1809-1817 mutation was the only factor associated with lower HBV viral load (<70 Meq/mL) (odds ratio = 9.01; 95% CI 1.11-71.43; P = 0.04). In conclusion, minor HBV variants with mutations in the core promoter and precore region were detectable in genotypes B and C. Such HBV variants are genotype specific and related to viraemia levels.

Genotypes and viremia of hepatitis B and D viruses are associated with outcomes of chronic hepatitis D patients

BACKGROUND & AIMS

Genotypes and viremia of hepatitis D virus (HDV) and hepatitis B virus (HBV) may be associated with outcomes. This study evaluated the impact of viral genotypes and viremia on outcomes of dual HBV and HDV infection.

METHODS

Viremia and viral genotypes were analyzed in 194 consecutive chronic hepatitis B patients with HDV superinfection and correlated with outcomes.

RESULTS

The numbers of HBV genotype A, B, C, and nonclassified were 4, 57, 23, and 110, respectively. There were 51 genotype I HDV, 74 genotype II HDV, 8 genotype IV HDV, and 61 nonclassified HDV genotype. In a median follow-up of 135 months, 24 progressed to cirrhosis and 41 developed hepatocellular carcinoma. Patients infected with genotype I HDV had a lower remission rate (15.2% vs 40.2%; P = .007) and more adverse outcomes (cirrhosis, hepatocellular carcinoma, or mortality) (52.2% vs 25.0%; P= .005) than those with genotype II HDV. Patients infected with genotype C HBV had a lower remission rate (0 vs 32.1%; P = .005) and more adverse outcomes (70.0% vs 33.9%; P = .005) than those with genotype B HBV. The presence of HBV or HDV viremia was associated with lower remission rates compared with those negative for both (26.4% and 24.3% vs 69.2%; P < .001). In multivariate analysis, age, genotype C HBV, and genotype I HDV were independent factors associated with adverse outcomes.

CONCLUSIONS

In chronic HBV and HDV dual infections, older age, genotype I HDV, and genotype C HBV correlated with adverse outcomes.

Multicentre study of hepatitis B virus genotypes in France: correlation with liver fibrosis and hepatitis B e antigen status

The clinical significance of hepatitis B virus (HBV) genotypes is still under debate. The aims of this study were to assess the distribution of HBV genotypes in France and to identify the associations between HBV genotypes and patient demographics, severity of liver disease and HBeAg status in patients referred to tertiary care centres. This was a French, multicentre, retrospective study on 262 patients with chronic HBV infection. HBV genotypes were determined using INNO-LiPA. Liver fibrosis damage was evaluated by histological analysis of biopsy samples. Patients were mainly male (74%), of Caucasian (65%), Asian (17%) or African (18%) ethnicity and 36% were HBeAg positive. All A-G genotypes were found, the most frequent being genotypes D (27%) and A (24%), followed by E (13%) and C (12%), and B (7%). Mixed genotypes were detected in 16% of the cases. Genotype A was associated with sexual contact (P < 0.001) and genotype D with transfusion (P < 0.001) and HBe antibody positivity (P = 0.03).The distribution of HBV genotypes differed with regard to the ethnicity, and may reflect migration patterns. Genotypes A and D were the most frequent in France. Genotype A was associated with HBeAg positivity and genotype D with HBe antibody positivity. In our European patients, we find no clear association between a given HBV genotype and liver disease severity.

Assessment and Management of Chronic Hepatitis B

An understanding of the natural history of CHB is critical for the management of the liver disease. Three clinical patterns with different clinical outcomes are recognized: HBeAg-positive CHB, HBeAg-negative CHB,and inactive CHB. Patients with elevated aminotransferase levels and HBV DNA greater than 105 viral copies per mL in serum and with features of chronic hepatitis on liver biopsy are candidates for therapy regardless of HBeAg status. Multiple host and viral factors and safety profiles of current therapies need to be considered carefully before recommending therapy. There appears to be no role for HBV genotyping in the management of patients. Three antiviral agents are approved for use against CHB infection:IFN-a, lamivudine, and adefovir. Efficacy is moderate at best and is limited by the poor tolerability of IFN and the development of resistance, coupled with concerns regarding the long-term safety with nucleoside analogs. Several new nucleoside and nucleotide analogs and novel agents are at various stages of development as potential therapies for CHB. The ideal compound would be one that is active against all replicative intermediates of the virus and has a low toxicity profile. Despite current shortcomings, the future of therapy for HBV is promising, as newer therapeutic options are being developed based on an understanding of the HBV life cycle.

Major role of hepatitis B genotypes in liver fibrosis during coinfection with HIV

BACKGROUND

Little is know about the determinants of liver fibrosis progression and genomic variability in hepatitis B virus (HBV) in HIV/HBV-coinfected patients.

METHODS

A cross-sectional analysis examined common characteristics of HBV infection in an ongoing cohort study of 308 patients with both HIV-1-positive Western blot and plasma HBV surface antigen (HBsAg) seropositivity. Risk factors for liver fibrosis were studied in a subset of 104 patients for whom liver biopsy and complete HBV genomic analysis were available. Analysis was performed by exact multiple regression analysis.

RESULTS

Mean age of the study population was 40.3 years, with a ratio male to female of 5.3 and a mean duration of HIV infection of 9.3 years. In the subset of 104 patients, plasma HBV e antigen (HBeAg) in HBV-replicative patients could not be detected in 28.4% and lamivudine-resistant mutants were detected in 67.8%. HBV genotype A was the most frequent genotype (73/104) and 25 patients were infected by the usually rare genotype G. METAVIR fibrosis score was rated F2-F4 in 70 patients. After adjustment for the most common known determinants of liver fibrosis, HBV genotype G [odds ratio (OR), 12.60; 95% confidence interval (CI), 1.72-infinite; P < 0.009], efavirenz exposure (OR, 3.55; 95% CI, 1.14-12.14; P < 0.03), and the duration of HIV infection (3.86; 95% CI, 1.27-12.64; P < 0.01) were strongly associated with the risk of grade F2-F4 fibrosis.

CONCLUSION

HBV genotype G is a determinant of liver fibrosis in HIV/HBV-coinfected patients and HBV genotyping should be considered as part of the management of patients with multiple risk factors for rapid progression of liver fibrosis.

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.

Treatment with Peg-interferon alpha-2b for HBeAg-positive chronic hepatitis B: HBsAg loss is associated with HBV genotype

BACKGROUND AND AIMS

Hepatitis B surface antigen (HBsAg) loss is the hallmark of a complete response to antiviral therapy for chronic hepatitis B. In this study, we investigated the frequency of HBsAg loss after treatment with pegylated (Peg)-interferon alpha-2b.

METHODS

In a multicenter randomized controlled trial, 266 HBeAg-positive patients were treated for 52 wks with Peg-interferon alpha-2b (100 microg/wk) in combination with either lamivudine (100 mg/day) or placebo. Posttreatment follow-up was 26 wks.

RESULTS

At the end of follow-up, 95 (36%) of the 266 patients exhibited HBeAg loss, 18 (7%) HBsAg loss, and 16 (6%) HBsAg seroconversion. Addition of lamivudine did not enhance HBeAg loss, HBsAg loss, or development of anti-HBs. All 18 patients who showed HBsAg loss had normal ALT; 11 (61%) of these patients were also hepatitis B virus (HBV) DNA negative (<400 copies/mL) at the end of follow-up. Loss of HBsAg differed according to HBV genotype: 14% for genotype A, 9% for genotype B, 3% for genotype C, and 2% for genotype D (A vs D: p = 0.006).

CONCLUSIONS

One year of Peg-interferon alpha-2b for HBeAg-positive patients led to HBsAg loss in 7%. Our study indicates that treatment with Peg-interferon alpha-2b is the best therapy to achieve HBsAg clearance in patients with genotype A.

Long-term lamivudine treatment is associated with a good maintained response in severe acute exacerbation of chronic HBeAg-negative hepatitis B

Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B is difficult to treat and there is little long-term data for lamivudine treatment of severe acute exacerbation. We report a prospective, consecutive cohort of severe acute exacerbation of HBeAg-negative chronic hepatitis B patients treated by lamivudine between 1999 and 2004. All patients had respectively increased alanine aminotransferase and serum bilirubin to at least 10 and 2 times the upper limit of laboratory normal. Thirty-two patients were treated with lamivudine for 130 +/- 58 (range 48-217) weeks. Five patients had evidence of virological breakthrough (HBV DNA >10,000 copies/ml) during lamivudine treatment. The cumulative probability of maintained response without any virological breakthrough was 94% (95% confidence interval [CI], 86-100%) at year 1, 94% (95% CI, 82-100%) at year 2 and 71% (95% CI, 41-100%) at year 3. At the last follow-up visit, 31 (97%) lamivudine patients had HBV DNA <10,000 copies/ml. The prevalence of lamivudine resistance mutation was 1 in 32 patients (3%; 95% CI, 0-9%) at year 1, 1 in 17 patients (6%; 95% CI, 0-17%) at year 2, 1 in 9 patients (11%, 95% CI, 0-32%) at year 3 and 1 in 4 patients (25%; 95% CI, 0-67%) at year 4 of lamivudine treatment. In conclusion, extended lamivudine treatment is associated with a high maintained virological response and a low rate of drug resistance in severe acute exacerbation of HBeAg-negative chronic hepatitis B.

Association of hepatitis B virus genotypes with clinical phenotypes of hepatitis B virus infection in Beijing

AIM: To investigate the relationship between the genotypes of hepatitis B virus (HBV) and the clinical outcomes of HBV infection in Beijing area.

METHODS: A total of 1 321 patients, including those with self limited HBV infection (n = 245), chronic hepatitis B (n = 668), liver cirrhosis (n = 108) and asymptomatic carriers (n = 300), were concluded in this study. Serum samples were collected for the detection of HBV markers by enzyme linked immunosorbent assay (ELISA). A simple and precise genotyping system based on polymerase chain reaction (PCR) using type-specific primers was developed for the determination of the genotypes of HBV.

RESULTS: Of the 1 321 serum samples, 804 (60.1%) were HBV DNA positive. HBV with the genotype of B, C, and B+C covered a larger percent. The percentage of HBV with genotype A, B, C, and B+C were 0.25% (2/804), 20.77% (167/804), 69.53% (559/804) and 9.45% (78/804), while none of HBV with genotype D, E, and F was found. Of all the patients with self limited HBV infection, 14 were HBV DNA positive, and the rates of genotype B, C, and B+C were 28.6% (4/14), 64.3% (9/14) and 7.1% (1/14), respectively. Of the samples from asymptomatic carriers, 128 were HBV DNA positive, and the rates of genotype B, C, and B+C were 28.1% (36/128), 68.8% (88/128), and 3.1% (4/128), respectively. Of the patients with in chronic hepatitis B, 608 cases were positive for HBV DNA, and the percentage of genotype B, C, B+C, and A were 19.9% (121/608), 68.6% (417/608), 10.4% (68/608), and 0.3% (2/608), respectively. Of the patients with liver cirrhosis, 54 were HBV DNA positive, and the percentage of genotype B, C, and B+C were 11.1% (6/54), 88.3% (45/54), and 5.6% (3/54), respectively. The rate of genotype C in liver cirrhosis patients was markedly higher than that in the patients with chronic hepatitis B, self limited HBV infection, and asymptomatic carriers (all P <0.05). In addition, genotype distribution showed no significant differences between the age and sex of patients.

CONCLUSION: Genotype B and C are major genotypes in Beijing. HBV with genotype C is predominant in patients with HBV infection, and it may be associated with the development of liver cirrhosis.

Hepatitis B virus genome variability and disease progression: the impact of pre-core mutants and HBV genotypes

The hepatitis B virus (HBV), a member of the Hepadnaviridae family, is prone to mutations due to its asymmetric replication via reverse transcription of an RNA intermediate. The estimated mutation rate of the hepadnavirus genome is 2 x 10(4) base substitutions/site/year. This mutation rate is approximately 100 times higher than that of other DNA viruses but between 100 and 1000 times lower than that of RNA viruses. Analyses of both naturally occurring viral variants and in vitro mutagenesis studies have identified some mutations that have a role in viral latency, pathogenesis of liver disease, immune escape, and resistance to antiviral therapy.

Factors related to post-treatment relapse in chronic hepatitis B patients who lost HBeAg after lamivudine therapy

BACKGROUND AND AIM

It is uncertain if a patient's lamivudine response after HBeAg loss is durable. In Korean chronic hepatitis B patients, the relapse rate is high after termination of lamivudine therapy for patients with HBeAg loss. We evaluated the factors related to relapse in chronic hepatitis B patients with HBeAg loss after lamivudine therapy.

METHODS

A total of 132 chronic hepatitis B patients, who initially had HBeAg and did not have decompensated features, were analyzed in this study. These patients lost the HBeAg after lamivudine therapy and then their therapy was stopped. Post-treatment serum alanine aminotransferase (ALT), HBeAg, anti-HBe and hepatitis B virus (HBV) DNA were monitored until relapse.

RESULTS

Seventy-five patients relapsed (cumulative relapse rate: 56% at 6 months). Upon univariate analysis, the factors of age, serum total bilirubin, presence of anti-HBe after HBeAg loss, and the duration of additional lamivudine therapy after HBeAg loss were associated with relapse. Upon multivariate analysis, older age, a higher serum total bilirubin and the shorter duration of additional lamivudine therapy were significant risk factors for relapse. Patterns of relapse were the re-elevation of ALT, re-emergence of HBV DNA (69 patients) and reappearance of HBeAg (55 patients).

CONCLUSIONS

To prevent relapse in patients with chronic hepatitis B infection after lamivudine therapy, age and serum bilirubin level of patients as well as a prolonged duration of additional lamivudine therapy should be considered.

Therapeutic implications of hepatitis B virus genotypes

BACKGROUND/AIMS

Hepatitis B virus (HBV) is a global health problem. In addition to the implementation of universal hepatitis B vaccination, effective and individualized treatment of chronic hepatitis B to prevent progression into end-stage liver diseases and hepatocellular carcinoma is still needed. HBV has been designated eight genotypes (A-H) based on genome sequence divergence. The epidemiology of HBV genotypes and their implications on the responses to antiviral therapy have become increasingly recognized in both Asian and Western countries.

METHODS

Published data are thus reviewed.

RESULTS

Each genotype has its distinct geographical and ethnic distribution. Genotypes A and D occur frequently in Africa, Europe, and India, while genotypes B and C are prevalent in Asia. Genotype E is restricted to West Africa, and genotype F is found in Central and South America. The distribution of genotypes G and H is less clear. Accumulating evidence indicates a better sustained response to conventional interferon in patients with genotype B than those with C, and in patients with genotype A than those with D. In contrast, conflicting results exist regarding the response to pegylated interferon. On the other hand, the therapeutic responses to nucleoside/nucleotide analogues are comparable among patients with different HBV genotypes. The impact of HBV subgenotypes, mixed genotype infections, and recombinants of different genotypes on the response to antiviral treatments awaits further examinations.

CONCLUSION

Remarkable clinical and pathogenic differences do exist among HBV genotypes; however, researches on molecular and virologic mechanisms underlying the clinical phenotypes of different HBV genotypes are urgently needed.

Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E

AIM: To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype.

METHODS: Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing.

RESULTS: HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E.

CONCLUSION: HBV/E is predominant in the Republic of Benin, and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP, which might influence the virological characteristics, is observed in HBV/E.

Community-based epidemiology of hepatitis B virus infection in West Bengal, India: prevalence of hepatitis B e antigen-negative infection and associated viral variants

BACKGROUND AND AIMS

There is a paucity of population-based epidemiological information regarding hepatitis B virus (HBV) infection in India. The present study was planned to outline the magnitude and pattern of HBV infection, hepatitis B e antigen (HBeAg)-negative infection and the associated viral mutants in India.

METHODS

A community-based epidemiological study of HBV infection was carried out in West Bengal, India. Serological markers of infection and potential risk factors for HBV transmission were determined. Among the infected individuals, HBV-DNA, genotypes and mutations in the precore (PC) stop codon and basal core promoter (BCP) regions were determined by DNA sequencing and polymerase chain reaction (PCR) restriction fragment length polymorphism methods.

RESULTS

Of the 7653 people included in the study, 227 (2.97%) tested positive for hepatitis B surface antigen (HBsAg), of whom 204 (90%) were HBeAg-negative and hepatitis B e antibody (anti-HBe)-positive, and 78% had normal alanine aminotransferase (ALT) levels. HBV-DNA could be detected by PCR in only 32% of people. G1896A PC stop codon mutants were present in 12% of people, BCP mutants in 18% and the remainder (70%) of the HBeAg-negative infections were associated with wild type sequences in these regions.

CONCLUSIONS

This first general population-based epidemiological study of HBV infection from India suggests that HBV acquisition starts in early childhood and peaks in adulthood. Most infections in the community are e-negative and inactive. The point prevalence of PC stop codon and BCP mutants is low in this primarily inactive and asymptomatic HBV-infected population sample in eastern India.

Mannose-binding lectin in chronic hepatitis B virus infection

Mannose binding lectin (MBL) is a pattern-recognition molecule of the innate immune system. The roles of MBL and its gene (mbl2) polymorphisms, -221X/Y and codon 54A/B, in hepatitis B virus (HBV) infection were investigated in this study. We recruited 320 nonprogressed hepatitis B surface antigen (HBsAg) carriers; 199 progressed HBsAg carriers with hepatocellular carcinoma or cirrhosis; 87 spontaneously recovered individuals who were HBsAg negative and anti-HBs and anti HBc positive; and 484 controls who were naïve to HBV. There was no significant difference between nonprogressed carriers, spontaneously recovered individuals, and controls in terms of serum MBL levels and mbl2 polymorphisms distributions. However, the low MBL genotypes had a dose-dependent correlation with the cirrhosis and hepatocellular carcinoma in progressed carriers with odds ratios of 1.36 and 3.21 for the low and extremely low MBL genotypes, respectively (P = .01). The low-expression promoter haplotype XA (OR = 1.97) and the mutant haplotype YB (OR = 1.90) were also associated with the cirrhosis and hepatocellular carcinoma (P = .002). As expected, the lower serum MBL levels in progressed carriers as compared with nonprogressed carriers were due to an overrepresentation of low and extremely low MBL genotypes. Moreover, MBL could bind HBsAg in a dose- and calcium-dependent and mannan-inhibitable manner in vitro, suggesting that binding occurs via the carbohydrate recognition domains. This binding also enhanced C4 deposition. In conclusion, these results suggest that low MBL genotypes associate with the occurrence of cirrhosis and hepatocellular carcinoma in progressed HBsAg carriers, and MBL can bind HBsAg.

Geographic distribution, virologic and clinical characteristics of hepatitis B virus genotypes in China

The significance of hepatitis B virus (HBV) genotypes for the heterogeneity of chronic HBV infection and severity of liver disease is not well understood. The aim of this study was to determine the distribution and virologic characteristics of HBV genotypes in China and possible association with the diversity of liver disease. The study includes 1096 chronic HBV carriers from nine provinces in China. We collected clinical and laboratory data and analysed the HBV strains in sera by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequencing techniques. The most common HBV genotypes were B (41%) and C (53%), while genotypes A and D were also found. A North-South divide was identified in genotype B and C distribution - genotype C was predominant in northern China, while genotype B was more prevalent in southern provinces. Patients with genotype B were younger than those with genotype C, and had a lower prevalence of HBeAg - 65%vs 72%, respectively (P = 0.03). However, the severity of liver disease did not differ significantly between patients infected with genotype B or C - neither when comparing liver function tests (1024 patients), nor hepatic inflammation and fibrosis (264 patients). Amongst 47 patients with genotype D (by PCR-RFLP), 37 (79%) were infected with a new subtype (designated Dc), having a recombination fragment from genotype C precore/core region. This is the first large-scale HBV genotype study from China and convincing documentation of the North-to-South gradient of genotypes C vs B in this country. HBV DNA recombination over the surface and precore/core genes increases the diversity of HBV strains and may have diagnostic and clinical implications.

Association of polymorphism of tumor necrosis factor-alpha gene promoter region with outcome of hepatitis B virus infection

AIM: To determine whether -238G/A and -857C/T polymor-phisms of tumor necrosis factor-alpha (TNF-α), gene promoter and hepatitis B (HB) viral genotypes were associated with outcomes of HBV infection.

METHODS: A total of 244 HBV self-limited infected subjects, 208 asymptomatic carriers, and 443 chronic HB patients were recruited to conduct a case-control study. TNF-α -238G/A and -857C/T gene promoter polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and HBV genotypes were examined by nested PCR.

RESULTS: The positive rate of HBV DNA in asymptomatic carrier group and chronic HB group was 46.6% and 49.9%, respectively. HBV genotype proportion among the asymptomatic carriers was 2.1% for genotype A, 25.8% for genotype B, 68.0% for genotype C, and 4.1% for genotype B+C mixed infection, and 0.9% for genotype A, 21.7% for genotype B, 71.5% for genotype C, 5.9% for genotype B+C mixed infection in chronic HB group. There was no significant difference in genotype distribution between the asymptomatic carrier group and chronic HB group (χ2 = 1.66, P = 0.647). The frequency of -238GG genotype in self-limited group was 95.1%, significantly higher than 90.7% in chronic HB group and 89.0% in asymptomatic carrier group (P = 0.041 and P = 0.016, respectively).The frequency of TNF-α-857 CC in chronic HB group was 79.7%, significantly higher than 64.4% in asymptomatic carrier group and 70.9% in self-limited group (P<0.001 and P = 0.023, respectively). A multiple logistic regression analysis revealed that TNF-α-238GA and -857CC were independently associated with chronic HB after gender and age were adjusted.

CONCLUSION: TNF-α promoter variants are likely to play a substantial role in the outcome of HBV infection.

Phylogeny of African complete genomes reveals a West African genotype A subtype of hepatitis B virus and relatedness between Somali and Asian A1 sequences

Hepatitis B virus (HBV) is a major cause worldwide of liver disease, including hepatocellular carcinoma. There are eight known genotypes (A-H), of which genotype A has been divided into two subtypes: A2, prevalent in Europe, and A1, which is prevalent in sub-Saharan Africa, but also occurs in southern Asia. In this study, which includes 14 new complete genomes of non-European genotype A HBV, it was found that West African strains seem to constitute a new subgroup, A3. The high degree of genetic diversity within Africa indicates that genotype A originates from Africa. Based on a 2 % genetic distance between Asian and Somali sequences, it seems that the A1 subtype has spread from East Africa to southern Asia during the last 1000-2000 years. Moreover, it is proposed here that the A2 subtype originates from southern Africa and was imported to Europe around 500 years ago or later. The finding of T-1809/1812 close to the precore start codon and T-1862 and A-1888 in the precore region in HBV e antigen-positive children with signs of a mimimal immune response indicates that these substitutions are stable variants, rather than mutations emerging during infection in individual carriers.

Relationship of genotypes of hepatitis B virus to mutations, disease progression and response to antiviral therapy

Phylogenetic analysis has led to the classification of hepatitis B virus into eight genotypes, designated A to H. The genotypes have differences in biological properties and show heterogeneity in their global distribution. These attributes of the genotypes may account not only for differences in the prevalence of hepatitis B virus mutants in various geographic regions, but also be responsible for differences in the clinical outcome and response to antiviral treatment in different population groups.

Hepatic necroinflammation and fibrosis in patients with genotypes Ba and C, core-promoter and precore mutations

The role of infection with hepatitis B virus (HBV) genotypes on liver histology is largely unknown. The aim of study was to investigate the relationships between HBV genotypes (B, C), core-promoter (CP) and precore mutants and liver histology in 66 patients. Liver biopsies were scored by histologic activity index (HAI). HBV genotypes were determined by enzyme-linked immunosorbent assay (ELISA). Eighteen (27.3%) and 48 patients (72.7%) had genotype B (all were subtype Ba) and C, respectively. Forty-seven (71.2%) and 27 (40.9%) had CP and precore mutations, respectively. Patients with genotype C compared with subtype Ba had higher median scores of HAI-necroinflammation (HAI-NI) (7 vs 3), HAI-fibrosis (HAI-F) (1 vs 0) and total HAI (8.5 vs 3) (all P < 0.03). Patients with CP mutations compared with wild-type had higher median scores of HAI-NI (7 vs 3), HAI-F (3 vs 0) and total HAI (9 vs 3) (all P < 0.03). Forty patients (83.5%) with genotype C had CP mutations. Age and alanine aminotransferase levels were positively correlated with HAI scores while albumin levels were negatively correlated (P < 0.01 for all, except albumin levels and HAI-F, P = 0.08). There was no association between precore mutations and HAI scores. Multivariate analysis indicated that higher alanine aminotransferase (ALT) levels were associated with higher HAI scores (P < 0.04) and CP mutations were associated with higher HAI-NI (P = 0.034), but not with HAI-F score (P = 0.3). CP mutations were associated with more severe necroinflammation. The association between genotype C and poor histology was probably because of the association between genotype C and CP mutations.

Genotype C hepatitis B virus infection is associated with a higher risk of reactivation of hepatitis B and progression to cirrhosis than genotype B: a longitudinal study of hepatitis B e antigen-positive patients with normal aminotransferase levels at baseline

BACKGROUND/AIMS

Longitudinal studies on the relationship between hepatitis B virus (HBV) genotypes and reactivation of hepatitis B and progression to cirrhosis were very rare.

METHODS

Liver biochemistry, virological markers and ultrasound were monitored in 202 hepatitis B e antigen (HBeAg)-positive patients with normal alanine aminotransferase (ALT) at baseline for 3-20 (average 10.8) years, and the outcome was correlated with HBV genotypes.

RESULTS

There were 150 genotype B and 52 genotype C patients. Hepatitis activity during the HBeAg-positive phase showed no significant difference. However, genotype B was associated with a significantly earlier and higher rate of HBeAg seroconversion. HBeAg seroconversion correlated with age at entry for genotype B and with ALT levels for genotype C. Reactivation of hepatitis B was significantly more common in genotype C patients. Five genotype B and 10 genotype C patients progressed to cirrhosis. Multivariate analysis revealed that genotype C (P = 0.03) and reactivation of hepatitis B (P = 0.0004) were independent factor predictive of cirrhosis.

CONCLUSIONS

Rate and factors of HBeAg seroconversion, and rate of reactivation of hepatitis B differed between genotype B and genotype C patients. Genotype C and reactivation of hepatitis B were associated with increased risk of cirrhosis.

Distinct geographic distributions of hepatitis B virus genotypes in patients with acute infection in Japan

Genotypes of hepatitis B virus (HBV) were determined in 145 patients with acute hepatitis B from various districts in Japan to establish their geographic distribution and evaluating the influence on the clinical illness and outcome. Genotypes were A in 27 (19%) patients, B in 8 (5%), C in 109 (75%) and mixed with B and C in the remaining one (1%). Genotype A was more frequent in metropolitan than the other areas (21/69 (30%) vs. 6/76 (8%), P < 0.001). On phylogenetic analysis, seven of the nine (78%) HBV/A isolates selected at random clustered with those from Europe and the United States, while the remaining two with those of subgroup A' prevalent in Asia and Africa. Maximum ALT levels were lower (2069 +/- 1075 vs. 2889 +/- 1867 IU/L, P = 0.03) and baseline HBV DNA titers were higher (5.90 +/- 1.45 vs. 5.13 +/- 1.36 log genome equivalents (LGE)/ml, P = 0.002) in patients infected with genotype A than C. Hepatitis B surface antigen persisted longer in patients infected with genotype A than C (1.95 +/- 1.09 vs. 1.28 +/- 1.42 months, P = 0.02). HBV infection became chronic in one (4%) patient with genotype A and one (1%) with genotype C infection. Fulminant hepatic failure developed in none of the patients with genotype A, one (13%) with genotype B and five (5%) with genotype C. The point mutation in the precore region (A1896) or the double mutations in the basic core promoter (BCP) region (T1762/A1764) were detected in none of the patients with genotype A, two (25%) with genotype B and 27 (26%) with genotype C. In conclusion, genotype A is frequent in patients with acute hepatitis B in metropolitan areas of Japan, probably reflecting particular transmission routes, and associated with longer and milder clinical course than genotype C.

Hepatitis B virus genotypes in Korea: an endemic area of hepatitis B virus infection

OBJECTIVES

It has been reported that distribution of hepatitis B virus (HBV) genotypes shows geographic difference and are associated with clinical outcomes of HBV infection, including response to antiviral therapy and progression of chronic liver diseases. In this study, we analyzed the distribution of HBV genotypes according to the various clinical outcomes of chronic HBV infection in Korea, which is one of the most endemic areas of HBV infection.

METHODS

A total of 200 patients with chronic HBV infection were enrolled. Clinical diagnoses of the 200 patients with chronic liver diseases were as follows: hepatitis B e antigen (HBeAg)-positive healthy carrier (defined as HBeAg(+), anti-HBe(-), HBV DNA(+) by hybridization, normal transaminase; n = 40); inactive HBsAg carrier (n = 40); chronic hepatitis B (n = 40); liver cirrhosis (n = 40); hepatocellular carcinoma (n = 40). HBV genotypes were determined by nested polymerase chain reaction using genotype-specific primers.

RESULTS

All patients except 2 (inactive HBsAg carriers) were positive for nested PCR and they have genotype C regardless of clinical outcomes.

CONCLUSIONS

HBV genotype was genotype C regardless of various clinical outcomes of chronic HBV infection in Korea. Considering that HBV genotypes have clinical relevance, distribution of HBV genotype in each area should be monitored when management for chronic HBV infection is planned.

Significance of hepatitis B virus genotype in liver transplantation for chronic hepatitis B

Hepatitis B virus (HBV) genotype influences chronic hepatitis B disease profile but its relevance in liver transplantation (LTx) is not known. HBV genotype was identified by direct sequencing from pre-transplant sera of 119 patients who underwent LTx using lamivudine prophylaxis (genotype A,1; B,43; C,74; D,1). The baseline characteristics and outcome of 43 genotype B and 74 genotype C patients were compared. Genotype B patients had significantly more pre-transplant acute flare, worse liver functions and higher model for end-stage liver disease score. Fewer genotype B patients had HBeAg (13% vs. 32%; p=0.017), but HBV DNA seropositivity (by bDNA assay) was comparable (26% vs. 23%; p=0.727). The 3-year graft survival was 83% for genotype B and 89% for genotype C (p=0.2). The rate of HBsAg clearance or seroreversion was the same. The cumulative rate of viral breakthrough due to lamivudine-resistant mutants at 3 years was 4% for genotype B and 21% for genotype C (p=0.017). Liver biopsy after viral breakthrough showed recurrent hepatitis B in 7 of 10 genotype C patients, including 2 with fibrosing cholestatic hepatitis, and no histologic recurrence in 2 genotype B patients. In conclusion, HBV genotypes B and C are associated with different patterns of end-stage liver diseases that required transplantation, and genotype C may carry a greater risk and severity of recurrence due to lamivudine-resistant mutants.

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Response to long-term lamivudine treatment (up to 5 years) in patients with severe chronic hepatitis B, role of genotype and drug resistance

Lamivudine is effective in suppressing viral replication, normalizing alanine aminotransferase (ALT), and improving histological appearance in HBe positive and negative hepatitis. It is unclear whether hepatitis B virus (HBV) genotype influences the response to lamivudine. We report the long-term response of patients with chronic hepatitis B with and without cirrhosis at baseline treated with lamivudine according to HBV genotype. Retrospective review of charts of all patients treated with lamivudine monotherapy between 1993 and 2002. Response to therapy defined as ALT in the normal range, undetectable HBV DNA, and in the HBeAg positive group loss of HBeAg and/or the development of anti-HBe. HBV DNA measured by the Digene Hybrid capture assay (sensitivity 1.4 x 10(6) copies/mL). YMDD mutation at rtL180M and rtM204V/I measured by restriction digest of amplified products. Genotyping performed by sequencing and phylogenetic tree analysis of the preS region of the virus genome. Seventy-one patients treated with lamivudine for 6 months or more, 53 (75%) were male, average age 47 years, 38 (54%) were HBeAg+ and 33 (46%) HBeAg-. Mean baseline HBV DNA viral titre was 1280.2 copies/mL and 518 copies/mL respectively. Cirrhosis was present in 30 (42%). Sera were examined for YMDD mutations at last patient visit in 61 (86%), and were detected in 45 (74%), there being no association with a particular genotype. Data from up to 5 years on lamivudine indicated no difference in biochemical or virological response between genotypes. Cirrhosis was more prevalent with specific genotypes. We found no influence of HBV genotype on the development of resistance to lamivudine, however liver disease severity was influenced by genotype.

Basal core-promoter mutant of hepatitis B virus and progression of liver disease in hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND/AIMS

The long-term outcomes in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B are distinct from those in HBeAg-positive chronic hepatitis. However, the molecular virological factors that contribute to the progression of liver disease in this special clinical setting remain largely unknown. We thus investigated the association of hepatitis B virus (HBV) genotypes as well as precore/basal core-promoter mutations with the clinical and virological characteristics of patients with HBeAg-negative chronic hepatitis B in Taiwan.

METHODS

HBV genotypes and sequences of precore and basal core-promoter regions of the HBV genome were determined in 174 HBeAg-negative chronic HBV infection patients including 62 inactive carriers and 112 with different stages of liver disease.

RESULTS

HBV carriers with older age (> 50 years) (odds ratio, 9.09; 95% confidence interval (CI), 3.22-25, P < 0.001) and basal core-promoter mutant of HBV (odds ratio, 4.12; 95% CI, 1.41-12.03, P = 0.01) were associated with the development of liver cirrhosis and hepatocellular carcinoma (HCC). The gender-related risk factors associated with the development of liver cirrhosis and HCC were further analyzed, and basal core-promoter mutant was only associated with the development of liver cirrhosis and HCC in male carriers (odds ratio, 4.35; 95% CI, 1.30-14.52, P = 0.02).

CONCLUSIONS

The risk of development of liver cirrhosis and HCC is significantly increased in patients with advanced age as well as with basal core-promoter mutant of HBV. In addition, basal core-promoter mutant might contribute to the gender difference of the progression of liver disease in HBeAg-negative chronic hepatitis B in Taiwan.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2005 update

BACKGROUND/AIMS

A large amount of new data on the treatment of chronic hepatitis B has become available such that the 2003 consensus statement requires revision and update.

METHODS

New data were presented, discussed and debated in an expert pre-meeting to draft a revision. The revised contents were finalized after discussion in a general meeting of APASL.

RESULTS

Conceptual background, including the efficacy and safety profile of currently available and emerging drugs, was reviewed. Nineteen recommendations were formed and unresolved issues and areas for further study were suggested.

CONCLUSION

The current therapy of chronic hepatitis B is modestly effective but not satisfactory. The development of new drugs and new strategies is required to further improve the outcomes of treatment.

Co-Infection with Hepatitis B Virus Genotype D and Other Genotypes in Western Japan

OBJECTIVE

Genotypes B and C are the prevalent hepatitis B virus (HBV) genotypes in eastern Asia. Although very rare in this region of the world, genotype D was found to be prevalent in a small area of western Japan. In this study, we confirm the frequency and clinical significance of co-infection with different genotypes among patients from that area infected with genotype D.

METHODS

Twenty-three patients from the same area of western Japan infected with HBV genotype D, determined using a genotyping enzyme immunoassay, were studied. Cloning was done using DNA extracted from serum samples, and polymerase chain reaction assays with the restriction fragment length polymorphism for HBV genotyping were performed with 10 clones from each patient.

RESULTS

Four (17.4%) of the 23 patients were found to be co-infected with HBV genotype C, and the HB surface antigen subtype was ayw in both mono- and co-infected patients. No clinical differences were found between mono-infected and co-infected patients carrying genotype D.

CONCLUSION

A significant number of patients from the study area found to be infected with HBV genotype D were co-infected with genotype C. Additional study with a larger number of patients is needed to elucidate the possible clinical significance.

Increased hepatocarcinogenic potential of hepatitis B virus genotype A in Bantu-speaking sub-saharan Africans

Genotypes A, D, and E of the hepatitis B virus (HBV) circulate in southern Africa, with genotype A predominating. Their hepatocarcinogenic potential in Bantu-speaking sub-saharan Africans is, however, unknown. Using a case/control format, we investigated the hepatocarcinogenic potential of these genotypes and subgenotype A1 of genotype A, which accounts for the great majority of genotype A isolates. HBV isolates from 111 unselected Bantu-speaking sub-saharan Africans with hepatocellular carcinoma (HCC) and 111 matched asymptomatic chronic carriers, serving as controls, were genotyped using the method of [Lindh et al. (1997): J Infect Dis 175:1285-1293]. Subgenotypes of genotype A were determined using an in-house restriction fragment length polymorphism assay. Genotype A was present in 96 (86.5%) of patients with HCC and 76 (68.5%) of the carriers, giving a 4.5-fold (95% confidence limits: 1.86, 10.90) increased risk of HCC in carriers infected with genotype A compared with those infected with non-A genotypes. HCC patients infected with genotype A were significantly younger than those infected with non-A genotypes (P = 0.02). The distributions between these two groups according to sex, geographic background, and tribe were not significantly different. Subgenotype A1 was present in all of the 77 cancer patients and 69 of 70 carriers analyzed, yielding a relative risk of 4.21 (95% confidence limits: 1.73,10.23) of HCC in those infected with subgenotype A1 compared with those infected with non-A genotypes. Genotype A has a greater hepatocarcinogenic potential than non-A genotypes in Bantu-speaking sub-saharan Africans and this is entirely attributable to subgenotype A1.

Distribution of hepatitis B virus genotypes in patients with chronic hepatitis B in Turkey

AIM: Hepatitis B virus (HBV) strains isolated worldwide has been classified into eight genomic groups deduced from genome comparisons and designated as genotypes A to H. We aimed to investigate prevalence of HBV genotypes and subtypes in Turkey.

METHODS: A total of 88 chronic hepatitis B (CHB) patients from 15 hospitals throughout the country were included. Patients who were HBsAg positive in serum at least for 6 mo, who had HBV-DNA in serum and elevation of ALT levels more than two times upper limit of normal, and who had percutaneous liver biopsy within 6 mo were included. Genotyping of HBV was done by restriction fragment length polymorphism (RFLP). The patients received subcutaneous 9 MU interferon-α 2a thrice a week for a period of 6 mo.

RESULTS: Genotype D was detected in 78 of 88 (88.7%) patients, however, genotyping failed in two patients (2.3%), while no product was obtained in eight (9.0%) patients. Regarding subtypes, D2 was more prevalent (67 patients between 78% and 85.9%) followed by subtype D2+deletion (seven patients of 78 or 8.9%), subtype D1 (three patients of 78% or 3.9%) and subtype D3 (one patient of 78% or 1.3%). Thirty-three patients (37.5%) were HBeAg positive compared to 55 (62.5%) anti-HBe positive patients. The endpoint for the viral response of HBeAg positive patients was 27.2%, while it was found 52.7% in HBeAg negative patients (P<0.05). Long-term persistent viral response was 29.5% for all patients.

CONCLUSION: This multi-center study indicates that the predominant genotype with CHB patients in Turkey like in other Mediterranean countries is genotype D.

Identification of chronic hepatitis B patients without significant liver fibrosis by a simple noninvasive predictive model

OBJECTIVE

Histological assessment of liver fibrosis is important in the management of chronic hepatitis B (CHB) infection but poorly accepted by patients because of its invasiveness. The aim of this study was to develop a noninvasive model to assess liver fibrosis in CHB patients using clinical and routine laboratory data.

PATIENTS AND METHODS

This was a retrospective study on 235 treatment-naive viremic CHB patients. Univariate analysis of data from the training cohort (n = 150) followed by multivariate logistic regression were performed to identify independent predictors of significant fibrosis and generate predictive models. The models were validated with the remaining patients or validation cohort (n = 85) and by receiver operating characteristics (ROC) analysis.

RESULTS

Body mass index (BMI), platelet count, serum albumin, and total bilirubin levels were identified as independent predictors of bridging fibrosis or cirrhosis (Ishak stage 3-6). ROC analysis was performed using the predictive probabilities derived from the regression models. The area under the ROC curve of the best model was 0.803 (95% CI: 0.729-0.878) for the training cohort, 0.765 (95% CI: 0.644-0.885) for the validation cohort, and 0.791 (95% CI: 0.728-0.854) for the entire cohort. Using the low cut-off probability of 0.15, significant fibrosis could be excluded in 83 patients of the total patient population (negative predictive value 0.92).

CONCLUSIONS

Our noninvasive model comprising BMI and three routine laboratory tests was accurate in predicting absence of significant fibrosis. Application of this model could provide useful additional information on the stage of disease, guide future management decisions, and potentially decrease the need for liver biopsy in some CHB patients.

Hepatitis B virus genotype and DNA level and hepatocellular carcinoma: a prospective study in men

BACKGROUND

Although chronic infection with hepatitis B virus (HBV) has been established as a cause of hepatocellular carcinoma (HCC), the roles of viral load and HBV genotype remain unclear.

METHODS

From 1988 through 1992, baseline blood samples were collected from 4841 Taiwanese men who were HBV carriers but had not been diagnosed with HCC. We used real-time polymerase chain reaction assays of plasma DNA samples to quantify HBV DNA levels (a measure of viral load) and determine HBV genotypes for 154 case patients who were diagnosed with HCC during 14 years of follow-up and 316 control subjects. Unconditional logistic regression was used to assess odds ratios (ORs) of HCC for HBV-related factors. All statistical tests were two-sided.

RESULTS

The risk of HCC increased with increasing HBV viral load (adjusted OR for the highest versus the lowest quintile of HBV DNA copies/mL = 7.26, 95% confidence interval [CI] = 3.54 to 14.89; P(trend)<.001). Genotype C HBV was associated with an increased risk of HCC compared with other HBV genotypes (adjusted OR = 5.11, 95% CI = 3.20 to 8.18). Both viral load and genotype were positively associated with HCC within 10-year age categories among subjects aged 30 years old to older than 60 years. Genotype C HBV was associated with increased viral load, and associations of HBV genotype and viral load with HCC risk were additive. The adjusted OR of HCC for those carrying genotype C HBV and with viral load in the highest quintile was 26.49 (95% CI = 10.41 to 67.42) compared with HBV carriers with other HBV genotypes and viral load in the lowest two quintiles.

CONCLUSIONS

Measurements of HBV viral load and genotype may help to define which male HBV carriers aged 30 years or older are at high risk for HCC.

Genetic diversity of hepatitis B virus strains derived worldwide: genotypes, subgenotypes, and HBsAg subtypes

Sequences of 234 complete genomes and 631 hepatitis B surface antigen genes were used to assess the worldwide diversity of hepatitis B virus (HBV). Apart from the described two subgenotypes each for A and F, also B, C, and D divided into four subgenotypes each in the analysis of complete genomes supported by significant bootstrap values. The subgenotypes of B and C differed in their geographical distribution, with B1 dominating in Japan, B2 in China and Vietnam, B3 confined to Indonesia, and B4 confined to Vietnam, all strains specifying subtype ayw1. Subgenotype C1 was common in Japan, Korea, and China; C2 in China, South-East Asia, and Bangladesh, and C3 in the Oceania comprising strains specifying adrq-, and C4 specifying ayw3 is encountered in Aborigines from Australia. This pattern of defined geographical distribution was less evident for D1-D4, where the subgenotypes were widely spread in Europe, Africa, and Asia, possibly due to their divergence having occurred a longer time ago than for genotypes B and C, with D4 being the first split and still the dominating subgenotype of D in the Oceania. The genetic diversity of HBV and the geographical distribution of its subgenotypes provide a tool to reconstruct the evolutionary history of HBV and may help to complement genetic data in the understanding of the evolution and past migrations of man.

Longitudinal study of hepatitis activity and viral replication before and after HBeAg seroconversion in chronic hepatitis B patients infected with genotypes B and C

The aims of this study were to compare chronic hepatitis B (CHB) patients with genotypes B and C for the probability of HBeAg seroconversion, hepatitis activity, and viral replication before and after HBeAg seroconversion and to compare the prevalence of core promoter and precore mutations. A total of 180 asymptomatic Chinese patients with CHB were monitored for a median of 53.8 months, and 38 patients with cirrhosis-related complications were studied. Hepatitis B virus (HBV) DNA levels were measured in 16 patients with HBeAg seroconversion at 3 months before, during, and 3 months after HBeAg seroconversion and in all patients at the last follow-up. Hepatitis B genotypes and core promoter and precore mutations were determined. Compared to patients with genotype C (n = 109), patients with subtype Ba (n = 69) had a higher rate of anti-HBe positivity on presentation (P = 0.05). HBeAg-positive patients with subtype Ba had a higher cumulative rate of HBeAg seroconversion than patients with genotype C (P = 0.02). However, there were no differences between the two groups with regard to the median HBV DNA levels before, during, and after HBeAg seroconversion; the probability of having persistently normal or elevated aminotransferase levels; and the median HBV DNA levels and liver biochemistry at the last follow-up. There was no difference in the prevalence of genotypes and core promoter and precore mutations between patients with and without cirrhosis-related complications. Though patients with subtype Ba had earlier HBeAg seroconversion, the liver biochemistry, HBV DNA levels in different phases of the disease, and the probability of development of cirrhosis-related complications were the same with genotypes Ba and C.