Specific mutations in enhancer II/core promoter of hepatitis B virus subgenotypes C1/C2 increase the risk of hepatocellular carcinoma

Impact of hepatitis B virus (HBV) x gene mutations on hepatocellular carcinoma development in chronic HBV infection

The hepatitis B virus (HBV) PreS mutations C1653T, T1753V, and A1762T/G1764A were reported as a strong risk factor of hepatocellular carcinoma (HCC) in a meta-analysis. HBV core promoter overlaps partially with HBx coding sequence, so the nucleotide 1762 and 1764 mutations induce HBV X protein (HBx) 130 and 131 substitutions. We sought to elucidate the impact of HBx mutations on HCC development. Chronically HBV-infected patients were enrolled in this study: 42 chronic hepatitis B (CHB) patients, 23 liver cirrhosis (LC) patients, and 31 HCC patients. Direct sequencing showed HBx131, HBx130, HBx5, HBx94, and HBx38 amino acid mutations were common in HCC patients. Of various mutations, HBx130+HBx131 (double) mutations and HBx5+HBx130+HBx131 (triple) mutations were significantly high in HCC patients. Double and triple mutations increased the risk for HCC by 3.75-fold (95% confidence interval [CI] = 1.101 to 12.768, P = 0.033) and 5.34-fold (95% CI = 1.65 to 17.309, P = 0.005), respectively, when HCC patients were compared to CHB patients. Functionally, there were significantly higher levels of NF-κB activity in cells with the HBx5 mutant and with the double mutants than that of wild-type cells and the triple-mutant cells. The triple mutation did not increase NF-κB activity. Other regulatory pathways seem to exist for NF-κB activation. In conclusion, a specific HBx mutation may contribute to HCC development by activating NF-κB activity. The HBx5 mutation in genotype C2 HBV appears to be a risk factor for the development of HCC and may be used to predict the clinical outcomes of patients with chronic HBV infection.

Association between Hepatitis B Virus X Gene Mutations and Clinical Status in Patients with Chronic Hepatitis B Infection

BACKGROUND/AIMS

Few reports have described the association between mutations in the entire X gene of the hepatitis B virus (HBV) and the clinical status of HBV-infected patients. We studied the association between HBV X gene mutations and the disease status of patients infected with HBV genotype C.

METHODS

Mutations in the HBV X genes of 194 patients were determined by direct sequencing. The subject population consisted of patients with chronic hepatitis (n=60), liver cirrhosis (n=65), and hepatocellular carcinoma (HCC) (n=69). The sequencing results of these 3 groups were compared.

RESULTS

Each of the mutations G1386M, C1485T, C1653T, T1753V, A1762T, and G1764A was significantly associated with the patient's clinical status. The T1753V (p<0.001) and A1762T/G1764A (p<0.001) mutations were found more frequently in Hepatitis B e antigen (HBeAg)-negative than in HBeAg-positive patients. Specific X gene mutations (G1386M, C1653T, and A1762T/G1764A) were more prevalent in patients with liver cirrhosis and HCC than in chronic hepatitis patients (p<0.005 for all). In addition, the T1753V (p<0.001) and C1485T (p<0.001) mutations were significantly more prevalent in HCC patients than in chronic hepatitis patients. Only the prevalence of the T1753V mutation increased as the HBV infection progressed from liver cirrhosis to HCC (p=0.023).

CONCLUSIONS

Our findings show a difference in the pattern of X gene mutations that were associated with the clinical status of patients with chronic HBV infection.

Recent advances in the research of hepatitis B virus-related hepatocellular carcinoma: epidemiologic and molecular biological aspects

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, and more than half of HCC patients are attributable to persistent hepatitis B virus (HBV) infections. The best and cheapest way to prevent HBV-related HCC is the implementation of universal hepatitis B vaccination program, by which the incidence rates of childhood HCC have been reduced in several countries, including Taiwan. However, there are still hundreds of millions of HBV carriers in the world that remain a global health challenge. In the past decade, several hepatitis B viral factors such as serum HBV DNA level, genotype, and naturally occurring mutants have already been identified to influence liver disease progression and HCC development in HBV carriers. Several easy-to-use scoring systems based on clinical and viral characteristics are developed to predict HCC risk in HBV carriers and may facilitate the communication between practicing physicians and patients in clinical practice. In addition, the role of nonviral factors in HBV-related HCC has also been increasingly recognized. On the basis of these emerging data, it is recommended that HBV carriers should be screened and monitored to identify those who have a higher risk of liver disease progression and require antiviral treatments. Regarding the molecular carcinogenesis of HCC development, despite some progress in the research of cell biology of HCC in the past decade, aberrant pathways involved in maintaining HCC phenotypes have not been completely elucidated yet. In the future, through comprehensive and integrated approaches to analyze the genomes of human HCC, novel target genes or pathways critically involved in hepatocarcinogenesis may hopefully be identified.

Combined pre-S deletion and core promoter mutations related to hepatocellular carcinoma: A nested case-control study in China

AIM

  To investigate the roles of biomedical factors, hepatitis B virus (HBV) DNA levels, genotypes, and specific viral mutation patterns on the progression of hepatocellular carcinoma (HCC) in Qidong, China.

METHODS

  A total of 2387 males (aged 20-65 years) who were seropositive for the hepatitis B surface antigen (HBsAg), but had not been diagnosed with HCC, were recruited to a community-based HCC screening study from August, 1996. Evaluation of virological parameters at recruitment was determined for 196 HCC patients during 10 years of follow-up and 323 controls.

RESULTS

  After adjustment for age at recruitment, history of cigarette smoking and alcohol consumption, alanine aminotransferase (ALT) elevation, alpha-fetoprotein (AFP) levels >20 ng/mL, hepatitis B e antigen positive, HBV DNA levels ≥4.00 log(10) copies/mL, pre-S deletion, T1653 mutation, T1762/A1764 double mutations, and T1766 and/or A1768 mutations were associated with subsequent risk of HCC. A significant biological gradient of HCC risk by HBV DNA levels from less than 2.69 log(10) copies/mL to 6.00 log(10) copies/mL or greater was observed. HBV with a complex mutation combination pattern (pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations) rather than a single mutation was associated with the development of HCC. The longitudinal observation demonstrated a gradual combination of pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations during the development of HCC.

CONCLUSIONS

  AFP levels >20 ng/mL, high HBV DNA levels, pre-S deletion, and T1762/A1764 double mutations at recruitment were independent risk factors of HCC. Combination of pre-S deletion and core promoter mutations increased the risk of HCC.

Management of hepatitis B: Consensus of the Japan Society of Hepatology 2009

Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described.

JGH Foundation emerging leadership lecture. Significance of hepatitis B virus genotypes and mutations in the development of hepatocellular carcinoma in Asia

Advances in molecular biology technology in the last two decades have allowed detailed study of the viral mutations and genomic heterogeneity of hepatitis B virus (HBV). The first mutant discovered was precore stop codon mutation. It was reported in HBeAg-negative patients and initially thought to associate with fulminant hepatitis. Subsequent studies have suggested that it is merely one of the mechanisms of losing HBeAg by the virus. Another mutation that can downregulate the production of HBeAg is the basal core promoter mutation, which is located in the X gene upstream of the precore region. Based on the configuration of codon 15 and the stability of the epsilon of the precore region, these two mutants will be differentially selected during the course of HBeAg seroconversion. The most common HBV genotypes in South-East Asia are genotype B and C HBV. The higher hepatocellular carcinoma (HCC) risk of genotype C HBV has been confirmed by longitudinal studies in Hong Kong and Taiwan. One possible carcinogenic mechanism is its association with basal core promoter mutation, which has also been found to be a risk factor of HCC. Within genotype C HBV, subgenotype Cs is predominant in South-East Asia and subgenotype Ce is predominant in East Asia. Subgenotype Ce HBV has been found to have the highest risk of HCC as compared with subgenotype Cs or genotype B HBV. The understanding of the carcinogenic mechanisms of these HBV strains may shed light into future therapeutics in the prevention and treatment of HBV-related HCC.

Genetic variations of hepatitis B virus and serum aflatoxin-lysine adduct on high risk of hepatocellular carcinoma in Southern Guangxi, China

BACKGROUND & AIMS

Southern Guangxi area is one of the endemic areas for hepatocellular carcinoma (HCC) in China. This study evaluates the roles of genetic variations of hepatitis B virus (HBV) and aflatoxin B(1) (AFB(1)) exposure in the formation of HCC in this high-risk area.

METHODS

The study recruited 60 HCC patients and 120 age-, gender-, and residency-matched controls. HBV genotype and basic core promoter (BCP) mutations were determined by nested-PCR/direct sequencing. Serum AFB(1)-lysine adduct was measured by high performance liquid chromatography-fluorescence detection.

RESULTS

HBV genotype C was predominant in 75.0% of cases and 84.2% of controls. The 1762(T)/1764(A) double mutations, 1753(V) mutations, and 1752(V) mutations were associated with HCC risk evidenced by the adjusted odds ratio (OR) [95% confidence interval (95% CI)] of 3.89 (1.40-10.77), 2.87 (1.49-5.49), and 5.96 (1.75-20.25), respectively. The adjusted OR (95% CI) was 6.94 (1.68-27.78) for subjects with 1762(T)/1764(A) double mutations and high AFB(1)-lysine adduct level; 2.01 (0.24-14.29), for those with only 1762(T)/1764(A) double mutations; and 4.26 (1.16-15.38) for those with only high AFB(1)-lysine adduct level, respectively. The adjusted OR was 5.13 (1.79-14.71) for subjects with 1753(V) mutations and high AFB(1)-lysine adduct level; 1.20 (0.47-3.08) for those with only 1753(V) mutations, and 2.28 (1.01-5.31) for those with high AFB(1)-lysine adduct level, respectively.

CONCLUSIONS

These data confirmed the association of BCP mutations with HCC risk and the additive effects of 1762(T)/1764(A) double mutations and 1753(V) mutations with dietary AFB(1) exposure in this high-risk area for HCC.

Temporal acquisition of sequential mutations in the enhancer II and basal core promoter of HBV in individuals at high risk for hepatocellular carcinoma

To investigate the roles of mutations in enhancer II (Enh II) and basal core promoter (BCP) of hepatitis B virus (HBV) in hepatocellular carcinoma (HCC), we determined the sequence of Enh II/BCP in 152 HCC and 136 non-HCC patients from a high-incidence area of East China. A longitudinal study was conducted on 21 cases in which serial plasma samples were available before HCC. In total, six point mutations, including T1653, V1753, T1762, A1764, T1766 and A1768, were found to occur more frequently in HCC patients. Multivariate analysis showed that the T1653 [odds ratio (OR), 2.07; 95% confidence interval (CI), 1.114-3.845] and V1753 (OR, 3.099; 95% CI, 1.520-6.317) were independent factors that were associated with HCC. Although a T1762/A1764 double mutation was found in 73.0% of the HCC patients and 66.9% of the non-HCC patients, if the combined pattern with other adjacent mutations was not taken into account, it alone showed a lower frequency in HCC patients compared with non-HCC patients (19.7 versus 34.6%, P = 0.005). Interestingly, while the OR of HCC patients with a double mutation was only 0.393 (95% CI, 0.234-0.660), it increased to 1.861 (95% CI, 1.161-2.984) with a triple mutation and to 4.434 (95% CI, 1.630-12.063) with a quadruple mutation. The longitudinal study demonstrated that the mutations in Enh II/BCP accumulated during the development of HCC. In conclusion, the T1653 and V1753 mutations were independent risk factors for HCC in East China. The T1762/A1764 double mutation was necessary but not sufficient to produce an association between Enh II/BCP mutations and HCC.

Hepatitis B virus BCP, Precore/core, X gene mutations/genotypes and the risk of hepatocellular carcinoma in India

The study aims to characterize mutations of the HBV genome involving BCP, Precore/core and X regions and also defines HBV genotypes in patients of hepatocellular carcinoma (HCC). The study involved 150 HBV-related HCC cases and 136 HBV-related chronic liver disease patients without HCC as controls. HBV DNA was subjected to mutational analysis using SSCP technique, genotyping by RFLP, and direct nucleotide sequencing. HBV DNA was found in 58.7% (88/150) of the HCC cases and 74.3% (101/136) of controls. HBV mutants were observed in 44.3% of HCC cases and 43.2% of controls. HBV/D was prevalent amongst the patients and controls, followed by HBV/A. The prevalence of the TT1504 mutation in the X gene, the V1753 and T1762/A1764 mutations in the BCP region, and G1914 mutation in the core gene were significantly higher in the HCC group than in the non-HCC group. Multivariate analyses showed that the TT1504, V1753, A1762T/G1764A, and the G1914 mutations and the patient's age, sex, and HBeAg status increased the risk of HCC development significantly. Also, patients with HCC had lower levels of serum albumin, viral load, and platelet counts but higher values of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bilirubin, and Alpha feto-protein than those of controls (P < 0.001 for all comparisons). HBV/D was the predominant genotype associated with HCC cases seen in India. The presence of different types of HBV mutations, age, sex, HBeAg status, and viral load was found to increase significantly the risk of HCC development in India.

Prevalent HBV point mutations and mutation combinations at BCP/preC region and their association with liver disease progression

Background

Mutations in the basic core promoter (BCP) and its adjacent precore (preC) region in HBV genome are common in chronic hepatitis B patients. However, the patterns of mutation combinations in these two regions during chronic infection are less understood. This study focused on single base mutations in BCP and preC region and the multi-mutation patterns observed in chronic HBV infection patients.

Methods

Total 192 blood samples of chronic HBV infection patients were included. Direct PCR sequencing on the target region of HBV genome was successfully conducted in 157 samples. The rest 35 samples were analyzed by clone sequencing. Only the nucleotide substitutions with their frequencies no less than 10% were included in multi-mutation analysis with the exception for the polymorphic sites between genotypes B and C.

Results

Five high frequency mutations (≥10%) were found in BCP and preC region. Thirteen types of multi-mutations in one fragment were observed, among which 3 types were common combinations (≥5%). The top three multi-mutations were A1762T/G1764A (36%), A1762T/G1764A/G1896A (11%) and T1753(A/C)/A1762T/G1764A/G1896A (8%). Patients with multi-mutations in viral genomes (≥3) were more likely to have liver cirrhosis or hepatocellular carcinoma (OR = 3.1, 95% CI: 1.6-6.0, P = 0.001). G1896A mutation seemed to be involved in liver disease progression independent of the patient age (OR = 3.6, 95% CI: 1.5-8.6; P = 0.004). In addition, patients with more viral mutations detected (≥3) were more likely to be HBeAg negative (OR = 2.7, 95% CI: 1.1-6.4; P = 0.027). Moreover, G1776A mutation was shown to contribute to HBeAg negativity in our study (OR = 8.6, 95% CI: 1.2-44.9; P = 0.01).

Conclusions

Patients with advanced liver diseases and with HBeAg negativity more likely have multi-mutations in HBV genomes but with different mutation combination patterns. G1896A mutation appears to be independent of infection history.

Nucleotide changes related to hepatocellular carcinoma in the enhancer 1/x-promoter of hepatitis B virus subgenotype C2 in cirrhotic patients

Hepatocellular carcinoma (HCC) is widely known to develop more frequently in cirrhotic patients with a high expression of Hepatitis B virus X protein (HBx), which is controlled by the enhancer 1 (Enh1)/X-promoter. To examine the effect of the mutations in the Enh1/X-promoter region in hepatitis B virus (HBV) genomes on the development of HCC, we investigated the differences in HBV isolated from cirrhotic patients with or without HCC along with the promoter activities of certain specific mutations within the Enh1/X-promoter. We examined 160 hepatitis B surface antigen (HBsAg)-positive cirrhotic patients (80 HCC patients, 80 non-HCC patients) by evaluating the biochemical, virological, and molecular characteristics. We evaluated the functional differences in certain specific mutations within the Enh1/X-promoter. The isolated sequences included all of the subgenotypes C2. The sites that showed higher mutation rates in the HCC group were G1053A and G1229A, which were found to be independent risk factors through multiple logistic analysis (P < 0.05). Their promoter activities were elevated 2.38- and 4.68-fold, respectively, over that of the wild type in the HepG2 cells. Similarly, both the mRNA and protein levels of HBx in these two mutants were much higher than that in wild type-transfected HepG2 cells. Mutated nucleotides of the Enh1/X-promoter, especially G1053A and G1229A mutations in the HBV subgenotype C2 of patients with cirrhosis, can be risk factors for hepatocarcinogenesis, and this might be due to an increase in the HBx levels through the transactivation of the Enh1/X-promoter.

A case-control study on sequence variations in the enhancer II/core promoter/precore and X genes of hepatitis B virus in patients with hepatocellular carcinoma

PURPOSE

To evaluate the sequence variations in the enhancer II (EnhII)/basal core promotor (BCP)/precore (PC) and X genes of hepatitis B virus (HBV) in Thai patients with hepatocellular carcinoma (HCC) by conducting a cross-sectional case-control study.

METHODS

As much as 60 patients with HCC and 60 patients without HCC, who were matched for sex, age, hepatitis B e antigen (HBeAg) status, and HBV genotype, were included. Viral mutations in the EnhII/BCP/PC and X regions were characterized by direct sequencing in serum samples.

RESULTS

The prevalence of T1753C/A, A1762T/G1764A and G1899A mutations were significantly higher in the HCC group compared to the non-HCC group (43.3 vs. 23.3%, P = 0.02; 88.3 vs. 53.0%, P < 0.001; and 35.0 vs. 8.3%, P = 0.001, respectively). No significant difference between groups was found with respect to G1613A, C1653T, C1766T/T1768A, A1846T/C, T1858C, and G1896A mutations. By multiple logistic regression analysis, the presence of cirrhosis, A1762T/G1764A and G1899A mutations were independently associated with the risk of HCC.

CONCLUSION

These data suggested that A1762T/G1764A and G1899A mutations were associated with the development of HCC in Thai patients.

HBV mutations in untreated HIV-HBV co-infection using genomic length sequencing

HIV infection has a significant impact on the natural progression of hepatitis B virus (HBV) related liver disease. In HIV-HBV co-infected patients, little is known about mutations in the HBV genome, which can influence severity of liver disease. The aim of this study was to characterize and to determine the frequency of known clinically significant mutations in the HBV genomes from HIV-HBV co-infected patients and from HBV mono-infected patients. To accomplish this, genomic length HBV sequencing was performed in highly-active anti-retroviral therapy (HAART)-naïve HIV-HBV co-infected patients (n=74) and in anti-HBV therapy-naïve HBV mono-infected patients (n=55). The frequency of HBV mutations differed between the co-infected and mono-infected patients when comparing patients with the same genotype. BCP mutations A1762T and G1764A were significantly more frequent in HBV genotype C mono-infection and the -1G frameshift was significantly more frequent in co-infection and was only observed in HBV genotype A co-infection. PreS2 deletions were observed more frequently in the setting of co-infection. Further work is needed to determine if these mutational patterns influence the differences in liver disease progression in HIV-HBV co-infected and HBV mono-infected patients.

T1653 mutation in the enhancer II region of the hepatitis B virus genome in southern African Blacks with hepatocellular carcinoma

BACKGROUND

An increased incidence of C-to-T1653 transversion (T1653) in the enhancer II region of the core promoter of hepatitis B virus has been reported in Japanese and Chinese patients with hepatocellular carcinoma infected with genotypes B or C of the virus, but little information is available in patients infected with other genotypes.

AIM

To document the prevalence of T1653 in Black Africans with hepatocellular carcinoma, in whom genotype A is the dominant genotype and subgenotype A1 the dominant subgenotype, and to correlate its presence with other core promoter mutations previously described in association with T1653.

METHODS

The presence of the mutations was determined in 84 patients with hepatitis B virus-induced hepatocellular carcinoma and 50 matched asymptomatic carriers of the virus by extracting viral DNA from serum, amplification by polymerase chain reaction assay, and nucleotide sequencing.

RESULTS

T1653 was not found significantly more often in the cancer patients with genotype A and subgenotype A1 than in the controls. An association was found not only between T1653 and T1762, A1764 and dual T1762/A1764 in the patients with hepatocellular carcinoma, but also in the asymptomatic carriers.

CONCLUSION

T1653 mutation of hepatitis B virus does not occur more often in Black African patients with hepatocellular carcinoma with genotype A and subgenotype A1 than in asymptomatic carriers of the virus. No correlation specific to hepatocellular carcinoma was found between T1653 and other core promoter mutations in these patients. The presence of the T1653 mutation did not influence the e antigen status of the patients.

Chronic hepatitis B: whom to treat and for how long? Propositions, challenges, and future directions

Recent guidelines of the American Association for the Study of Liver Diseases, the European Association for the Study of the Liver, and the Asian Pacific Association for the Study of the Liver 2008 update of the "Asian-Pacific consensus statement on the management of chronic hepatitis B" offer comprehensive recommendations for the general management of chronic hepatitis B (CHB). These recommendations highlight preferred approaches to the prevention, diagnosis, and treatment of CHB. Nonetheless, the results of recent studies have led to an improved understanding of the disease and a belief that current recommendations on specific therapeutic considerations, including CHB treatment initiation and cessation criteria, particularly in patient populations with special circumstances, can be improved. Twelve experts from the Asia-Pacific region formed the Asia-Pacific Panel Recommendations for the Optimal Management of Chronic Hepatitis B (APPROACH) Working Group to review, challenge, and assess relevant new data and inform future updates of CHB treatment guidelines. The significance of and controversy about reported findings were discussed and debated in an expert meeting of the Working Group in Beijing, China, in November 2008. This review paper attempts to identify areas requiring improved CHB management and provide suggestions for future guideline updates, with special emphasis on treatment initiation and duration.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

X gene mutations in hepatitis B patients with cirrhosis, with and without hepatocellular carcinoma

Specific mutations in the hepatitis B virus (HBV) genome have been reported to be associated with the development of hepatocellular carcinoma (HCC). The goal of this study was to determine whether mutations in the HBV X gene are associated with the development of HCC in hepatitis B patients with cirrhosis. Forty-two patients infected with HBV genotype C2 with cirrhosis and HCC were compared with 46 patients with cirrhosis but without HCC. X gene mutations were determined by direct sequencing in all patients. The HCC and non-HCC groups were similar with respect to clinical characteristics, and the presence of T1762/A1764, T1653, and V1753 mutations was not significantly different between the two groups (P = 0.068, P = 0.097, P = 0.442, respectively). Only the B1499 mutation was associated significantly with HCC (P = 0.015) (odds ratio: 3.42, 95% CI: 1.24-9.48). In hepatitis Be antigen (HBeAg)-positive patients, advanced age was associated significantly with HCC (P = 0.038), whereas in HBeAg-negative patients, the B1499 mutation was associated more significantly with HCC (P = 0.01). Patients in the B1499 mutation group exhibited significantly higher AST and ALT levels compared with patients infected the wild-type virus. In conclusion, B1499 is a novel mutation associated with HCC in Korean patients with cirrhosis infected with HBV genotype C2.

Subgenotypes of hepatitis B virus genotype D (D1, D2, D3 and D5) in India: differential pattern of mutations, liver injury and occult HBV infection

Hepatitis B genotype D (HBV/D) is the most widespread genotype and exists as at least five subgenotypes (HBV/D1-D5). However, little is known about the association of virological characteristics with clinical differences among HBV/D subgenotypes. To investigate the virological characteristics of these subgenotypes and their clinical implications, we selected a cohort of 109 genotype D infected individuals from the state of West Bengal, India, including 68 HBsAg positive patients and 41 with occult HBV infection. Among the HBsAg positive subjects 28 had chronic hepatitis B virus infection, 40 were asymptomatic carriers based on clinical examination, liver function test and ultrasonograph results. Overall, HBV/D1 was found in 17%, HBV/D2 in 29%, HBV/D3 in 34% and HBV/D5 in 20% of the cases. HBV/D1 was significantly associated with chronic liver disease (P = 0.01), and in this subgenotype A1896 (PreC mutations) were most common. Although BCP mutations (A/C1753 and T1762/A1764) were found to be frequently associated with HBV/D2 (33% and 33%) and D5 (47% and 59%), no apparent clinical correlation was observed. On the other hand, occult HBV infection was significantly associated with HBV/D3 infection, along with low level of BCP and PreC mutations and several non-synonymous substitutions in the catalytic reverse transcriptase (RT) domain of polymerase gene. Similar nucleotide substitutions in the surface (S) gene region were observed from both northern and eastern Indian HBV/D3 isolates. In conclusion, HBV/D subgenotypes differ in their mutational patterns in the S, polymerase and the BCP/PreC regions that may influence their clinical outcomes.

Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia

AIM: To identify the distribution of hepatitis B virus (HBV) subgenotype and basal core promoter (BCP) mutations among patients with HBV-associated liver disease in Indonesia.

METHODS: Patients with chronic hepatitis (CH, n = 61), liver cirrhosis (LC, n = 62), and hepatocellular carcinoma (HCC, n = 48) were included in this study. HBV subgenotype was identified based on S or preS gene sequence, and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.

RESULTS: HBV genotype B (subgenotypes B2, B3, B4, B5 and B7) the major genotype in the samples, accounted for 75.4%, 71.0% and 75.0% of CH, LC and HCC patients, respectively, while the genotype C (subgenotypes C1, C2 and C3) was detected in 24.6%, 29.0%, and 25.0% of CH, LC, and HCC patients, respectively. Subgenotypes B3 (84.9%) and C1 (82.2%) were the main subgenotype in HBV genotype B and C, respectively. Serotype adw2 (84.9%) and adrq+ (89.4%) were the most prevalent in HBV genotype B and C, respectively. Double mutation (A1762T/G1764A) in the BCP was significantly higher in LC (59.7%) and HCC (54.2%) than in CH (19.7%), suggesting that this mutation was associated with severity of liver disease. The T1753V was also higher in LC (46.8%), but lower in HCC (22.9%) and CH (18.0%), suggesting that this mutation may be an indicator of cirrhosis.

CONCLUSION: HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia. Mutations in BCP, such as A1762T/G1764A and T1753V, might have an association with manifestations of liver disease.

Worldwide genetic diversity of HBV genotypes and risk of hepatocellular carcinoma

Hepatitis B viruses (HBV) are responsible for over 50% of the worldwide attributable risk of hepatocellular carcinoma (HCC) and this figure increases even further in regions of high endemicity. Systematic sequencing of HBV genomes has identified that this common virus existed as eight distinct genotypes (denoted A-H), each regrouping variants with less than 8% divergence in their DNA sequence. These genotypes differ by their geographic distribution in populations around the globe. There is evidence that HBV genotypes also differ by their pathogenic properties, including their risk of persistence as chronic infection and their capacity to induce precursor disease or cancer. On the other hand, HBV genes may undergo mutations that become selected during the course of chronic infection and progressive liver disease. The most significant of these mutations in the context of HCC are those occurring in the pre-core (Pre-C) and basal core promoter (BCP) regions. These mutations may upregulate HBV expression and increase its virulence. These mutations may occur in all HBV genotypes but are more common in genotypes associated with more severe disease and cancer, in particular genotype C. Understanding the molecular basis of pathological variations between HBV variants is critical for prediction of disease severity. It will also be important to determine whether differences among genotypes may have an impact on the long-term protective efficacy of universal HBV vaccination.

Low pretreatment serum HBsAg level and viral mutations as predictors of response to PEG-interferon alpha-2b therapy in chronic hepatitis B

BACKGROUND

Viral genomic mutations have become increasingly recognized as being associated with the outcome of chronic HBV infection. However, the role of viral mutations as a predictor of response to pegylated-interferon (PEG-IFN) therapy has so far remained unclear.

STUDY DESIGN

Viral mutations in the enhancer II/basal core promoter (BCP)/precore and the pre-S regions were characterized by direct sequencing in pretreatment serum samples of 50 patients with chronic hepatitis B (33 HBeAg-positive and 17 HBeAg-negative), who were treated for 48 weeks with PEG-IFN alpha-2b.

RESULTS

Sustained virological response at 48 weeks post treatment, defined as HBeAg seroconversion and HBV DNA<2000IU/mL for HBeAg-positive patients, and HBV DNA<200IU/mL for HBeAg-negative patients, was achieved in 12 (36.4%) and 6 (35.3%) of HBeAg-positive and HBeAg-negative patients, respectively. Response to PEG-IFN therapy correlated to low pretreatment HBsAg level but did not correlate with HBV genotype, pretreatment alanine transaminase and HBV DNA levels. In HBeAg-positive hepatitis, PEG-IFN response correlated with the appearance of double BCP mutations (A1762T/G1764A) at baseline (P=0.041). In the HBeAg-negative group, response to PEG-IFN therapy was associated with the presence of pre-S mutation/deletions (P=0.028). Multivariate analysis identified low pretreatment HBsAg level as an independent factor associated with SVR in both groups.

CONCLUSIONS

Pretreatment quantitative HBsAg determination is useful for predicting response to PEG-IFN therapy. The presence of double BCP and pre-S mutation/deletions at entry may be associated with a high rate of antiviral response in HBeAg-positive and HBeAg-negative hepatitis, respectively.

The duration of lamivudine therapy for chronic hepatitis B: cessation vs. continuation of treatment after HBeAg seroconversion

OBJECTIVES

The aim of this study was to compare the virological and biochemical relapse rates in Asian chronic hepatitis B patients with lamivudine-induced hepatitis B e antigen (HBeAg) seroconversion, between those who stopped therapy after HBeAg seroconversion and those who continued to receive lamivudine.

METHODS

All patients with lamivudine-induced HBeAg seroconversion were included. Patients who stopped lamivudine after HBeAg seroconversion (n=22) were compared with 79 patients who continued to receive lamivudine (n=79). Demographic, virological, and biochemical parameters were recorded at baseline, and throughout the duration of follow-up.

RESULTS

In patients who stopped lamivudine, the median follow-up after stopping lamivudine was 20 months. Of these patients, 14 (64%) had virological rebound, with a cumulative incidence of 82% at 4 years. There was no significant difference in number of flares between patients with normal alanine aminotransferase (ALT) and undetectable hepatitis B virus (HBV) DNA at the time of stopping lamivudine compared with that in patients with either abnormal ALT, detectable HBV DNA, or both (P=0.73). The cumulative incidence of HBeAg seroreversion and ALT flares at 5 years after stopping lamivudine was 9 and 44%, respectively. Of the 79 patients who continued with lamivudine, 62 (78%) had undetectable HBV DNA at the time of last follow-up, whereas no patients had undetectable HBV DNA after stopping lamivudine (P<0.001). The cumulative incidence of ALT flares at 5 years was 16% (P<0.001 compared with those who stopped taking lamivudine). After a median treatment duration of 79 months, lamivudine-resistant mutations occurred in eight patients (10%).

CONCLUSIONS

In Asian HBeAg-positive patients, continuing with lamivudine after achieving HBeAg seroconversion was associated with a higher proportion of undetectable HBV DNA and a lower number of ALT flares, when compared with those with cessation of lamivudine. In patients who achieved HBeAg seroconversion with lamivudine, the resistance rate was not high when treatment was continued after HBeAg seroconversion.

Associations between hepatitis B virus mutations and the risk of hepatocellular carcinoma: a meta-analysis

Background

The association between hepatitis B virus (HBV) mutations and hepatocarcinogenesis remains controversial because of conflicting data in the literature. We conducted a meta-analysis of case–control and cohort studies to examine HBV PreS, enhancer II (EnhII), basal core promoter (BCP), and precore mutations in relation to the risk of hepatocellular carcinoma (HCC).

Methods

We searched databases for studies of these associations that were published in English or Chinese up to August 31, 2008. HBV mutation–specific odds ratios and relative risks were pooled by use of a random-effects model and stratified by potential confounders. All statistical tests were two-sided.

Results

Of the 43 studies included in this meta-analysis, 40 used a case–control design. The 43 studies evaluated a total of 11 582 HBV-infected participants, of whom 2801 had HCC. Statistically significant summary odds ratios of HCC were obtained for any PreS mutation (3.77, 95% confidence interval [CI] = 2.57 to 5.52), C1653T in EnhII (2.76, 95% CI = 2.09 to 3.64), T1753V (2.35, 95% CI = 1.63 to 3.40), and A1762T/G1764A in BCP (3.79, 95% CI = 2.71 to 5.29). PreS mutations were more strongly associated with an increased risk of HCC in subjects who were infected with HBV genotype C than in those who were infected with HBV genotype B, whereas the opposite was true for A1762T/G1764A. C1653T, T1753V, and A1762T/G1764A were more strongly associated with an increased risk of HCC in hepatitis B e antigen (HBeAg)–positive subjects than in HBeAg-negative subjects. PreS mutations, C1653T, T1753V, and A1762T/G1764A accumulated during the progression of chronic HBV infection from the asymptomatic carrier state to HCC (P_trend < .001 for each mutation). PreS mutations, C1653T, C1653T + T1753V, and A1762T/G1764A-based combinations of mutations had specificities greater than 80% for the prediction of HCC. The precore mutations G1896A and C1858T were not associated with the risk of HCC, regardless of HBeAg status and HBV genotype.

Conclusions

HBV PreS mutations, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. These mutations alone and in combination may be predictive for hepatocarcinogenesis.

Associations between hepatitis B virus mutations and the risk of hepatocellular carcinoma: a meta-analysis

BACKGROUND

The association between hepatitis B virus (HBV) mutations and hepatocarcinogenesis remains controversial because of conflicting data in the literature. We conducted a meta-analysis of case-control and cohort studies to examine HBV PreS, enhancer II (EnhII), basal core promoter (BCP), and precore mutations in relation to the risk of hepatocellular carcinoma (HCC).

METHODS

We searched databases for studies of these associations that were published in English or Chinese up to August 31, 2008. HBV mutation-specific odds ratios and relative risks were pooled by use of a random-effects model and stratified by potential confounders. All statistical tests were two-sided.

RESULTS

Of the 43 studies included in this meta-analysis, 40 used a case-control design. The 43 studies evaluated a total of 11 582 HBV-infected participants, of whom 2801 had HCC. Statistically significant summary odds ratios of HCC were obtained for any PreS mutation (3.77, 95% confidence interval [CI] = 2.57 to 5.52), C1653T in EnhII (2.76, 95% CI = 2.09 to 3.64), T1753V (2.35, 95% CI = 1.63 to 3.40), and A1762T/G1764A in BCP (3.79, 95% CI = 2.71 to 5.29). PreS mutations were more strongly associated with an increased risk of HCC in subjects who were infected with HBV genotype C than in those who were infected with HBV genotype B, whereas the opposite was true for A1762T/G1764A. C1653T, T1753V, and A1762T/G1764A were more strongly associated with an increased risk of HCC in hepatitis B e antigen (HBeAg)-positive subjects than in HBeAg-negative subjects. PreS mutations, C1653T, T1753V, and A1762T/G1764A accumulated during the progression of chronic HBV infection from the asymptomatic carrier state to HCC (P(trend) < .001 for each mutation). PreS mutations, C1653T, C1653T + T1753V, and A1762T/G1764A-based combinations of mutations had specificities greater than 80% for the prediction of HCC. The precore mutations G1896A and C1858T were not associated with the risk of HCC, regardless of HBeAg status and HBV genotype.

CONCLUSIONS

HBV PreS mutations, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. These mutations alone and in combination may be predictive for hepatocarcinogenesis.

A new isolate of hepatitis B virus from the Philippines possibly representing a new subgenotype C6

Hepatitis B virus (HBV) genotypes and subgenotypes show distinct geographical prevalence. A genotyping analysis of 28 samples from asymptomatic HBV carriers from the Philippines gave a distribution of HBV genotypes as expected from a previous study: 54% B (15/28), C5 18% (5/28), 14% D (4/28), 7% A1 (2/28). In addition, 7% (2/28) of the samples showed a double infection with genotypes B and D. One of the isolates sequenced completely, ph105, did not group into one of the known subgenotypes after phylogenetic analysis. Ph105 formed a separate clade in genotype C. With a genome length of 3,215 nt. and a serological subtype adr, ph105 exhibited the main features of most genotype C strains. However, ph105 differed by 4.1-7.2% from HBV subgenotypes C1 to C5 when comparing the nucleotide sequence of whole genomes. With only 4.1% difference ph105 was most closely related to subgenotype C2. SimPlot analysis gave no indication for recombination with known HBV genotypes. Ph105 fulfils all criteria for a new subgenotype C6.

Specific mutations in the enhancer II/core promoter/precore regions of hepatitis B virus subgenotype C2 in Korean patients with hepatocellular carcinoma

Recently, hepatitis B virus (HBV) genotypes and mutations have been reported to be related to hepatocellular carcinoma (HCC). This cross-sectional case-control study examined the relationship between HCC and mutations in the enhancer II/core promoter and precore regions of HBV by comparing 135 Korean HCC patients infected with HBV genotype C2 (HBV/C2; HCC group) with 135 age-, sex-, and hepatitis B e antigen (HBeAg) status-matched patients without HCC (non- HCC group). Age and sex were also matched between HBeAg-positive and -negative patients. The prevalence of T1653, A1689, V1753, T1762/A1764, T1846, A1850, C1858, and A1896 mutations was evaluated in this population. The prevalence of the T1653 mutation in the box alpha region, the T1689 [corrected] mutation in between the box alpha and beta regions, and the T1762/A1764 mutations in the basal core promoter region was significantly higher in the HCC group compared to the non-HCC group (8.9% vs. 2.2%, P = 0.017; 19.3% vs. 4.4%, P < 0.001; and 60.7% vs. 22.2%; P < 0.001). Among HBeAg-negative patients, the frequency of the T1653 mutation was higher in the HCC group. Regardless of HBeAg status, the prevalence of the T1689, [corrected] and T1762/A1764 mutations was higher in the HCC group than in the non-HCC group. However, no association was observed between mutations in the precore region and HCC. Upon multivariate analysis, the presence of the T1653, T1689, [corrected] and T1762/A1764 mutations was an independent predictive factor for HCC. The addition of the T1653 or T1689 [corrected] mutation to T1762/A1764 increased the risk of HCC. In conclusion, the T1653, T1689, [corrected] and/or T1762/A1764 mutations were associated with the development of HCC in Korean patients infected with HBV/C2.

[Hepatitis B virus genetic diversity and mutant]

Hepatitis B virus (HBV) is a partially double stranded DNA virus with genetic diversity represented by eight genotypes (A to H). Natural course and response to treatment could be affected by HBV genotypes. HBV shows high rates of turn over in the absence of proof-reading ability. As a result, large amounts of quasispecies are produced naturally or antiviral-associated. HBV consists of four open reading frames, namely preS/S gene, precore/core gene, polymerase gene, and X gene. Mutations on preS gene can result in undetectable HBsAg even in case that HBV is replicating. Surface gene mutation leads to decreased binding affinity to anti-HBs, which is associated with a vaccine escape mutant. Precore mutation abolishes HBeAg whereas mutations on basal core promoter gene down-regulate the HBeAg production. Mutations on basal core promoter are associated with increased HBV replication and high incidence of progressive liver diseases such as liver cirrhosis and hepatocellular carcinoma. Mutations on polymerase genes are often induced by antiviral therapy. Emergence of antiviral-resistant mutation is the major cause of treatment failure. Furthermore, existence of prior antiviral-resistant mutations limits the options of subsequent antiviral agents. Therefore, judicious use of antivirals and selection of the most potent drug with the lowest resistance rate are of the utmost importance for the prevention of antiviral-associated mutants. Detailed knowledge and understanding of HBV genetic diversity and mutant would be critical to establish strategies for the diagnosis and management of HBV infection.

Direct cytopathic effects of particular hepatitis B virus genotypes in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mouse with human hepatocytes

BACKGROUND & AIMS

Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes.

METHODS

Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera.

RESULTS

Histologic analysis of mice infected with HBV/C2 for 22-25 weeks showed abundant ground-glass appearance of the hepatocytes and fibrosis in the humanized part of the murine liver owing to the activation of hepatic stellate cells mediated by oxidative stress through transforming growth factor-beta1 signaling, whereas neither was observed with HBV/A2 and B1. The HBV-DNA level in sera was the highest in mice infected with HBV/C2 compared with those with HBV/A2 and HBV/B1 (10(9), 10(7), and 10(4) log copies/mL, respectively, P < .05) during 6-8 weeks postinoculation. HB core-related antigen excretion had a similar trend among the genotypes, whereas secretion of HB surface antigen was more pronounced for HBV/A2 followed by HBV/C2 and much less for HBV/B1. Introduction of precore stop-codon mutation in the HBV/B1 caused a significant increase in viral replication, antigen expression, and a histopathologic picture similar to HBV/C2.

CONCLUSIONS

By using a humanized in vivo model, we show that different HBV genotypes and even particular mutations resulted in different virologic and histopathologic outcomes of infection, indicating that particular genetic variants of HBV may be directly cytopathic in immunosuppressive conditions.

Hepatitis B virus pre-S deletion mutations are a risk factor for hepatocellular carcinoma: a matched nested case-control study

A matched nested case-control study of 33 paired cases and controls was conducted, based on a study cohort in Long An county, Guangxi, China, to determine whether infection with hepatitis B virus (HBV) with pre-S deletions is independently associated with the development of hepatocellular carcinoma (HCC), without the confounding effects of basal core promoter (BCP) double mutations. The prevalence of pre-S deletions was significantly higher in HCC (45.5 %, 15 of 33) than the controls (18.2 %, 6 of 33) (P<0.01), under the control of the influence of BCP double mutations. Most of the pre-S deletions occurred in, or involved, the 5' half of the pre-S2 region and the difference between HCC (93.3 %, 14 of 15) and controls (66.7 %, four of six) was significant for this region (P=0.015). There was no significant difference in pre-S deletions between the BCP mutant group and BCP wild-type group (P>0.05), nor was the prevalence of pre-S deletions significantly different between genotypes B and C (P>0.1). These results suggest that pre-S deletions constitute an independent risk factor for HCC and their emergence and effect are independent of BCP mutations. The 5' terminus of pre-S2 is the favoured site for the deletion mutations, especially in HCC cases. Further prospective studies are required to confirm the role of these mutations in the development of HCC.

Frequency and distribution of hepatitis B virus genotypes among eastern Indian voluntary blood donors: Association with precore and basal core promoter mutations

AIM

To screen hepatitis B virus (HBV) genotypes and associated basal core promoter (BCP; T1762/A1764) and precore (PreC; A1896) mutations among the HBV surface antigen (HBsAg) positive voluntary blood donors in eastern India.

METHODS

HBV genotypes, BCP and PreC mutations of 141 HBsAg positive voluntary blood donors were determined by the restriction fragment length polymorphism (RFLP) method and a phylogenetic tree was constructed from surface (S) gene region sequences of representative HBsAg positive donors to confirm the results.

RESULTS

HBV/D was the most predominant (79, 56.0%) genotype followed by HBV/C (33, 23.4%) and HBV/A (29, 20.6%). HBV/C infected blood donors are mostly young (18-25 years). The occurrence of BCP mutation was found to be significantly higher in HBV/C (24, 72.7%) than in HBV/A (7, 24.1%, P < 0.001) and HBV/D (17, 21.5%, P < 0.001), whereas PreC mutation was more frequent in HBV/D (28, 35.4%) than in HBV/C (9, 27.3%). However, the simultaneous presence of BCP and PreC mutations was more common in HBV/C (8/33, 24.2%), followed by HBV/D (6/79, 7.6%).

CONCLUSION

In addition to HBV/D and HBV/A, a significant proportion of HBV/C (23.4%) was also present among the voluntary blood donors from eastern India, most frequently in the 18-25 year age group. BCP mutation was more common in HBV/C infected donors.

Combined mutations in pre-s/surface and core promoter/precore regions of hepatitis B virus increase the risk of hepatocellular carcinoma: a case-control study

BACKGROUND

We sought to investigate the role of sequence variations in pre-S/surface and basal core promoter (BCP)/precore regions of the hepatitis B virus (HBV) in hepatocellular carcinoma (HCC).

METHODS

The direct sequencing in pre-S/surface and BCP/precore regions of HBV was determined for 80 patients with HCC and 160 control patients with HBV infection.

RESULTS

Compared with control patients, patients with HCC had higher frequencies of pre-S deletions and amino acid substitutions at codon 4, 7, and 81 in pre-S1 genes; at the start codon in pre-S2 genes; and at codon 68 in surface genes. Patients also had a lower frequency of amino acid substitution at codon 2 in pre-S2 genes, compared with control patients. In BCP/precore regions, patients with HCC had higher frequencies of C or G1753, A1762/T1764, T1846, and A1899. Multivariate analysis showed that pre-S deletions, I68T surface gene, T1762/A1764, and A1899 were independent factors associated with the development of HCC. The HBV strain with a complex mutation pattern rather than a single mutation was associated with HCC, and the HCC risks increased for patients having these factors in combination.

CONCLUSIONS

Pre-S deletions, I68T in surface gene, T1762/A1764, and A1899 were independent risk factors for HCC. Combination of these viral mutations appeared to increase the risk of HCC.

Sequential accumulation of the mutations in core promoter of hepatitis B virus is associated with the development of hepatocellular carcinoma in Qidong, China

BACKGROUND/AIMS

To investigate the mutations in hepatitis B virus (HBV) that might be related to hepatocellular carcinoma (HCC) in the high-risk area Qidong, China.

METHODS

DNA sequences of HBV basal core promoter (BCP) and the overlapping X gene were determined in 58 HCC and 71 chronic hepatitis (CH) patients. In addition, a consecutive series of plasma samples from 15 HCC cases were employed to compare the CP/X sequences before and after the occurrence of HCC.

RESULTS

T1762/A1764 double mutation was frequently found in Qidong patients, regardless of clinical status (65.5% in HCC and 73.2% in CH, P>0.05). Unexpectedly, the adjacent T1766/A1768 mutation significantly increased the risk of HCC (P<0.05). Moreover, the prevalence of triple mutations in BCP was significantly higher in patients with HCC than those with CH (P<0.05). The longitudinal study demonstrated that the mutations in BCP were gradually accumulated during the development of HCC. Colony formation assay showed while A1764 mutation alone did not alter the colony-inhibitory activity of HBx, double or triple mutations largely abrogated this effect.

CONCLUSIONS

The complex mutation involving T1766/A1768 was closely related to HCC. The enhanced risk of HCC caused by BCP variants could be attributable partially to the aberrant activity of HBx.

HBV A1762T, G1764A mutations are a valuable biomarker for identifying a subset of male HBsAg carriers at extremely high risk of hepatocellular carcinoma: a prospective study

OBJECTIVES

Surveillance of hepatocellular carcinoma (HCC) can detect small tumors for resection but at a huge cost of health resources. The challenge is to reduce the surveillance population. We reported that 96% of HCC patients but only 24% of controls were infected with the hepatitis B virus (HBV) with A(1762)T, G(1764)A mutations in Guangxi, China. It is likely to be extremely beneficial in terms of cost and resources if a significant number of tumors can be detected early by screening this selected population. Our aim is to test this hypothesis.

METHODS

A cohort of 2,258 hepatitis B surface antigen-positive subjects aged 30-55 yr was recruited in Guangxi. Following evaluation of virological parameters at baseline, HCC is diagnosed by 6-monthly measurements of serum alpha-fetoprotein levels and ultrasonographic examinations.

RESULTS

Sixty-one cases of HCC were diagnosed after 36 months of follow-up. The HCC rate was higher in the mutant than wild-type group (P < 0.001, rate ratio [RR] 6.23, 95% confidence interval [CI] 2.83-13.68). The HCC rate in the male mutant group was higher than that in the male wild-type group (P < 0.001, RR 11.54, 95% CI 3.58-37.24). Specifically, 93.3% of male cases are infected with the mutant. Multivariate analyses showed that in men, increasing age and A(1762)T, G(1764)A double mutations are independently associated with developing HCC.

CONCLUSIONS

HBV A(1762)T, G(1764)A mutations constitute a valuable biomarker to identify a subset of male HBsAg carriers aged >30 yr at extremely high risk of HCC in Guangxi, and likely elsewhere.

Hepatitis B virus mutations associated with in situ expression of hepatitis B core antigen, viral load and prognosis in chronic hepatitis B patients

In this retrospective study, we investigated the prevalence and significance of mutations in part of the hepatitis B virus (HBV) x gene, and tried to clarify their relationship with clinicopathological or histopathological characteristics and prognosis in patients with chronic hepatitis B (CHB). A total of 83 consecutive CHB patients (1986-1994) were chosen for the present study. Sequence analysis was performed using polymerase chain reaction (PCR) and the direct sequencing method. The histological activity index was described using Scheuer scores. Two-step immunohistochemical staining showed the expression of viral antigens in situ. Tissue HBV DNA levels were determined by fluorescence quantitative real-time PCR. For the prognostic study, all the patients were followed up using clinical and laboratory data. Mutation at nt1726-1730 correlated significantly with decreased expression of HBcAg in situ (P = 0.006) and with lower HBV DNA levels in the liver (P = 0.004). In particular, the CTGAC mutation showed the strongest decrease of the viral load (P = 0.007). By contrast, nt1762/1764 mutation correlated with increased HBcAg (P = 0.005) and higher HBV DNA levels (P = 0.006). The mutants with the wild-type of nt1726-1730 or nt1762/1764 mutation were more prevalent in hepatocellular carcinoma (HCC) patients than in CHB patients. Although the mutations did not correlate with cirrhosis, the frequency of nt1762/1764 mutation in patients with hepatocarcinogenesis was significantly higher than in those without hepatocarcinogenesis (P = 0.011). Mutations at nt1726-1730 and nt1762/1764 are associated with in situ expression of HBcAg and viral load. Higher HBV DNA levels in the liver may be associated with hepatocarcinogenesis. Mutation at nt1762/1764 remarkably increases the risk of hepatocarcinogenesis.

Recurrence of hepatitis B-related hepatocellular carcinoma is associated with high viral load at the time of resection

BACKGROUND/AIMS

To identify the risk factors for recurrence of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after resection.

METHODS

Seventy-two patients who underwent liver resection for HBV-related HCC were recruited. Demographic, biochemical, tumor, and viral factors at the time of resection were evaluated by univariate and multivariate analyses to identify risk factors associated with recurrence after resection.

RESULTS

The median follow-up period was 18.9 months and the median age was 53 yr, with male-to-female ratio of 59:13. Age >60 yr, tumor size >5 cm, poorly differentiated tumor, lymphovascular permeation, the presence of microsatellite lesions, alpha-fetoprotein (AFP) level >1,000 ng/mL and HBV viral load >2,000 IU/mL (4 log(10) copies/mL) at the time of tumor resection, HBV genotype C, core promoter mutations, and patients with no antiviral treatment after tumor resection were associated with increased cumulative risk of HCC recurrence. By multivariate analysis, HBV viral load >2,000 IU/mL (4 log(10) copies/mL) (P= 0.001, odds ratio [OR] 22.3), AFP >1,000 ng/mL (P= 0.02, OR 7.4), tumor size >5 cm (P= 0.02, OR 5.1), and age >60 yr (P= 0.01, OR 4) at the time of tumor resection remained to be the independent risk factors.

CONCLUSIONS

Viral load of >2,000 IU/mL (4 log(10) copies/mL) is the most important correctable risk factor for HCC recurrence after resection. Whether antiviral therapy in these patients can decrease tumor recurrence requires further investigations.

A complete genomic analysis of hepatitis B virus genotypes and mutations in HBeAg-negative chronic hepatitis B in China

We aimed to study the distribution of hepatitis B virus (HBV) genotypes/subgenotypes in different parts of China and their clinical impact on the severity of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. Residual serum samples from a cohort of HBeAg-negative chronic hepatitis B patients in Hong Kong, Shanghai and Beijing were studied. Complete HBV genomic sequencing was performed for phylogenetic tree analysis and determination of HBV mutations was carried out. Mutations associated with severe liver fibrosis (Ishak score 4 or more) were selected by computerized information gain criteria. Genotype B (all subgenotype Ba) HBV was present in 19 of 45 (42%), 12 of 31 (39%) and 5 of 25 (20%) patients in Hong Kong, Shanghai and Beijing, respectively (P = 0.16). Ninety-seven per cent of genotype C HBV in Shanghai and Beijing belonged to subgenotype Ce whereas 69% of genotype C patients in Hong Kong belonged to subgenotype Cs (P < 0.001). Patients infected by subgenotype Cs had the lowest serum albumin and highest alanine aminotransferase levels compared with subgenotype Ce and Ba. Patients infected by subgenotype Cs also had more severe histological necroinflammation than subgenotype Ce. Two HBV mutations were identified to associate with severe liver fibrosis (G2858C and C2289A) and one mutation was protective against severe liver fibrosis (T2201C). The T2201C mutation was found exclusively among patients (21 of 46 patients, 45%) infected by HBV subgenotype Ce. The clinical differences in HBeAg-negative chronic hepatitis B in China may be influenced by different distribution of subgenotype C HBV.

Virological and clinical implication of core promoter C1752/V1753 and T1764/G1766 mutations in hepatitis B virus genotype D infection in Mongolia

BACKGROUND AND AIM

The aim of the present study was to reveal virological and clinical features of hepatitis B virus (HBV) genotype D infection.

METHODS

One hundred and twenty-two Mongolian chronic liver disease (CLD) patients infected with HBV were subjected for serological HBV-markers screening and HBV-enzyme immunoassay (EIA) genotyping. Nucleotide sequences were analyzed for 48 HBV/D strains (23 isolated from hepatocellular carcinoma (HCC) and 25 from CLD patients).

RESULTS

Prevalence of hepatitis B e antigen (HBeAg) positivity was low (25.9%) in young patients (< or =30 years old) indicating early HBeAg seroclearance in HBV/D carriers. The T1764/G1766 double mutation was the most common basal core promoter (BCP) mutation (29.2%) and was frequent in HBeAg-negative patients (39.3%). Patients harboring T1764/G1766 mutants exhibited lower HBV-DNA and HBV core antigen (HBcAg) levels than those with wild-type BCP strains (P = 0.024, 0.049, respectively). C1752 and/or V (not T) 1753 mutation was significantly prevalent in HCC patients (HCC vs CLD; 52.2% vs 20%, P = 0.033). T1762/A1764 mutation was detected in 75.0% of HCC patients with high viral load (> or =5 log copies/mL). Precore stop codon mutation A1896 was detected in (70.8%) of HBV/D-infected patients.

CONCLUSIONS

In Mongolians infected with HBV/D, C1752 and/or V1753 mutation was associated with HCC.

High viral load and hepatitis B virus subgenotype ce are associated with increased risk of hepatocellular carcinoma

PURPOSE

We aimed to investigate the impact of hepatitis B virus (HBV) DNA and HBV genotypes/subgenotypes on the risk of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

A prospective cohort of patients infected with chronic HBV in a surveillance program for HCC since 1997 was studied. Ultrasound and alpha-fetoprotein evaluation were regularly performed to detect HCC. Risk factors for HCC and the relationship between HBV DNA and HBV genotypes were determined.

RESULTS

Among 1,006 patients with a median follow-up of 7.7 years, 86 patients (8.5%) developed HCC. With reference to the low HBV DNA stratum (log HBV DNA </= 4.5 copies/mL), the hazard ratio for HCC of the intermediate HBV DNA stratum (log HBV DNA > 4.5 to 6.5 copies/mL) was 1.62 (95% CI, 1.05 to 2.48; P = .027) and that of the high HBV DNA stratum (log HBV DNA > 6.5 copies/mL) was 2.73 (95% CI, 1.76 to 4.25; P < .001). Among patients with genotyping results, 330 patients had HBV genotype B and 439 patients had HBV genotype C (94 subgenotype Ce and 345 subgenotype Cs). With reference to HBV genotype B, HBV subgenotype Ce has the highest risk of HCC (hazard ratio = 2.75; 95% CI, 1.66 to 4.56; P < .0001) and HBV subgenotype Cs has intermediate risk (hazard ratio = 1.70; 95% CI, 1.09 to 2.64; P = .020). On multivariate analysis, HBV DNA, HBV genotypes, liver cirrhosis, male sex, older age, and lower serum albumin were independent risk factors of HCC.

CONCLUSION

High HBV DNA level and HBV genotype C, particularly subgenotype Ce, increased the risk of HCC in chronic hepatitis B.

Transmission of hepatitis B virus (HBV) genotypes among Japanese immigrants and natives in Bolivia

Hepatitis B virus genotypes are associated with transmission pattern, virological and clinical features and outcome of the chronic infection course. HBV genotypes other than Genotype F (HBV/F) are considered a reflection of human migration into South America. A total of 487 individuals in Bolivia, including Japanese immigrants (n=287) and natives (n=200), were screened for HBV serological markers. Overall 22/487 (4.5%) of the subjects were positive for HBsAg, 217/487 (44.5%) for anti-HBc and 162/487 (33.3%) for anti-HBs. Genotypes were determinable in 22 cases by EIA, followed by sequencing and phylogenetic analysis in 17 cases. HBV genotype distribution in Japanese and Bolivians was HBV/F (4 and 8); HBV/C (5 and 3); and HBV/B (1 and 1), respectively. Phylogenetic analyses of nine complete and eight partial (HBsAg/pre-core/core region) genomes, revealed that HBV/F strains cluster with previously reported regional strains, whereas HBV/B and HBV/C strains belonged to Asian subgenotype B2 (Ba) and C2 (Ce), respectively. Japanese immigrants might have introduced HBV/B and HBV/C to natives in Bolivia, conversely, exposed to the indigenous HBV/F. This report provides evidence of an inter-communities transmission of HBV revealed by its genotypes. Further study is required to investigate peculiarities of the genotypes in different ethnic groups in Bolivia.

Role of hepatitis B virus genotype mixture, subgenotypes C2 and B2 on hepatocellular carcinoma: compared with chronic hepatitis B and asymptomatic carrier state in the same area

The role of genotype mixture and subgenotypes remains controversial in determining the clinical outcome of chronic hepatitis B virus (HBV) infection. We aimed to determine their role on the development and the recurrence of hepatocellular carcinoma (HCC). HBV genotypes, serum viral load and hepatitis B e antigen (HBeAg) seroconversion were determined in 462 HCC patients, 234 chronic hepatitis patients and 425 asymptomatic carriers born in Eastern China. In the 462 HCC patients, 62 (13.4%), 337 (72.9%) and 49 (10.6%) had HBV subgenotype B2, C2 and genotype mixture, respectively. Genotype mixture in HCC patients and hepatitis patients was associated with higher viral load than HBV C2 (P = 0.012, P = 0.000) and more frequent than asymptomatic carriers (P = 0.005, P = 0.000). HBV C2 was more prevalent in HCC patients compared with controls. Proportion of HBV B2 in HCC patients decreased consecutively from <30 to 50-59 years group (P = 0.024). Age-related changes of HBeAg seroconversion were not consistent with serum viral load in HCC patients with HBV B2 and genotype mixture, quite in contrast to hepatitis patients. By multivariate regression analysis, age >or=40 years and serum viral load (>or=10 000 copies/ml) were independently associated with hepatocarcinogenesis, whereas age <or=50 years and HBV B2 were independently associated with HCC recurrence after surgical resection. In conclusion, HBV coinfections with two or three genotypes were associated with higher viral load and more severe course of the disease. HBV B2 infection was related to HCC recurrence. HBV C2 predominance in HCC patients was related to the high prevalence in Eastern China.

The association of complex liver disorders with HBV genotypes prevalent in Pakistan

Background

Genotyping of HBV is generally used for determining the epidemiological relationship between various virus strains and origin of infection mostly in research studies. The utility of genotyping for clinical applications is only beginning to gain importance. Whether HBV genotyping will constitute part of the clinical evaluation of Hepatitis B patients depends largely on the availability of the relevance of the evidence based information. Since Pakistan has a HBV genotype distribution which has been considered less virulent as investigated by earlier studies from south East Asian countries, a study on correlation between HBV genotypes and risk of progression to further complex hepatic infection was much needed

Methods

A total of 295 patients with HBsAg positive were selected from the Pakistan Medical Research Council's (PMRC) out patient clinics. Two hundred and twenty six (77%) were males, sixty nine (23%) were females (M to F ratio 3.3:1).

Results

Out of 295 patients, 156 (53.2%) had Acute(CAH), 71 (24.2%) were HBV Carriers, 54 (18.4%) had Chronic liver disease (CLD) Hepatitis. 14 (4.7%) were Cirrhosis and HCC patients. Genotype D was the most prevalent genotype in all categories of HBV patients, Acute (108), Chronic (39), and Carrier (53).

Cirrhosis/HCC (7) were HBV/D positive. Genotype A was the second most prevalent with 28 (13%) in acute cases, 12 (22.2%) in chronics, 14 (19.7%) in carriers and 5 (41.7) in Cirrhosis/HCC patients. Mixed genotype (A/D) was found in 20 (12.8%) of Acute patients, 3 (5.6%) of Chronic and 4 (5.6%) of carriers, none in case of severe liver conditions.

Conclusion

Mixed HBV genotypes A, D and A/D combination were present in all categories of patients except that no A/D combination was detected in severe conditions. Genotype D was the dominant genotype. However, genotype A was found to be more strongly associated with severe liver disease. Mixed genotype (A/D) did not significantly appear to influence the clinical outcome.

Genotyping and genomic sequencing in clinical practice

The global prevalence of chronic hepatitis B and its associated serious sequelae demand technologically advanced techniques of management. Nucleic acid testing (NAT) plays a key role in the diagnosis, surveillance, and treatment of chronic hepatitis B. NAT includes quantitative PCR-based HBV DNA assays, HBV genotyping, tests for mutations associated with resistance to antiviral medications, and assays to detect precore and core promoter mutations. This article reviews the uses of NAT in the diagnosis and management of chronic hepatitis B.