Differences of Hepatocellular Carcinoma Patients with Hepatitis B Virus Genotypes of Ba, Bj or C in Japan

Characteristics of Hepatitis B Virus Genotype and Sub-Genotype in Hepatocellular Cancer Patients in Vietnam

Untreated chronic hepatitis B virus (HBV) infection can lead to chronic liver disease and may progress to cirrhosis or hepatocellular carcinoma (HCC). HBV infection has been prevalent in Vietnam, but there is little information available on the genotypes, sub-genotypes, and mutations of HBV in patients with HBV-related HCC confirmed by histopathological diagnosis. We studied the molecular characteristics of HBV and its genetic variants in Vietnamese HCC patients after liver tumor resection. We conducted a descriptive cross-sectional study on 107 HBV-related HCC hospitalized patients from October 2018 to April 2019. The specimens collected included EDTA anticoagulant blood and liver tissues. Extracted HBV DNA was subjected to whole genome sequencing by the Sanger method. We discovered 62 individuals (57.9%) with genotype B and 45 patients (42.1%) with genotype C, with only sub-genotypes B4 and C1. Among the mutations, the double mutation, A1762T-G1764A, had the most significant frequency (73/107 samples; 68.2%) and was higher in genotype C than in genotype B (p < 0.001). The most common genotypes found in HCC patients in this investigation were B and C, with sub-genotypes B4 and C1 for each. The prevalence of genotype B4 was greater in HBV-infected Vietnamese HCC patients.

Viral hepatitis and hepatocellular carcinoma: From molecular pathways to the role of clinical surveillance and antiviral treatment

Hepatocellular carcinoma (HCC) is a global health challenge. Due to the high prevalence in low-income countries, hepatitis B virus (HBV) and hepatitis C virus infections remain the main risk factors for HCC occurrence, despite the increasing frequencies of non-viral etiologies. In addition, hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection. The molecular processes underlying HCC development are complex and various, either independent from liver disease etiology or etiology-related. The reciprocal interlinkage among non-viral and viral risk factors, the damaged cellular microenvironment, the dysregulation of the immune system and the alteration of gut-liver-axis are known to participate in liver cancer induction and progression. Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis. The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance, both through clinical-biochemical scores and periodic ultrasound assessment. This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.

HBV Genotype: A Significant Risk Factor in Determining Which Patients With Chronic HBV Infection Should Undergo Surveillance for HCC: The Hepatitis B Alaska Study

BACKGROUND AND AIMS

Information is limited regarding HBV genotype and the outcome of chronic HBV (CHB) infection. We examined the effect of HBV genotype on HCC occurrence in Alaska Native (AN) persons with CHB, where five HBV genotypes are found: A2, B6, C2, D, and F1.

APPROACH AND RESULTS

We calculated HCC incidence per 1,000 person-years of follow-up to determine which groups by age, sex, and genotype met current American Association for the Study of Liver Diseases (AASLD) HCC surveillance criteria. We used Poisson regression to compare HCC risk by genotype, age, sex, and Alaska region. Incidence of HCC was calculated using the sex-specific AASLD cutoff recommended for the Asian population of 50 years for women and 40 years for men. HCC screening was conducted semiannually using alpha-fetoprotein levels and abdominal ultrasound. Among 1,185 AN persons, median follow-up was 35.1 years; 667 (63%) were male. The HBV genotype distribution was 49% D, 18% F, 13% A, 6% C, 3% B, 0.1% H, and 12% undetermined. Sixty-three cases of HCC occurred. HCC incidence for genotype F was 5.73 per 1,000 person-years of follow-up, followed by 4.77 for C, 1.28 for A, 0.47 for D, and 0.00 for B. The HCC risk was higher for genotypes F (relative rate [RR], 12.7; 95% CI, 6.1-26.4), C (RR, 10.6; 95% CI, 4.3-26.0), and A (RR, 2.9; 95% CI, 1.0-8.0) compared to genotypes B and D. Among men < 40 years of age and women < 50 years of age, genotype F had the highest incidence (4.79/1,000 person-years).

CONCLUSIONS

HBV genotype was strongly associated with HCC. HBV genotype should be considered in risk factor stratification.

Genomic analysis of Hepatitis B virus and its association with disease manifestations in Bangladesh

The direct cytopathic effects of the hepatitis B virus (HBV) on subsequent liver damage are not fully understood in HBV-infected patients. However, associations between the prevalence of various HBV genotypes and the extent of liver damage have been reported from different parts of the world. The purpose of this study was to determine the distribution of HBV genotypes in patients with chronic HBV infection in Bangladesh, a country of 160 million people, of which approximately 3–6 million are chronically infected HBV patients. In addition, whole and partial genome sequencing of HBV was performed to evaluate the relationship between HBV mutations and genotypes. We found that 42% of the patients with low HBV DNA and normal levels of alanine aminotransferase (ALT) had HBV genotype D. In contrast, the HBV genotype C was dominant among patients with high HBV DNA levels (>2000 IU/ml) and elevated ALT and in patients with liver cirrhosis (LC) and hepatocellular carcinomas (HCC). Whole and partial genome sequences of HBV revealed that most patients with LC and HCC had HBV genotype C with mutations at the T1762/A1764 positions. It seems that Bangladesh represents a borderline country, situated within East Asia, which mainly consists of individuals with HBV genotypes B and C, whereas in the western parts of Asia, HBV genotypes A and D are prevalent. Bangladesh is, therefore, an excellent model for the comparison of the pathophysiology of three major HBV genotypes in a single population. The findings of this study suggest a possible association between HBV viral factors and the extent of liver damage in chronic HBV-infected patients.

Hepatitis B (HB) immunoglobulin plus HB vaccine for intrauterine HB virus infection

BACKGROUND

Vaccination against hepatitis B virus (HBV) infection in infants born to hepatitis B surface antigen (HBsAg)-positive mothers using HB immunoglobulin (HBIG) and hepatitis B (HB) vaccine was launched in Japan in 1985. Infants testing positive for HBsAg at 1 month of age are considered to have prenatally acquired the infection and are usually excluded from the prevention program. Infants born to HB e antigen (HBeAg)-positive mothers are at a high risk of perinatally acquiring the infection. In this study, long-term outcome was evaluated in children with prenatal HBV infection who received the HBIG and HB vaccine in Japan.

METHODS

Newborns of both HBsAg- and HBeAg-positive carrier mothers received HBIG within 48 h of birth and at 2 months of age. Subsequently, three doses of recombinant HB vaccine were given at 2, 3, and 5 months of age. Outcome was compared between the following two groups: infants who completed the vaccination program, even if they were HBsAg positive at 1 month of age (n = 15), and infants who did not (n = 51).

RESULTS

Seroconversion from HBeAg to anti-HBe antibody (HBeAb) before 3 years of age was observed in five children (33%) who completed the vaccination program and in two (4%) who did not (P = 0.005). In 2/5 children who completed the vaccination program and achieved HBeAb seroconversion, seroconversion from HBsAg to anti-HBs antibody was also noted.

CONCLUSION

This specific vaccination program for children with prenatal HBV infection has the potential to alter immune tolerance to HBV.

Hepatitis B virus genotypes and variants

At least 10 hepatitis B virus (HBV) genotypes (A to J) with distinct geographic distributions and several HBV mutants, including precore/core promoter mutations and pre-S/S deletion mutations, have been recognized to be not only predictive of liver disease progression but also associated with response to antiviral therapy. HBV genotype-specific pathogenesis may contribute to heterogeneous clinical outcomes in chronic hepatitis B patients across the world. For example, patients with HBV genotypes C and D infection have a lower rate of spontaneous HBeAg seroconversion. In addition, HBV genotypes C and D have a higher frequency of core promoter and pre-S mutations than genotypes A and B. Genotypes C and D also carry a higher lifetime risk of cirrhosis and HCC development than genotypes A and B. Core promoter and pre-S mutations also correlate with an increased risk of hepatocellular carcinoma (HCC). Therapeutically, genotypes A and B patients have a better response to interferon-based therapy than genotypes C and D patients, but the response to nucleos(t)ide analogs is comparable across different HBV genotypes. In conclusion, HBV genotypes and variants may serve as viral genetic markers to predict disease progression as well as help practicing physicians optimize individualized antiviral therapy in clinical practice.

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.

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.

Clinical features of hepatitis B virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer death, and chronic hepatitis B is a serious worldwide problem. The epidemiology of HCC is distinctive. Hepatitis B virus (HBV) plays a major role in hepatocarcinogenesis. Prevention of HBV-related HCC is a key issue in current hepatology. This paper describes the prevention and clinical features of HBV-related HCC, along with a short review of the disease.

Hepatitis B virus subgenotype C2 is the most prevalent subgenotype in northeast China

The geographical distribution of hepatitis B virus (HBV) subgenotypes and their clinical implications in patients with acute and chronic hepatitis B in the Heilung-kiang province of northeast China were investigated. Nested PCR and multiplex PCR were performed with genotype-specific primers and with subgenotype-specific primers to identify genotypes and subgenotypes from serum samples of 412 HBV infections including 69 with acute self-limited hepatitis (ASH) and 343 with chronic hepatitis (CH). A total of 361 samples were genotyped and 304 were further subgenotyped. The most common HBV genotype was C (93.63%, 338/361), with subgenotype group C2 (83.73%, 283/338) predominating. Genotype B was also found and subgenotype B2 predominated within this genotype. Out of 69 infected patients with ASH, 48 were identified as genotype C and all belonged to subgenotype C2. Of 343 infected patients with CH, 313 were genotyped and 256 were subgenotyped; amongst these, C2 (91.80%, 235/256), B2 (7.42%, 19/256) and mixed subgenotypes B2 and C2 (0.78%, 2/256) were found. In HBV subgenotype C2 infections, ASH had a higher ratio of women than CH patients. These results show that HBV subgenotypes C2 and B2 were found in Heilung-kiang province of northeast China. In ASH and CH groups, the distributions of subgenotypes were coincident with C2, the predominant subgenotype. Analysis of the association between subgenotype and the outcomes of HBV infection was inconclusive in our study.

Epidemiology of hepatocellular carcinoma in Japan

Primary liver cancer, 95% of which is hepatocellular carcinoma (HCC), is ranked third in men and fifth in women as a cause of death from malignant neoplasms in Japan. The number of deaths and death rate of HCC began to increase sharply in 1975. These numbers peaked at 34,510 and 27.4/100,000, respectively, in 2004, but decreased to 33,662 annual deaths and a 26.7/100,000 death rate in 2006. Although hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are both major causes of HCC, HCV-related HCC represents 70% of all cases. The incidence of HCC without hepatitis B surface antigen (HBsAg) or antibodies to HCV (anti-HCV) accounts for 8%-15% of HCC patients nationwide. Geographically, HCC is more frequent in western than eastern Japan, and death rates of HCC in each prefecture correlate with anti-HCV, but not HBsAg, prevalence. Interferon therapy for chronic hepatitis C reduces the risk of development of HCC, especially among patients with sustained virological response. Further research should focus on the mechanisms of carcinogenesis by HCV and HBV, development of more effective treatments, and establishment of early detection and preventative approaches. Better understanding of HCC unrelated to HCV and HBV, possibly caused by steatohepatitis and diabetes, should also be a major concern in future studies.

Current antiviral therapies for chronic hepatitis B

Among current treatment options for chronic hepatitis B, nucleoside/nucleotide analog therapy has better tolerability and most patients respond to the therapy, while interferon (IFN) therapy has rather severe side-effects and a lower response rate. However, nucleoside/nucleotide analog therapies have problems of the emergence of drug resistance and poor sustainability of response after discontinuation. After the first nucleoside/nucleotide analog lamivudine, adefovir and entecavir are now utilized in many countries. Adefovir has efficacy for lamivudine resistant patients and current data suggests that adding adefovir to ongoing lamivudine is better than switching to adefovir in terms of viral suppression and the occurrence of resistance. Entecavir can be the first choice for naïve patients, although cross-resistance has been known for lamivudine resistant patients and mutational screening should take place before using entecavir with such patients. Many other new nucleoside/nucleotide analogs are being developed such as telbivudine, clevudine and tenofovir; the details of each drug will be disclosed in near future.

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.

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.

Classification of hepatitis B virus genotype B into 2 major types based on characterization of a novel subgenotype in Arctic indigenous populations

Hepatitis B virus genotype B (HBV/B) has been classified into 5 subgenotypes. Except for Bj/B1 in Japan, the subgenotypes (Ba/B2-B5) have undergone recombination with HBV/C in the core promoter/precore/core genomic region. Phylogenetic analyses of complete sequences show that the Arctic strains belong to a novel subgenotype (HBV/B6) without the recombination, analogous to what is seen with Bj/B1. Comparison of 50 HBV/B6 carriers from the Arctic versus 50 Bj and 50 Ba age- and sex-matched carriers from Asia revealed that clinical characteristics of HBV/B6 carriers were similar to those of Bj/B1 carriers in Japan. The results suggest that HBV/B may be classified into nonrecombinant (Bj/B1 and B6) and recombinant (Ba/B2-B5) types.

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

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

Epidemiology of hepatocellular carcinoma in Japan

Primary liver cancer, 95% of which is hepatocellular carcinoma (HCC), has ranked third in men and fifth in women as a cause of death from malignant neoplasm in Japan. Although the number of deaths and death rates from HCC increased until 2002 in Japan, annual deaths (34 089) and the death rate (27.0/100 000) from liver cancer decreased in 2003. Hepatitis C virus (HCV)-related HCC represents 75% of all HCC in Japan. The incidence of HCC without hepatitis B surface antigen (HBsAg) or anti-HCV accounted for 7-12% of HCC in Japan andhalf of non-B non-C-HCC was of unknown origin. Geographically, HCC is more frequent in western than eastern Japan, and the death rates from HCC in each prefecture correlate with the prevalence of anti-HCV, but not with HBsAg prevalence. Interferon therapy for chronic hepatitis C has reduced the risk factors for development of HCC, especially among patients with sustained response.

Hepatitis B virus genotypes in children and adolescents in Japan: before and after immunization for the prevention of mother to infant transmission of hepatitis B virus

The genotype distribution of hepatitis B virus (HBV) was investigated in 118 children in Japan. One hundred and sixteen children (98%) had chronic HBV infection, and the remainder had acute hepatitis. Genotyping of HBV was determined by PCR and sequencing analysis in the S gene. Genotype C (86%) was the most frequent, followed by genotype B (9%), D (2.5%), and A (1.0%). Transmission routes of HBV to children were from mothers in 91 patients (77%), fathers in 8 (6.5%), mother or father in 1 (1%), family members other than the parents in 5 (4%), and unknown in 13 (11.5%). The relationship between routes of HBV transmission and HBV genotypes was studied. Eighty-eight (97%) of 91 children of mother-to-infant transmission were genotype C, while 13 (49%) of 27 children of the routes other than the mother to infant transmission were genotype C. The number of children with genotype C who were infected from their mothers was significantly higher than those with genotype B, D, or A (P < 0.01). In conclusion, HBV genotypes influence not only clinical characteristics but also the mechanisms of inter-personal HBV transmission.

Differences of HBV genotypes and hepatocellular carcinoma in Asian countries

Hepatitis B virus (HBV) genotype B (HBV B) and genotype C (HBV C) are prevalent in Asia. Recently HBV B has been classified into two subtypes, HBV Ba, which is ubiquitous in Asia, and HBV Bj specific to Japan. However, little is known about etiological, virological and clinical differences among patients who have various genotypes and who developed hepatocellular carcinoma (HCC). We investigated the relation of HBV subgenotype with etiological and clinical differences of HCC patients between Taiwan and Okinawa in Japan. HBV Bj may be associated with lower incidence of HCC and older development of HCC while HBV Ba or HBV C may be associated withhigher incidence of HCC and younger development of HCC. In addition, we demonstrated the relationship of the specific mutation of HBV, T1653 mutation in the core promoter region, with development of HCC in Japanese patients with HBV C. These data suggest that great differences exist among patients with HCC who are infected with different HBV genotypes or genotype-specific mutations.

Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China

Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies.

Hepatitis B virus (HBV) genotypes/subgenotypes in China: mutations in core promoter and precore/core and their clinical implications

BACKGROUND

The association of hepatitis B virus (HBV) genotypes with clinical course of infection is increasingly recognized.

OBJECTIVES

In order to investigate the genetic diversity of HBV and its clinical implications, 241 HBV-infected patients including 34 with hepatocellular carcinoma (HCC) were enrolled in this study.

METHODS

HBV genotyping was performed with an ELISA assay. HBV subgenotypes were determined by PCR-RFLP. HBV core promoter/precore/core mutations were analyzed by direct sequencing.

RESULTS

The overall prevalence of HBV/B and C was 65% and 33%, respectively. Among HBV/C, 42% were Cs/C1 and 58% were Ce/C2. The HBV/C1 was only found in the patients originating from Southern China (p=0.0001). Among HCC patients, HBV/C2 was only found in the elder age group (> or =51 years; p<0.05) and HBV/Ba was associated with young HCC patients (<35 years). Mutations associated with HCC were V1753 and T1762/A1764 (p<0.01). The prevalence of the V1753 was higher in HBV/C1 strains (p<0.04), A1898 was only found among HBV/C1 (p=0.056). T1762/A1764 was frequently demonstrated in both subgenotypes. The T1858 (90%) and A1896 (40%) mutations were most frequent in HBV/C2 (p<0.008).

CONCLUSIONS

HBV/C1 and HBV/C2 have distinct geographic distributions in China. V1753 in addition to T1762/A1764 double mutation in the basal core promoter region seems to be associated with HCC development, especially in the patients with HBV/C1.

Comparison of hepatitis B virus subgenotypes in patients with acute and chronic hepatitis B and absence of lamivudine-resistant strains in acute hepatitis B in Japan

Hepatitis B virus (HBV) has been classified into eight genotypes and can be further divided into several subgenotypes that have different geographic distributions. Because of increased human migration, the prevalence of rare subgenotypes is increasing in Japanese patients with acute hepatitis B. Lamivudine-resistant strains of HBV have begun to emerge in association with chronic hepatitis B. The aim of this study was to investigate the distribution of HBV subgenotypes and lamivudine-resistant strains in patients in Japan with acute hepatitis B. One hundred twenty-three patients with acute hepatitis B and 123 with chronic hepatitis B were studied. HBV subgenotypes and lamivudine-resistance mutations were determined by direct sequencing of the preS and polymerase region, respectively. HBV subgenotypes Aa (n=3), Ae (n=23), Ba (n=7), Bj (n=3), Cs (n=7), Ce (n=76), D (n=2), and H (n=2) were detected in patients with acute hepatitis. In patients with chronic hepatitis, HBV subgenotypes Ae (n=4), Ba (n=1), Bj (n=18), and Ce (n=100) were found. Non-common Japanese subgenotypes, that is, non-Bj and non-Ce, were detected more frequently in patients with acute hepatitis (35.8%) than in patients with chronic hepatitis (4.1%) (Odds ratio, 0.076; 95%CI, 0.029-0.200; P<0.0001). Lamivudine-resistance mutations were detected in chronic hepatitis patients with breakthrough hepatitis but not in other patients. In conclusion, the prevalence of uncommon Japanese HBV subgenotypes is expected to increase, although lamivudine-resistant strains have not yet been found in patients with acute hepatitis B.

Genotype B and younger patient age associated with better response to low-dose therapy: a trial with pegylated/nonpegylated interferon-alpha-2b for hepatitis B e antigen-positive patients with chronic hepatitis B in China

BACKGROUND

Cost and clinically significant adverse effects are the major limiting factors of interferon (IFN) use in therapy for chronic hepatitis B virus (HBV) infection. A clinical trial was conducted in China to study the efficiency and clinical relevance of low-dose regimen of IFN treatment for chronic HBV infection and to reveal factors predicting sustained combined response.

METHODS

During a randomized, open-label control study, hepatitis B e antigen (HBeAg)-positive patients with chronic HBV infection (n=230) were assigned to receive pegylated IFN- alpha -2b (1.0 micro g/kg) (n=115) or IFN- alpha -2b (3 MIU; n=115) for a 24-week period. Sustained combined response was assessed 24 weeks after the completion of treatment.

RESULTS

The greater rate of HBeAg loss in the pegylated IFN-group (23%) was the only statistically significant difference between the 2 treatment arms observed at the end of follow-up. The results of the multivariate statistical analysis revealed that HBV genotype B and patient age (< or =25 years) were 2 independent factors associated with sustained combined response. A total of 40% of patients with HBV genotype B aged < or =25-years achieved sustained combined response. Only 4 (1.7%) of 230 patients discontinued therapy because of clinically significant adverse effects.

CONCLUSIONS

The choice of low-dose IFN regimen might be a relevant clinical option to reduce the cost and adverse effects of therapy for younger patients with chronic HBV infection and genotype B infection in countries where it is prevalent.

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

BACKGROUND/AIMS

Hepatitis B virus genotype C (HBV/C) has been classified into two geographically distinct subgenotypes; HBV/C1/Cs (Southeast Asia) and HBV/C2/Ce (East Asia).

METHODS

Viral differences in enhancer II/core promoter and precore regions between the subgenotypes and their association with hepatocellular carcinoma (HCC) were assessed in a matched cross-sectional control study of 118 carriers (from Hong Kong) with HBV/C1/Cs (48.0 years, 81% male, 40% HBeAg+, 44% HCC) and 210 HBV/C2/Ce (172 from Japan, 38 from Hong Kong) (50.2 years, 78% male, 30% HBeAg+, 46% HCC).

RESULTS

Univariate analyses showed that mutation V1753 was predictive for HCC among HBeAg-positive-C1/Cs-carriers (P=0.0055), and T1653 among HBeAg-positive-C2/Ce-carriers (P=0.018), and T1653 or V1753 or T1762/A1764 among HBeAg-negative-C2/Ce-carriers (P<0.05). In the multivariate analysis on all HBV/C subjects, independent predictive factors for HCC were subgenotype C2/Ce (odds ratio, 4.21; 95% confidence interval, 1.07-16.23), T1653 (3.64; 1.93-6.86), V1753 (3.07; 1.66-5.65) and T1762/A1764 (2.58; 1.21-5.49) mutations, age (50 years), gender (male) and HBeAg (positive).

CONCLUSIONS

Our data indicate that T1653 and/or V1753 mutations in addition to T1762/A1764 are differently associated with HCC in context of HBeAg status among HBV/C1/Cs and C2/Ce-carriers. HBV/C subgenotypes have specific mutation patterns, which is probably responsible for increased carcinogenesis of HBV/C2/Ce.