Variations of hepatitis B virus precore/core gene sequence in acute and fulminant hepatitis B

Variations of the hepatitis B virus (HBV) precore/core sequence has been shown to play a role in the development of active liver disease in chronic hepatitis B. Whether this is also an important viral factor in the pathogenesis of acute and fulminant hepatitis B is unknown. To determine the precore/core gene sequence in patients with acute and fulminant hepatitis B, 11 patients with fulminant hepatitis B and seven patients with acute hepatitis B were studied. The sequences of precore/core gene were determined by direct sequencing of the polymerase chain reaction amplicons generated from the HBV isolated from patients' serum. For the 11 patients with fulminant hepatitis B, the precore/core regions were successfully amplified in 10 patients. Eight patients exhibited precore stop codon mutations. In addition, nine of the 10 fulminant hepatitis B patients had frequent nucleotide substitutions with corresponding changes in the predicted amino acid sequences in the mid-core and the 5 terminus region of the core gene. In contrast, precore stop codon mutants were not detected, and variations of the HBV core gene were minimal in patients with acute hepatitis B. The association of HBV precore mutants and HBV core gene variations with fulminant hepatitis B and not acute hepatitis B suggested that these variations may be important in modulating the clinical course of HBV infection.     

Impact of acute hepatitis C virus superinfection in patients with chronic hepatitis B virus infection

BACKGROUND & AIMS: Superinfection in patients with chronic hepatitis B virus (HBV) infection is not uncommon. Acute hepatitis delta virus (HDV) superinfection is associated with severe and/or progressive liver disease. The natural course following acute hepatitis C virus (HCV) superinfection has not been well studied. The aim of this study was to investigate the impact of acute HCV superinfection. METHODS: The clinical features during acute phase and long-term outcomes of acute HCV superinfection were studied and compared with a cohort of acute HDV superinfection and a matched control group of active chronic hepatitis B. RESULTS: Acute HCV superinfection typically occurs as acute icteric hepatitis. The severity is similar to acute HDV superinfection in that hepatic decompensation developed in 34% of patients, hepatitis failure occurred in 11%, and 10% died. During a follow-up period of 1-21 years, patients with acute HCV superinfection had a significantly higher cumulated incidence of cirrhosis (48% at 10 years) and hepatocellular carcinoma (14% at 10 years, 21% at 15 years, and 32% at 20 years) than acute HDV superinfection or active chronic hepatitis B. Hepatitis B surface antigen (HBsAg) seroclearance occurred earlier in HCV superinfected patients. Continuing hepatitis after HBsAg seroclearance was observed only in HCV superinfected patients. CONCLUSIONS: Acute HCV superinfection in patients with chronic HBV infection is clinically severe during its acute phase. The long-term prognosis following acute HCV superinfection is much worse than that following HDV superinfection or active hepatitis B in terms of continuing hepatitis activity after HBsAg loss and the development of cirrhosis or hepatocellular carcinoma.     

Hepatitis B genotypes and precore/basal core promoter mutants in HBeAg-negative chronic hepatitis B

Background. Mutations in the precore stop codon (G1896A) and the basal core promoter (A1762T and G1764A) are frequently found in hepatitis B envelope antigen (HBeAg)-negative chronic hepatitis B. However, the clinical significance of these mutations remains controversial. We therefore investigated the influence of hepatitis B virus (HBV) genotypes, as well as precore/basal core promoter mutants, on the clinical and virological features of patients with HBeAg-negative chronic hepatitis B. Methods. Serum samples from 37 patients with HBeAg-negative chronic hepatitis B were collected for serological and molecular assays. The precore and basal core promoter regions were amplified by polymerase chain reaction and the amplicons were directly sequenced and analyzed. HBV geno-type was determined by polymerase chain reaction-restriction fragment length polymorphism. Results. Most of the patients had detectable serum HBV DNA, and genotypes B and C were the predominant strains. The overall prevalence of the precore stop codon mutant and basal core promoter mutant was 67% and 60%, respectively. The baseline clinical and virological features of patients with genotype B and genotype C infection were comparable. However, in the patients with precore/basal core promoter dual mutations there was a significantly lower proportion of individuals with a high detectable serum HBV DNA level (>100 pg/ml) than in the patients with either the precore stop codon mutation alone or the basal core promoter mutation alone (P = 0.04 by the logistic regression test for the trend). Conclusions. Our data suggest a high prevalence of precore stop codon and basal core promoter mutation in Taiwanese patients with HBeAg-negative chronic hepatitis B, and the influence of the basal core promoter mutation on HBV replication is modulated by the emergence of the precore stop codon mutation. Received: May 14, 2001 / Accepted: September 14, 2001     

Natural history and treatment of chronic delta hepatitis

Summary. Chronic delta hepatitis (CDH) represents a severe form of chronic viral hepatitis, induced by the hepatitis delta virus (HDV) in conjunction with the hepatitis B virus (HBV). Delta hepatitis may lead to disease in humans through co‐infection. The former leads to acute hepatitis which clinically can range from mild hepatitis to fulminant hepatitis and death. Severe or fulminant hepatitis is more often observed with HBV‐HDV co‐infection compared to HBV mono‐infection. Chronic infection after acute hepatitis B + D co‐infection is infrequent and similar to the rate in mono‐infected patients. CDH develops in 70–90% of patients with superinfection. CDH runs a more progressive course than chronic hepatitis B and may lead to cirrhosis within 2 years in 10–15% of patients. However, as with any immune‐mediated disease, different patterns of progression, ranging from mild to severe progressive disease, are observed. Active replication of both HBV and HDV may be associated with a more progressive disease pattern. Further, different HDV and HBV genotypes may contribute to various disease outcomes. CDH may be frequently associated with hepatocellular carcinoma development although recent studies provided conflicting results. The only established therapy for CDH is treatment with interferons for a duration of at least 1 year. On treatment, 6 month HDV RNA assessment may give clues as to whether to stop treatment at 1 year or continue beyond 1 year. New approaches to treatment of CDH are an urgent need of which the use of prenylation inhibitors appears the most promising.     

Association of mutations in the core promoter and precore region of hepatitis virus with fulminant and severe acute hepatitis in Japan

It was recently reported that mutations in the precore and core promoter region of hepatitis B virus (HBV) are associated with fulminant hepatitis. The aim of this study was to investigate the association of mutations in the precore and core promoter region of HBV with fulminant and severe acute hepatitis. We studied Japanese patients with acute HBV infection, including seven patients with fulminant hepatitis, 12 with severe acute hepatitis and 41 with acute self-limited hepatitis. The presence of HBV mutants was examined by using a point mutation assay to detect a G to A transition at position 1896 in the precore region and an A to T transition at position 1762 and a G to A transition at position 1764 in the core promoter region. Significant differences in the proportion of mutations in the precore or core promoter region were present between patients with fulminant hepatitis and self-limited acute hepatitis (7/7 (100%) vs 4/41 (9.8%), P < 0.01) and between severe acute hepatitis and self-limited acute hepatitis (6/12 (50.0%) vs 4/41 (9.8%), P < 0.01). The frequency of mutation increased proportionately with the severity of disease in patients with acute HBV infection. Fulminant hepatitis B in Japan is closely associated with mutations in the core promoter and precore gene of HBV. Point mutation assays for HBV precore and core promoter analysis may be useful to predict the outcome of liver disease in patients with acute HBV infection.     

Profound suppression of chronic hepatitis C following superinfection with hepatitis B virus.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis C virus (HCV) share similar transmission routes; thus, coinfection is frequent. The consequences of acute HBV infection in patients with chronic hepatitis C are unknown. METHODS: We describe a 47-year-old male with chronic hepatitis C who acquired HBV and then spontaneously and apparently completely cleared HCV but developed chronic hepatitis B. Five serum samples collected over 14 months and lymphoid cells obtained after acquiring HBV were tested for HCV and HBV by both standard assays and ultra-sensitive polymerase chain reaction/nucleic acid hybridization (PCR/NAH) (sensitivity approximately 2 IU/ml). RESULTS: After superinfection with HBV, HBV surface antigen-positive chronic hepatitis developed with readily detectable HBV DNA. All sera collected after acquisition of HBV, which tested negative for HCV RNA by standard laboratory assay, were positive for HCV genomes when analysed by PCR/NAH. Peripheral lymphoid cells carried HBV DNA and covalently closed circular DNA, but were negative for HCV. CONCLUSIONS: This is the first reported case of profound suppression of chronic hepatitis C after superinfection with HBV and establishment of chronic hepatitis B. It is hypothesized that HBV infection precipitated generalized and/or virus-specific cellular immune responses that profoundly suppressed HCV replication and yet failed to inhibit progression to chronic hepatitis B.     

Interferon-α2a for chronic hepatitis B with e antigen or antibody: comparable antiviral effects on wild-type virus and precore mutant

Summary. Recombinant interferon-α2a (IFN-α2a) in a total dose of 702 MU was given to 31 patients: nine with wild-type hepatitis B virus (HBV) and hepatitis B e antigen (HBeAg) (A); four with HBeAg and a mixed infection with wild-type HBV and precore mutants (B); 11 with antibody to HBeAg (HBeAb) and a mixed infection (C); and seven with HBeAb and precore mutants alone (D). HBV DNA was not cleared in any patient in groups A and B. By contrast, in patients with HBeAb, HBV DNA was ultimately lost in four patients in group C, as well as in 10 patients in group D. Thus, patients with HBeAb and infected with precore mutants alone (D) lost serum HBV DNA more often than those with HBeAg and wild-type HBV (A). Patients with low pre-treatment levels of HBV DNA cleared virus more frequently, and the response of precore mutant to IFN was comparable with that of wild-type HBV in patients who had a mixed infection. Based on these results, precore mutants do respond to IFN, and therefore, IFN is indicated in patients with HBeAb, especially those with low serum HBV DNA levels.     

Relationship of clinical and virological factors with hepatitis activity in hepatitis B e antigen-negative chronic hepatitis B virus-infected patients

To investigate the factors associated with active disease among hepatitis B surface antigen (HBsAg) positive/hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) infection we studied chronic HBV infected patients who had undetectable HBeAg at the first visit. HBV DNA was determined by the cross-linking assay (NAXCOR) and polymerase chain reaction (PCR). Mutations in the core promoter and precore regions and viral genotypes were studied. Clinical outcome of these patients were followed and categorized as: (i) relapse (ALT > 200 IU/L or three times the previous levels); (ii) active hepatitis (elevated ALT < 200 IU/L with concomitant detectable HBV DNA); or (iii) remission. A total of eighty-five patients were followed up for 5.5 ± 1.0 years. At first visit, 31 (36.5%) patients had elevated ALT levels, 12 (14.1%) had measurable HBV DNA by the cross-linking assay and 26 (30.6%) by PCR. Sixteen (18.8%) patients had hepatitis relapse, 13 (15.3%) had active hepatitis, and 56 (65.9%) remained in remission. Core promoter and precore stop codon mutants were found in 27 and 12 patients, respectively. Eleven and 20 had genotype B and C HBV, respectively. Initial elevated ALT and detectable HBV DNA were associated with active liver disease. Patient demographics, viral mutants or genotypes failed to predict disease activity. Hence, serum ALT and HBV DNA levels offer the best prediction of natural course of HBeAg-negative chronic HBV infection.     

重叠HCV感染对HBV／C基因热点变异的影响

为探讨乙型肝炎病毒（ＨＢＶ）重叠丙型肝炎病毒（ＨＣＶ）感染时ＨＣＶ对ＨＢＶ复制和基因变异的影响，采用套式聚合酶链反应（ＰＣＲ）与限制性片段长度多态性（ＲＦＬＰ）相结合。对１９例ＨＢＶ感染重叠ＨＣＶ感染（Ａ组）和３１例单独ＨＢＶ感染（Ｂ组）的慢怀肝病患者分析前Ｃ区密码２８终止是（Ａ８３）和Ｃ密码９７异亮氨酸变为亮氨酸变异Ｌ９７）。结果显示Ａ组第一次ＰＣＲ阳性率（１６％）明显低于Ｂ组（６５％）（Ｐ，０     

Impact of acute hepatitis B virus superinfection on chronic hepatitis C virus infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) dual infection is not uncommon, but the impact of acute HBV superinfection in patients with chronic HCV infection is still unknown. Two patients with well documented chronic HCV infection were hospitalized for acute hepatitis, which was serologically confirmed to be acute HBV superinfection. One patient who was seropositive for both HBV-DNA and HCV-RNA upon admission died of hepatic failure. The other became seronegative for HCV-RNA and recovered with alanine aminotransferase normalization, seroclearance of HBsAg, and antibodies to HCV. These findings confirm that acute superinfection in patients with chronic hepatitis may increase the risk for severe hepatitis, and suggest that HBV as the newcomer may suppress the pre-existing HCV. Together with the earlier observation that acute HCV superinfection suppresses pre-existing HBV, it seems that the timing or sequence of infection is a factor influencing the outcome of viral interactions.     

Effect of Acute Self-Limited Hepatitis C Virus (HCV) Superinfection on Hepatitis B Virus (HBV)-Related Cirrhosis. Virological Features of HBV–HCV Dual Infection

We investigated the virological impact of acute hepatitis C virus (HCV) superinfection on two patients with hepatitis B virus (HBV)-related cirrhosis. In both patients, chronic HBV-infection persisted while acute HCV infection resolved spontaneously. HBV DNA was transiently suppressed in both patients but increased with HCV resolution. In Case 1 (HBeAg-positive; wild type of basic core promoter [BCP] and precore [PreC]), fluctuations of HBV DNA and HBeAg state were accompanied by mutations of the BCP and PreC. In Case 2 (HBeAg-negative; mutant type of the BCP and PreC), changes in HBV DNA levels were associated with mutations of PreC. In both cases, mutant PreC changed to the wild type upon HCV resolution, and no nucleotide A insertion at position 193 of the HCV 5'-untranslated region, which influences HCV spontaneous clearance, was detected. The putative DNA-binding motif in the HCV core was SPRG (amino acids 99-102). HCV infection was associated with changes in the nucleotide sequences of the binding site for the nuclear receptor family in HBV enhancer 2 (Enh2) including the BCP rather than Enh1. Our results suggest that the impact of acute HCV infection on chronic HBV infection varies according to HBV virological state.     

Replicative efficiency and pathogenicity of hepatitis B virus e-minus precore variant

Abstract To study the replicative efficiency and pathogenicity of hepatitis B virus precore variant (A1896), anti-hepatitis B virus e antigen (HBe) titre was studied in naturally occurring wild-type virus infection, A1896 variant infection and dual infection. Higher titre of anti-HBe was found in patients with no virus replication and in patients coinfected with the wild-type virus and A1896 variant, which suggest that anti-HBe may either act as an inhibitor of virus replication or as selective pressure for the A1896 variant. Three site-directed mutants were constructed in the duck hepatitis B virus (DHBV) precore region. A frame shift in the encapsidation signal region abolished replication of DHBV; mutation in the initiation codon of the precore and mutation to generate a termination codon at the distal region of the precore resulted in decreased replication in the duck model. More significant pathological changes were found in the liver tissues of ducks infected with the mutant which mimicked the HBV A1896 variant.     

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

BACKGROUND/AIMS: The long-term outcomes in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B are distinct from those in HBeAg-positive chronic hepatitis. However, the molecular virological factors that contribute to the progression of liver disease in this special clinical setting remain largely unknown. We thus investigated the association of hepatitis B virus (HBV) genotypes as well as precore/basal core-promoter mutations with the clinical and virological characteristics of patients with HBeAg-negative chronic hepatitis B in Taiwan. METHODS: HBV genotypes and sequences of precore and basal core-promoter regions of the HBV genome were determined in 174 HBeAg-negative chronic HBV infection patients including 62 inactive carriers and 112 with different stages of liver disease. RESULTS: HBV carriers with older age (> 50 years) (odds ratio, 9.09; 95% confidence interval (CI), 3.22-25, P < 0.001) and basal core-promoter mutant of HBV (odds ratio, 4.12; 95% CI, 1.41-12.03, P = 0.01) were associated with the development of liver cirrhosis and hepatocellular carcinoma (HCC). The gender-related risk factors associated with the development of liver cirrhosis and HCC were further analyzed, and basal core-promoter mutant was only associated with the development of liver cirrhosis and HCC in male carriers (odds ratio, 4.35; 95% CI, 1.30-14.52, P = 0.02). CONCLUSIONS: The risk of development of liver cirrhosis and HCC is significantly increased in patients with advanced age as well as with basal core-promoter mutant of HBV. In addition, basal core-promoter mutant might contribute to the gender difference of the progression of liver disease in HBeAg-negative chronic hepatitis B in Taiwan.     

Relationship between the serum alanine aminotransferase level at the end of interferon treatment and histologic changes in wild-type and precore mutant hepatitis B virus infections

Summary Unravelling the role of interferon (IFN) in the treatment of chronic hepatitis B is complicated by many factors. Several mutant forms of hepatitis B virus (HBV) have recently been discovered; the most common of these is the precore mutant, characterized by hepatitis Be antigen (HBeAg) negativity and hepatitis Be antibody (HBeAb) positivity in an individual with an active HBV infection. The aim of this study was to compare the response rate to IFN therapy in patients with wild-type HBV infection and in individuals infected with the precore mutant. A second aim was to evaluate the role of an increased serum ferritin in terms of the IFN response rate in these two different types of HBV infection.
Therapy ministered at a dose of 5 MU subcutaneously three times weekly for 6 months to 41 individuals with a chronic wild-type hepatitis B infection and 16 individuals with a precore mutant chronic HBV infection. An IFN response was defined as normalization of the serum alanine aminotransferase (ALT) level and an HBeAg to HBeAb seroconversion (in wild-type hepatitis infection), and a normalization of the serum ALT in individuals infected with a precore mutant infection.
Ntrywo groups were matched for age, gender, serum ALT, serum iron, total iron binding capacity (TIBC), serum ferritin and liver histology. Forty-six per cent of the subjects with wild-type disease responded to IFN therapy. By contrast, only four of the 16 cases (25%) of the precore mutant cases responded ( P < 0.05). Ferritin levels correlated well with the type of IFN response; as the serum ferritin level increased, the response rate to IFN declined. Hapatic infection caused by a precore HBV mutant is more resistant to IFN therapy than wild-type infection. The serum ferritin level appears to influence the type of IFN response achieved. Individuals with a serum ferritin level greater than 300 ng ml^-1 failed to respond to IFN in 93% of the cases studied.     

HBeAg negative variants and their role in the natural history of chronic hepatitis B virus infection

Molecular virology methods including polymerase chain reaction,cloning and sequencing have revolutionised our understanding of viral genome variation.In the case of hepatitis B virus(HBV),sequencing studies have identified a number of virus variants normally found during the natural course of chronic infection.The appearance of the precore stop codon(with G-for-A substitution at position 1896)and basal core promoter(BCP)(with A-for-T and G-for-A,at positions 1762 and 1764,respectively)variants which reduce or abrogate hepatitis B e antigen(HBeAg)production,heralds the initiation of the seroconversion phase from HBeAg to antiHBe positivity.The gradual removal of the tolerogenic effect of HBeAg leads to the awakening of the immune response(immune clearance phase).Most patients after HBeAg seroconversion become"inactive HBsAg carriers".However during the course of infection precore and/or BCP variants may emerge and be selected leading to HBeAg negative chronic hepatitis B(CHB)with high viremia levels(reactivation phase).The prevalence of HBeAg negative CHB has been increasing over the last few decades and has become the commonest type of HBV infection in many countries of the world.This probably reflects the aging of existing HBV carriers and the effective prevention measures restricting new HBV infections.Frequent acute exacerbations accompanied by high viral replication,elevated alanine aminotransferase levels and histological activity are a common feature of HBeAg negative CHB leading to cirrhosis much faster than in HBeAg positive CHB patients.     

Hepatic flares in chronic hepatitis C: Spontaneous exacerbation vs hepatotropic viruses superinfection

The hepatitis C virus(HCV)causes an acute infection that is frequently asymptomatic,but a spontaneous eradication of HCV infection occurs only in one-third of patients.The remaining two-thirds develop a chronic infection that,in most cases,shows an indolent course and a slow progression to the more advanced stagesof the illness.Nearly a quarter of cases with chronic hepatitis C(CHC)develop liver cirrhosis with or without hepatocellular carcinoma.The indolent course of the illness may be troubled by the occurrence of a hepatic flare,i.e.,a spontaneous acute exacerbation of CHC due to changes in the immune response,immunosuppression and subsequent restoration,and is characterized by an increase in serum aminotransferase values,a frequent deterioration in liver fibrosis and necroinflammation but also a high frequency of sustained viral response to pegylated interferon plus ribavirin treatment.A substantial increase in serum aminotransferase values during the clinical course of CHC may also be a consequence of a superinfection by other hepatotropic viruses,namely hepatitis B virus(HBV),HBV plus hepatitis D virus,hepatitis E virus,cytomegalovirus,particularly in geographical areas with high endemicity levels.The etiology of a hepatic flare in patients with CHC should always be defined to optimize follow-up procedures and clinical and therapeutic decisions.     

Cytoplasmic expression of hepatitis B core antigen in chronic hepatitis B virus infection: role of precore stop mutants

Abstract: Aims/Background: The cytoplasmic expression of HBcAg is a possible target of immune hepatocytolysis and it is important for the pathogenesis of hepatic injury in chronic hepatitis B virus (HBV) infection. Cytoplasmic HBcAg expression has been suggested to be related to the precore sequence of HBV, HBV DNA level or cell cycle of hepatocytes and the aim of this study was to understand its mechanism. Material/Methods: We studied the expression pattern of HBcAg and its relationship to serum HBV DNA levels, cell proliferation activity of hepatocytes and precore mutation using 66 patients' sera and biopsied liver specimens of chronic hepatitis B. Results: The expression patterns of HBcAg were cytoplasmic predominant (CP) in 17 cases, nuclear and cytoplasmic (NC) in 10 cases and nuclear predominant (NP) in 9 cases and negative in 30 cases. CP expression cases showed a higher grade of hepatitis activity than NP expression cases. Serum HBV DNA levels showed a wide range and there was no significant difference according to the expression pattern of HBcAg. Cell proliferation activity of hepatocytes, measured by Ki-67 (MIB-1) labelling index was higher in CP expression cases than in NP expression cases and it was also significantly higher in cases of high grade than in low grade hepatitis activity. The precore region was evaluated by primer extension assay in 51 cases and there were 16 cases of 1896 precore mutant, 23 cases of wild type, 12 cases of mixed infection of 1896 precore mutant type and wild type. CP expression of HBcAg was significantly more frequent in 1896 precore mutant cases (86%) than in wild type cases (26%). Conclusion: CP expression of HBcAg is the major pattern of 1896 precore mutant cases and it might be involved in the severe liver injury of precore mutants. One of the mechanisms regulating CP HBcAg expression is suggested to be precore mutation of HBV as well as cell cycle of hepatocyte.     

重型病毒性肝炎病原学与预后的关系探讨

目的探讨重型病毒性肝炎的病原学特点。方法收集各型重型病毒性肝炎418例,分析其病原学分型及乙型肝炎病毒不同病原学模式与重型肝炎预后的关系。结果急性重型肝炎以甲型和戊型病毒性肝炎为主,乙型肝炎病毒感染治愈后病毒阴转率较高。亚急性及慢性重型肝炎以乙型肝炎病毒感染居首位,占92.8％。在乙型肝炎病毒感染的病原学模式中,以HBsAg、HBeAb、HBcAb阳性的重型肝炎发病及死亡率最高。乙型肝炎病毒与其他肝炎病毒重叠感染与单纯感染比较死亡率无显著差异。单纯TTV感染可导致重型肝炎。重型肝炎发病后HBV DNA可自然阴转,阴转率可达53.6％。结论重型肝炎仍以乙型肝炎病毒感染为主。乙型肝炎病毒前C区发生基因突变可能较易发生重型肝炎。     

Response to interferon-alpha in chronic hepatitis B with and without precore mutant strain detected by mutation site-specific assay

GOALS: We investigated whether the presence of precore mutant (stop codon mutation at codon 28) affects the response to interferon-alpha in patients with chronic hepatitis B. BACKGROUND: Mutations of hepatitis B virus (HBV) may influence the response to treatment. The association of precore mutant with the response to interferon is controversial. STUDY: Thirty-one Japanese patients with hepatitis B e antigen-positive chronic hepatitis were treated with natural interferon-alpha. HBV DNA with the precore mutation was assayed in serum using a mutation site-specific assay before and after treatment. RESULTS: Before treatment, precore mutant was detected in 22 cases (group A) and not detected in 9 cases (group B). Serum HBV DNA level before treatment was not different between the 2 groups. At the end of treatment, serum HBV DNA was decreased to undetectable levels in 13% (4 of 31). Six months after treatment, the percentage of cases with loss of hepatitis B e antigen and a decrease in the transaminase level to within the normal range was significantly higher in group B than in group A (67%, 18%, P = 0.015). CONCLUSIONS: Chronic hepatitis without precore mutant strain before treatment is more responsive to IFN-alpha.     

Incidence and clinical significance of hepatitis B virus precore gene translation initiation mutations in e antigen-negative patients

Hepatitis Be antigen (HBeAg)-negative chronic hepatitis B (CHB) is associated with hepatitis B virus (HBV) variants harbouring changes in the precore region. Most commonly, a G to A point mutation at nucleotide 1896 (m1896) creates a novel translation stop codon that prevents HBeAg production. In the Mediterranean region the m1896 mutation prevails in greater than 98% of HBeAg-negative CHB patients. In this study the prevalence of additional mutations in the precore region was investigated among patients with chronic HBV infection. Precore sequences were determined by sequencing serum HBV DNA amplified by polymerase chain reaction (PCR) with primers flanking the precore/core region. Thirty-one HBeAg-negative and five HBeAg-positive individuals were studied. All HBeAg-negative patients (100%) harboured the m1896 mutation and 20 (64.5%) also had a G to A mutation at nucleotide 1899 (m1899). Additional mutations affecting the translation initiation of the precore gene were found in seven (22.5%) patients, all with active liver disease, five of whom had episodes of HBV reactivation. HBeAg-positive patients had no mutations in these positions and neither did any of the five HBeAg-negative patients with normal levels of liver enzymes, representing the healthy carrier state of HBV infection. Serial sample analysis from one patient revealed that the initiation codon mutation developed following HBeAg seroconversion and the appearance of m1896. During periods of high HBV replication, the ratio of mutant to wild-type ATG was found to increase in parallel with HBV DNA levels. These data show that a significant proportion of HBeAg-negative patients who already harbour the 1896 stop codon mutation may subsequently develop precore translation initiation mutations, which appear to be associated with enhanced HBV replication and severe liver disease.