Undetectable HCV-RNA at treatment-week 8 results in high-sustained virological response in HCV G1 treatment-experienced patients with advanced liver disease: the International Italian/Spanish Boceprevir/Peginterferon/Ribavirin Name Patients Program.

In many countries, first-generation protease inhibitors (PIs)/peginterferon/ribavirin (P/R) still represent the only treatment option for HCV-infected patients. Subjects with advanced disease and previous failure to P/R urgently need therapy, but they are under-represented in clinical trials. All treatment-experienced F3/4 Metavir patients who received boceprevir (BOC)+P/R in the Italian-Spanish Name Patient Program have been included in this study. Multivariate logistic regression analysis (MLR) was used to identify baseline and on-treatment predictors of SVR and adverse events (AEs). Four hundred and sixteen patients, mean age 57.7 (range 25-78 years), 70% males, 69.5% (289/416) F4, 14% (41/289) Child-Pugh class A6, 24% (70/289) with varices and 42% (173/416) prior null responders to P/R, were analysed. Overall, SVR rate (all 381 patients who received one dose of BOC) was 49%, (58% in F3, 45% in F4, 61% in relapsers, 51% in partial, 38% in null responders, and 72% in subjects with undetectable HCV-RNA at treatment-week (TW)8. Among patients with TW8 HCV-RNA ≥ 1000 IU/L, SVR was 8% (negative predictive value = 92%). Death occurred in 3 (0.8%) patients, while decompensation and infections were observed in 2.9% and 11%, respectively. At MLR, SVR predictors were TW4 HCV-RNA ≥ 1log10 -decline from baseline, undetectable TW8 HCV-RNA, prior relapse, albumin levels ≥3.5 g/dL and platelet counts ≥100 000/µL. Metavir F4, Child-Pugh A6, albumin, platelets, age and female gender were associated with serious and haematological AEs. Among treatment-experienced patients with advanced liver disease eligible for IFN-based therapy, TW8 HCV-RNA characterised the subset with either high or poor likelihood of achieving SVR. Using TW8 HCV-RNA as a futility rule, BOC/P/R appears to have a favourable benefit-risk profile.

Peginterferon alfa-2b plus weight-based ribavirin for 24 weeks in patients with chronic hepatitis C virus genotype 1 with low viral load who achieve rapid viral response.

In chronic hepatitis C (CHC), treatment duration may be individualized according to time to first undetectable hepatitis C virus (HCV) RNA, with patients who attain undetectable HCV RNA early in treatment being candidates for shorter regimens. The aim of this study was to determine the relapse rate in patients with CHC genotype (G) 1 infection and low baseline viral load who achieved undetectable HCV RNA by week 4 [rapid virologic response (RVR)] when treated for 24 weeks. This was an open-label, multicentre, noninterventional study. Adult patients with G1 CHC infection and baseline viral load <600,000 IU/mL who attained RVR were treated with peginterferon alfa-2b (1.5 µg/kg/week) plus ribavirin (800-1200 mg/day) for 24 weeks, then followed for a further 24 weeks. The primary endpoint was relapse rate, defined as the proportion of patients with undetectable HCV RNA at treatment week 24 and detectable HCV RNA at week 24 follow-up. The secondary efficacy endpoint was sustained virologic response (SVR). Overall, 170 patients were included in the efficacy-evaluable population. The relapse rate was 9.7% (16/165, 95% confidence interval: 0.06-0.15), and SVR was attained by 149 of 170 patients (87.6%). Virologic outcomes were consistent regardless of age, gender, body weight and genotype. Seven patients reported treatment-emergent serious adverse events (AEs), and four patients discontinued treatment because of an AE. This study further demonstrates that peginterferon alfa-2b plus weight-based ribavirin for 24 weeks is an effective treatment strategy for treatment-naive patients with G1 CHC and low viral load who attain RVR.

Monitoring SCCA-IgM complexes in serum predicts liver disease progression in patients with chronic hepatitis.

About 30% of the patients with chronic hepatitis develop a progressive liver disease and one of the most intriguing issues is the detection of noninvasive markers for fibrosis stage and disease progression. High levels of squamous cell carcinoma antigen (SCCA)-immunoglobulin M (IgM) are detectable in hepatocellular carcinoma and their increase in cirrhotic patients can predict tumour development. As SCCA-IgM can also be detectable at low percentages in patients with chronic hepatitis, the aim of this study was to assess SCCA-IgM complexes in relation to disease outcome in this group of patients. An ELISA assay was used to determine the presence of SCCA-IgM in 188 patients with chronic hepatitis and in 100 controls. An additional serum sample was available after a median period of 6 years in 57 untreated patients: these patients were subdivided in group A, including eight patients with a fibrosis score increase > or =2 in a second liver biopsy and group B, including 49 patients without fibrosis progression during a similar follow up. SCCA-IgM complexes were detectable in 63 of 188 (33%) patients but in none of the controls. A significant increase of SCCA-IgM levels over time was observed in patients with fibrosis progression (mean +/- SD: 117 +/- 200 U/mL/year), but not in those without histologic deterioration (mean +/- SD: -8.8 +/- 31 U/mL/year, P < 0.0001). In conclusion, monitoring SCCA-IgM levels over time appears a useful approach to identify patients with chronic hepatitis at higher risk for cirrhosis development.

Focal nodular hyperplasia of the liver: an emerging complication of hematopoietic SCT in children.

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.

Coinfection by hepatitis B virus and hepatitis C virus.

Coinfection by hepatotropic viruses can occur due to the fact that hepatitis B virus (HBV) and hepatitis C virus (HCV) share similar routes of transmission. Different clinical features of liver disease can be observed in infected patients, ranging from fulminant, acute and chronic hepatitis to hepatocellular carcinoma (HCC). The relative role of the infecting viruses in determining the final clinical picture is not yet well defined. Several reports indicate that clinical and pathological severity of liver disease among coinfected patients is increased and in patients with HCC, co-occurrence of both viruses is a common event. The potential mechanism of tumour development still remains speculative, although direct and indirect roles for both HBV and HCV have been proposed. At the molecular level, reciprocal interference of virus replication has been repeatedly described and the extent of interference is influenced by the infecting HCV genotype, genotype 1 of HCV having more efficient inhibitory activity on HBV than genotype 2. Sequence similarities between an arginine-rich nucleocapsid motif of both viruses could support these clinical observations. Concerning response rates to interferon therapy, no satisfactory results have been achieved to date, although identification of effective therapeutic schemes, based on virological status of both viruses are warranted.

Hepatitis B virus (HBV) infection and liver disease after allogeneic bone marrow transplantation: a report of 30 cases.

Among 145 consecutive patients undergoing bone marrow transplantation (BMT) for leukemia or aplastic anemia. 30 (21%) were found positive for hepatitis B surface antigen (HBsAg) in serum either before or after BMT. Their serologic profile and clinical outcome are described. Nine out of 30 patients were HBsAg positive before BMT: four were chronic carriers and five were found HBsAg+ at transplant. Three of the former and one of the five latter patients remained persistently HBsAg+ after transplant with signs of liver disease; none developed liver failure, indicating that HBsAg positivity is not an absolute contra-indication to BMT. Among the remaining 21 patients. HBsAg was detected early (n = 12) or late (n = 9) after transplant. All 21 cleared the antigen during follow-up and liver disease was either mild and asymptomatic (nine cases) or clinically overt (12 cases), but none had life-threatening liver disease. Several HBV-infected patients were constantly seronegative for antibody to HBcAg even in the presence of active HBV replication. These results show that the serologic pattern of HBV markers in BMT patients is unpredictable. HBV infection was rarely associated with severe hepatitis and HBsAg carriage.

Comparison of genotyping and serotyping methods for the identification of hepatitis C virus types.

The usefulness of identification of hepatitis C virus (HCV) genotype has recently been investigated for the clinical management of patients infected by HCV. In the present study, the HCV genotype infecting 127 patients was determined by two different methods: HCV genotyping using a dot-blot assay with type-specific probes derived from the 5'-UTR of HCV genome and HCV serotyping using an ELISA system in which type-specific antibodies against the NS4 region were detected. Overall, a good correlation of the two methods was observed, the main discrepancy being 4 patients with sequence-confirmed HCV-2 (2 cases) and HCV-3 (2 cases) genotypes recognized as HCV-1 by serotyping. Mixed infections were not detected by either method. In 19 PCR negative sera, in which the HCV genotype could not be evaluated, no particular serotype profile was observed. In conclusion, the molecular and serological techniques are almost equivalent in determining the viral type, although in individual cases, especially in PCR negative patients, the clinical meaning of the serotyping result remains to be determined.

Human leucocyte interferon-alpha in the treatment of chronic hepatitis C.

AIM: To assess the efficacy of different schedules of human leucocyte interferon alpha in chronic hepatitis C. PATIENTS AND METHODS: A total of 213 naive patients with chronic hepatitis C were treated with 4 different schedules of human leucocyte interferon alpha. Sustained response was defined as persistently normal alanine amino transferase values with negative serum hepatitis C virus-RNA up to 12 months after therapy withdrawal. RESULTS: Rates of sustained response were 16% with 3 MU tiw for 6 months, 33% with 6 MU tiw for 5 months after a priming dose of 9 MU tiw for a month, 32% with 3 MU tiw for 12 months and 20% with 3 MU daily for 6 months. The major factors affecting the response rate were age and the hepatitis C virus genotype, as a sustained response was significantly higher in patients under 45 years and infected by hepatitis C virus types other than hepatitis C virus-1. Treatment was well tolerated and side-effects and drop-out events were similar to those described with other types of alpha-interferons. CONCLUSIONS: Human leucocyte interferon alpha appears to be equivalent to recombinant interferon-alpha in the treatment of chronic hepatitis C.

Long-term clinical outcome after beta-interferon therapy in cirrhotic patients with chronic hepatitis C. TVVH Study Group.

BACKGROUND/AIMS: Few data are available concerning the short and long-term effects of beta-IFN in patients with chronic hepatitis C. METHODOLOGY: We randomized 61 consecutive patients with HCV-related cirrhosis to receive: a) natural beta-IFN with a 6 MU/tiw for 6 months followed by 3 MU/tiw for 6 months schedule or b) no treatment. Biochemical and virological response was defined by normalization of ALT and negativization of serum HCV-RNA. Patients were followed-up for 5 years. RESULTS: A biochemical end-of-therapy response (ETR) was observed in 5/38 patients (13%) who received beta-IFN compared to 2/23 (9%) of untreated cases, but a virological ETR appeared only in 4/38 (11%) treated cases. At long-term follow-up, 6 cases (16%) who received beta-IFN and 4 untreated (17%) developed a persistent normalization of alanine aminotransferase (ALT) but only 2 (5%) and 1 (4%), respectively, were also HCV-RNA negative. The cumulative probability of liver decompensation (variceal bleeding ascites or hepatic encephalopathy) at 60 months was 24% in treated and 35% in untreated cases. Hepatocellular carcinoma developed in 2 treated and in 1 untreated patients. CONCLUSIONS: beta-IFN therapy was not associated with a significant improvement either in biochemical or virological response in cirrhotic patients with chronic hepatitis C. No significant reduction of cirrhosis related clinical events was linked to treatment.

Squamous cell carcinoma antigen-1 (SERPINB3) polymorphism in chronic liver disease.

BACKGROUND: The serpin squamous cell carcinoma antigen (SCCA, SERPINB3) has been found over-expressed in primary liver cancer and at lower extent in cirrhosis and chronic hepatitis. A novel SCCA-1 variant (SCCA-PD), presenting a single mutation in the reactive centre (Gly351Ala), has been recently identified (rs3180227). AIM: To explore SCCA-1 polymorphism in patients with HCV infection as single etiologic factor and different extent of liver disease. METHODS: One hundred and fourty-eight patients with chronic HCV infection (45 chronic hepatitis, 53 cirrhosis, 50 HCC) and 50 controls were evaluated. SCCA-1 polymorphism was studied by restriction fragment length polymorphism and confirmed randomly by direct sequencing. Circulating SCCA-IgM complex was determined by ELISA. RESULTS: SCCA-PD was detected with higher frequency in cirrhotic patients (45.3%, odds ratio=2.62; 95%CI 1.13-6.10, p=0.038) than in patients with chronic hepatitis or in controls (24.4% and 24%, respectively). Intermediate figures were found in hepatocarcinoma (36.0%). SCCA-IgM in serum was lower in patients carrying SCCA-PD than in wild type patients and the difference was statistically significant in cirrhotic patients (mean+/-S.D.=117.45+/-54.45 U/ml vs. 268.52+/-341.27 U/ml, p=0.026). CONCLUSIONS: The newly identified SCCA-PD variant was more frequently found in liver cirrhosis, suggesting that patients carrying this polymorphism are more prone to develop progressive liver fibrosis.

Peripheral neurotoxicity of pegylated interferon alpha: a prospective study in patients with HCV.

OBJECTIVE: To assess whether pegylated interferon alpha (PEG-IFNalpha) may induce peripheral neuropathy or antibodies to peripheral nerve antigens in patients with hepatitis C virus (HCV) infection. METHODS: We studied 52 patients with HCV (38 men, 14 women; mean age 44.6 +/- 10.6 years) treated with IFNalpha. Before therapy (T(0)), patients underwent quantitative viral RNA determination, HCV genotype analysis, and neurologic and electrophysiologic evaluation. At the end (T(1)) and after therapy (T(2)), patients were neurologically and electrophysiologically re-evaluated. Antibodies to gangliosides and sulfatides were assayed by ELISA at T(0) and T(1). Twenty-three patients with HCV with comparable age, viral load, and genotype, not treated with IFNalpha, were studied as controls. RESULTS: Seven patients (six in IFNalpha, one control) had peripheral neuropathy at recruitment. No significant differences in the electrophysiologic measures were detected between T(0) and T(1) (repeated-measures analysis of variance [ANOVA]) in any of the 52 patients or in those with neuropathy at T(0). No changes were found at T(2), independent of the viral response to treatment. Two patients, one with neuropathy, had antiganglioside antibodies at recruitment. Two patients, one not treated with IFNalpha, developed low antibody titers during follow-up, without symptoms or signs of neuropathy. CONCLUSIONS: Pegylated interferon alpha therapy was not associated with the occurrence (or worsening) of peripheral neuropathy or antibodies to peripheral nerve antigens in patients with hepatitis C virus.

Natural history of hepatitis C.

Ten years after the discovery of the hepatitis C virus (HCV) and its association with NANB hepatitis as a major cause of chronic liver disease worldwide, our knowledge of the natural history of hepatitis C is still limited. The asymptomatic course of the disease in most patients, its slow and silent progression and heterogeneous outcome and the widespread use of interferon therapy during the past decade explain why many questions are still unsolved. The changing epidemiological pattern of HCV and the significant contribution of several cofactors to the severity of liver disease also complicate the development of a general model describing the natural history of hepatitis C. Available data indicate that HCV infection may resolve without any clinical signs of liver disease in individuals exposed to low dose inoculum and that these cases may develop T cell immunity even in the absence of anti-HCV seroconversion. Rates of complete biochemical and virological resolution of acute hepatitis C range between 10 and 50%, and are probably affected by the route of infection, size and type of inoculum and acute phase clinical features. Chronic HCV infection may develop with or without ALT abnormalities and with or without chronic inflammation and increasing fibrosis in the liver. Studies conducted in patients who acquired hepatitis C by blood transfusion 15-25 years ago indicate that 20-30% of them have now progressed to cirrhosis, including 5-10% with end stage liver disease and 4-8% who died of liver-related causes. Similar studies conducted in patients infected by other routes have shown a more benign course of hepatitis C, with little evidence of cirrhosis and no liver-related mortality during the first two decades. Outcomes after longer follow-up need to be assessed. In patients presenting with chronic hepatitis C, fibrosis progression is extremely variable over time and can be partially predicted by the age at infection, disease duration, liver histologic activity and stage of fibrosis and by the ALT profile. However, it is often difficult to predict clinical outcomes in individual cases. In patients who have developed cirrhosis, the 5-year risk of decompensation is between 15 and 20% and that of hepatocellular carcinoma around 10%. Several variables have been shown to influence the natural course of shown C, the most significant being age at infection, alcohol consumption and coinfection with HBV and HIV Studies are being performed to assess the role of host genetics. Viral factors, such as the HCV type and load, seem to have inconsistent or marginal effects.

The effect of interferon alfa and ribavirin combination therapy in naive patients with chronic hepatitis C.

BACKGROUND: Chronic hepatitis C may lead to cirrhosis and hepatocellular carcinoma in a subset of patients. Because response rates with interferon alfa therapy are unsatisfactory, new therapies are needed. METHODS: We conducted a three-arm, randomized trial in 45 interferon-naive men (mean age 40.6 +/- 12 years) with chronic hepatitis C to compare treatments: group A, ribavirin alone (15 mg/kg daily for 6 months); group B, interferon alone (3 MU thrice weekly for 6 months); and group C, interferon plus ribavirin at the above doses. Histologic outcomes of therapy were assessed by pretreatment and post-treatment liver biopsies. RESULTS: In group A, alanine aminotransferase levels normalized during therapy in 66% of those with HCV-1b and 34% of those with HCV-2a, but all patients relapsed after treatment ended. In group B, alanine aminotransferase levels normalized during treatment in 66%, 75%, and 100% of patients infected with HCV-1b, HCV-2a, and HCV-3, respectively; however, a sustained response was noted in only 25% of those with HCV-3. In group C, a sustained normalization of alanine aminotransferase with negative serum HCV RNA was seen in 20% of those with HCV-1b, 40% of those with HCV-2a, and 75% of those with HCV-3 12 months after therapy. One year after therapy ended, group C demonstrated a significant sustained response (47%) as well as a significant reduction in piecemeal necrosis and portal inflammation (p < 0.05). CONCLUSIONS: Combination therapy was significantly superior to ribavirin or interferon monotherapy in producing a sustained response in interferon-naive patients with chronic hepatitis C (p < 0.05). The results of our study suggest that ribavirin potentiates the effect of interferon therapy in chronic hepatitis C.

Concurrent hepatitis B and C virus infection and risk of hepatocellular carcinoma in cirrhosis. A prospective study.

BACKGROUND: Patients with cirrhosis have a high risk of hepatocellular carcinoma (HCC) but it is unclear how the etiology of liver disease influences tumor development. The authors evaluated hepatitis B and C virus (HBV, HCV) infection in cirrhosis in relation to the risk of HCC. METHODS: Two hundred and ninety consecutive cirrhotic patients were followed prospectively with periodic ultrasound examination. At entry, patients were tested for markers of HBV and HCV to assess relation to tumor development during follow-up. RESULTS: Twenty and five-tenths percent of patients were hepatitis B surface antigen (HBsAg) positive and 68.9% were positive for HCV antibodies. Previous alcohol abuse was present in 26.2%. During follow-up (46.3 +/- 21.4 months), HCC developed in 32 patients (11.0%) (annual incidence approximately 3%) including 19.6% of HBsAg-positive patients, 12.2% of HCV antibody positive patients and 14.4% of patients with a history of alcohol abuse. The highest rate of HCC was in patients with dual HBsAg and anti-HCV positivity with or without previous alcohol abuse, whereas the lowest incidence (0%) was in cases without risk factors. By univariate analysis, age older than 59 years (P < 0.005), longer duration of cirrhosis (P < 0.005), serum alpha-fetoprotein levels higher than 20 ng/ml (P < 0.05), and dual HBsAg and HCV positivity (P < 0.02) appeared to be associated with HCC. By multivariate analysis, age (P < 0.01), positivity for HBsAg and HCV antibodies (P < 0.05), male sex (P < 0.05), and previous alcohol abuse (P < 0.08) were independently related to tumor appearance. CONCLUSIONS: These results, although confirming that male sex and previous alcohol abuse are risk factors for hepatocellular carcinoma in cirrhosis, indicate that concurrent hepatitis B and C virus infection determines the highest risk of developing hepatocellular carcinoma.

Serum markers of hepatic fibrogenesis in chronic hepatitis type C treated with alfa-2A interferon.

Hepatic fibrogenesis is a dynamic process which characterizes the course of chronic hepatitis. It has stimulated interest in the possible effect of interferon therapy on liver fibrosis. We have evaluated a panel of serum markers of fibrogenesis, namely N-terminal procollagen III peptide (PII-INP), C-terminal procollagen I peptide (PICP), laminin and hyaluronate in 35 patients with chronic hepatitis type C, before, during and after interferon treatment. Before treatment, PIIINP was elevated in 8.5%, 44% and 71% of patients with chronic persistent hepatitis, chronic active hepatitis and cirrhosis, respectively, while the corresponding figures for PICP were 0%, 50% and 46%, and for laminin 16.5%, 70% and 71%; hyaluronate was elevated in only five out of seven patients with cirrhosis. Patients with high PIIINP levels at presentation and a persistent response to treatment showed persistent normalization of this parameter, which was not observed in non-responders. In contrast, the other markers showed no significant correlation with interferon response. These results indicate that PIIINP correlates with interferon response in chronic hepatitis type C.

A model to predict long-term sustained response to interferon therapy in chronic hepatitis C.

Interferon therapy is used widely for chronic hepatitis C but only a minority of treated patients achieve a long-lasting sustained response. We have developed, by logistic regression, a mathematical model to estimate the probability of sustained response in an individual patient with chronic hepatitis C when treated with interferon-alpha (IFN-alpha). The model, which includes age, sex, disease duration, pretreatment serum gamma-glutamyl-transpeptidase, alanine aminotransferase and virus genotype, was developed from a database of 307 patients and validated in a new set of 200 patients. It performed well as goodness-of-fit (P = 0.71 and P = 0.15 in the development and test sample, respectively) and discrimination (area under receiver operating curve = 0.79 in the development and 0.78 in the test sample, respectively). This model may provide decision support in the treatment of chronic hepatitis C with IFN-alpha.

Serum hepatitis B virus DNA in acute hepatitis type B.

Sera obtained within 7 days after clinical onset of acute hepatitis type B were positive for hepatitis B virus (HBV) DNA by spot hybridization only in 4 out of 45 patients who subsequently recovered, but in 10 out of 10 patients who instead developed chronic infection. These results indicate that in uncomplicated acute hepatitis B, virus replication is limited to an early phase of infection, often preceding the onset of clinical symptoms, and suggest that serum HBV-DNA may represent an early and predictive marker of chronicity.

Monoclonal radioimmunoassay for hepatitis B surface antigen in sera of children with acute leukemia.

Hepatitis B surface antigen (HBsAg) was detected by a monoclonal antibody radioimmunoassay in sera from five of 43 children (11.6%) with acute leukemia, who were negative by conventional assay. None of the nine positive sera had evidence of reactivity for HBV-DNA or DNA-polymerase activity. No correlation was found between the presence of HBsAg in serum by monoclonal RIA and the behaviour of anti-viral antibodies. Twenty-two children could be studied for liver HBsAg by immunofluorescence, and nine of them (40.9%) were positive, including three patients having HBsAg reactivity in serum. These data indicate that monoclonal antibodies increase the sensitivity of RIA for the detection of serum HBsAg in children with acute leukemia, who previously have frequently been found to have an atypical hepatitis B virus (HBV) serology.

Hepatitis B core antigen (HBcAg) in serum of patients with chronic hepatitis B detected by a modified radioimmunoassay.

Serum hepatitis B core antigen (HBcAg) was investigated in 85 patients with chronic hepatitis B virus (HBV) infection using a modified radioimmunoassay technique, based on high molarity treatment of samples to avoid masking of the antigen by the excess homologous antibody. Eighty-eight percent of HBeAg-positive cases and 19% of anti-HBe-positive cases were HBcAg positive in serum, with a positive correlation with the presence of HBcAg in the liver. Although the sensitivity of the method for the presence of complete virions was not absolute, as shown by the comparison with serum HBV-DNA testing, this technique may be helpful for assessing virus synthesis in patients with HBV infection.