Hepatitis B and C (HBV/HCV) coinfected patients have a potential risk of hepatitis B reactivation (HBVr) after direct-acting antivirals (DAAs) treatment. The study intends to investigate the predictive role of HBV biomarkers in HBVr. Forty-six HBV/HCV coinfected patients receiving DAAs were enrolled. All patients completed treatment and follow-up to the 12th-week post-DAA treatment (P12). Blood samples were measured for HBV biomarkers, including hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg), and HBV pregenomic RNA (HBV pgRNA). The predictive factors for HBVr after DAA treatment were analyzed. Among 31 patients without nucleot(s)ide analogue (NA) treatment, seven (22.5%, 7/31) developed HBVr without hepatitis flare-up. Patients with HBVr had higher HBsAg titers than those without HBVr from baseline to P12 (p = 0.008, 0.009, 0.004, and 0.006 at baseline, week 4, end of treatment, and P12, respectively). The baseline HBsAg level was the only predictive factor associated with HBVr (HR, 2.303; 95% CI, 1.086−4.882; p = 0.030). In predicting HBVr, a baseline HBsAg titer > 20 IU/mL had a sensitivity, specificity, positive predictive value, and negative predictive value of 85.7%, 75.0%, 50%, and 94.7%, respectively. No patient had HBVr if the baseline HBsAg titer was <8 IU/mL. Serum HBcrAg and HBV pgRNA levels had no role in predicting HBVr. In conclusion, HBV/HCV coinfected patients are at risk of HBVr after DAA treatment. The baseline HBsAg level was the predictive factor associated with HBVr. Patients with a baseline HBsAg titer < 8 IU/mL can be considered as not having HBVr.

Hepatitis B (HBV) and Hepatitis C (HCV) infection place a significant burden on the global health system, with chronic carriage leading to cirrhosis and hepatocellular carcinoma. HBV/HCV coinfection can be seen in highly endemic areas and present a heterogenous group given varying virologic profiles. Coinfected patients have a greater risk of advanced liver disease; hence, diagnosis and early antiviral therapy (AVT) should be a priority. Optimal treatment regimens for coinfected patients remain unknown with differing recommendations, particularly relating to the risk of HBV reactivation whilst on AVT for HCV.

This article summarizes the available data on HBV/HCV coinfection with regards to epidemiology, virologic interactions, and risk of HBV reactivation. The authors also provide a framework for the assessment and treatment of coinfected patients.

There is a moderate risk of HBV reactivation in hepatitis B surface antigen (HBsAg) positive patients undergoing HCV direct-acting antiviral (DAA) treatment; however, clinically significant events are rare. The risk of HBV reactivation in HBsAg negative patients undergoing HCV DAA treatment is negligible. Thus, prophylactic HBV treatment in both groups is not required. The authors recommend close monitoring with HBV treatment if there is evidence of HBV reactivation or elevated alanine aminotransferase levels.

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

HBV and HCV are both hepatotrophic pathogens that share common routes of transmission, namely through exposure to infected blood and body fluids. Available natural history studies suggest dual infection with HBV and HCV increases the risk of progressive liver disease, and the risk of cirrhosis and liver cancer. Owing to the dynamic nature of these chronic infections, with fluctuations in viral level and disease activity, close monitoring is needed to determine the appropriate time to intervene with treatment. The clinical profile most commonly encountered is for active HCV infection (HCV RNA-positive) with or without active HBV infection (HBsAg-positive with variable HBV DNA levels). For these patients, treatment with pegylated interferon and ribavirin is the treatment of choice. For those with HBV-predominant disease (and HCV RNA-undetectable), the treatment is identical to that with HBV infection alone. For patients unresponsive to these initial treatments, there are no specific guidelines, and additional studies to define the treatment algorithms for nonresponders or relapsers are needed.

Because of the shared modes of transmission, hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection is not uncommon in highly endemic areas and among subjects with a high risk of parenteral infections. The worldwide prevalence of HBV/HCV coinfection is unknown and might be underestimated with the phenomenon of silent (occult) HBV infection. HCV superinfection in patients with chronic HBV infection was the most common clinical features of coinfection in Asia-Pacific countries. Further, most, but not all, clinical observations suggested that interference between the two viruses was more frequently characterized by an inhibition of HBV replication exerted by HCV. However, longitudinal follow-up studies have demonstrated that the virological patterns in coinfection cases are widely divergent and have dynamic profiles over time. As compared with monoinfected patients, HBV/HCV coinfected persons tend to have more severe liver injury, a higher probability of liver cirrhosis and hepatic decompensation, and a higher incidence of hepatocellular carcinoma. Detailed serological and virological evaluations are required for coinfected patients before initiation of antiviral therapy. Previous studies demonstrated that HBV/HCV coinfected patients responded poorly to interferon (IFN) monotherapy. Currently, for patients with dominant HCV infection and low level HBV viremia (<10(4) IU/mL), IFN or pegylated IFN plus ribavirin can achieve comparable sustained virus response as expected with HCV monoinfection. However, phenomenon of reciprocal viral interference can happen, and resultant "flare" of hepatitis activity may cause liver function deterioration. For coinfected patients with dually-active HBV/HCV, the optimal regimen for therapy remains unclear although adding oral nucleos(t)ide analogs to pegylated IFN and ribavirin seems a reasonable empiric option.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. Because the two hepatotropic viruses share same modes of transmission, coinfection with the two viruses is not uncommon, especially in areas with a high prevalence of HBV infection and among people at high risk for parenteral infection. Patients with dual HBV and HCV infection have more severe liver disease, and are at an increased risk for progression to hepatocellular carcinoma (HCC). Treatment of viral hepatitis due to dual HBV/HCV infection represents a challenge.

Patients with dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection have responded poorly to interferon (IFN) monotherapy. The purpose of the present paper was to assess the effect of combined IFN-alpha and ribavirin therapy in patients infected with both hepatitis B and C.

Thirty-six patients received 3 or 5 MU IFN-alpha-2b thrice weekly and oral ribavirin (800-1200 mg/day) for 24 weeks. All patients had positive hepatitis B surface antigen, antibody to HCV, and HCV-RNA. Before treatment, one patient had positive hepatitis B e antigen. Eighteen patients had positive HBV-DNA tested by Amplicor (Cobas Amplicor Monitor, Roche Diagnostics, Branchburg, NJ, USA), with a mean HBV-DNA level of 3.1 +/- 0.9 log copies/mL. Another 72 patients with HCV infection alone served as controls.

Adverse events led to withdrawal in three patients receiving 5 MU IFN. Based on an intent-to-treat analysis, the biochemical response and serum HCV clearance rate at the end of 48 weeks follow up was similar in patients with dual infection and HCV infection alone (56% vs 72%; and 69% vs 71%, respectively). There was no significant difference in sustained HCV clearance rate between the 3-MU group (n = 13) and the 5-MU group (n = 23; 85% vs 61%). At the end of 48 weeks follow up, two (11%) of 18 pretreatment viremic patients had negative serum HBV-DNA (<200 copies/mL), while eight of those without pretreatment viremia had re-occurrence of HBV-DNA.

Combination therapy with IFN-alpha and ribavirin was effective in achieving sustained HCV clearance in patients with dual HBV and HCV infection, comparable to those with hepatitis C infection alone. Combination therapy using 3 MU IFN-alpha seemed as effective as 5 MU, and was well tolerated in the study population. However, large-scale control trials are necessary to clarify these findings.

In patients with multiple hepatotropic viral infections (B and C, or B, C and D), the reciprocal influence of each virus remains controversial. The aims of this study were twofold: first, to determine the impact of multiple infection on the replication status of B, C and D viruses and on histological features; and second, to compare patients with multiple infection to patients infected only with the hepatitis C virus (HCV). We retrospectively included 50 patients with multiple infection and 50 control HCV patients, who were matched on independent factors associated with fibrosis, such as age, gender, alcohol consumption and duration of infection. The replication status of hepatitis B virus (HBV), HCV and hepatitis D virus (HDV), and histological lesions, were determined. In patients with multiple infection, HCV RNA was present less frequently (44% vs 98%, P < 0.001) and the prevalence of cirrhosis was higher (35% vs 8%, P < 0.001). Among patients with triple infection (n = 16), HBV replication was observed in 25%, HCV RNA was detectable in only two (P < 0.0001) and HCV viremia was significantly lower than in the matched HCV patients (0 vs 54.7, P < 0.0001). Among patients with dual infection (n = 34), HCV RNA was present less frequently in those with serological markers of active HBV infection than in those without (30% vs 79%, P = 0.01). Hence, multiple infection is associated with a decrease of HCV replication. Cirrhosis seems to be more frequently observed in patients with multiple infection. In patients with triple infection, serum HCV RNA and markers of HBV replication were absent in 80%, suggesting that HDV acts as a dominant virus. In patients with dual infection, HBV and HCV exert an alternative, dominant replication.

The treatment of patients with HCV in itself represents a challenge for the treating physicians, but is particularly difficult in special situations where experience is limited. In patients with normal aminotransferases or an incomplete response to IFN, the safety of IFN administration is not the major issue, but one should consider the limited effectiveness of the therapy. In other patients, such as those with concomitant autoimmune hepatitis, an immunosuppressed state or a major psychiatric illness, IFN can be administered but may be associated with serious risks. In these cases, IFN should be used under strictly supervised circumstances and only by physicians with considerable familiarity with the drug. After needle stick exposures, IFN may prevent progression of acute infection to chronic hepatitis. Finally, in patients with well-established cirrhosis, IFN treatment may prevent decomposition or the development of hepatocellular carcinoma. In each of these categories, treatment must be tailored to the individual case based on good clinical judgment. It is hoped that greater experience, newer therapies, and a better understanding of the natural history of HCV infection will simplify the treatment of these cases that currently present difficult management problems.

The aim of this study was to assess the implications of dual infection with hepatitis B virus (HBV) and hepatitis C virus (HCV). The HBV and HCV status in 100 patients with chronic hepatitis was analysed. HBV DNA was studied using liquid hybridization and the polymerase chain reaction (PCR). HCV viremia was measured using qualitative and quantitative PCR. The HCV genotype was determined by PCR. Patients were divided into three groups according to their HCV-RNA and HBsAg status: group I consisted of 40 patients with chronic hepatitis caused by HBV; group II, 40 patients with chronic hepatitis caused by HCV; and group III, 20 patients infected with both viruses. The HBV-DNA level was higher in group I than in group III (66.4 vs. 11.5 pg/ml; p < 0.05). Quantification of HCV viremia revealed mean values of 36.9 copies x 10(5)/ml in group II and 5.5 copies/ml x 10(5) in group III (p < 0.05). The mean aminotransferase level and histological activity were higher in group III. HCV genotype lb was the predominant type. The data suggest that there is reciprocal inhibition of viral replication in patients with dual HBV and HCV infection. Liver disease appears to be more severe in patients with chronic hepatitis B and C.

Many of the current reverse transcription (RT)-PCR assays for the detection of hepatitis C virus (HCV) RNA are multistep processes which use multiple enzymes and buffers. The assays are also often suboptimal, requiring nested amplification to achieve the desired levels of sensitivity. As a result, these assays are cumbersome and prone to false-positive results. The susceptibility to contamination is further aggravated by the lack of carryover controls. We have previously reported the development of a combined RT-PCR assay for HCV RNA detection which is sensitive and simple to perform. We have since successfully integrated dUTP-uracil-N-glycosylase carryover prevention into the combined assay. Restriction of as much as 0.5 microliter of deoxyuridine-containing amplification products has been achieved. The performance of the improved combined assay was compared directly with conventional nested RT-PCR and antibody detection. The combined assay was found to have sensitivity similar to that of nested RT-PCR in detecting HCV RNA from HCV antibody-positive specimens. In an analysis of hepatitis B virus antibody-positive specimens, nested amplification had false-positive rates ranging from 8 to 31%, while no false-positive results were seen with the combined assay. In comparison with serological methods, the combined assay had specificity and sensitivity of 100 and 95%, respectively.

To assess the influence of HBV infection on anti-HCV-positive chronic liver disease, we performed a prospective case-control study comparing 19 HBsAg-positive, anti-HCV-positive patients with 38 HBsAg-negative, anti-HCV-positive patients, pair-matched for age, sex, and ALT levels. HBV and HCV infections were investigated by standard serology and polymerase chain reaction. HCV RNA was found in all patients with CAH and in 90.0% with cirrhosis (33% HBsAg-positive). HBV DNA sequences were found, in the HBsAg-positive subjects, in 71.4% of CAH and in 83.3% of cirrhotics; in the HBsAg-negative ones, only 10% of CAH but 77.7% of cirrhotics had demonstrable HBV DNA sequences. Consequently, 80.0% of cirrhotics had evidence of both HBV and HCV infection. Conventional serology gives partial information on the true occurrence of HBV infection in HBsAg-negative patients, while PCR defines more accurately the HBV status. When the rate of double infection is defined in this way, it correlates with the presence of cirrhosis.

Hepatitis B and C viruses (HBV and HCV, respectively) are associated with acute and chronic liver diseases and hepatocellular carcinoma. To elucidate the molecular status of superinfection with these two hepatitis viruses, we cotransfected the full-length or truncated version of HCV structural genes (core and envelope 1) together with the cloned HBV DNA into a human hepatoma cell line (HuH-7). Expression of HBV-specific major transcripts (3.5 and 2.1 kb), as well as HBV antigens (hepatitis B surface antigen and hepatitis B e and core antigens), was reduced about two- to fourfold by the presence of the HCV structural genes. In addition, the secretion of HBV viral particles, including the viral nucleocapsid and mature virion, was drastically suppressed about 20-fold. Analysis of the intracellular HBV core protein-associated nucleic acid indicated that the encapsidated HBV pregenomic RNA was similarly reduced about 14-fold. Deletion analysis of the HCV structural genes demonstrated that the core gene alone or the fragment containing the core protein's N-terminal 122 amino acid residues conferred the same level of suppressive activity as the full-length structural genes. By indirect immunofluorescence, we found that the core protein of HCV was located in the cytoplasm of transfected HuH-7 cells at day 3 posttransfection and was targeted to the nucleus at day 6. Thus, the kinetics of the suppressive effect exerted by HCV constructs matched the timing of core protein entrance into the nucleus. Our results substantiate the clinical finding that HBV markers are suppressed by superinfection with HCV and further imply that this inhibitory effect may occur in the processes of transcription and encapsidation of HBV pregenomic RNA and may be mediated by the core protein of HCV. The deduced amino acid sequence of the HCV core protein has revealed that it is a basic protein which contains a putative DNA-binding motif (SPRG), as well as triplicate nuclear localization signals and several putative protein kinase A and C recognition sites. These characteristics imply that the HCV core protein can also function as a gene-regulatory protein.