Occult hepatitis B virus infection does not affect liver histology or response to therapy with interferon alpha and ribavirin in intravenous drug users with chronic hepatitis C

Prevalence of occult hepatitis B virus infection in Egypt: a systematic review with meta-analysis

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is a major public health problem. The clinical importance of OBI stems from the fact that it can be transmitted to healthy individuals at extremely low viral load levels. Additionally, immunosuppression has the potential to trigger viral replication, which can result in life-threatening liver decompensation. Despite several studies examining the prevalence of OBI, the pooled prevalence of OBI in Egypt remains unknown, particularly among blood donors and high-risk individuals, to whom intervention should be targeted.

METHODS

A comprehensive literature search of the following databases was conducted from inception to October 2022 using the following keywords: occult hepatitis B virus infection or occult HBV infection or OBI and Egypt in MEDLINE [PubMed], Scopus, Google Scholar, and Web of Science. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. I-squared and Cochran's Q were used to measure the heterogeneity between the studies, and based on the random effects model, results were reported as proportions (%) with a 95% confidence interval (CI). Analyses of subgroup analyses were conducted based on the target population. Sensitivity analyses were conducted using the leave-one-out approach to test the robustness of the results.

RESULTS

A total of 50 studies with 62 estimations of OBI were included, 19 in patients who were HBsAg-negative and anti-HBc-positive and 43 in patients who were HBsAg-negative. The highest prevalence (41%) was among multi-transfused patients according to  studies that report occult hepatitis B virus prevalence in an HBsAg-negative population, while the pooled prevalence of OBI among patients on hemodialysis, patients with chronic hepatitis C infection, patients with hepatocellular carcinoma (HCC), and patients with liver cirrhosis was 17%, 10%, 24%, and 13%, respectively. On the other hand, among studies that report OBI prevalence in HBsAg-negative and anti-HBc-positive individuals, the pooled prevalence of OBI among blood donors, patients with chronic hepatitis C infection, and patients with HCC was 12%, 15%, and 31%, respectively. Also, the majority of studies examining the genetic background of OBI have found that genotype D is the most prevalent.

CONCLUSION

 This study highlights the high prevalence in OBI among blood donors and high-risk populations in Egypt. The implementation of HBV nucleic acid amplification testing (NAT) may increase the safety of blood transfusions by excluding all HBV DNA-positive donations. However, the cost-effectiveness of these tests should be investigated.

Occult Hepatitis (B) Infection in Hepatitis (C) Virus Infection Patients after the Treatment with Direct Acting Antiviral Drugs

Background: The prevalence of occult hepatitis B ranges widely in patients with hepatitis C. This may have an impact on treatment of hepatitis C. Aims: The current study aimed to evaluate the prevalence of occult hepatitis B infection in chronic hepatitis C patients who finished the course of treatment with direct acting antiviral drugs and it’s correlation with treatment failure. Setting: Outpatient Clinic of Internal Medicine Department, Faculty of Medicine, Menoufia University, Egypt. Patients and methods: This study was conducted on 900 Egyptian patients chronically infected with HCV. All patients tested positive for serum real time polymerase chain reaction for HCV- RNA and received DAAs therapy for 12 weeks. Patients were categorized to:  Group I: 450 patients with chronic hepatitis C after direct antiviral treatment who responded to treatment. Group II: 450 patients with chronic hepatitis C after direct antiviral treatment who didn’t respond to treatment. All patients were submitted to clinical examination, laboratory investigations and abdominal ultrasonography. Detection of HBV- DNA and HCV- RNA was performed by PCR. Results: The prevalence of OBI detected in sera of HCV patients was 10.6 % (96/900). The present study showed no significant correlation between prevalence of OBI and virologic failure (p-value: 0.084).  There was no statistically significant difference (p-value > 0.05) between the studied groups as regard prevalence of OBI. Conclusion: The prevalence of OBI was 10.6% in patients chronically infected with HCV. OBI doesn't affect the anti-HCV DAAs outcomes.

Prevalence of occult HBV infection in Western countries

Due to a lack of standardized tests, it is difficult to obtain prevalence data and define the real impact of occult HBV infection (OBI) in Western countries. The present review article addresses the prevalence of OBI, defined as presence of hepatitis B virus (HBV) DNA in liver tissue or plasma in HBsAg-negative subjects, in Western countries. This varies in different studies according to the different methodologies used (based on serology vs virology), to the sample analyzed for the diagnosis (liver tissue vs plasma), to the different populations studied, to the different geographical variations in the HBV spread, to the host characteristics (age, gender, risk factors for acquiring HBV infection) and to the presence of other parenteral infections (hepatitis C virus and/or human immunodeficiency virus [HIV] infections). Considering the different liver diseases analyzed, that is in patients with cryptogenic cirrhosis or advanced liver fibrosis, the prevalence of OBI ranges 4% to 38%. Considering the different populations studied, in the case of parenteral blood exposure it is about 45%, in patients with chronic hepatitis C it is estimated at about 52%, in HIV-infected patients it ranges from 0% to 45%, in blood donors from 0% to 22.7% and in hemodialysis patients it ranges from 0% to 54%. In conclusion, OBI is a virological entity to be considered when performing the patient's evaluation for immunosuppressive diseases, liver pathologies, or for blood transfusions. Knowing the prevalence and clinical impact of OBI will allow better patient management.

An estimation of the prevalence of occult HBV infection in Western Europe and in Northern America: A meta-analysis

Data on the prevalence of occult HBV infection (OBI) in Western Europe and in Northern America are few; hence, we conducted a systematic review and meta-analysis. All studies included had to fulfil the following inclusion criteria: (a) they investigated the prevalence of OBI (HBV DNA in liver tissue in HBsAg-negative subjects), (b) were carried out in Western Europe and in Northern America; (c) were available as a full-text manuscript, (d) written in English and (e) published up to December 2018. The exclusion criteria were as follows: (a) meta-analyses, letters, reviews, meeting abstracts or editorial comments; (b) studies investigating HBsAg-positive patients; (c) those investigating OBI outside Western Europe and in Northern America; and (d) to avoid small sample bias in the random-effects model, those enrolling less than five subjects. Thirty-four studies met the inclusion criteria, allowing a meta-analysis on 2729 patients. The overall prevalence of OBI was 34% (95% CI = 26%-42%), 28% (CI 95%: 12%-48%) in 329 subjects without chronic liver disease and 35% (95% CI 26%-44%) in 2400 patients with chronic liver disease. The prevalence of OBI was 51% (95% CI 40%-62%) in the 823 anti-HBc-positive subjects and 19% (95% CI 10%-30%) in the 1,041 anti-HBc-negative subjects. Evaluating the data from 17 studies comparing anti-HBc-positive and negative subjects, the prevalence of OBI was higher in the 641 anti-HBc-positive subjects than in the 1041 anti-HBc-negative (prevalence ratio = 2.29; 95% CI = 1.61-3.26, P < .001). This meta-analysis showed that in HBsAg-negative subjects the prevalence of OBI was high and was associated with anti-HBc positivity.

Evaluation of impact of occult hepatitis B infection in chronic HCV-infected patients: A retrospective cohort study

CONTEXT

Occult hepatitis B infection (OBI) may contribute to liver damage and variable therapeutic response in patients with chronic hepatitis C (CHC) infection.

AIMS

To study the prevalence of OBI and to evaluate its impact and/or that of anti-HBc total seropositivity on clinical outcomes and response to directly acting antiviral (DAA) therapy in CHC-infected patients.

SETTINGS AND DESIGN

A retrospective cohort study was conducted in a tertiary care liver hospital from January to May 2017.

SUBJECTS AND METHODS

Eighty HBsAg-negative CHC patients who were initiated on DAA therapy were retrospectively included. Archived pretreatment baseline plasma samples were retrieved and tested for quantitative HBV DNA, anti-HBs, and anti-HBc total antibodies. HCV RNA, genotype, clinical, biochemical and histopathological parameters & treatment response data were obtained from the hospital information system.

STATISTICAL ANALYSIS USED

Comparison of continuous variables was done by Mann-Whitney and Kruskal-Wallis tests and categorical variables by Fisher's exact test or Pearson's Chi-square test.

RESULTS

Prevalence of OBI was 1.25%. Anti-HBc total positivity was seen in 25% patients. Based on anti-HBc total status, patients were categorized into two groups namely Group 1 (anti-HBc positive) and Group 2 (anti-HBc negative). Group 1 patients were further categorized into three subgroups based on signal/cutoff (S/Co) of HBc total antibody semi-quantitative values. HBc total antibody levels did not influence the severity of CHC disease. Comparative evaluation of parameters such as median log₁₀ baseline RNA (P = 0.929 and 0.464), median alanine aminotransferase (ALT 0) (P = 0.519 and 0.449), ALT at 12 weeks (P = 0.875 and 0.594), sustained virological response (SVR) at 12 weeks (P = 0.405 and 0.263) and SVR at 24 weeks (P = 0.265 and 0.625) between Groups 1 and 2 and among three categories within Group 1, respectively, were not found to be statistically significant.

CONCLUSIONS

Very low prevalence of OBI was seen in CHC patients. HBc total antibody levels did not influence clinical outcome and response to DAA therapy in this cohort.

Hepatitis B reactivation in hepatitis B and C coinfected patients treated with antiviral agents: A systematic review and meta-analysis

There is an increased awareness of hepatitis B (HBV) reactivation in chronic hepatitis C (CHC) patients coinfected with HBV treated with pan-oral direct-acting antiviral agents (DAAs). We performed a systematic review and meta-analysis to compare the rate of HBV reactivation in CHC patients coinfected with overt HBV (hepatitis B surface antigen [HBsAg] positive) and occult HBV (HBsAg negative with positive HBV DNA) infection separately, treated with interferon (IFN)-based therapy to those with pan-oral DAAs. The primary outcome was HBV reactivation, and the secondary outcomes included hepatitis due to HBV reactivation, sustained virologic response (SVR) for CHC, loss of HBV DNA and HBsAg seroclearance. Although the pooled incidence rate of HBV reactivation, among CHC patients with overt HBV (n = 779), was similar among those treated with IFN-based therapy (14.5%, P < 0.001) and DAAs (12.2%, P = 0.03; P = 0.91 for heterogeneity between subgroups), it was reported to occur much earlier in those treated with DAAs (4-12 weeks during treatment) than in those treated with IFN-based therapies (most at the end of treatment and some during follow-up). Also, studies with DAA-based therapies were more likely to report incidence of hepatitis due to HBV reactivation (12.2% in DAAs vs. 0% in IFN; P = 0.009 for heterogeneity between subgroups). HBV reactivation and hepatitis due to HBV reactivation also occurred, though less frequently in CHC patients with occult HBV infection. CHC SVR was not affected by HBV reactivation (P = 0.27).

CONCLUSION

HBV reactivation occurs earlier and is clinically more significant in CHC patients coinfected with overt and occult HBV who are treated with pan-oral DAAs compared with IFN-based therapy. It is therefore important to have all patients screened for evidence of overt or occult HBV infection and managed during pan-oral DAAs therapy. (Hepatology 2017;66:13-26).

No response to hepatitis B vaccine in infants born to HBsAg(+) mothers is associated to the transplacental transfer of HBsAg

BACKGROUND

No or low hepatitis B (HB) vaccine response is more frequent in infants from HBsAg(+) mothers than those from HBsAg(-). Our previous study found temporary positivity of HBsAg in infants from HBsAg(+) mothers. In this study, we hypothesized that HBsAg in infant blunt immune response to standard hepatitis B vaccination.

METHODS

A total of 328 consecutive HBsAg(+) mothers and their offspring were enrolled. Blood samples were taken from mothers and their infants and quantified for HBsAg, anti-HBs titer and HBV DNA load concentration; Placenta samples were collected to stain for HBsAg.

RESULTS

First, 6.7% infants (22/328) showed anti-HBs titer lower than 10 mIU/mL after HB vaccination (non-response to HB vaccine). HBsAg(+) newborns showed higher risk of non-response than HBsAg(-) infants (13.0% versus 5.0%, p = 0.016). Infants from high HBsAg titer mothers displayed higher risk of HBsAg positivity at birth than those from low titer mothers (45.3% versus 2.8%, p < 0.001). HBsAg titer in mothers of HBsAg(+) newborns was much higher than mothers of HBsAg(-) newborns (p < 0.001). All those data supported HBsAg can be transferred through placenta. Our hypothesis was further reinforced by immunostaining with specific antibody against HBsAg, a substantial higher prevalence (87.5% versus 30.8%, p = 0.024) and stronger immunostaining (p = 0.008) was demonstrated in HBsAg(+) group comparing with placenta of the HBsAg(-) group.

CONCLUSION

No response to HB vaccine in infants of HBsAg(+) mothers was associated to the transplacental transfer of HBsAg.

PREVALENCE OF OCCULT HEPATITIS B INFECTION IN IRANIAN CANCER PATIENTS BEFORE CHEMOTHERAPY TREATMENT

BACKGROUND

Occult hepatitis B infection is characterized by negative hepatitis B surface antigen (HBsAg) and also detectable hepatitis B virus (HBV) -DNA, with or without hepatitis B core antibody (anti-HBc). HBV reactivation in individuals under immunosuppressive therapy is critical, occurring in occult HBV.

OBJECTIVE

In this study, we aimed to determine the prevalence of occult HBV infection among hepatitis B surface antigen negative in cancer patients before receiving chemotherapy.

METHODS

Sera from 204 cancer patients who were negative for HBsAg, were tested for anti-HBc antibodies. The samples that were negative for HBsAg but positive for anti-HBc also examined for HBV-DNA by polymerase chain reaction (PCR).

RESULTS

Of the 204 HBsAg negative blood samples, 11 (5.4%) samples were positive for anti-HBc antibodies. HBV-DNA was detected in 9/11 (81%) of anti-HBc positive samples. Occult HBV infection in hematological cancers was more than solid cancers, 4.8% and 4.3% respectively. There was no significant difference in HBc antibody positivity based on vaccination, previous blood transfusions, history of familial hepatitis or biochemical parameters (ALT, AST, total and direct bilirubin levels) (P>0.05).

CONCLUSION

Screening of occult HBV infection by HBsAg, HBV DNA and anti HB core antibody should be suggested as a routine investigation in cancer patients before receiving chemotherapy.

Occult hepatitis B virus infection is not associated with disease progression of chronic hepatitis C virus infection

AIM

To clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma (HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus (HCV) infection.

METHODS

This prospective cohort study enrolled 174 patients with chronic HCV infection (chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or more different viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome.

RESULTS

The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively (P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase > 40 IU/L, Child-Pugh score and sustained virologic response (SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development.

CONCLUSION

The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.

Occult hepatitis B virus infection among people with a family history of chronic hepatitis B virus infection

The prevalence of occult hepatitis B virus infection (OBI) among people with a family history of chronic hepatitis B virus (HBV) infection is unclear. Serum samples were collected from 747 hepatitis B surface antigen (HBsAg)-negative people with a family history of HBV infection and 579 HBsAg-negative volunteer blood donors. The presence of HBV DNA was evaluated using nested PCR with primers specific for the X, S, and C regions of HBV. The Pre-S1/Pre-S2/ S region PCR products for the OBI group and their family members with chronic HBV infection (control group) were sequenced and compared. The prevalence of OBI was 8.0% (60/747) among HBsAg-negative people with a family history of chronic HBV infection, compared to 2.6% (15/579) among the blood donors (P < 0.05). The prevalence of HBV genotype B infection was lower in the OBI group than in the control group (P = 0.031). The substitution rates in the major hydrophilic region and the "a" determinant seemed to be higher in the OBI group (0.893 vs. 0.507; 1.042 vs. 0.403, respectively), and stop codon mutations more frequent in the OBI sequences (OBI: 2/26, 7.7% vs.

CONTROL

0/31, 0%). However, none of these differences was statistically significant (P = 0.237, 0.199, 0.201, respectively). In summary, the prevalence of OBI among HBsAg-negative people with a family history of chronic HBV infection was significantly higher than that in Chinese blood donors. However, S region mutations and the escape mechanism are not likely to be the major causes of increased prevalence of OBI.

Prevalence of occult hepatitis B virus in plasma and peripheral blood mononuclear cell compartments of patients with chronic hepatitis C infection in tehran-iran

BACKGROUND

Occult hepatitis B virus (HBV) infection (OBI) is frequently reported in patients with chronic hepatitis C virus (HCV) infection. An association between OBI and more liver damage, cirrhosis, hepatocellular carcinoma, and reduced response to interferon therapy in patients with HCV infection is suggested.

OBJECTIVES

The aim of this study was to determine the prevalence of occult HBV, and evaluate its clinical influence on patients with chronic HCV.

PATIENTS AND METHODS

A cohort study including50 patients with positive results for HCV, and negative results for HBsAg tests was performed. The patients were divided into two groups: one group had positive results for both HCV and occult HBV tests (n = 18), and the other had positive results for HCV, but negative findings for occult HBV (n = 32). All were treated with PEG-IFN alpha-2a and Ribavirin. Presence of HCV RNA was followed in these patients.

RESULTS

HBV-DNA was detected using nested-PCR in 20% of plasma and 32.6% of peripheral blood mononuclear cell (PBMC) compartments. No significant differences were observed between patients with and without occult HBV for sex, age, duration of HCV infection, histological markers, presence of anti-HBc, HCV viral load, and HCV genotype. The response rate was significantly higher in patients with positive results for HBV-DNA test compared to those with negative findings (100% vs. 71.9 %, P < 0.05).

CONCLUSIONS

In conclusion, occult HBV was found in 36% of patients with negative results for HBsAg, but positive results for HCV. Detection of HBV-DNA in both PBMCs and plasma together in comparison with plasma alone provided more true identification of OBI.The SVR rate was significantly higher in coinfected patients than mono-infected ones.

Occult hepatitis B infection in Portuguese patients with chronic hepatitis C liver disease: prevalence and clinical significance

INTRODUCTION

Occult hepatitis B virus (HBV) infection, defined as the presence of HBV DNA in the liver (with detectable or undetectable HBV DNA in the serum), has been reported in patients with chronic hepatitis C. Some data suggest its association with a more severe liver disease and a worse response to interferon therapy in this subgroup of patients. However, the clinical significance of this condition is still under debate.

AIM

To determine the prevalence of occult HBV infection and its clinical significance in patients with chronic hepatitis C liver disease.

MATERIALS AND METHODS

A prospective analysis of consecutive outpatients with chronic hepatitis C who underwent a liver biopsy recruited between January 2008 and June 2011 was carried out. Data included patient's sex and age, source of hepatitis C virus (HCV) infection, HCV genotype and viral load, presence of serologic markers of previous HBV infection, HBV DNA presence in the liver, histologic findings, and response to interferon and ribavirin treatment. HBV DNA and HCV RNA detection were carried out using a sensitive commercially available PCR kit. HBV DNA was tested in liver samples using a nested PCR procedure.

RESULTS

One hundred patients were included, 73% men, mean age 49 ± 11.9 years. Most patients had a genotype 1, with a high viral load, HCV infection. Of the patients, 33% had HBV serologic markers of past infection. The presence of HBV DNA in liver samples was found in 57% of the patients. No statistically significant difference in the epidemiological, histological, or virological or response to therapy data was found in patients with occult HBV infection.

CONCLUSION

Occult HBV infection occurred in a high percentage of patients but was not clinically significant.

Occult hepatitis B virus infection in patients with chronic hepatitis C treated with antiviral therapy

BACKGROUND

Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the liver and/or in the serum of patients with negative results of hepatitis B s antigen (HBsAg) test with or without serological markers of previous viral exposure. The impact of OBI in patients with chronic hepatitis C (CHC) is still unclear.

OBJECTIVES

The Aim of this study was to assess OBI prevalence and its potential implications on treatment outcome in a cohort of patients with CHC underwent standard antiviral therapy.

PATIENTS AND METHODS

Baseline serum samples from 137 HBsAg-negative CHC patients treated with pegylated-interferon and ribavirin (73 Responders/74 Non Responders),were retrospectively analyzed for HBV status.

RESULTS

Seventy-three patients (53.3%) showed markers of previous exposure to HBV. HBV DNA was detected in 2 of 137 serum samples (1.5%), both carrying HBV antibodies. Liver biopsies and post-therapy sera were available for 35 patients (12 Responders/23 Non Responders). HBV DNA sequences were found in 13 of 35 specimens (37.1%), all of patients with HBV DNA negativity in basal and post-therapy serum samples. Among OBI-positive patients, 5 (38.5%) carried serological markers of HBV infection. Regarding therapy outcome, in the OBI-positive group there were 5 of 13 (38.5%) sustained virological responders (SVR) compared to 7 of 22 (31.8%) in the OBI-negative one.

CONCLUSIONS

Despite the high prevalence rate of liver HBV DNA in patients with CHC, SVR was not affected by occult HBV infection.

High prevalence of occult hepatitis B virus infection in children born to HBsAg-positive mothers despite prophylaxis with hepatitis B vaccination and HBIG

BACKGROUND & AIMS

Occult hepatitis B virus (HBV) infection is a well-recognized clinical entity characterized by the detection of HBV DNA in serum and/or liver in the absence of detectable hepatitis B surface antigen (HBsAg). The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. We aimed at determining the prevalence of occult HBV infection in a high risk group of children who developed HBV infection despite immunoprophylaxis.

METHODS

The sera of 75 children born to HBsAg-positive mothers previously immunized by HBIG and prophylaxic vaccine regimen were assayed for HBV DNA by real-time PCR. Subsequently, the samples were tested using a sensitive standard PCR, with an independent set of primers for all HBV genes, and analyzed by direct sequencing.

RESULTS

HBV DNA was detected in 21/75 (28%) children, and ranged between 77 and 9240 copies/ml. All were positive for anti-HBs. Five (24%) children were found to be positive for anti-HBc, while anti-HBc-only positive individuals were not observed. Eight isolates (38%) did not carry any mutation. Thirteen infected children (62%) had at least one mutation in regions known to be involved in functional and/or immune epitope activity. Ten had G145R mutations.

CONCLUSIONS

HBV occult infection seems to be relatively frequent in immunized children born to HBsAg-positive mothers. HBsAg negativity is not sufficient to completely exclude HBV DNA presence. These findings emphasize the importance of considering occult HBV infection in hypo-endemic areas.

Molecular mechanisms underlying occult hepatitis B virus infection

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.

Molecular mechanisms underlying occult hepatitis B virus infection

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.

Role of occult hepatitis B virus in chronic hepatitis C patients with flare of liver enzymes

BACKGROUND

Occult HBV infection is defined by detection of HBV DNA in the serum or liver tissue of patients who test negative for HBsAg. The prevalence of occult HBV is higher in hepatitis C virus (HCV) positive patients than HCV negative patients and may have an impact on their clinical outcome. In this study, we evaluated the role of occult hepatitis B virus infection in chronic hepatitis C patients with ALT flare.

METHODS

Sixty HBsAg negative patients with chronic hepatitis C virus infection were included. Patients were divided into 2 groups according to their ALT level: 30 patients with normal or slightly high ALT and 30 patients with ALT flare (≥ 5 times normal values). Patients in both groups were examined for the detection of anti-HBs, anti-HBc IgM, and anti-HBc IgG. HBV DNA was detected using semi-nested PCR technique.

RESULTS

In patients with normal or slightly high ALT, HBV DNA was detected in 4 (13.3%) patients, while in those with ALT flare, HBV DNA was detected in 19 (63.3%) patients (p<0.001). No association was found between the presence of HBV DNA and various serology markers of HBV infection.

CONCLUSION

Presence of occult hepatitis B, with its added deleterious effect, must always be considered in chronic hepatitis C patients especially those with flare in liver enzymes; HBsAg should not be used alone for the diagnosis of HBV infection.

Influence of occult hepatitis B virus infection in chronic hepatitis C outcomes

Persistence of hepatitis B virus-DNA in the sera, peripheral blood mononuclear cells or in the liver of hepatitis B surface antigen (HBsAg)-negative patients with or without serological markers of previous exposure (antibodies to HBsAg and/or to HB-core antigen) defines the entity called occult hepatitis B infection (OBI). Co-infection with hepatitis B and hepatitis C viruses is frequent in highly endemic areas. While this co-infection increases the risk of liver disease progression, development of cirrhosis and hepatocellular carcinoma and also increases the rate of therapeutic failure to interferon-based treatments than either virus alone, a potentially negative effect of OBI on clinical outcomes and of therapeutic response to current antiviral regimes of patients with chronic hepatitis C remains inconclusive.

Occult hepatitis B infection in egyptian chronic hepatitis C patients: prevalence, impact on pegylated interferon/ribavirin therapy

BACKGROUND

Chronic HCV infection combined with occult hepatitis B infection has been associated with liver enzymes flare, advanced hepatic fibrosis and cirrhosis, poor response to standard interferon-α, and increased risk of HCC. This study aimed to elucidate the prevalence of occult hepatitis B infection in Egyptian chronic HCV patients, and to clarify its role in non-response of those patients to pegylated interferon/ribavirin therapy. This study enrolled 155 consecutive chronic HCV patients under pegylated interferon/ribavirin therapy. All patients were exposed to clinical assessment, biochemical, histological and virological examinations. HBV parameters (HBV DNA, anti-HBc, anti-HBs) and patients' response status to the combination therapy were determined.

RESULTS

In this study, occult hepatitis B infection occurs in 3.9% of Egyptian chronic HCV patients; tends to affect younger age patients, associated with higher base line HCV viral load, less hepatic fibrosis than monoinfected patients. This occult hepatitis B infection is not a statistically significant cause of non-response to pegylated interferon/ribavirin therapy. Anti-HBs was not associated with any biochemical, histological or virological abnormalities in those patients, contrary to low response rate to therapy and higher HCV viral load that was observed with anti-HBc.

CONCLUSIONS

Detection of HBV DNA in HBsAg negative chronic HCV patients plays a non significant role in non-response of Egyptian patients to pegylated interferon/ribavirin therapy.

Current Concepts of HBV/HCV Coinfection: Coexistence, but Not Necessarily in Harmony

Hepatitis B and hepatitis C are important causes of chronic liver disease globally. Although HBV/HCV coinfection is not uncommon, its epidemiology is poorly defined. Numerous studies provided evidence that coinfection accelerates liver disease progression and increases the risk of hepatocellular carcinoma. By applying new cell culture models to examine the interaction of both viruses, investigators concluded that HBV and HCV replicate in the same hepatocyte without interference. The roles of innate and adaptive immunity in determining the viral replication and disease outcomes still need rigorous investigation. To date, no standard-of-care recommendation exists for HBV/HCV coinfection. Pegylated interferon and ribavirin combination therapy demonstrated similar efficacy in suppressing HCV RNA in coinfection and HCV monoinfection. However, HBV reactivation during therapy can be a challenge. Future clinical trials evaluating the addition of a nucleoside/nucleotide analog for selective patients with HBV/HCV coinfection are essential for successful management of HBV/HCV coinfection.

Treatment of HBV/HCV coinfection

IMPORTANCE OF THE FIELD

Hepatitis B (HBV) and hepatitis C (HCV) virus infections are among the most common causes of advanced chronic liver disease worldwide. HBV/HCV coinfection is not uncommon with an estimated 7 - 20 million individuals affected worldwide. Patients with HBV/HCV coinfection have an increased risk for cirrhosis, hepatocellular carcinoma (HCC) and even death.

AREAS COVERED IN THIS REVIEW

The pathophysiology of HBV/HCV coinfection is complex, as different patterns of virological dominance may occur, which can even fluctuate over time. Recently, combination of pegylated interferon (PEG-IFN) plus ribavirin has been explored in HBV/HCV coinfected patients who are positive for HCV-RNA. HBV polymerase inhibitors may be indicated if HBV-DNA concentrations are above 2000 IU/ml. In this review, we summarize the epidemiology, viral interaction, its clinical features and the available treatment options.

WHAT THE READER WILL GAIN

Insights into viral interaction of HBV/HCV coinfection and treatment individualization strategies are provided in the review.

TAKE HOME MESSAGE

Detailed serological and virological evaluations are required for HBV/HCV coinfected patients before initiation of antiviral therapy. At present, PEG-IFN-alpha plus ribavirin should be the treatment of choice in patients with dominant HCV replication. However, HBV rebound may occur after elimination of HCV, and thus close monitoring for both viruses is recommended even for patients with initially suppressed HBV-DNA.

Therapeutic effects of pegylated interferon plus ribavirin in chronic hepatitis C patients with occult hepatitis B virus dual infection

BACKGROUND AND AIM

Occult hepatitis B virus (HBV) infection is defined by the detectable serum HBV-DNA in HBV surface antigen-negative patients. This retrospective study aims to evaluate the therapeutic effects of combined pegylated interferon (PEG-IFN) plus ribavirin (RBV) in patients with concurrent occult HBV/hepatitis C virus (HCV) dual infection.

METHODS

In total, 126 consecutive chronic hepatitis C (CHC) patients who received combined PEG-IFN and RBV therapy were included. Patients were divided into the occult HBV/HCV dual infection group or the HCV-monoinfected group according to whether or not they had the detectable serum HBV-DNA. The biochemical and virological responses to combined therapy were compared between these two groups. Serum HCV-RNA and HBV-DNA were checked before treatment, at the end of treatment as well as at 6- and 12-months' follow up in the occult HBV/HCV group.

RESULT

Six patients were seropositive for HBV-DNA and were included in the occult HBV/HCV dual infection group. There were no statistical differences in the biochemical and virological responses to combined therapy between these two groups. Undetectable serum HBV-DNA was noted at the end of the treatment and the 6- and 12-months' follow up in patients with occult HBV/HCV dual infection.

CONCLUSION

Occult HBV infection in CHC patients is rare. The biochemical and virological responses to combined PEG-IFN and RBV therapy might be similar in CHC patients with or without occult HBV infection. The serum HBV-DNA level was low in patients with occult HBV/HCV dual infection who responded to combined therapy.

Occult hepatitis B infection and its possible impact on chronic hepatitis C virus infection

As a well-recognized clinical phenomenon, persistent detectable viral genome in liver or sera in the absence of other serological markers for active hepatitis B virus (HBV) replication is called occult HBV infection. The main mechanism through which occult infection occurs is not completely understood and several possible explanations, such as integration into human genome and maintenance in peripheral mononuclear cells, exist. Occult HBV infection has been reported in different populations, especially among patients with Hepatitis C (HCV) related liver disease. The probable impact of occult HBV in patients with chronic HCV infection has been previously investigated and the evidence suggests a possible correlation with lower response to anti-viral treatment, higher grades of liver histological changes, and also developing hepatocellular carcinoma. However, in the absence of conclusive results, further studies should be conducted to absolutely assess the impact of occult HBV contamination on the HCV related liver disease.

Impact of hepatitis B exposure on sustained virological response rates of highly viremic chronic hepatitis C patients

AIM

To evaluate the impact of hepatitis B core antibody (anti-HBc) seropositivity in sustained virological response (SVR) rates in treatment-naïve, chronic hepatitis C (CHC) patients with high pretreatment viral load (>800000 IU/mL).

METHODS

185 consecutive CHC patients (14.4% cirrhotics, 70.2% prior intravenous drug users) treated with pegylated interferon-a2b plus ribavirin, for 24 or 48 weeks based on viral genotype, were retrospectively analyzed. SVR was confirmed by undetectable serum HCV-RNA six months after the end of treatment schedule.

RESULTS

Thirty percent of CHC/HBsAg-negative patients were anti-HBc-positive. Anti-HBc positivity was more prevalent in cirrhotic, compared to noncirrhotic patients (76.9% versus 19.5%, P < .05). Serum HBV-DNA was detected in the minority of anti-HBc-positive patients (1.97%). Overall, 62.1% of patients exhibited SVR, while 28.6% did not; 71.4% of non-SVRs were infected with genotype 1. In the univariate analysis, the anti-HBc positivity was negatively associated with treatment outcome (P = .065). In the multivariate model, only the advanced stage of liver disease (P = .015) and genotype-1 HCV infection (P = .003), but not anti-HBc-status (P = .726), proved to be independent predictors of non-SVR.

CONCLUSION

Serum anti-HBc positivity does not affect the SVR rates in treatment-naïve CHC patients with high pretreatment viral load, receiving the currently approved combination treatment.

Occult hepatitis B virus infection in patients with autoimmune liver diseases

BACKGROUND

Occult hepatitis B virus (HBV) infection is characterized by undetectable serum HBV surface antigen (HBsAg) but detectable HBV-DNA in serum or liver.

AIMS

To determine the prevalence and clinical impact of occult HBV in autoimmune liver diseases as similar data are missing.

METHODS

One hundred and ninety-six sera samples from HBsAg-negative patients, including 66 autoimmune hepatitis (AIH), 93 primary biliary cirrhosis (PBC) and 37 primary sclerosing cholangitis (PSC), were investigated for HBV-DNA using the polymerase chain reaction (PCR) before treatment initiation. One hundred and three serial samples from 38 AIH patients under immunosuppression and 282 selected blood donors (HBsAg negative; antibodies to HBV-core antigen positive) were also investigated. Fourteen available paraffin-embedded AIH liver samples were also investigated for HBV-DNA by nested-PCR.

RESULTS

Hepatitis B virus DNA was detected in the serum of 24/196 patients (12.2%) and 0/282 donors (P=0.0000). Nine patients had AIH (13.6%), eight had PBC (8.6%) and seven had PSC (18.9%) (P=0.0000 vs healthy). HBV-DNA detection in AIH livers was higher than in serum. HBV-DNA was associated neither with HBV markers nor with epidemiological, laboratory and clinical data. Serial testing of AIH patients revealed two HBV-DNA-negative patients before treatment becoming positive during treatment, while all HBV-DNA-positive patients before immunosuppression became negative.

CONCLUSION

Based mainly on serum HBV-DNA, we found a significant proportion of autoimmune liver disease patients with occult HBV compared with donors. However, taking into account our results in a small number of liver tissues, it should be emphasized that occult HBV could be even higher when both serum and liver specimens are investigated. Occult HBV does not seem to affect the clinical and laboratory features of the diseases, while AIH patients with occult HBV under immunosuppression do not deteriorate during follow-up.

Clinical and histological impact of previous hepatitis B virus infection in patients with chronic hepatitis C

BACKGROUND

Recent reports suggest that hepatitis C virus (HCV) carriers with serological markers of prior hepatitis B virus (HBV) infection have more advanced liver fibrosis, irrespective of HBV-DNA detection.

AIMS

We sought to assess the prevalence and impact of previous HBV infection in patients with HCV chronic infection.

METHODS

This cross-sectional study included hepatitis B surface antigen- and human immunodeficiency virus-negative subjects with positive HCV-RNA. All patients had prior parenteral exposure as the probable source of HCV infection. Serum samples were tested for HBV-DNA using a commercial assay. The METAVIR system was used for histological analysis.

RESULTS

One-hundred and eleven patients were evaluated. Thirty-one out of 111 patients (28%) tested positive for antihepatitis B core antigen (anti-HBc). HBV-DNA was not detected in any sample. Anti-HBc-positive patients showed higher histological grading, staging and a higher fibrosis progression rate. By multivariate analysis, anti-HBc-positivity was predictive of moderate to severe activity [odds ratio (OR)=3.532; P=0.032] and significant hepatic fibrosis (OR=3.364; P=0.017). After approximately 20 years of infection, advanced liver fibrosis (F3/F4) can be expected in 13% of anti-HBc-negative subjects who acquired HCV before the age of 30 and in 57% of those anti-HBc-positive patients who were infected by HCV after 30 years of age (P<0.001).

CONCLUSION

Previous HBV infection is common among HCV carriers and may exert a negative impact on the natural history of HCV infection, independently of the presence of significant HBV replication.

Prevalence and impact of GBV-C, SEN-V and HBV occult infections in HIV-HCV co-infected patients on HCV therapy

BACKGROUND/AIMS

It has been suggested that, in HIV-HCV co-infected patients, co-infections with other viruses may affect the response to HCV therapy. We aimed to assess the prevalence of GBV-C, SEN-V and occult HBV infections, their impact on HCV and HIV infections and on the response to HCV therapy in HIV-HCV co-infected patients.

METHODS

Three-hundred and sixty eight patients were tested before starting interferon-ribavirin for the presence of occult hepatitis B DNA, GBV-C RNA and SEN-V DNA by using real time PCR. Clinical, immunological, virological, histological characteristics and response to HCV therapy were compared according to the presence or not of each viral co-infection.

RESULTS

HBV DNA, GBV-C RNA and SEN-V DNA were found in 5 (1.4%, CI95%: 0.2-2.4%), 104 (29.9%, CI95%: 25.1-34.7%) and 209 patients (57.9%, CI95%: 52.8-63.0%), respectively. GBV-C positive patients had significantly higher CD4 count at baseline, during and after HCV therapy, even after stratification on antiretroviral treatment. No other significant difference was observed according to the presence or not of GBV-C or SEN-V co-infection, in particular regarding virological responses to HCV combination therapy.

CONCLUSIONS

There is no reason to withhold HCV therapy in HIV infected patients who have access to HAART, because of occult HBV, GBV-C or SEN-V co-infections.

Occult hepatitis B virus and hepatitis C virus infections

Occult HBV infection is a well-recognised clinical entity characterised by the detection of HBV-DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV-RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV-RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody-(anti-HCV) negative and serum HCV-RNA-negative patients with abnormal liver function tests and in anti-HCV-positive patients who have no detectable serum HCV-RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation.

The characteristics of the cell-mediated immune response identify different profiles of occult hepatitis B virus infection

BACKGROUND & AIMS

Hepatitis B virus (HBV) DNA detection in serum and/or in the liver of hepatitis B surface antigen (HBsAg)-negative patients with or without serologic markers of previous viral exposure is defined as occult HBV infection. Because the role of the adaptive response in keeping HBV replication under control in occult infection still is undefined, this study was performed to characterize the features of the HBV-specific T-cell response in this condition.

METHODS

HBV-specific T-cell frequency and function were tested ex vivo and after in vitro expansion in 32 HBsAg-negative patients undergoing diagnostic liver biopsy for chronic hepatitis C: 18 with occult HBV infection (11 anti-HBc-negative and 7 anti-HBc-positive patients) defined by the detection of intrahepatic HBV DNA by polymerase chain reaction; 14 without detectable intrahepatic HBV DNA (5 anti-HBc-positive and 9 anti-HBc-negative patients). Six patients with chronic hepatitis B and 7 HBsAg-inactive carriers were studied for comparison.

RESULTS

The presence or absence of serologic HBV markers defined 2 profiles of HBV-specific T-cell responses in occult infection. Anti-HBc-positive patients showed a T-cell response typical of protective memory, suggesting that this condition represents a resolved infection with immune-mediated virus control. In contrast, HBV-specific T cells in anti-HBc-negative patients did not readily expand and produce interferon-gamma in vitro, suggesting the possibility of a low-dose infection insufficient to allow maturation of protective memory.

CONCLUSIONS

Our results suggest different mechanisms of control of viral replication in seropositive and seronegative occult infections. Additional studies aimed at understanding possible different clinical implications are needed.

Prevalence and clinical relevance of occult hepatitis B in the fibrosis progression and antiviral response to INF therapy in HIV-HCV-coinfected patients

Occult hepatitis B virus (HBV) infection is diagnosed when HBc antibodies (HBcAb) and HBV DNA are detectable in serum while hepatitis B surface antigen (HBsAg) is not. This situation has been frequently described in patients with chronic hepatitis C virus (HCV) infection. The objective of this study was to evaluate the prevalence of occult hepatitis B in HIV-HCV-coinfected patients and its clinical relevance in liver histology and viral response after interferon therapy for HCV. A total of 238 HIV-HCV-infected patients,negative for HBsAg, were included. Serum samples were analyzed for the presence of HBV DNA and HBcAb.HBV DNA quantification was determined with the Cobas TaqMan HBV Test (detection limit 6 IU/ml). Data from liver biopsy and laboratory tests were also analyzed. HBcAb resulted in 142 (60%) patients, being the independent associated factors: male gender, previous history of intravenous drug use, age, CD4 count,and HAV antibody presence. Among 90 HBcAb patients that we could analyze, HBV DNA was positive in 15 (16.7% of occult hepatitis B infection in this group, and 6.3% in the whole HIV-HCV cohort studied). No baseline factors, liver histology, or HCV therapy response were related to the presence of HBV DNA. We found that occult hepatitis B is a frequent condition present in at least 6.3% of our HCV-HIV patients and in more than 16% of those with HBcAb. Despite the high prevalence, this phenomenon does not seem to affect the clinical evolution of chronic hepatitis C or modify the viral response to interferon-based HCV therapies

Occult hepatitis B virus infection in patients with chronic liver disease due to hepatitis C virus and hepatocellular carcinoma in Brazil

BACKGROUND

The prevalence and consequences of occult HBV infection in patients with chronic liver disease by HCV remain unknown.

AIMS

To evaluate the prevalence of occult HBV infection in a population of HCV-infected patients with hepatocellular carcinoma.

METHODS

The serum samples were tested for HBV DNA by nested PCR and liver tissue analysis was carried out using the immunohistochemical technique of 66 HBsAg-negative patients: 26 patients with chronic hepatitis by HCV (group 1), 20 with hepatocellular carcinoma related to chronic infection by HCV (group 2) and 20 with negative viral markers for hepatitis B and C (control group).

RESULTS

Occult HBV infection was diagnosed in the liver tissue of 9/46 (19.5%) HCV-infected patients. Prevalence of occult B infection was evaluated in the HCV-infected patients with and without hepatocellular carcinoma, and there were seven (77.7%) of whom from group 2, conferring a 35% prevalence of this group. No serum sample was positive for HBV DNA in the three groups.

CONCLUSION

Occult infection B is frequently detected in liver tissue of HCV-infected patients, especially in cases of hepatocellular carcinoma. However large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population.

Occult HBV infection may represent a major risk factor of non-response to antiviral therapy of chronic hepatitis C

Occult hepatitis B virus (HBV) infection is common in chronic hepatitis C patient. However, its significance and consequences are still unclear. The aim of this study was to evaluate the prevalence of occult HBV among HCV chronic carriers in France and to assess its impact on liver histology and response to antiviral therapy. To this end a cohort of 203 patients with chronic hepatitis C without hepatitis B surface antigen (HBsAg) has been examined. Serum HBV-DNA was detected using a highly sensitive PCR with primers located in the S and X genes. HBV viraemia levels were further determined by real-time PCR. Results showed that 47 of 203 (23%) patients had occult HBV infection with a low HBV load (10(2)-10(4) copies/ml) but significantly higher HCV-RNA titers (P < 0.05). No significant difference in age, gender, serum ALT level, HCV genotypes, and the presence of anti-HBc was observed between patients with or without HBV-DNA. When compared histologically, patients with occult HBV infection had higher activity (A2-A3 in 53% vs. 38%, P < 0.01) and more advanced fibrosis (60% vs. 33%, P < 0.001) than HBV-DNA negative cases. Sustained response to combination therapy against Chronic hepatitis C was achieved in 11 (28%) of 40 HBV-DNA positive cases, compared with 65 (45%) of the 144 HBV-DNA negative cases (P < 0.05). Among the 144 HBV-DNA negative HCV patients those with genotype 1 responded less frequently to therapy as compared to other genotypes infected patients (38% vs. 55%, P < 0.05). Surprisingly, when considering all patients studied, irrespective to the HBV-DNA status no significant difference was observed in response to combination therapy regarding HCV genotypes (39% vs. 44%, P > 0.05). In conclusion, HBV-DNA is found in 1/4 of French chronic hepatitis C patients regardless of the presence of anti-HBc. Such an occult HBV co-infection is associated with more severe liver disease, higher HCV viral load and decreased response to antiviral therapy irrespective of HCV genotypes.

Occult hepatitis B virus infection in the setting of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection: Clinically relevant or a diagnostic problem?

The clinical relevance of occult hepatitis B virus (HBV) infection, defined as detectable HBV DNA serum/liver, in the absence of hepatitis B surface antigen (HBsAg), is unclear. We determined the prevalence of serum occult HBV infection in HIV/HCV co-infected patients enrolled in APRICOT, a randomized multinational trial that investigated the efficacy and safety of peginterferon alfa-2a (40 kDa) plus ribavirin for treatment of HCV. We also examined the effect of prior HBV exposure to liver histology at baseline. Only HBsAg-negative patients were eligible. At screening, serum HBV DNA was assessed by commercial assay (detection limit = 200 copies/mL). Patients were divided into four serological groups: anti-HBs+/anti-HBc+; anti-HBs-/anti-HBc+; anti-HBs+/ anti-HBc-; anti-HBs-/anti-HBc-. Baseline liver biopsy grade and stage were compared among groups. Serum HBV DNA was undetectable in all patients, (n = 866). Results of anti-HBs and anti-HBc was available for 176 patients: 60 (34.1%) anti-HBs+/anti-HBc+; 60 (34.1%) anti-HBs-/anti-HBc+; 11 (6.3%) anti-HBs+/anti-HBc-; 45 (25.6%) anti-HBs-/anti-HBc-. There were no differences among the groups in the histological grade or stage at baseline liver biopsies. Occult HBV infection in serum was not detected in this large immunocompetent cohort. Moreover, prior exposure to HBV did not appear to have any affect on baseline liver histology.

Viral interaction and clinical implications of coinfection of hepatitis C virus with other hepatitis viruses

Coinfection with other hepatitis viruses modifies the viral profile in serum and leads to more liver damage and more rapid progression during the course of hepatitis C virus infection. The viral interference is not only carried out by virus-virus or by virus-cell interactions but also by an enhanced immune response. A superinfecting viral infection does not crossactivate protective immune responses to the pre-existing virus albeit the latter can become undetectable. The induced cytokine stimulation might enhance the hepatic inflammation. Moreover, hepatitis B virus coinfection increases the risk of development of hepatocellular carcinoma in hepatitis C virus patients through common necro-inflammatory pathways or by direct oncogenic activity of hepatitis B virus. Viral interaction also complicates the management of the coinfection because hepatitis C virus impairs the humoral response to hepatitis A virus and hepatitis B virus vaccines, and because pharmacological suppression of hepatitis C virus endangers dually infected patients with reactivation of coinfected hepatitis B virus. Optimized strategies and follow-up are thus necessary in the treatment of infection with multiple viruses. It seems thus necessary to look for markers of hepatitis B virus and/or hepatitis D virus infection in chronic hepatitis patients positive for hepatitis C virus antibodies but negative for hepatitis C virus RNA, and equally well to search for hepatitis C virus RNA in HBsAg-negative/anti-HBc-positive patients with a low level of serum hepatitis B virus DNA.

Isolated antibody to hepatitis B core antigen in patients with chronic hepatitis C virus infection

AIM: To evaluate the prevalence of isolated anti-HBc in patients with chronic hepatitis C virus (HCV) infection, and its relation to disease severity.

METHODS: We screened all patients with chronic HCV infection referred to King Faisal Specialist Hospital and Research Center for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), and anti-HBc. One hundred and sixty nine patients who tested negative for both HBsAg and anti-HBs were included in this study.

RESULTS: Pathologically, 59 had biopsy-proven cirrhosis and 110 had chronic active hepatitis (CAH). Of these 169 patients, 85 (50.3%) tested positive for anti-HBc. Patients with CAH had significantly higher prevalence of isolated anti-HBc than patients with cirrhosis, 71 (64.5%) and 14 (23.7%) respectively (P < 0.001). Twenty-five patients were tested for HBV DNA by qualitative PCR. The test was positive in 3 of them (12%; occult HBV infection).

CONCLUSION: Isolated anti-HBc alone is common in Saudi patients with chronic HCV infection, and is significantly more common in those with CAH than those with cirrhosis. Therefore, a screening strategy that only tests for HBsAg and anti-HBs in these patients will miss a large number of individuals with isolated anti-HBc, who may be potentially infectious.

Natural history of patients with recurrent chronic hepatitis C virus and occult hepatitis B co-infection after liver transplantation

It is uncertain whether occult hepatitis B virus co-infection will hasten progressive liver disease in chronic hepatitis C patients after liver transplantation. This study evaluated fibrosis progression and severe fibrosis in 118 consecutive hepatitis B surface antigen-negative patients with virological and histological evidence of recurrent chronic hepatitis C infection co-infected with occult hepatitis B virus after liver transplantation. HBV DNA was detected from serum at the time of recurrent chronic hepatitis C infection by polymerase chain reaction. Each subject underwent a repeat liver biopsy 5 years post-liver transplantation. Occult hepatitis B virus co-infection was present in 41 of the 118 (34.7%) patients. At 5 years post-liver transplantation, 13 of the 41 occult hepatitis B virus co-infected patients compared with 16 of the 77 patients without occult hepatitis B virus co-infection developed fibrosis progression (31.7% vs. 20.8%, respectively, p = 0.39). Eight of 41 the occult hepatitis B virus co-infected patients compared with 13 of the 77 patients without occult hepatitis B virus co-infection had severe fibrosis (19.5% vs. 16.9%, respectively, p = 0.97). In conclusion, occult hepatitis B virus co-infection in patients with recurrent chronic hepatitis C infection was not associated with accelerated fibrosis progression or severe fibrosis after liver transplantation.

Prevalence of occult HBV infection in haemodialysis patients with chronic HCV

AIM: To study the prevalence and clinical effects of occult HBV infection in haemodialysis patients with chronic HCV.

METHODS: Fifty chronic hemodialysis patients with negative HbsAg, and positive anti-HCV were included in the study. These patients were divided into two groups: HCV-RNA positive and HCV-RNA negative, based on the results of HCV-RNA PCR. HBV-DNA was studied using the PCR method in both groups.

RESULTS: None of the 22 HCV-RNA positive patients and 28 HCV-RNA negative patients revealed HBV-DNA in serum by PCR method. The average age was 47.2 ± 17.0 in the HCV-RNA positive group and 39.6 ± 15.6 in the HCV-RNA negative group.

CONCLUSION: The prevalence of occult HBV infection is not high in haemodialysis patients with chronic HCV in our region. This result of our study has to be evaluated in consideration of the interaction between HBsAg positivity (8%-10%) and frequency of HBV mutants in our region.

Hepatitis C -- identifying patients with progressive liver injury

Hepatitis C follows a variable course with some patients developing progressive liver fibrosis, cirrhosis and hepatocellular carcinoma, while others have minimal or no significant liver disease after decades of infection. Studies have identified both host and viral factors associated with disease progression. The importance of general factors such as age at infection, gender, immune status and alcohol consumption has long been recognized; however recently, polymorphisms in a wide array of genes have also been shown to be associated with progressive fibrosis. How specific viral proteins may contribute to disease progression has also been studied. This review highlights what is currently known about the factors associated with progressive liver injury in patients with hepatitis C. A greater understanding of the determinants of disease progression will hopefully lead to improved utilization of existing treatments and ultimately may aid in identification of new therapeutic targets.

Fibrosis progression in chronic hepatitis C patients with occult hepatitis B co-infection

Occult hepatitis B virus (HBV) infection in individuals without hepatitis B surface antigen (HBsAg) can be identified in hepatitis C virus (HCV) infected patients. However, its role in fibrosis progression remains uncertain. This retrospective study compared the fibrosis progression (defined as fibrosis progression by at least one stage) and progression to severe fibrosis (fibrosis stage 3 or 4) in HCV patients with occult HBV infection. Occult HBV infection was diagnosed by the detection of HBV DNA in the serum of 74 consecutive anti-HCV positive patients by PCR. Thirty-one patients (41.9%) had occult HBV infection. All 74 patients had a median of 2 (range 2-3) liver biopsies. The median time between the first and last liver biopsy was 57.7 (range 15.0-132.8) months. Eleven of the 31 patients with occult HBV infection compared with 12 of the 43 patients without occult HBV infection had fibrosis progression (35.5% versus 27.9%, respectively, p=0.608). Six of the 31 patients with occult HBV infection compared with 8 of the 43 patients without occult HBV infection developed severe fibrosis (19.4% versus 18.6%, respectively, p=0.946). In conclusion, chronic HCV patients with occult HBV co-infection does not seem to progress more than patients without occult HBV infection. However, more large-scale studies are needed before a definite conclusion can be obtained.