Occult hepatitis B virus infection is associated with the development of hepatocellular carcinoma in chronic hepatitis C patients

An overview of occult hepatitis B infection (OBI) with emphasis on HBV vaccination

Background

The prevalence of chronic hepatitis B virus (HBV) poses a significant threat to the lives of 257 million individuals globally, potentially resulting in severe outcomes such as liver cirrhosis or hepatocellular carcinoma. Among the existing preventive measures, yeast-derived vaccines have proven to be the most efficacious approach in combatting hepatitis B. Nonetheless, as scientific inquiries focus more on occult HBV infection (OBI) in vaccinated persons and the lingering risk of vertical transmission affecting 10-30 % of babies born to HBsAg-positive mothers, there is a growing apprehension regarding the inability of HBV vaccines to ensure complete immunity. This study aims to offer a more comprehensive understanding of the implications of widespread HBV vaccination initiatives on OBI while tackling the primary limitations associated with current vaccine formulations.

Methods

The exploration was conducted on PubMed, Scopus, and Web of Science databases to pinpoint research on OBI within vaccinated cohorts. A sum of 76 suitable studies was recognized.

Discussion

Multiple studies have documented the occurrence of OBI in fully vaccinated individuals, including both the general population and high-risk groups, such as newborns born to HBsAg-positive mothers. Factors contributing to vaccine failures include low-level anti-HBs antibodies, high maternal viral loads in mother-to-child transmission cases, as well as the presence of vaccine escape mutants and heterologous HBV genotypes. However, further research is needed to precisely understand the impact of active immunization on the emergence of OBI in vaccinated populations. Nonetheless, it is apparent that the advancement of more effective HBV vaccines could potentially lead to the extinction of HBV.

Occult Hepatitis B Virus Infection: An Update

Occult hepatitis B virus (HBV) infection (OBI) refers to a condition in which replication-competent viral DNA is present in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing negative for the HBV surface antigen (HBsAg). In this peculiar phase of HBV infection, the covalently closed circular DNA (cccDNA) is in a low state of replication. Many advances have been made in clarifying the mechanisms involved in such a suppression of viral activity, which seems to be mainly related to the host's immune control and epigenetic factors. OBI is diffused worldwide, but its prevalence is highly variable among patient populations. This depends on different geographic areas, risk factors for parenteral infections, and assays used for HBsAg and HBV DNA detection. OBI has an impact in several clinical contexts: (a) it can be transmitted, causing a classic form of hepatitis B, through blood transfusion or liver transplantation; (b) it may reactivate in the case of immunosuppression, leading to the possible development of even fulminant hepatitis; (c) it may accelerate the progression of chronic liver disease due to different causes toward cirrhosis; (d) it maintains the pro-oncogenic properties of the "overt" infection, favoring the development of hepatocellular carcinoma.

What is the clinical impact of occult HBV infections and anti-HBc positivity in patients with chronic hepatitis C?

Occult hepatitis B infection (OBI) is defined by the persistence of the hepatitis B virus (HBV) genome in the liver of individuals testing negative for hepatitis B surface antigen (HBsAg). Hepatitis B core antibody (anti-HBc) is the serological marker that indicates HBV exposure. The impact of anti-HBc and OBI on patients with chronic hepatitis C remains unclear. The aim of the present study was to determine the prevalence of anti-HBc and OBI and to evaluate their impact on the clinical and pathological outcomes of patients with chronic hepatitis C. The study included 59 HBsAg-negative chronic hepatitis C patients who underwent a liver parenchymal biopsy. The presence of HBV DNA was investigated using an in-house nested PCR method. OBI was detected in 16 (27.1%) of the 59 cases and also in 10 (62.5%) of 22 (37.3%) anti-HBc-positive patients. None of the patients had positive serum HBV DNA. OBI was associated with the presence of anti-HBV antibodies (p<0.05). There was also an association between anti-HBc positivity and the activity grades and fibrosis stages of the liver and also a prevalence of liver steatosis (p<0.05). Positive anti-HBc results may predict OBI and also be associated with the progression of liver injury in HBsAg-negative patients with chronic hepatitis C. Therefore, it is suggested that patients with chronic hepatitis C should be screened for anti-HBc positivity, and anti-HBc-positive patients should be carefully evaluated for disease progression. This article is protected by copyright. All rights reserved.

Occult hepatitis B virus infection in hepatitis C virus negative chronic liver diseases

Data concerning the prevalence of hepatitis B virus (HBV) occult infection (OBI) varies greatly in the different studies according to the sensitivity and specificity of the diagnostic approaches and the HBV prevalence in the different populations examined. The clinical implications of OBI are still debated. While the impact of OBI in HBV transmission as well as in HBV reactivation under immunosuppression are well established, the role of OBI in liver disease and hepatocellular carcinoma (HCC) development are still not definitively elucidated. It has been hypothesized that OBI might contribute to worsening the liver disease course when other causes of liver damage co-exist. Furthermore, much evidence suggests a role of OBI in the hepato-carcinogenesis processes through both indirect and direct oncogenic mechanisms that might favour HCC development. Data on the OBI clinical implications mainly come from studies performed in patients with hepatitis C virus (HCV) infection. However, HCV prevalence has dramatically fallen in the past years also because of the advent of specific and highly effective direct acting antivirals, with a consequent abrupt change of the worldwide scenario of chronic liver disease. Information about OBI prevalence and possible clinical impact in non-HCV-related liver disease are fragmentary, and the objective of this review is to critically summarize the available data in this field.

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.

The roadmap towards cure of chronic hepatitis B virus infection

Global elimination of HBV is feasible thanks to the availability of a safe, effective and inexpensive vaccine. However, this will not help almost 300 million adults living with chronic HBV infection. Current therapy can reduce complications but is administered life-long and is associated with risk of breakthrough and potential cumulative toxicity. There is therefore great interest in developing new therapies which can achieve sustained disease remission after a finite course of treatment i.e. an HBV CURE. Steps of HBV life cycle other than the polymerase that are targeted by new direct antiviral therapies include HBV entry, HBV capsid assembly, HBV mRNA transcription and translation and HBsAg secretion. As chronic HBV infection is characterised by high viral load and antigen burden and inadequate host immune responses innovative approaches to restore innate and adaptive immune responses against HBV, are currently in clinical development. These include therapeutic vaccines and TLR agonists. It is likely that HBV Cure will require combinations of novel immunomodulatory and antiviral approaches. In the future, strategies which directly silence or eliminate cccDNA could provide a single agent cure. Efficacy, safety, route of administration and cost will ultimately determine the impact of these new regimens on the burden of HBV. Abbreviations: ACTG: AIDS Clinical Trials Group network; ALT: alanine aminotransferase; ASGPR: Asialoglycoprotein Receptor; ASO: anti-sense oligonucleotide; CAM: capsid assembly modulator; CAM-A: capsid assembly modulator with abhorrent structure; CAM-N: capsid assembly modulator with normal structure; cccDNA: covalently closed circular DNA; CHB: chronic hepatitis B; c-Raf-1/MAP: cellular Rapidly Accelerated Fibrosarcoma-1/mitogen-activated protein kinase; DR1 and DR2: direct repeat sequences 1 and 2; ETV: entecavir; FDA: Food and Drug Administration; GalNAc: N-acetylgalactosamine; HBcrAg: hepatitis B core-related antigen; HBeAg: hepatitis B e antigen; HBIG: hepatitis B immunoglobulin; HBsAg: hepatitis B surface antigen; HBV: hepatitis B virus; HBV DNA: hepatitis B virus deoxyribonucleic acid; HCC: hepatocellular carcinoma; HDV: hepatitis delta virus; ir-AE: immune-related adverse events; LNA: locked nucleic acid; MAD: multiple ascending dose; mRNA: messenger ribonucleic acid; NAPs: nucleic acid polymers; NTCP: sodium taurocholate co-transporting polypeptide; PD-1: programmed death receptor 1; PD-L1: programmed death receptor ligand 1; pgRNA: pregenomic ribonucleic acid; R-CHOP: rituximab plus cyclophosphamide plus doxorubicin plus vincristine plus prednisolone; RISC: RNA-induced silencing complex; RNAi: ribonucleic acid interference; SAD: single ascending dose; siRNA: short (small) interfering ribonucleic acid; STOPs: S-antigen traffic-inhibiting oligonucleotide polymers; TAF: tenofovir alafenamide; TDF: tenofovir disoproxil; USD: United States dollars; WHO: World Health Organization.

Occult hepatitis B infection and hepatocellular carcinoma: Epidemiology, virology, hepatocarcinogenesis and clinical significance

Occult hepatitis B infection (OBI) refers to a condition where replication-competent HBV DNA is present in the liver, with or without HBV DNA in the blood, in individuals with serum HBsAg negativity assessed by currently available assays. The episomal covalently closed circular DNA (cccDNA) in OBI is in a low replicative state. Viral gene expression is mediated by epigenetic control of HBV transcription, including the HBV CpG island methylation pathway and post-translational modification of cccDNA-bound histone, with a different pattern from patients with chronic HBV infection. The prevalence of OBI varies tremendously across patient populations owing to numerous factors, such as geographic location, assay characteristics, host immune response, coinfection with other viruses, and vaccination status. Apart from the risk of viral reactivation upon immunosuppression and the risk of transmission of HBV, OBI has been implicated in hepatocellular carcinoma (HCC) development in patients with chronic HCV infection, those with cryptogenic or known liver disease, and in patients with HBsAg seroclearance after chronic HBV infection. An increasing number of prospective studies and meta-analyses have reported a higher incidence of HCC in patients with HCV and OBI, as well as more advanced tumour histological grades and earlier age of HCC diagnosis, compared with patients without OBI. The proposed pathogenetic mechanisms of OBI-related HCC include the influence of HBV DNA integration on the hepatocyte cell cycle, the production of pro-oncogenic proteins (HBx protein and mutated surface proteins), and persistent low-grade necroinflammation (contributing to the development of fibrosis and cirrhosis). There remain uncertainties about exactly how, and in what order, these mechanisms drive the development of tumours in patients with OBI.

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.

Among Patients with Undetectable Hepatitis B Surface Antigen and Hepatocellular Carcinoma, a High Proportion Has Integration of HBV DNA into Hepatocyte DNA and No Cirrhosis

BACKGROUND & AIMS

In some individuals with undetectable serum levels of hepatitis B surface antigen (HBsAg), hepatitis B virus (HBV) DNA can still be detected in serum or hepatocytes and HBV replicates at low levels-this is called occult HBV infection (OBI). OBI has been associated with increased risk of hepatocellular carcinoma (HCC). We investigated the incidence of OBI in patients with HCC and other liver diseases. We also investigated whether, in patients with OBI and HCC, HBV DNA has integrated into the DNA of hepatocytes.

METHODS

We collected clinical information and liver tissues from 110 HBsAg-negative patients (90 with HCC and 20 without HCC; median ages at surgical resection and biopsy collection, 64.1 and 48.6 years, respectively) who underwent liver resection or liver biopsy from November 2002 through July 2017 in Hong Kong. HBV DNA and covalently closed circular DNA (cccDNA) were analyzed and quantified by PCR in liver tissues. Integration of HBV DNA into the DNA of liver cells was detected by Alu-PCR.

RESULTS

Of the 90 HBsAg-negative patients with HCC, 18 had alcoholic liver disease (20%), 14 had non-alcoholic fatty liver disease or steatohepatitis (16%), 2 had primary biliary cholangitis, 2 had recurrent pyogenic cholangitis, 1 had autoimmune hepatitis, and 53 had none of these (59%). Among the 20 patients without HCC, 7 had non-alcoholic fatty liver disease or steatohepatitis, 7 had primary biliary cholangitis, and 6 had autoimmune hepatitis. OBI was detected in 62/90 patients with HCC (69%) and 3/20 patients without HCC (15%) (P < .0001). cccDNA was detectable in liver cells of 29 patients with HCC and OBI (47%) and HBV DNA had integrated into DNA of liver cells of 43 patients with HCC and OBI (69%); cccDNA and integrated HBV DNA were not detected in the 3 patients who had OBI without HCC. There were 29 patients with integration of HBV DNA among 33 patients with undetectable cccDNA in liver tissues (88%) and 14 patients with integration of HBV DNA among the 29 patients with cccDNA in liver tissues (48%) (P = .001). HBV DNA was found to integrate near genes associated with hepatocarcinogenesis, such as those encoding telomerase reverse transcriptase, lysine methyltransferase 2B, and cyclin A2. Among the 43 patients with integration of HBV DNA, 39 (91%) did not have cirrhosis.

CONCLUSIONS

In an analysis of clinical data and liver tissues from 90 HBsAg-negative patients with HCC, we found that almost 70% had OBI, of whom 70% had integration of HBV DNA into liver cell DNA; 90% of these patients did not have cirrhosis. HBV DNA integrated near hepatic oncogenes; these integrations might promote development of liver cancer.

Occult HBV infection status and its impact on surgical outcomes in patients with curative resection for HCV-associated hepatocellular carcinoma

BACKGROUND

We sought to clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and to determine whether OBI affects the surgical outcomes in curatively resected Japanese patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

METHODS

A total of 257 patients with HCV-related HCC who underwent curative surgical resection were enrolled. All enrolled patients were serologically negative for HBV surface antigen and positive for HCV antibody. DNA was extracted from formalin-fixed paraffin-embedded liver tissue. OBI was determined by the HBV-DNA amplification of at least two different sets of primers by TaqMan real-time polymerase chain reaction. Surgical outcomes were evaluated according to overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS).

RESULTS

OBI was identified in 15 of the 257 (5.8%) cases. In the multivariate analyses, the factors significantly correlated with OS were BMI >25 (P=0.0416), portal vein invasion (P=0.0065), and multiple tumors (P=0.0064). The only factor significantly correlated with DSS was T-stage (P=0.0275). The factors significantly correlated with DFS were liver fibrosis (P=0.0017) and T-stage (P=0.0001). The status of OBI did not show any significant correlation with OS, DSS or DFS, but a weak association with DSS (P=0.0603) was observed.

CONCLUSIONS

The prevalence of OBI was 5.8% in 257 cases of HCV-related HCC. Although a weak association between DSS and OBI was observed, and statistical analyses were limited by small number of OBI cases, no significant correlation between OBI and surgical outcomes was detected.

In Silico Analysis of Hepatitis B Virus Occult Associated Mutations in Botswana Using a Novel Algorithm

Occult hepatitis B infections (OBI) represent a reservoir of undiagnosed and untreated hepatitis B virus (HBV), hence the need to identify mutations that lead to this phenotype. Functionally characterizing these mutations by in vitro studies is time-consuming and expensive. To bridge this gap, in silico approaches, which predict the effect of amino acid (aa) variants on HBV protein function, are necessary. We developed an algorithm for determining the relevance of OBI-associated mutations using in silico approaches. A 3 kb fragment of subgenotypes A1 and D3 from 24 chronic HBV-infected (CHB) and 24 OBI participants was analyzed. To develop and validate the algorithm, the effects of 68 previously characterized occult-associated mutations were determined using three computational tools: PolyPhen2, SNAP2, and PROVEAN. The percentage of deleterious mutations (with impact on protein function) predicted were 52 (76.5%) by PolyPhen2, 55 (80.9%) by SNAP2, and 65 (95.6%) by PROVEAN. At least two tools correctly predicted 59 (86.8%) mutations as deleterious. To identify OBI-associated mutations exclusive to Botswana, study sequences were compared to CHB sequences from GenBank. Of the 43 OBI-associated mutations identified, 26 (60.5%) were predicted by at least two tools to have an impact on protein function. To our knowledge, this is the first study to use in silico approaches to determine the impact of OBI-associated mutations, thereby identifying potential candidates for functional analysis to facilitate mechanistic studies of the OBI phenotype.

Impact of previous hepatitis B infection on the clinical outcomes from chronic hepatitis C? A population-level analysis

Chronic coinfection with hepatitis C virus (HCV) and hepatitis B virus (HBV) is associated with adverse liver outcomes. The clinical impact of previous HBV infection on liver disease in HCV infection is unknown. We aimed at determining any association of previous HBV infection with liver outcomes using antibodies to the hepatitis B core antigen (HBcAb) positivity as a marker of exposure. The Scottish Hepatitis C Clinical Database containing data for all patients attending HCV clinics in participating health boards was linked to the HBV diagnostic registry and mortality data from Information Services Division, Scotland. Survival analyses with competing risks were constructed for time from the first appointment to decompensated cirrhosis, hepatocellular carcinoma (HCC) and liver-related mortality. Records of 8513 chronic HCV patients were included in the analyses (87 HBcAb positive and HBV surface antigen [HBsAg] positive, 1577 HBcAb positive and HBsAg negative, and 6849 HBcAb negative). Multivariate cause-specific proportional hazards models showed previous HBV infection (HBcAb positive and HBsAg negative) significantly increased the risks of decompensated cirrhosis (hazard ratio [HR]: 1.29, 95% CI: 1.01-1.65) and HCC (HR: 1.64, 95% CI: 1.09-2.49), but not liver-related death (HR: 1.02, 95% CI: 0.80-1.30). This is the largest study to date showing an association between previous HBV infection and certain adverse liver outcomes in HCV infection. Our analyses add significantly to evidence which suggests that HBV infection adversely affects liver health despite apparent clearance. This has important implications for HBV vaccination policy and indications for prioritization of HCV therapy.

Occult HBV infection in HCC and cirrhotic tissue of HBsAg-negative patients: a virological and clinical study

Aim

To evaluate the virological and clinical characteristics of occult HBV infection (OBI) in 68 consecutive HBsAg-negative patients with biopsy-proven cirrhosis and HCC.

Methods

HBV DNA was sought and sequenced in plasma, HCC tissue and non-HCC liver tissue by PCRs using primers for HBV core, surface and x regions. OBI was identified by the presence of HBV DNA in at least two different PCRs.

Results

OBI was detected in HCC tissue of 13 (20%) patients and in non-HCC liver tissue of 3 of these 13. OBI was detected in HCC tissue of 54.5% of 11 anti-HBs- negative/anti-HBc-positive patients, in 29.4% of 17 anti-HBs/anti-HBc-positive and in 5% of 40 anti-HBs/anti-HBc-negative (p < 0.0005). The 13 patients with OBI in HCC tissue more frequently than the 55 without showed Child-B or -C cirrhosis (53.9% vs. 5.5%, p < 0.0001) and BCLC-B or -C stages (46.1% vs. 1.8%, p < 0.0001). The pre-S1, pre-S2 and S region sequences in HCC tissue showed amino acid (AA) substitutions (F19L, P24L, S59F, T131I, Q129H) and deletions (in positions 4,8, 17 and 86) in the S region, AA substitutions (T40S, P124K, L54P, G76A, N222T and I273L) in pre-S1 region and AA substitutions in pre-S2 region (P41H and P66L). In the 3 patients showing OBI also in non-HCC liver tissue the S, pre-S1 and pre-S2 sequencing displayed patterns of mutations different.

Conclusions

The study showed a significant correlation between OBI and the severity of liver damage, several patterns of mutations in the S, pre-S1 and pre-S2 regions in HCC tissue, some at their first description.

Occult hepatitis B virus infection in Greek patients with congenital bleeding disorders

Occult Hepatitis B Infection (OBI) is a form of chronic HBV infection characterized by low level HBV DNA, without detectable HBV surface antigen (HBsAg). OBI is frequently associated with the presence of anti-HBc and in some cases also with anti-HBs. Patients, who formerly received non-inactivated factor concentrates, can potentially be considered at high risk for OBI, especially since these patients usually are HIV or HCV co-infected. This study aimed to assess the prevalence of occult HBV infection in Greek patients with hereditary bleeding disorders. The study sample comprised of 114 patients from a single haemophilia center. All patients were screened for HBV serum markers and individually tested for HBV DNA using a qualitative PCR. Presence of HBV DNA was further confirmed by quantification of viral load with an ultrasensitive in-house real time PCR. 88 and 21 patients with haemophilia A and B, respectively, 4 patients with von Willebrand Disease and 1 patient with severe factor VII deficiency were screened for the presence of OBI. Anti-HBc were detected in 53 (46.5%) subjects; 18 of them were anti-HBs(-) and 35 anti-HBs(+). Anti-HBe were present in 26 subjects. Two out of 114 patients were HBsAg(+). Of the remaining 112 HBsAg(-) patients tested, two (1.8%) were found HBsAg(-), HBV DNA(+), anti-HBc(+) and anti-HBs(-) and were identified as potential OBI cases. Both cases exhibited very low DNA levels; 38.2IU/mL in patient A and 14.2IU/mL in patient B. Both patients were HBeAg(-), but patient A had HBe antibodies. Patient B was also HIV/HCV co-infected. In conclusion, two cases of OBI with low HBV viraemia were identified among patients with congenital bleeding disorders. Although the incidence in our sample is moderately low (1.8%), close monitoring of these infections is of great clinical significance, especially in patients with co-infections and concomitant immunosuppression.

Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia

BACKGROUND

Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease.

METHODS

Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique.

RESULTS

In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X.

CONCLUSIONS

This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis.

Indoleamine 2,3-dioxygenase: As a potential prognostic marker and immunotherapeutic target for hepatocellular carcinoma

Tumor cells induce an immunosuppressive microenvironment which leads towards tumor immune escape. Understanding the intricacy of immunomodulation by tumor cells is essential for immunotherapy. Indoleamine 2,3-dioxygenase (IDO) is an immunosuppressive enzyme which mediates tumor immune escape in various cancers including hepatocellular carcinoma (HCC). IDO up-regulation in HCC may lead to recruitment of regulatory T-cells into tumor microenvironment and therefore inhibit local immune responses and promote metastasis. HCC associated fibroblasts stimulate natural killer cells dysfunction through prostaglandin E2 and subsequently IDO promotes favorable condition for tumor metastasis. IDO up-regulation induces immunosuppression and may enhance the risk of hepatitis C virus and hepatitis B virus induced HCC. Therefore, IDO inhibitors as adjuvant therapeutic agents may have clinical implications in HCC. This review proposes future prospects of IDO not only as a therapeutic target but also as a prognostic marker for HCC.

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.

Update on occult hepatitis B virus infection

The event of mutations in the surface antigen gene of hepatitis B virus (HBV) results in undetectable hepatitis B surface antigen with positive/negative anti-hepatitis B core (anti-HBc) antibody status in serum and this phenomenon is named occult hepatitis B infection (OBI). The presence of anti-HBc antibody in serum is an important key for OBI tracking, although about 20% of OBI cases are negative for anti-HBc antibody. The diagnosis of OBI is mainly based on polymerase chain reaction (PCR) and real-time PCR assays. However, real-time PCR is a more reliable method than PCR. OBI is a great issue for the public health problem and a challenge for the clinical entity worldwide. The persistence of OBI may lead to the development of cirrhosis and hepatocellular carcinoma. With regard to OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for: (1) patients with a previous history of chronic or acute HBV infection; (2) patients co-infected with hepatitis C virus/human immunodeficiency virus; (3) patients undergoing chemotherapy or anti-CD20 therapy; (4) recipients of organ transplant; (5) blood donors; (6) organ transplant donors; (7) thalassemia and hemophilia patients; (8) health care workers; (9) patients with liver related disease (cryptogenic); (10) hemodialysis patients; (11) patients undergoing lamivudine or interferon therapy; and (12) children in time of HBV vaccination especially in highly endemic areas of HBV. Active HBV vaccination should be implemented for the close relatives of patients who are negative for OBI markers. Thus, the goal of this review is to evaluate the rate of OBI with a focus on status of high risk groups in different regions of the world.

Occult HBV infection in the oncohematological setting

INTRODUCTION

Occult hepatitis B infection (OBI), a virological condition characterized by a low release of Hepatitis B Virus (HBV) from liver cells and low HBV-DNA levels in serum and/or liver tissue of HBsAg-negative subjects, may reactivate in oncohematological patients undergoing immunosuppression by aggressive chemotherapy or hematopoietic stem cell transplantation. The entity of OBI reactivation varies from an increase in HBV replication without liver damage to an active HBV replication followed by liver cell necrosis, frequently severe and in some cases life threatening. Because of a possible severe outcome associated with OBI reactivation (hepatic failure or death due to the discontinuation of chemotherapy), prophylaxis with anti-HBV nucleot(s)ide analogues is recommended in relation to the foreseeable degree of immunosuppression.

MATERIALS AND METHODS

This review article focuses on the clinical impact of OBI in the oncohematological setting and is addressed to all health care workers having in care oncohematological patients or involved in the treatment of HBV infection and OBI prophylaxis.

CONCLUSION

International guidelines have indicated lamivudine prophylaxis in hematopoietic stem cell transplantation and when high-dose corticosteroids or anti-CD20 or anti-CD52 monoclonal antibodies are used. Entecavir or tenofovir should replace lamivudine for patients with advanced liver diseases for whom reactivation of OBI may be life threatening. When anti-CD20 or anti-CD52 sparing schedules or other non-aggressive chemotherapies are used, monitoring may be indicated, but very early treatment with highly effective antiviral drugs (entecavir or tenofovir) should be administered once a reactivation of OBI has occurred.

Diagnosis of hepatitis B

Hepatitis B virus (HBV) infection is a major global health problems leading to severe liver disease such as cirrhosis and hepatocellular carcinoma (HCC). HBV is a circular, partly double-stranded DNA virus with various serological markers: hepatitis B surface antigen (HBsAg) and anti-HBs, anti-HBc IgM and IgG, and hepatitis B e antigen (HBeAg) and anti-HBe. It is transmitted by sexual, parenteral and vertical route. One significant method to diminish the burden of this disease is timely diagnosis of acute, chronic and occult cases of HBV. First step of HBV diagnosis is achieved by using serological markers for detecting antigens and antibodies. In order to verify first step of diagnosis, to quantify viral load and to identify genotypes, quantitative or qualitative molecular tests are used. In this article, the serological and molecular tests for diagnosis of HBV infection will be reviewed.

Association between anti-HBc positivity and hepatocellular carcinoma in HBsAg-negative subjects with chronic liver disease: A meta-analysis

A meta-analysis was performed to ascertain to what extent hepatitis B surface antigen (HBsAg)-negative/anti-hepatitis B core (anti-HBc)-positive subjects with chronic liver disease are at a higher risk of developing hepatocellular carcinoma (HCC) than the anti-HBc-negative.All studies included had to fulfill the following characteristics and inclusion criteria: they investigated the relationship between HBsAg-negative/anti-HBc-positive serology and the occurrence of HCC, whether a case-control or cohort study, they provided relative risk (RR) or odds ratios (ORs) and 95% confidence intervals (CIs), were available as a full text written in English, and were published and indexed up to April 2015.Twenty-six original studies met the inclusion criteria, allowing a meta-analysis on 44,553 patients. The risk of HCC among the 9986 anti-HBc-positive subjects was 67% higher than in the 34,567 anti-HBc-negative (95% CI = 1.44-1.95, P < 0.0001). The results were similar when groups of patients with a different stage of liver disease (patients with chronic liver disease, patients with cirrhosis), with different ethnicity (Asian and non-Asian) and etiology (HCV and non-HCV) were considered. The risk of HCC was significantly higher in the 651 anti-HBs/anti-HBc-positive patients (RR = 1.36; 95% CI = 1.17-1.58, P = 0.03) and in the 595 anti-HBs-negative/anti-HBc-positive subjects (RR = 2.15; 95% CI = 1.58-2.92, P < 0.0001) than in the 1242 anti-HBs/anti-HBc negative. However, the RR from 8 studies indicated that the risk of HCC was 35% lower among the anti-HBs/anti-HBc-positive subjects compared to the anti-HBs-negative/anti-HBc-positive (RR = 0.65; 95% CI = 0.52-0.8, P < 0.0001).This meta-analysis shows that in HBsAg-negative subjects with chronic liver disease, anti-HBc positivity is strongly associated with the presence of HCC, an association observed in all subgroups according to the stage of the disease, etiology, and ethnicity.

Establishing the link between hepatitis B virus infection and colorectal adenoma

BACKGROUND

Chronic hepatitis B (CHB) infection has been associated with malignancy, most notably hepatocellular carcinoma. Previous research has shown that hepatitis C is associated with increased colorectal adenomas and neoplasia. Currently, there are no studies on the association of CHB and colorectal adenomas. We aimed to identify a possible link between CHB and colorectal adenoma.

METHODS

A retrospective chart review was performed on 588 consecutive patients undergoing screening or diagnostic colonoscopy that were previously screened or diagnosed with hepatitis B. Comparisons between categorical variables were analyzed with Chi Square test and t-test for continuous variables. Unconditional logistic regression was used to generate age-, gender-and race-adjusted odds ratios and their 95% confidence intervals (CI) comparing medication users with non-users. Statistical analyses were performed with SAS 9.3 software.

RESULTS

A total of 487 patients were analyzed in the control group vs. 71 in the hepatitis B group. The adenoma detection rate was 23.9% in hepatitis B vs. 15.9% in the non-hepatitis B group for all cause colonoscopy; however this did not reach statistical significance. There was a significantly higher number of adenomas present in the distal colon compared to control (OR =2.16; 95% CI, 1.06-4.43; P=0.04). There were no significant findings between hepatitis B infection with size, multiplicity or presence of proximal adenomas. There was a significant difference noted in regards to smoking history, BMI and age between two groups.

CONCLUSIONS

Although the adenoma detection rate was higher in hepatitis B population vs. the non-hepatitis B group this did not reach statistical significance. However, we did find an association between CHB infection and the presence of distal colorectal adenomas. Larger prospective studies are needed to strengthen our findings along with future studies examining hepatitis B virus (HBV) and mechanisms inducing colorectal carcinogenesis.

Prevalence and clinical relevance of occult hepatitis B virus infection in patients on the waiting list for kidney transplantation

BACKGROUND

Occult hepatitis B virus (HBV) infection can be defined as the long-lasting persistence of viral genomes in the liver tissue, and sometimes also in the serum at low levels of viremia in individuals with undetectable HBV surface antigen (HBsAg). Viral replication can be reactivated by immunosuppressive therapies or immunologic diseases, leading to the development of typical hepatitis B.

METHODS

All patients on the waiting list for renal transplantation at the only 2 transplant centers in our region (Piemonte, Italy) were checked for the presence of occult HBV infection by an highly sensitive quantitative HBV-DNA polymerase chain reaction (PCR) assay (nested PCR); the only exclusion criterion was HBsAg-positivity. The enrollment lasted from October 1, 2006, to May 31, 2007. The prospective follow-up will continue for 5 years.

RESULTS

HBV-DNA sequences were detected in blood samples from 10 of 300 cases examined (3.3%), being more frequent among Asian (1/3; 33.3%) and African (1/16; 6.25%) subjects as compared with the Caucasians (8/281; 2.8%; P = .011), among anti-hepatitis C virus (HCV) positive versus HCV negative patients (3/32 [9.3%] vs 7/268 [2.6%]; P = .004) and mainly among patients with a previous history of overt liver diseases (3/22 [14%] vs 7/278 [2.5%]; P = .019). HBV-DNA sequences became undetectable at 1 month after renal transplantation in 3 patients; the follow-up is in progress for these and the other patients.

CONCLUSION

Occult HBV infection occurs in patients undergoing renal transplantation. Longer observation and prospective studies will clarify the clinical impact of this occult infection on transplant outcomes and the possibility of viral reactivation related to immunosuppressive therapy.

Molecular mechanisms underlying HBsAg negativity in occult HBV infection

Although genomic detection is considered the gold standard test on HBV infection identification, the HBsAg investigation is still the most frequent clinical laboratory request to diagnose HBV infection in activity. However, the non-detection of HBsAg in the bloodstream of chronic or acutely infected individuals has been a phenomenon often observed in clinical practice, despite the high sensitivity and specificity of screening assays standardized commercially and adopted in routine. The expansion of knowledge about the hepatitis B virus biology (replication/life cycle, genetic variability/mutability/heterogeneity), their biochemical and immunological properties (antigenicity and immunogenicity), in turn, has allowed to elucidate some mechanisms that may explain the occurrence of this phenomenon. Therefore, the negativity for HBsAg during the acute or chronic infection course may become a fragile or at least questionable result. This manuscript discusses some mechanisms that could explain the negativity for HBsAg in a serological profile of individuals with HBV infection in activity, or factors that could compromise its detection in the bloodstream during HBV infection.

Patients with chronic hepatitis C without advanced fibrosis and hepatocellular carcinoma: a retrospective clinical-pathological study

BACKGROUND

There are very few studies on the incidence and risk factors of hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC) in the absence of advanced fibrosis. Our objective was to identify the clinical-pathological features of these patients.

METHODS

We retrospectively reviewed 162 patients admitted to our hospital for HCV-related HCC between 2000 and 2010. Patients with hepatitis of other aetiologies, human immunodeficiency virus co-infection, or treated with interferon were excluded. We compared demographic, laboratory, clinical and outcome parameters of patients with and without advanced fibrosis.

RESULTS

137 patients had advanced fibrosis (85%). Median age was higher in the advanced fibrosis vs. the non-advanced fibrosis group (62 vs. 65 years, respectively; p = 0.025). Steatosis was significantly more frequent in patients with advanced fibrosis compared to those without advanced fibrosis (43% vs. 20%, respectively; p = 0.032). Independent predictors associated to the occurrence of HCC in patients without advanced fibrosis were hepatitis B core antigen (odds ratio: 3.86; p = 0.044) and duration of hepatitis C infection (odds ratio: 1.21; p = 0.003).

CONCLUSIONS

Risk factors such as steatosis or diabetes were not frequent in patients without advanced fibrosis. Further studies are needed to evaluate the role of occult hepatitis B and the duration of hepatitis infection in patients with HCC and chronic hepatitis C without advanced fibrosis.

MiR-122 in hepatitis B virus and hepatitis C virus dual infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the most common causes of chronic liver diseases and hepatocelluar carcinomas. Over the past few years, the liver-enriched microRNA-122 (miR-122) has been shown to differentially regulate viral replication of HBV and HCV. It is notable that the level of miR-122 is positively and negatively regulated by HCV and HBV, respectively. Consistent with the well-documented phenomenon that miR-122 promotes HCV accumulation, inhibition of miR-122 has been shown as an effective therapy for the treatment of HCV infection in both chimpanzees and humans. On the other hand, miR-122 is also known to block HBV replication, and HBV has recently been shown to inhibit miR-122 expression; such a reciprocal inhibition between miR-122 and HBV suggests an intriguing possibility that miR-122 replacement may represent a potential therapy for treatment of HBV infection. As HBV and HCV have shared transmission routes, dual infection is not an uncommon scenario, which is associated with more advanced liver disease than either HBV or HCV mono-infection. Thus, there is a clear need to further understand the interaction between HBV and HCV and to delineate the role of miR-122 in HBV/HCV dual infection in order to devise effective therapy. This review summarizes the current understanding of HBV/HCV dual infection, focusing on the pathobiological role and therapeutic potential of miR-122.

Occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI) refers to the presence of HBV DNA in the absence of detectable hepatitis B surface antigen. Since OBI was first described in the late 1970s, there has been increasing interest in this topic. The prevalence of OBI varies according to the different endemicity of HBV infection, cohort characteristics, and sensitivity and specificity of the methods used for detection. Although the exact mechanism of OBI has not been proved, intra-hepatic persistence of viral covalently closed circular DNA under the host’s strong immune suppression of HBV replication and gene expression seems to be a cause. OBI has important clinical significance in several conditions. First, OBI can be transmitted through transfusion, organ transplantation including orthotopic liver transplantation, or hemodialysis. Donor screening before blood transfusion, prophylaxis for high-risk organ transplantation recipients, and dialysis-specific infection-control programs should be considered to reduce the risk of transmission. Second, OBI may reactivate and cause acute hepatitis in immunocompromised patients or those receiving chemotherapy. Close HBV DNA monitoring and timely antiviral treatment can prevent HBV reactivation and consequent clinical deterioration. Third, OBI may contribute to the progression of hepatic fibrosis in patients with chronic liver disease including hepatitis C. Finally, OBI seems to be a risk factor for hepatocellular carcinoma by its direct proto-oncogenic effect and by indirectly causing persistent hepatic inflammation and fibrosis. However, this needs further investigation. We review published reports in the literature to gain an overview of the status of OBI and emphasize the clinical importance of OBI.

Occult hepatitis B virus infection in Chinese cryptogenic intrahepatic cholangiocarcinoma patient population

BACKGROUND

There is no information available about occult hepatitis B virus (HBV) infection (OBI) in individuals with intrahepatic cholangiocarcinoma (ICC).

GOALS

To investigate the correlation between OBI and ICC.

STUDY

A retrospective case-control study was conducted. The cases were 183 cryptogenic ICC patients (group I), and the controls were 549 healthy individuals (group II). The cases and controls were matched for age, sex, and inhabitancy. Adjusted odds ratios and 95% confidence intervals were calculated. Intrahepatic total HBV DNA in 63 paraffin-embedded samples was collected from patients in group I (n=44), HBV-associated ICC patients (n=3), and hepatic cavernous hemangioma patients with seronegative HBsAg (hepatitis B S antigen) (group III; n=16). We determined the levels of serum and intrahepatic HBV DNA and compared the level of intrahepatic HBV DNA in 44 cryptogenic patients from group I with the level in the patients from group III.

RESULTS

Compared with group II, group I had a lower prevalence of anti-HBs (antibody against HBsAg) and a higher prevalence of anti-HBe (antibody against hepatitis B e antigen) and anti-HBc (antibody against hepatitis B c antigen). Multivariate analysis confirmed that anti-HBe and anti-HBc positivity were associated with ICC. The odds ratios and 95% confidence intervals for anti-HBe and anti-HBc were 2.482 and 1.482-4.158, 4.556 and 2.938-7.066, respectively. Compared with group III, cryptogenic ICC cases showed more frequent detection of intrahepatic total HBV DNA (63.64% vs. 18.75%, P=0.002).

CONCLUSIONS

OBI may represent an important risk factor for ICC. HBsAg seroclearance does not signify eradication of HBV and may not entirely prevent the development of ICC.

Natural history of hepatitis C

There has long been evidence that hepatitis C can lead to persistent infection in a high proportion of infected individuals, and can progress to chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC). The transition from acute to chronic hepatitis C is usually sub-clinical. Accurate studies of the time course for clearance of acute hepatitis C are difficult to carry out because of the silent onset of the acute disease. The likelihood of spontaneous HCV resolution is associated with several genetic factors, including IL28B inheritance and the DQB1*0301 allele of the major histocompatibility complex class II. Most data suggest that resolution in the acute phase without progression to chronic disease is not accompanied by significant disease, but minor histological lesions have been observed in anti-HCV positive, HCV RNA negative individuals. The risk of reinfection remains a possibility after clearance of acute hepatitis C. High rates of sexually-transmitted infection are being reported in HIV positive men who have sex with men (MSM). Chronic infection with HCV is the leading cause of end-stage liver disease, hepatocellular carcinoma (HCC) and liver related death in the Western world. The natural history of the chronic disease remains incompletely defined. It is generally a slowly progressive disease characterized by persistent hepatic inflammation, leading to the development of cirrhosis in approximately 10-20% of patients over 20-30 years of HCV infection. However, the published data indicate varying progression rates to cirrhosis. Overall, once cirrhosis has developed there is a 1-5% annual risk of HCC and a 3-6% annual risk of hepatic decompensation. Following an episode of decompensation the risk of death in the following year is between 15% and 20%. The high number of chronically infected individuals, the burden of disease, and the absence of a vaccine indicates that treatment will form part of the disease control but the impact, effectiveness and outcomes of treatment in various groups remain uncertain. Several studies and meta-analysis have concluded that eradication of HCV with antiviral therapy reduces the risk of HCC in patients with chronic hepatitis C, independent of fibrosis stage, but the risk is not eliminated.

Advances in the treatment of hepatitis B virus/hepatitis C virus coinfection

INTRODUCTION

Patients with chronic hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection are at a high risk of developing liver cirrhosis and hepatocellular carcinoma, and consequently, warrant effective treatment.

AREAS COVERED

Effective treatment should eradicate HCV infection and inhibit HBV replication but without serious adverse reactions. Careful evaluation of disease progression, predominance of one virus over another, comorbidities and concomitant hepatitis delta virus and/or HIV infection are essential for better therapy choices. In the case of HCV predominance, Peg-interferon plus ribavirin with or without a first-generation directly acting antiviral (DAA) should be the first choice, but future treatments will be DAA-based and interferon-free. In the case of HBV predominance, tenofovir or entecavir should be part of treatment. Patients should be closely monitored for early identification and treatment of HCV or HBV reactivation.

EXPERT OPINION

High potency and high genetic barrier nucleos(t)ide analogues to inhibit HBV replication have been used for years, with no urgency for new drugs. Several DAAs for interferon-free therapy for HCV eradication will be available in the near future. We hope that the high cost of these drugs will not be a limitation to their use in developing countries. Further investigation of HBV/HCV interaction is needed before and during the administration of new therapies.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

[Occult hepatitis B virus infection in chronic hepatitis C]

Occult HBV infection is defined as the presence of HBV DNA in the liver (with or without detectable or undetectable HBV DNA in the serum) of individuals testing negative for HBsAg. Studies on occult HBV infection in hepatitis C patients have reported highly variable prevalence, because the prevalence of occult HBV infection varies depending on the hepatitis B risk factors and methodological approaches. The most reliable diagnostic approach for detecting occult HBV detection is through examination of liver DNA extracts. HCV has been suspected to strongly suppress HBV replication up to the point where it may be directly responsible for occult HBV infection development. However, more data are needed to arrive at a definitive conclusion regarding the role of HCV in inducing occult HBV infection. Occult HBV infection in chronic hepatitis C patients is a complex biological entity with possible relevant clinical implications. Influence of occult HBV infection on the clinical outcomes of chronic hepatitis C may be considered negative. However, recent studies have shown that occult HBV infection could be associated with the development of hepatocellular carcinoma and contribute to the worsening of the course of chronic liver disease over time in chronic hepatitis C patients. Nevertheless, the possible role of occult HBV infection in chronic hepatitis C is still unresolved and no firm conclusion has been made up until now. It still remains unclear how occult HBV infection affects the treatment of chronic hepatitis C. Therefore, in order to resolve current controversies and understand the pathogenic role and clinical impacts of occult HBV infection in chronic hepatitis C patients, well-designed clinical studies are needed.

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.

Occult hepatitis B virus infection and hepatocellular carcinoma: a systematic review

Occult hepatitis B (OHB) infection has been reported to play an important role in the development of hepatocellular carcinoma (HCC). In this systematic review, a significantly higher prevalence of OHB was observed in patients with HCC in the presence or absence of HCV infection when compared with control populations without HCC. Correspondingly, among adequately designed prospective studies, the cumulative probability of developing HCC was significantly greater among patients with OHB than among HBV DNA-negative patients in the presence or absence of HCV infection. Study design, inclusion criteria, treatment options, methodology and potential confounding variables were evaluated, and immunopathogenic mechanisms that could be involved in OHB as a risk factor in HCC were reviewed. From this analysis, we conclude that although OHB is an independent risk factor in HCC development in anti-HCV-negative patients, a synergistic or additive role in the occurrence of HCC in HCV-coinfected patients is more problematic due to the HCC risk attributable to HCV alone, especially in patients with advanced fibrosis and cirrhosis.

Latent hepatitis B is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis C

AIM: To study the potential association between hepatocellular carcinoma (HCC) in patients with chronic hepatitis C (CHC), cirrhosis and latent hepatitis B (LHB) infection, defined as the absence of detectable serum hepatitis B surface antigen (HBsAg) and the presence of hepatitis B core antibody (HBcAb).

METHODS: This retrospective analysis is comprised of 185 cirrhotic patients with HCC who were hepatitis C virus antibody (HCV Ab) (+) and HBsAg(-) at Wayne State University between 1999 and 2008. From these, 108 patients had HCV polymerase chain reaction confirmation of viremia while the remaining (77) were considered to have CHC on the basis of a positive HCV Ab and the absence of any other cause of liver disease. Controls were drawn from our institutional database from the same time period and consisted of 356 HBsAg(-) age, race and gender matched patients with HCV RNA-confirmed CHC and without evidence of HCC. A subgroup of controls included 118 matched patients with liver cirrhosis. χ² test and t test were used for data analysis.

RESULTS: Seventy-seven percent of patients in all 3 groups were African Americans. Patients with HCC had a significantly higher body mass index (P = 0.03), a higher rate of co-infection with human immunodeficiency virus (HIV) (P = 0.05) and a higher prevalence of alcohol abuse (P = 0.03) than the controls. More patients with HCC had LHB than controls (78% vs 39%, P = 0.01). Sixty three percent of patients with HCC were both hepatitis B surface antigen (HBsAb)(-) and HBcAb(+) compared to 23% of controls (P < 0.01). When compared to cirrhotic controls, the frequency of HBcAb(+) remained higher in patients with HCC (78% vs 45%, P = 0.02). Patients with HCC were more likely to be both HBsAb(-) and HBcAb(+) than the cirrhotic controls (63% vs 28%, P = 0.01). Although not statistically significant, 100% of CHC and HIV co-infected patients with HCC (n = 11) were HBcAb(+) when compared to controls (44%; n = 9).

CONCLUSION: These data suggest that LHB occurs at a significantly increased frequency in patients with CHC and HCC than in patients with CHC without HCC.

Impact of occult hepatitis B virus infection on the outcome of chronic hepatitis C

BACKGROUND & AIMS

Occult hepatitis B virus infection (OBI) frequently occurs in patients with hepatitis C virus (HCV) related chronic hepatitis (CHC), but the influence of OBI on the CHC outcome is still uncertain. This observational cohort study evaluated the clinical evolution of CHC patients according to their OBI status.

METHODS

From 1991 to 2000, 326 hepatitis B surface antigen negative CHC patients were tested for OBI by the analysis of liver biopsy DNA extracts. A total of 128/326 cases (39.2%) tested OBI positive and 198/326 (60.8%) OBI negative. Ninety-four of 326 patients (37 OBI positive, 57 OBI negative) were followed-up for a median time of 11 years (range 5-19 years). During the follow-up, 79/94 patients underwent anti-HCV treatments and 25 [corrected] achieved a sustained virological response that occurred independently of their OBI status

RESULTS

Eighteen patients (13/37 OBI positive, 5/57 OBI negative, p < 0.01) developed hepatocellular carcinoma (HCC). Among the 76 non-HCC individuals, 15 subjects (8/24 OBI positive, 7/52 OBI negative, p < 0.05) developed advanced forms of cirrhosis. Eighteen patients died during follow-up and 2 underwent liver transplantation. OBI positive individuals had a cumulative survival rate significantly shorter than OBI negative individuals (p = 0.003). Liver-related deaths were more frequently found in OBI positive than OBI negative patients (12/37 OBI positive vs. 6/57 OBI negative patients respectively, p < 0.01). Finally, non-response to anti-HCV therapy was significantly associated with lower survival (p = 0.02).

CONCLUSIONS

Among CHC patients, occult HBV co-infected individuals are a category at high risk of progression toward cirrhosis, HCC development, and lower survival.

Effect of occult hepatitis B virus infection on the early-onset of hepatocellular carcinoma in patients with hepatitis C virus infection

Although overt hepatitis B virus (HBV) infection promotes the onset of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-infected patients, the effect of occult HBV infection remains unclear. The aim of this study was to investigate the effect of occult HBV infection on the early-onset of HCC in HCV-infected patients. A total of 173 HCC patients with HCV infection were enrolled and classified into 2 groups according to the median age of HCC onset: the early-onset group (n=91; 61.1±5.6 years) and the late-onset group (n=82; 73.8±3.7 years). Independent factors associated with the early-onset of HCC were assessed by multivariate analysis. In the overall analysis, independent risk factors for the early-onset of HCC were the white blood cell count and alanine aminotransferase level, but not the presence of HBV DNA. In a stratification analysis according to albumin levels of ≥3.5 g/dl, the presence of HBV DNA was a significant independent risk factor for the early-onset of HCC (OR 145.18, 95% CI 1.38-15296.61, P=0.036), whereas the presence of antibodies against hepatitis B core antigen was not found to be a risk factor. The presence of HBV DNA was not a risk factor for the early-onset of HCC in the overall analysis. However, its presence was an independent factor for the early-onset of HCC in HCV-infected patients with an albumin level of ≥3.5 g/dl. Thus, occult HBV infection may accelerate hepatocarcino-genesis in HCV-infected patients with relatively low carcinogenic potential.

Non-B, non-C hepatocellular carcinoma (Review)

Although most hepatocellular carcinoma (HCC) is related to viral infection, there is a substantial population of HCC patients (5-20%) who are negative for both markers of hepatitis B virus and hepatitis C virus infection [non-B, non-C (NBNC) hepatitis] in Japan and the incidence of NBNC-HCC has recently tended to increase. The most common cause of liver disease in developed countries is non‑alcoholic fatty liver disease (NAFLD), which includes non‑alcoholic steatohepatitis (NASH) and its related complications. Increased body mass index and diabetes mellitus are associated with developing NAFLD and NASH, which is a severe form of NAFLD. Furthermore, increasing clinical evidence supports the fact that NAFLD and NASH can progress to liver cirrhosis and even HCC. A detailed understanding of the epidemiology, etiology, molecular mechanism, clinical features and prognosis of NBNC-HCC could improve our screening and therapy of this disease. In this review, we primarily focus on clinical aspects of NBNC-HCC and refer to our current knowledge of this cancer.

Prevalence of occult hepatitis B virus infection in kidney transplant recipients

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

Clinical significance of occult hepatitis B infection in progression of liver disease and carcinogenesis

Occult hepatitis B infection (OBI) is defined as long-lasting persistence of hepatitis B virus (HBV) DNA in the liver of patients with hepatitis B surface antigen (HBsAg)-negative status, with or without serological markers of previous exposure (antibodies to HBsAg and/or to hepatitis B core antigen). Over the past two decades, significant progress has been made in understanding OBI and its clinical implications. OBI as a cause of chronic liver disease in patients with HBsAg-negative status is becoming an important disease entity. In conditions of immunocompetence, OBI is inoffensive in itself and detection of HBV DNA in the liver does not always indicate active hepatitis. However, when other factors that cause liver damage, such as hepatitis C virus infection, obesity and alcohol abuse are present, the minimal lesions produced by the immunological response to OBI might worsen the clinical course of the underlying liver disease. Several lines of evidence suggest that OBI is associated with progression of liver fibrosis and the development of hepatocellular carcinoma in patients with chronic liver disease. The major interest in OBI is primarily associated with the growing, widely discussed evidence of its clinical impact. The aim of this review is to highlight recent data for OBI, with a major focus on disease progression or carcinogenesis in patients with chronic liver disease.

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.

Lack of correlation between the antibody to hepatitis B core antigen and survival after surgical resection for hepatitis C virus-related hepatocellular carcinoma

The impact of antibodies to hepatitis B core antigen (anti-HBc) on survival after curative surgical resection (SR) for hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) remains unclear. The aim of the present study was to examine the relationship between anti-HBc positivity and survival of HCV-related HCC patients who underwent curative SR. A total of 222 patients with HCV-related, hepatitis B surface antigen (HBsAg)-negative HCC who underwent curative SR were analyzed. They included 119 anti-HBc-positive patients (53.6%) and 103 anti-HBc-negative patients (46.4%). Overall survival (OS) and recurrence-free survival (RFS) rates were compared between the two groups. The median follow-up periods in the anti-HBc-positive and anti-HBc-negative groups were 3.4 years (range, 0.3-10.9 years) and 3.2 years (range, 0.5-10.9 years), respectively. The 1-, 3- and 5-year cumulative OS rates were 88.8, 70.2 and 50.0%, respectively, in the anti-HBc-positive group and 95.8, 77.1 and 61.7% in the anti-HBc-negative group (P=0.300). The corresponding RFS rates were 68.7, 33.0 and 20.0%, respectively, in the anti-HBc-positive group and 74.4, 38.5 and 16.5% in the anti-HBc-negative group (P=0.482). Multivariate analyses identified serum albumin ≥3.8 g/dl (P=0.005) and the presence of microvascular invasion (P<0.001) as independent factors linked to OS, and interferon therapy after surgery (P=0.011), α-fetoprotein ≥40 ng/ml (P=0.030) and the presence of microvascular invasion (P<0.001) were significant predictors linked to RFS. In subgroup analyses according to maximum tumor size and background liver disease in terms of OS and RFS, no significant difference between the anti-HBc-positive and anti-HBc-negative groups was observed except in patients with non-cirrhotic liver in terms of RFS. In conclusion, anti-HBc-positivity is not a useful predictor for survival of patients with HCV-related HCC after curative SR.