Liver enzyme flares and occult hepatitis B in persons with chronic hepatitis C infection

Biomarkers of transfusion transmitted occult hepatitis B virus infection: Where are we and what next?

Blood transfusion is a vital procedure, where transfusion-transmitted infection of hepatitis B virus (HBV) remains an important issue, especially from blood donors with occult hepatitis B virus infection (OBI). Occult hepatitis B virus infection is a complex entity to detect using surrogate blood biomarkers for intrahepatic viral transcriptional activity, requiring a continually refined battery of tests utilised for screening. This review aims to critically evaluate the latest advances in the current blood biomarkers to guide the identification of OBI donors and discuss novel HBV markers that could be introduced in future diagnostic practice. Challenges in detecting low HBV surface antigen levels, mutants, and complexes necessitate ultrasensitive multivalent dissociation assays, whilst HBV DNA testing requires improved sensitivity but worsens inaccessibility. Anti-core antibody assays defer almost all potentially infectious donations but have low specificity, and titres of anti-surface antibodies that prevent infectivity are poorly defined with suboptimal sensitivity. The challenges associated with these traditional blood HBV markers create an urgent need for alternative biomarkers that would help us better understand the OBI. Emerging viral biomarkers, such as pre-genomic RNA and HBV core-related antigen, immunological HBV biomarkers of T-cell reactivity and cytokine levels, and host biomarkers of microRNA and human leucocyte antigen molecules, present potential advances to gauge intrahepatic activity more accurately. Further studies on these markers may uncover an optimal diagnostic algorithm for OBI using quantification of various novel and traditional blood HBV markers. Addressing critical knowledge gaps identified in this review would decrease the residual risk of transfusion-transmitted HBV infection without compromising the sustainability of blood supplies.

Ultrasensitive PCR system for HBV DNA detection: Risk stratification for occult hepatitis B virus infection in English blood donors

Occult hepatitis B (HBV) infection (OBI), characterized by low viral loads, accounts for much of the risk of HBV transfusion-transmitted infection. With anticore antibodies (anti-HBc) screening introduced in England, the imperative to identify OBI donors has increased. We aimed to develop an ultra-sensitive PCR system and investigate risk factors for HBV DNA presence in blood donations. Seven extraction methods and three PCR assays were compared. The optimal system was sought to determine HBV DNA presence in anti-HBc-positive donations. Predictors of DNA positivity were subsequently investigated. Extraction from 5 mL of plasma increased sample representation and resulted in HBV DNA detection in low viral load samples (~0.5 IU/mL). Screening of 487 763 donations in 2022 identified two OBI donors and 2042 anti-HBc-positive donors, 412 of the latter with anti-HBs < 100 mIU/mL. Testing of 134 anti-HBc-positive donations utilizing the 5 mL extraction method identified two further HBV DNA-positive donations. Higher anti-HBc titer and anti-HBs negativity were significant predictors of DNA detectability in anti-HBc-positive donations. An ultrasensitive PCR assay identified potentially infectious donations increasing HBV DNA detection in anti-HBc-positive donors from 0.5% to 1.9%. Anti-HBc titers may further complement the risk stratification for DNA positivity in anti-HBc screening and minimize unnecessary donor deferral.

Hepatitis C virus/Hepatitis B virus coinfection: Current prospectives

In endemic areas, hepatitis C virus (HCV)/hepatitis B virus (HBV) coinfection is common, and patients with coinfection have a higher risk of developing liver disease such as hepatocellular carcinoma, liver fibrosis and cirrhosis. In such cases, HCV predominates, and HBV replication is suppressed by HCV. HCV core proteins and interferons that are activated by HCV are responsible for the suppression of HBV. Immunosuppression is also seen in patients with HCV and HBV coinfections. A decrease in HCV-neutralizing antibody response and circulation of Th1-like Tfh cells is observed in patients with HCV and HBV coinfection. Both viruses interacted in the liver, and treatment of HCV/HBV coinfection is genotype-based and complex due to the interaction of both viruses. In HCV-dominant cases, direct-acting antiviral drugs and peg interferon plus ribavirin are used for the treatment, with continuous monitoring of AST and ALT. HBV-dominant cases are less common and are treated with peg interferon and nucleoside nucleotide analogues with monitoring of AST and ALT. The SVR rate in HCV-HBV coinfection is higher than that in monoinfection when treated with direct-acting antiviral drugs. But there is a risk of reactivation of HBV during and after therapy. The rate of reactivation is lower in patients treated with direct-acting antiviral drugs as compared to those treated with peg interferon plus ribavirin. Biomarkers of HBV such as HBcrAg, HBV DNA and HBVpg RNA are not effective in the prediction of HBV reactivation; only the hepatitis B surface antigen titre can be used as a biomarker for HBV reactivation. HCV can also be reactive, but this is found in very rare cases in which HBV is present and is treated first.

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.

A roadmap for serum biomarkers for hepatitis B virus: current status and future outlook

Globally, 296 million people are infected with hepatitis B virus (HBV), and approximately one million people die annually from HBV-related causes, including liver cancer. Although there is a preventative vaccine and antiviral therapies suppressing HBV replication, there is no cure. Intensive efforts are under way to develop curative HBV therapies. Currently, only a few biomarkers are available for monitoring or predicting HBV disease progression and treatment response. As new therapies become available, new biomarkers to monitor viral and host responses are urgently needed. In October 2020, the International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) held a virtual and interactive workshop on HBV biomarkers endorsed by the International HBV Meeting. Various stakeholders from academia, clinical practice and the pharmaceutical industry, with complementary expertise, presented and participated in panel discussions. The clinical utility of both classic and emerging viral and immunological serum biomarkers with respect to the course of infection, disease progression, and response to current and emerging treatments was appraised. The latest advances were discussed, and knowledge gaps in understanding and interpretation of HBV biomarkers were identified. This Roadmap summarizes the strengths, weaknesses, opportunities and challenges of HBV biomarkers.

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.

Current laboratory tests for diagnosis of hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) has a long history in human infectious diseases. HBV infection can progress chronically, leading to cancer. After introduction of a vaccine, the overall incidence rate of HBV infection has decreased, although it remains a health problem in many countries.

PURPOSE

The aim of this review was to summarise current diagnostic efforts for HBV infection and future HBV diagnosis perspectives.

METHODS

We reviewed and summarised current laboratory diagnosis related with HBV infection in clinical practice.

RESULTS

There have been various serologic- and molecular-based methods to diagnose acute or chronic HBV infection. Since intrahepatic covalently closed circular DNAs (cccDNAs) function as robust HBV replication templates, cure of chronic HBV infection is limited. Recently, new biomarkers such as hepatitis B virus core-related antigen (HBcrAg) and HBV RNA have emerged that appear to reflect intrahepatic cccDNA status. These new biomarkers should be validated before clinical usage.

CONCLUSION

An effective diagnostic approach and current updated knowledge of treatment response monitoring are important for HBV infection management. Brand new ultrasensitive and accurate immunologic methods may pave the way to manage HBV infection in parallel with immunotherapy era.

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.

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.

Behaviour of occult HBV infection in HCV-infected patients under treatment with direct-acting antivirals

BACKGROUND

There is controversial data on possible occult HBV reactivation in HCV patients successfully treated with direct-acting antivirals (DAA). However, diagnosis of occult HBV infection (OBI) was not performed by gold standard procedures in any study.

METHODS

By using several highly sensitive assays, we examined serially collected serum samples from 40 HBV-surface-negative DAA-treated HCV patients with OBI identified by testing liver biopsy specimens through nested-PCR technique. Serum samples were obtained at four time points from each patient (at baseline, at 4 weeks after starting, at the end and 12 weeks after stopping therapy) and tested for HBV DNA by nested-PCR and real-time PCR techniques.

RESULTS

All tested serum samples were negative by both quantitative HBV surface antigen (HBsAg) and HBV core-related antigen assays. 26/40 patients were anti-HBs-positive and in all of them, the amount of this antibody was stable at the four time points evaluated. Serum HBV DNA was detected in 10 samples at baseline, in 6 samples 4 weeks after starting therapy, in 11 samples at the end of therapy and in 21 samples 12 weeks after stopping treatment (P=0.001). Aminotransferase values dropped within the normal levels at week 4 of therapy and persisted normal over time in all cases.

CONCLUSIONS

A slight increase in the amount of HBV DNA 3 months after stopping DAA therapy was the only parameter showing a possible reappearance of HBV activity in OBI patients cured for a concomitant HCV infection, but it was insufficient to lead toward a virological reactivation capable of inducing liver injury.

Update of the statements on biology and clinical impact of occult hepatitis B virus infection

In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.

HBV-HCV Coinfection: Viral Interactions, Management, and Viral Reactivation

Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is a complex clinical entity that has an estimated worldwide prevalence of 1-15%. Most clinical studies have shown that progression of disease is faster in HBV-HCV coinfected patients compared to those with monoinfection. Hepatocellular carcinoma development appears to have higher rate in coinfections. Viral replication in coinfected cells is characterized by a dominance of HCV over HBV replication. There are no established guidelines for treatment of HBV-HCV coinfection. Studies on interferon-based therapies and direct-acting antivirals have shown varying levels of efficacy. Clinical reports have indicated that treatment of HCV without suppression of HBV increases the risk for HBV reactivation. In this review, we appraise studies on both direct-acting antivirals and interferon-based therapies to evaluate the efficacy and rates of reactivation with each regimen. Screening for and prevention of coinfection are important to prevent serious HBV reactivations.

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.

Occult hepatitis B virus infection among hepatitis C virus seropositive and seronegative blood donors in Alexandria, Egypt

BACKGROUND AND AIMS

Occult hepatitis B virus infection (OBI, serum hepatitis B surface antigen negative but hepatitis B virus DNA positive) is an emerging problem in the safety of blood transfusion. The introduction of hepatitis B surface antigen in the screening panel for blood bank donors has substantially reduced, but not entirely eliminated, the risk of hepatitis B virus infection. It has been suggested that infection with hepatitis C virus may inhibit hepatitis B virus replication. Therefore, this study aimed at estimating the prevalence and risk factors for OBI among blood donors and determining its relationship with hepatitis C virus infection.

SUBJECTS AND METHODS

Presence of hepatitis B virus DNA and hepatitis C virus RNA was investigated for among 508 hepatitis B surface antigen-negative blood donors in Alexandria, Egypt. Half of the donors were identified as hepatitis C virus antibody reactive.

RESULTS

OBI was detected in 21 donors (4.1%) from the studied population: eight were among hepatitis C virus antibody positive donors (3.2%), among whom seven (33.3%) had hepatitis C virus RNA in their serum, and 13 (5.1%) were among hepatitis C virus antibody negative donors, with no statistically significant difference. The only significant risk factor for OBI among the studied blood donors was visiting local barbers.

CONCLUSION AND RECOMMENDATIONS

OBI is a considerable risk in blood banks, making screening for hepatitis B virus infection only on the basis of surface antigenemia insufficient.

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.

Therapy of occult hepatitis B virus infection and prevention of reactivation

Occult hepatitis B virus infection (OBI) is highly prevalent worldwide. In some cases, it is a consequence of infection with variant viruses mutated in the S gene and producing a surface antigen not recognized by diagnostic kits. In most cases, OBI is due to a strong inhibition of hepatitis B virus (HBV) activities exerted by host defense mechanisms. OBI may reactivate in patients undergoing immunosuppressive therapy and/or chemotherapy with the possibility of a consequent development of acute hepatitis that may lead to hepatic failure. Hematological malignancies and therapeutic schedules including rituximab are the conditions most frequently associated with OBI reactivation. However, this event may occur in a large number of additional clinical and therapeutic settings. Identification of patients prone to undergo reactivation is of great importance for promptly starting a proper antiviral therapy that may stop the HBV reactivation and prevent its clinical sequelae.

Occult HBV infection in Morocco: from chronic hepatitis to hepatocellular carcinoma

BACKGROUND & AIMS

Morocco is one of low to intermediate endemic areas for hepatitis B virus (HBV) infection, but no reports have been published on Occult HBV infection (OBI). To determine the prevalence of OBI and its clinical impact among patients with cryptogenic and HCV-related chronic liver disease in Morocco.

METHODS

A total of 152 HBsAg-negative patients (60 patients with cryptogenic hepatitis and 92 HCV carriers) were enrolled in this study. Sera collected from all patients were tested for anti-HBc and anti-HBs antibodies. OBI was assessed in serum and liver tissue samples using highly sensitive PCR assays targeting Surface, X and core regions of the HBV genome and confirmed by Southern blot hybridization.

RESULTS

A high rate of anti-HBc positivity was found among patients with HCV infection (57/92, 61.95%) compared to those with cryptogenic hepatitis (24/60, 40%) (P = 0.034). A high prevalence of OBI was found among patients with HCV infection (42/92, 45.65%) compared to those with cryptogenic hepatitis (17/60, 28.3%) (P = 0.013). In both groups, the prevalence of OBI increased in parallel with advancing stage of liver disease (χ2 = 6.73; P = 0.0095). The highest proportion of OBI was reached among HCV-related HCC cases (62.5%). Multivariate Cox regression analysis revealed that older age (≥56 years), positivity for anti-HBc and presence of OBI were independent risk factors for the development of HCC in HCV-infected patients.

CONCLUSION

This study helps to understand the current status of OBI and its impact on the severity of liver disease in Moroccan patients.

[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.

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.

Prevalence of occult hepatitis B virus infection in a cohort of HIV-positive patients resident in Sicily, Italy

Occult hepatitis B virus (OBI) in HIV-infected groups is still debated, as well as the associated risk-factors and clinical significance. In this paper, we examined a total of 405 HBsAg-negative/HIV-infected patients enrolled from January 2007 to December 2009. Overall, the prevalence of OBI was 5.9% (95% confidence interval (CI_95%): 3.8–8.7%); it was more frequently associated with “anti-HBc alone” serological marker (11.3%; adjusted odds ratio = 3.7, CI_95%: 1.4–9.8), although it was also detected in the absence of any HBV serological marker (4.9%; CI_95%: 2.3–9.1%). A low prevalence of anti-HCV-positive patients with OBI was found (3.1%; CI_95%: 0.6–8.7%). HIV RNA plasma levels or other immunological/clinical characteristics were not significantly associated with OBI. All but one occult HBV infections were sustained by genotype D viral strains. OBI is relatively frequent in HIV-infected patients, although it does not seem to exert a relevant clinical impact. Viral genotypes in occult HBV infections reflect those circulating in the Mediterranean area.

Risk of occult hepatitis B virus infection reactivation in patients with solid tumours undergoing chemotherapy

BACKGROUND

Hepatitis B virus reactivation may occur in occult-infected carriers with haematological malignancies, whereas little data are available in patients undergoing chemotherapy for solid tumours.

AIMS

Evaluation of cancer patients undergoing chemotherapy to investigate occult hepatitis B virus infection and its clinical-virological outcome.

METHODS

Forty-four patients with solid tumours and without liver disease were prospectively enrolled and sampled before starting chemotherapy and between the second and third chemotherapy cycles (time points 1 and 2, respectively); 24 were also sampled 6 months after the end of chemotherapy (time point 3). At each time point, subjects were tested for liver biochemistry, hepatitis B serology and occult infection.

RESULTS

No sample tested positive for virus surface antigen. Twelve subjects (27.3%) were antibody positive to hepatitis B virus. Overall, occult infection was detected in 4 cases (9%), with positive HBV DNA at time points 1 and 2 (one case), at time point 1 only (one case), only at time points 2 and 3 (two cases), respectively. No occult-infected carrier experienced liver biochemistry flares and/or viral surface antigen positivity.

CONCLUSIONS

Occult hepatitis B virus infection may occur in subjects with solid tumours, although the risk of its reactivation under chemotherapy appears to be very low.

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.

Correlation of viral load with bone marrow and hematological changes in pale patients with chronic hepatitis C virus

Liver is considered the target of hepatitis C virus (HCV), which has marked tropism for hepatocytes. In this study, we investigated changes in bone marrow (BM) and blood and their correlation with viremia level in 30 pale patients with chronic HCV who were selected before antiviral therapy. Patients with BM positive for HCV RNA (53.33 %) showed moderate to high viremia, while patients with BM negative for RNA (46.67 %) had low viremia. There was no significant difference in the liver histopathology between patients with HCV-RNA-negative and positive BM. Patients with BM positive for HCV RNA showed significant changes in BM cells, including the degree of immune complex deposition and alterations in peripheral blood counts compared to patients with BM negative for RNA and healthy controls, suggesting that BM changes could be a sequel or a reservoir for HCV viremia.

Occult HBV infection

The long-lasting persistence of hepatitis B virus (HBV) genomes in the liver (with detectable or undetectable HBV DNA in the serum) of individuals testing negative for the HBV surface antigen (HBsAg) is termed occult HBV infection (OBI). Although in a minority of cases the lack of HBsAg detection is due to infection with variant viruses unrecognized by available assays (S-escape mutants), the typical OBI is related to replication-competent HBVs strongly suppressed in their replication activity. The causes of HBV suppression are not yet well clarified, although the host's immune surveillance and epigenetic mechanisms are likely involved. OBI is a worldwide diffused entity, but the available data of prevalence in various categories of individuals are often contrasting because of the different sensitivity and specificity of the methods used for its detection in many studies. OBI may have an impact in several different clinical contexts. In fact, it can be transmitted (i.e., through blood transfusion and liver transplantation) causing classic forms of hepatitis B in newly infected individuals. The development of an immunosuppressive status (mainly by immunotherapy or chemotherapy) may induce OBI reactivation and development of acute and often severe hepatitis. Finally, evidence suggests that OBI can favor the progression of liver fibrosis, in particular in HCV-infected patients. The possible contribution of OBI to the establishment of cirrhosis also implies its possible indirect role in the development of hepatocellular carcinoma. On the other hand, OBI may maintain most of the direct transforming properties of the overt HBV infection, such as the capacity to integrate in the host's genome and to synthesize pro-oncogenic proteins.

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.

Successful treatment of activated occult hepatitis B in a non-responder chronic hepatitis C patient

We reported a 23 years old male with chronic hepatitis C virus infection, discontinued from pegylated interferon/ribavirin combination therapy due to a lack of early virological response. He has developed activation of occult hepatitis B virus that was successfully treated by a one year of lamivudine therapy.

An overview of occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI), alternatively defined as occult hepatitis B (OHB), is a challenging clinical entity. It is recognized by two main characteristics: absence of HBsAg, and low viral replication. The previous two decades have witnessed a remarkable progress in our understanding of OBI and its clinical implications. Appropriate diagnostic techniques must be adopted. Sensitive HBV DNA amplification assay is the gold standard assay for detection of OBI. Viral as well as host factors are implicated in the pathogenesis of OBI. However, published data reporting the infectivity of OBI by transfusion are limited. Several aspects including OBI transmission, infectivity and its relation to the development of chronic liver diseases and hepatocellular carcinoma have to be resolved. The aim of the present review is to highlight recent data on OBI with a focus on its virological diagnosis and clinical outcome.

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.

Hepatitis C-associated hepatocellular carcinomas in non-cirrhotic livers

Chronic hepatitis C viral infection can lead to cirrhosis and hepatocellular carcinoma. It is generally believed that hepatitis C infection is not oncogeneic per se, but that the presence of cirrhosis determines the increased risk for hepatocellular carcinoma. However, a search of surgical pathology files from two large tertiary care centers for the years 2001-2008 identified a total of 18 hepatocellular carcinomas in non-cirrhotic livers with chronic hepatitis C infection. In six cases the background livers showed bridging fibrosis, while the remainder showed lower stages of fibrosis. Cases were negative for clinical and serological evidence of hepatitis B co-infection, and occult hepatitis B test was negative by PCR of formalin-fixed, paraffin embedded tissues. The tumors were also negative for TP53, exon 7, codon 249 mutations, a characteristic mutation strongly linked to aflatoxin exposure. The hepatocellular carcinomas had typical histology with no enrichment for unusual growth patterns or histological features. Among all resected hepatocellular carcinomas in non-cirrhotic livers over this time period, the prevalence of 16% with HCV infection was significantly greater than that expected by chance. In conclusion, these results demonstrate that hepatocellular carcinomas can arise in livers chronically infected with hepatitis C but without cirrhosis. These findings raise the possibility that in some cases hepatitis C infection and inflammation can be directly oncogeneic. It is also possible that established cirrhosis may have regressed in some cases. Regardless of the mechanism, these findings highlight an important and previously under-recognized risk for hepatocellular carcinoma in HCV-infected individuals who do not have cirrhosis.

Occult hepatitis B virus infection in a cohort of HIV-positive patients: correlation with hepatitis C virus coinfection, virological and immunological features

BACKGROUND

An evaluation of the prevalence of occult hepatitis B virus (HBV) infection in HIV-positive individuals is important as HBV infection may have an impact on the outcome of the liver disease in these patients.

MATERIALS AND METHODS

Of the 1,593 HIV-positive subjects enrolled in the Italian Cohort Naïve Antiretroviral (ICONA) program, 175 (10.9%) were selected for inclusion in the study on the basis of hepatitis B surface antigen (HBsAg) negativity and antibody to hepatitis B core antigen (anti- HBc) positivity; 101/175 (58%) were also anti-hepatitis C virus (HCV) positive. HBV-DNA was detected in plasma using a highly sensitive PCR assay (detection limit: 2.6 copies/ml). Two different genomic regions were assayed. Quantification was performed by real-time PCR. The HBV genotype was determined in 20 cases with occult HBV infection. Data on the antiretroviral therapy (ART) regimen was obtained in 169 individuals: 53 (31.4%) patients were ART-naive, 46 (27.2%) were under ART without lamivudine or tenofovir, and the remaining 70 (41.4%) were under ART including lamivudine or tenofovir.

RESULTS

27/175 (15%) patients had detectable HBV-DNA in their plasma: 21/101 (21%) were anti-HCV positive and 6/74 (8%) were anti-HCV negative. Genotype D was invariably found in the 20 cases analyzed. Occult HBV infection was significantly higher in HCV-coinfected subjects: adjusted OR 5.02, 95% CI 1.31-19.26, p = 0.02. The value was not associated with immune status, HIV load, or ART regimen.

CONCLUSIONS

In relation to the high prevalence of occult HBV infection, particularly in HIV/HCV-coinfected individuals, it is necessary to clarify the clinical impact of this cryptic infection by monitoring HBV-DNA in plasma using the correct approach. Similarly to HBsAg-positive individuals of the Mediterranean area, HBV genotype D is invariably detected in this cohort of HIV-infected patients with occult HBV infection.

Molecular characterization and functional analysis of occult hepatitis B virus infection in Chinese patients infected with genotype C

Occult HBV infection is defined as the persistence of HBV DNA in individuals negative for HBV surface antigen (HBsAg), and many different mechanisms have been reported in different countries. However, in China, one of the endemic areas for HBV infection, no reports have been published on occult HBV infection. The present study investigated the virological features and the mechanism of occult HBV infection in China. Full-length HBV DNA from eight patients with occult HBV infection (S1-S8) and three HBsAg-positive cases (SWT1-SWT3) was cloned and sequenced. Additionally, four entire linear HBV genomes from occult cases were transfected transiently into HepG2 cells. The sequencing results showed two major mutations in patients with occult HBV infection as follows: deletions in the pre-S1 (S3, S4, and S7) and X (S1, S2, and S5) regions. Such deletions covered the S promoter and the basal core promoter (BCP), and function analysis of these variants also showed a decrease in DNA replication and antigen expression. Two patients with occult infection (S6 and S8) had no mutations capable of interfering with viral replication and gene expression in the major viral population. Thus, the deletions in the S promoter and the BCP regions that disable the regulatory elements may be the reason for the absence of HBsAg, and multiple mechanisms may be responsible for occult HBV infection.

Comprehensive genetic and epigenetic analysis of occult hepatitis B from liver tissue samples

BACKGROUND

Occult infection with hepatitis B virus (HBV) is a type of chronic HBV infection that is characterized by the absence of a detectable hepatitis B surface antigen in the blood and by very low levels of HBV DNA in the blood and liver. The mechanisms leading to occult HBV infection remain poorly understood but include possible genetic mutations and deletions. Recently, it has been shown that HBV has CpG islands that are methylated, raising the possibility that epigenetic changes may also be important.

METHODS

The full-length genomes of isolates from 5 cases of occult HBV infection were cloned and analyzed for mutations and deletions. Additional studies were performed to examine for APOBEC3G (1 member of a family of deaminating proteins that are part of the innate immune system's defense against viral infection) hyperediting and methylation of viral DNA.

RESULTS

Numerous mutations and deletions were found in the genomes of occult HBV. However, similar types and locations of polymorphisms were also noted in the genome sequences of HBV isolated from control liver tissue samples obtained from individuals with nonoccult HBV infection. Evidence of APOBEC3G hyperediting was found in 1 case of occult HBV infection, but hyperedited sequences made up only a small proportion of the viral sequences. Methylation of HBV CpG islands 1 and 2 was evident in both occult and nonoccult HBV sequences, with island 2 more densely methylated in occult HBV sequences and island 1 more densely methylated in nonoccult HBV sequences.

CONCLUSION

Deletions and mutations are common in occult HBV but are also found in control nonoccult HBV, and no unique genetic signature for occult HBV was found. Methylation patterns differ between cases of occult and nonoccult HBV infection, suggesting that epigenetic changes may be relevant to occult HBV. Together, these findings suggest that multiple mechanisms can contribute to occult HBV infection.

Incidence of transaminitis among HIV-infected patients with occult hepatitis B

BACKGROUND

The clinical significance of occult hepatitis B virus (HBV) infection, defined as the presence of HBV DNA in individuals with HBV core antibodies (anti-HBc) in the absence of HBV surface antigen (HBsAg), is unclear in HIV-infected patients. This information is needed to determine the importance of detecting and treating occult HBV in this population.

OBJECTIVE

To determine if HIV-infected patients with occult HBV infection have an increased incidence of transaminitis.

STUDY DESIGN

We performed a cohort study among randomly selected HBsAg-/anti-HBc+ HIV-infected patients in the Penn CFAR Database and Specimen Repository. HBV DNA was qualitatively detected using a transcription-mediated amplification assay. Hepatic transaminase levels, the main study outcome, were collected at 6-month intervals from the time of occult HBV determination.

RESULTS

Among 97 randomly selected subjects without baseline transaminitis, 13 (13%) had occult HBV. These subjects more frequently had detectable HIV RNA. The 2-year incidence of transaminitis among HIV-infected subjects with occult HBV (50 events/100 person-years) was not significantly different from those without occult HBV (38 events/100 person-years; adjusted incidence rate ratio=1.36 [95% CI, 0.72-2.59]).

CONCLUSIONS

Occult HBV did not increase the incidence of hepatic transaminitis over 2 years. Future studies should determine whether occult HBV is associated with other clinically important outcomes, particularly hepatocellular carcinoma.