Control of occult hepatitis B virus infection

Background

The diagnosis of hepatitis B virus (HBV) infection requires HBV DNA testing and serologic testing for detection of the surface antigen (HBsAg) and the hepatitis B core antibody (anti-HBc). There is a population of patients with occult HBV infection (OBI), which is not detected by HBsAg or HBV DNA quantification in blood, despite the presence of active replication in the liver.

Scope

This document provides a definition of OBI and describes the diagnostic techniques currently used. It also addresses the detection of patients with risk factors and the need for screening for OBI in these patients.

Summary

Correct diagnosis of OBI prevents HBV reactivation and transmission. Diagnosis of OBI is based on the detection of HBV DNA in patients with undetectable HBsAg in blood.

Perspectives

A high number of patients with OBI may remain undiagnosed; therefore, screening for OBI in patients with factor risks is essential. For a correct diagnosis of OBI, it is necessary that new markers such as ultrasensitive HBsAg are incorporated, and a more comprehensive marker study is performed by including markers such as cccDNA.

Revisión de la infección oculta por el virus de la hepatitis B

Introducción

El diagnóstico actual del virus de la hepatitis B (VHB) está basado en la detección mediante técnicas moleculares de ADN de VHB y ensayos serológicos, como el antígeno de superficie (HBsAg) y anticuerpos frente al core VHB (anti-HBc). Existe un grupo de pacientes con infección oculta de VHB (OBI) en los que estos ensayos no son capaces de detectar el HBsAg ni la cuantificación de ADN de VHB en sangre, aunque exista replicación activa en hígado.

Contenido

El documento define la OBI, y los métodos actuales para su diagnóstico. También aborda la detección de pacientes con factores de riesgo y la necesidad de realizar el cribado de OBI en ellos.

Resumen

Un correcto diagnóstico de OBI, previene la reactivación del VHB y su transmisión. El diagnóstico de OBI actualmente está basado en la detección de ADN de VHB en pacientes con HBsAg indetectable en sangre.

Perspectivas

Un número elevado de pacientes con OBI puede permanecer sin diagnosticar. Es importante realizar el cribado de OBI en determinados pacientes con factores de riesgo. La introducción de nuevos marcadores, como el HBsAg ultrasensible, y estudios más profundos de marcadores, como el ADNccc hepático, serán necesarios para un correcto diagnóstico de OBI.

Prevalence of occult HBV infection in Western countries

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

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

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

Prior hepatitis B virus infection as a co-factor of chronic hepatitis C patient survival after resection of hepatocellular carcinoma

Background

Prior hepatitis B virus infection (PBI) may increase the risk of developing hepatocellular carcinoma (HCC), but the impact of PBI on clinical outcomes following treatment for HCC remains unknown. The aim of this study was to clarify whether PBI affects clinical outcomes after liver resection for hepatitis C virus (HCV)-related HCC by retrospective cohort study.

Methods

PBI patients were defined as those negative for hepatitis B surface antigen and positive for anti-hepatitis B core antibody. Surgical outcomes of HCV-related HCC patients with PBI were compared to those without PBI. Survival of patients with non-B non-C HCC with and without PBI were also compared.

Results

In the HCV group, the median overall survival of 165 patients with PBI was 4.7 years (95% confidence interval [CI], 3.9–5.9), and was significantly shorter compared with 263 patients without PBI (6.6 years [5.3–9.8]; p = 0.015). Conversely, there was no significant difference in recurrence-free survival between the two groups (1.8 years [95% CI, 1.4–2.0] vs 2.0 years [1.7–2.3]; p = 0.205). On Cox proportional hazards regression model, independent factors for overall survival were PBI (hazard ratio 1.38 [95% CI, 1.02–1.87]; p = 0.033), multiple tumors (p = 0.007), tumor size (p = 0.002), and liver cirrhosis (p <  0.001). On the other hand, in the non-B non-C HCC group, both the median overall survival (6.5 years [95% CI, 4.8–7.1]) and recurrence-free survival (2.4 years, [95% CI, 1.5–3.3]) in 104 patients with PBI were not significantly different from those (7.5 years [5.5 − NA; p = 0.932]; and 2.2 years [1.7–2.7; p = 0.983]) in 213 patients without PBI.

Conclusions

PBI and HCV in conjunction with each other affect the survival of patients that have undergone resection for HCC.

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.

A Diagnostic Laboratory-Based Study on Frequency and Distribution of Viral Hepatitis B and C Among Sudanese

Background:

Hepatitis B infection is an alarming public health problem. Almost two billion people of the population alive today, would have been infected at some time in their lives by hepatitis B. Hepatitis C virus is another life threatening condition, and about 425,000 deaths occur each year due to its complications.

The current study was carried out to provide care givers and health planners basic epidemiological data regarding the frequency and distribution of HBV and HCV based on age and sex during a time period of more than 5 years.

Result:

A total of 2109 different patients were found to be infected by HBV during the study period; 1641 (77.81%) were males and 468 (22.19%) were females with the age group of 20-39 years predominating (64%). In addition,16% of patients tested for HBeAg were found reactive.

Conclusion:

There were significant correlations observed between the levels of HBV DNA and ALT, AST and AFP. Regarding HCV, 70 males (54.9%) and 63 females (45.1%) were found to be infected, with preponderance of the age group 41 - 60 years and the genotype 4. Designing knowledge raising campaigns is appreciated as well as repetition of similar studies among larger populations in the following few years will help track a way to improvement.

Synergistic impact of mutations in Hepatitis B Virus genome contribute to its occult phenotype in chronic Hepatitis C Virus carriers

We characterized occult HBV (OHBV) from hepatitis B surface antigen (HBsAg)-negative chronic HCV carriers of Eastern India to explore the impact of genomic variability of HBV in causing undetectability of HBsAg and low viremia that define the occult phenomenon. Screening of sera samples revealed the presence of OHBV in 17.8% of HCV-infected patients. Determination of full-length OHBV sequences and comparison with that from HBsAg-positive carriers led to the detection of distinct substitutions/mutations in PreS2, S, P and X ORFs and in X-promoter and Enhancer-II of OHBV. These mutations were introduced in wild-type HBV and their effects were evaluated by transfection in Huh7 cells. In vitro assays demonstrated that S-substitutions resulted in antigenically modified HBsAg that escaped detection by immunoassays whereas those in ORF-P caused significant decline in viral replication. Impairment in Enhancer-II and X-promoter activities were noted due to occult-associated mutations that generated reduced pregenomic RNA and intracellular HBV-DNA. Additionally, Enhancer-II mutations altered the small to large surface protein ratio and diminished extracellular HBV-DNA and HBsAg secretion. Further, mutations in PreS2, X and enhancer-II increased Grp78-promoter activity, suggesting that OHBV could trigger endoplasmic reticulum stress. Thus viral mutations contribute synergistically towards the genesis of occult phenotype and disease progression.

The influence of anti-HBc status on the sustained virological response rate in HCV-infected patients treated with pegylated interferon alfa 2 and ribavirin

Aim of the study

To determine the influence of HBsAg and HBeAg negative but anti-HBc positive status on the sustained virological response (SVR) rate in HCV-infected patients treated with pegylated interferon alfa 2 (Peg-IFNα-2) and ribavirin (RBV).

Material and methods

The study was based on the retrospective analysis of medical records of HCV-infected patients who started Peg-IFNα and RBV treatment between 1 January 2011 and 31 December 2013 at the 1^st and 2^nd Department of Infectious Diseases of the Regional Hospital in Wrocław, Poland.

Results

Among 240 patients included in the analysis 99 were anti-HBc positive and 141 anti-HBc negative. In the genotype 1, anti-HBc positive group the SVR rate was 47% and in the anti-HBc negative group it was 42.7% (p = 0.591). In the genotype 3, anti-HBc positive group the SVR rate was 60% and in anti-HBc negative patients it was 63.2% (p = 0.79). Differences in SVR rates between anti-HBc positive and negative groups were not statistically significant. None of the anti-HBc positive patients developed reactivation of HBV infection during or in the 24 weeks following the end of treatment.

Conclusions

Anti-HBc determination does not seem to be useful in predicting treatment outcome of conventional Peg-IFNα/RBV therapy in patients infected with HCV genotypes 1 and 3.

Occult HBV infection status among chronic hepatitis C and hemodialysis patients in Northeastern Egypt: regional and national overview

INTRODUCTION

Occult hepatitis B infection (OBI) is considered to be one of the major risks for patients suffering from end-stage renal disease (ESRD) on regular hemodialysis (HD) and patients with chronic hepatitis C virus (HCV) infection. This study compared the prevalence of OBI among these two high-risk groups in the Suez Canal region, Northeastern Egypt, to obtain a better national overview of the magnitude of OBI in this region.

METHODS

Serum samples were collected from 165 HD patients and 210 chronic HCV-infected patients. Anti-HCV antibody, hepatitis B surface antigen (HBsAg), total hepatitis B core (anti-HBc) antibody, and hepatitis B surface antibody (anti-HBs) were detected by enzyme-linked immunosorbent assay (ELISA). HCV RNA was detected using a quantitative real-time RT-PCR assay, and HBV was detected using a nested PCR.

RESULTS

All patients were negative for HBsAg. A total of 49.1% and 25.2% of the patients in the HD and HCV groups, respectively, were anti-HBc-positive. In addition, more anti-HBs-positive patients were detected in the HD group compared to the HCV group (52.1% and 11.4%, respectively). Three cases were positive for HBV DNA in the HD group, while eighteen positive cases were detected in the HCV group. Both study groups showed significant differences in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level as well as anti-HBc, anti-HBs and HBV-DNA positivity.

CONCLUSIONS

OBI was more prevalent among chronic HCV patients than HD patients in the Suez Canal region, Egypt, with rates of 8.5% and 1.8%, respectively. However, more precise assessment of this infection requires regular patient follow-up using HBV DNA detection methods.

Role of occult hepatitis B virus infection in chronic hepatitis C

The development of sensitive assays to detect small amounts of hepatitis B virus (HBV) DNA has favored the identification of occult hepatitis B infection (OBI), a virological condition characterized by a low level of HBV replication with detectable levels of HBV DNA in liver tissue but an absence of detectable surface antigen of HBV (HBsAg) in serum. The gold standard to diagnose OBI is the detection of HBV DNA in the hepatocytes by highly sensitive and specific techniques, a diagnostic procedure requiring liver tissue to be tested and the use of non-standardized non-commercially available techniques. Consequently, in everyday clinical practice, the detection of anti-hepatitis B core antibody (anti-HBc) in serum of HBsAg-negative subjects is used as a surrogate marker to identify patients with OBI. In patients with chronic hepatitis C (CHC), OBI has been identified in nearly one-third of these cases. Considerable data suggest that OBI favors the increase of liver damage and the development of hepatocellular carcinoma (HCC) in patients with CHC. The data from other studies, however, indicate no influence of OBI on the natural history of CHC, particularly regarding the risk of developing HCC.

Occult hepatitis B virus infection among chronic hemodialysis patients in Alexandria, Egypt

The prevalence of end-stage renal disease has increased dramatically in developing countries. Hepatitis B virus (HBV) infection is a global health problem that represents a significant co-morbidity event that has led to outbreaks of hepatitis B. There are inadequate data concerning occult HBV infection among Egyptian chronic hemodialysis patients. This study aimed to detect occult HBV infection among chronic hemodialysis patients in Alexandria, Egypt. A cross-sectional study was performed on 100 patients with end-stage renal disease that received maintenance hemodialysis and had tested negative for HBV surface antigen. Blood samples were collected before the initiation of hemodialysis. Sera were tested for hepatitis C virus (HCV) and hepatitis B core (HBc) antibodies using ELISA, and HBV DNA was detected by SYBR Green real-time PCR using specific primers for the s and c genes and by nested PCR using pol gene-specific primers. The serum activity of alanine and aspartate aminotransferase (ALT and AST) were also measured. Anti-HCV and anti-HBc antibodies were detected in 34% and 48% of patients, respectively, and 70.6% of anti-HCV positive patients were also positive for anti-HBc antibodies. This association was statistically significant (p=0.001). HBV DNA was detected in 32% of the hemodialysis patients. A significant association was determined between the presence of HBV DNA and anti-HCV positivity (p=0.021). Aminotransferases were elevated in 21% of the studied patients, more often in patients with positive anti-HCV profiles than in patients negative for anti-HCV (p<0.05). In conclusion, the serological markers of HBV infection should be verified with molecular tests to investigate possible occult infections, especially among anti-HBc-positive hemodialysis patients, to improve our understanding of their clinical, laboratory, and epidemiological characteristics.

[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.

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.

Detection of occult hepatitis B virus infection among blood donors in Sudan

BACKGROUND

Sudan is classified among countries with a high hepatitis B surface antigen (HBsAg) endemicity of more than 8%. Cross-sectional studies have showed a marked increase in the prevalence of occult hepatitis B infection (OBI) in patients with cirrhosis or hepatocellular carcinoma. In terms of OBI infectivity by transfusion, it is largely unknown whether residual risk estimates translate into true rates of infection.

AIM

The current study aimed to determine the frequency of OBI among blood donors in Sudan.

MATERIALS AND METHODS

This study was carried out during the period between 2011 and 2012. It included 100 HBsAg-negative blood donors who attended the Central Blood Bank in Sudan. Sera collected from all donors were tested for HBsAg, antibodies against hepatitis B core antigen (anti-HBc), antibodies against hepatitis Be antigen (anti-HBe), and antibodies against hepatitis B surface antigen (anti-HBs) by enzyme-linked immunosorbant assay. Anti-HBc-positive patients were tested for hepatitis B virus (HBV)-DNA.

RESULTS

The anti-HBc was detected in 42% of the blood donors, among whom 90.5% were positive for HBV-DNA. Two main profiles have been detected, namely, the presence of the three genes (S, C, and X genes) together in 35.7% of the blood donors or the presence of the X gene in addition to the core gene.

CONCLUSION AND RECOMMENDATIONS

With the use of HBsAg as the sole detection marker for HBV, there is a danger of HBV transmission through blood transfusion. Anti-HBc testing should be added to the routine blood donor screening test if occult hepatitis B is to be diagnosed.

Occult hepatitis B: clinical viewpoint and management

Occult HBV infection (OBI) is defined as HBV DNA detection in serum or in the liver by sensitive diagnostic tests in HBsAg-negative patients with or without serologic markers of previous viral exposure. OBI seems to be higher among subjects at high risk for HBV infection and with liver disease. OBI can be both a source of virus contamination in blood and organ donations and the reservoir for full blown hepatitis after reactivation. HBV reactivation depends on viral and host factors but these associations have not been analyzed thoroughly. In OBI, it would be best to prevent HBV reactivation which inhibits the development of hepatitis and subsequent mortality. In diverse cases with insufficient data to recommend routine prophylaxis, early identification of virologic reactivation is essential to start antiviral therapy. For retrieving articles regarding OBI, various databases, including OVID, PubMed, Scopus, and ScienceDirect, were used.

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

BACKGROUND

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Presence of plus-strand HCV RNA in serum and PBMCs as an indicator for relapse and resistance to IFN therapy in patients infected by HCV

Aim: The aim of our study was to investigate the correlation between the presence of plus-/minus-strand HCV RNA in peripheral blood mononuclear cells (PBMCs) and serum following pegylated IFN/ribavirin therapy with response to therapy in HCV-infected patients. Methods: Forty-three HCV-infected patients who completed 48 weeks of IFN/ribavirin therapy, including 25 sustained virologic responders, 12 resistants and six relapsers, comprised the study population. Plus-/minus-strand HCV RNA was detected by reverse transcription PCR in serum and PBMCs. Results: The frequency of plus-strand HCV RNA was significantly higher in PBMC and serum samples of relapsers and resistants, and this might have important implications in clinical practice and patient management. There was no correlation between presence of plus- and minus-strand HCV RNA and genotypes, except the fact that most of the patients who had plus-strand HCV RNA in PBMCs (60%) and in serum (61.53%) belonged to genotype 1a. Conclusion: Presence of plus-strand HCV RNA in PBMCs and serum after termination of therapy is associated with viral relapse and resistance to IFN/ribavirin treatment in HCV-infected patients.

Hepatitis B virus genotype, HBsAg mutations and co-infection with HCV in occult HBV infection

BACKGROUND

The association between mutations in the hepatitis B surface antigen (HBsAg) gene and the occurrence of occult HBV (OBI) in patients has not been studied adequately to determine if the two are correlated. The current study was aimed to investigate HBsAg mutations, the genotype of HBV and co-infection with HCV in OBI in the central part of Iran to determine any possible associations.

MATERIAL AND METHODS

In this study, 3700 plasma samples were examined for the presence of HBsAg, anti-HBc and HBV-DNA. All HBsAg(-)/anti-HBc(+)/HBV-DNA(+) samples were regarded as OBI. The genotype of HBV was identified using Gap-PCR and RT-PCR was used to determine possible co-infection with HCV. Finally, direct sequencing was performed to analyse mutations within the surface antigen gene of HBV in occult versus acute HBV infection.

RESULTS

Of the 3700 patient samples analysed, 352 (9.5%) cases were determined to be HBsAg(-)/anti-HBc(+) in which HBV-DNA was detected in 57 (16.1%), these latter patients were classified as OBI. All of the patients studied carried the D genotype. Direct sequencing of the S-gene from occult and acute HBV patients revealed one silent and one glycine to arginine mutation but the acute HBV patients showed an additional mutation (alanine to threonine). All the mutations were outside the range of the α-determinant. Furthermore, none of the OBI patients were co-infected with HCV.

CONCLUSIONS

The absence of conformational mutations in the α-determinant of HBsAg confirmed that this antigen could be detected by commercial Elisa kits and therefore was not responsible for false negatives during blood screening. However, it can be concluded that suitable amounts of HBsAg were not expressed by HBV in the OBI patients to be detected by Elisa. Low level expression of HBsAg might be related to the D genotype of the virus. Furthermore, our results suggest that OBI is not related to co-infection with HCV.

Occult hepatitis B virus infection: A complex entity with relevant clinical implications

Occult hepatitis B virus (HBV) infection is a world-wide entity, following the geographical distribution of detectable hepatitis B. This entity is defined as the persistence of viral genomes in the liver tissue and in some instances also in the serum, associated to negative HBV surface antigen serology. The molecular basis of the occult infection is related to the life cycle of HBV, which produces a covalently closed circular DNA that persists in the cell nuclei as an episome, and serves as a template for gene transcription. The mechanism responsible for the HBsAg negative status in occult HBV carriers is a strong suppression of viral replication, probably due to the host’s immune response, co-infection with other infectious agents and epigenetic factors. There is emerging evidence of the potential clinical relevance of occult HBV infection, since this could be involved in occult HBV transmission through orthotopic liver transplant and blood transfusion, reactivation of HBV infection during immunosuppression, impairing chronic liver disease outcome and acting as a risk factor for hepatocellular carcinoma. Therefore it is important to bear in mind this entity in cryptogenetic liver diseases, hepatitis C virus/HIV infected patients and immunosupressed individuals. It is also necessary to increase our knowledge in this fascinating field to define better strategies to diagnose and treat this 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.