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

BACKGROUND: The prevalence and consequences of occult HBV infection in patients with chronic liver disease by HCV remain unknown. AIMS: To evaluate the prevalence of occult HBV infection in a population of HCV-infected patients with hepatocellular carcinoma. METHODS: The serum samples were tested for HBV DNA by nested PCR and liver tissue analysis was carried out using the immunohistochemical technique of 66 HBsAg-negative patients: 26 patients with chronic hepatitis by HCV (group 1), 20 with hepatocellular carcinoma related to chronic infection by HCV (group 2) and 20 with negative viral markers for hepatitis B and C (control group). RESULTS: Occult HBV infection was diagnosed in the liver tissue of 9/46 (19.5%) HCV-infected patients. Prevalence of occult B infection was evaluated in the HCV-infected patients with and without hepatocellular carcinoma, and there were seven (77.7%) of whom from group 2, conferring a 35% prevalence of this group. No serum sample was positive for HBV DNA in the three groups. CONCLUSION: Occult infection B is frequently detected in liver tissue of HCV-infected patients, especially in cases of hepatocellular carcinoma. However large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population.     

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

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

慢性乙型肝炎病毒感染者家族隐匿性乙型肝炎病毒感染的调查

目的 了解慢性HBV感染者家族隐匿性HBV感染的发生率及其与HBV标志物、年龄和性别等的关系.方法 ELISA方法检测慢性HBV感染者家族成员的HBV血清学标志物,套式PCR法检测136例HBsAg阴性家族成员的血清HBV DNA,并将隐匿性HBV感染者和HBsAg、HBV DNA均阴性者分别作为试验组和对照组进行HBV标志物、年龄、性别和生物化学检测结果的比较.两组均数比较采用t检验.率的比较采用χ~2检验或Fisher确切概率法检验.结果 在52个慢性HBV感染者家族中共检测到92例HBsAg阳性者和136例HBsAg阴性者,其中15例为隐匿性HBV感染者,慢性HBV感染者家族HBsAg阳性率和隐匿性HBV感染的发生率分别为40.4%和11.0%,15例隐匿性HBV感染者中有7例抗-HBc阳性(χ~2=5.341,P=0.02),但隐匿性HBV感染的存在与年龄、性别等无关.结论 HBV感染存在家庭聚集现象,且在其家族中存在隐匿性HBV感染,并在抗-HBc阳性者中发生率较高.     

Current hepatitis B virus infection situation in Indonesia and its genetic diversity

Indonesia has a moderate to high endemicity of hepatitis B virus(HBV) infection. The risk for chronic HBV infection is highest among those infected during infancy. Since 1997, hepatitis B(Hep B) vaccination of newborns has been fully integrated into the National Immunization Program. Al though HBV infection has been reduced by the universal newborn Hep B immunization program, it continues to occur in Indonesia. The low birth dose coverage and the presence of vaccine escape mutants might contribute to this endemicity among children. Although limited information is available for an analysis of occult HBV infection(OBI), several variations and substitutions in the pre-S/S region have been detected in Indonesian HBV strains. Additionally, persistent infection and disease progression of chronic hepatitis B are related to not only viral factors but also the host genome. Indonesia is one of the most ethnically heterogeneous nations, with Javanese and Sundanese as the two highest ethnic groups. This multi-ethnicity makes genomic research in Indonesia difficult. In this article, we focused on and reviewed the following aspects: the current hepatitis B immunization program and its efficacy, OBI, HBV infection among high-risk patients, such as hemodialysis patients, and research regarding the host genome in Indonesia.     

Occult hepatitis B virus infection and its clinical implications

Occult hepatitis B virus (HBV) infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg). Serum HBV level is usually less than 10⁴ copies/mL in these patients. Diagnosis of occult HBV infection requires sensitive HBV-DNA PCR assay. Several possibilities have been hypothesized as the mechanisms of occult HBV infection. These include: (i) mutations of HBV-DNA sequence; (ii) integration of HBV-DNA into host's chromosomes; (iii) infection of peripheral blood mononuclear cells by HBV; (iv) formation of HBV-containing immune complex; (v) altered host immune response; and (vi) interference of HBV by other viruses. The precise prevalence of occult HBV infection remains to be defined. The clinical implications of occult HBV infection involve different clinical aspects. First of all, occult HBV infection harbours potential risk of HBV transmission through blood transfusion, haemodialysis, and organ transplantation. Second, it may serve as the cause of cryptogenic liver disease, contribute to acute exacerbation of chronic hepatitis B, or even fulminant hepatitis. Third, it is associated with development of hepatocellular carcinoma. Fourth, it may affect disease progression and treatment response of chronic hepatitis C. Most of the previous studies utilized retrospective observation without control groups, and lacked direct association of occult HBV infection with specific pathological changes and disease progression. Highly sensitive, quantitative, and functional molecular analyses of HBV, combined with a well-designed prospective clinical assessment will provide the best approach for the future study of occult HBV infection.     

Diagnostic strategy for occult hepatitis B virus infection

In 2008,the European Association for the study of the liver(EASL) defined occult hepatitis B virus infection (OBI) as thepresence of hepatitis B virus(HBV) DNA in the liver(with detectable or undetectable HBV DNA in the serum) of individuals testing hepatitis B surface antigen(HBsAg) negative by currently available assays.Several aspects of occult HBV infection are still poorly understood,including the definition itself and a standardized approach for laboratory-based detection,which is the purpose of this ...     

Frequent delayed spontaneous seroclearance of hepatitis B virus after incident HBV infection among adult high‐risk groups

High rates (~25%) of developing chronic hepatitis B virus (HBV) infection (hepatitis B surface antigen (HBsAg)‐positive for > 6 months following infection) have been observed in people who use drugs (PWUD) and men who have sex with men (MSM). We aimed to estimate the frequency of delayed HBsAg seroclearance, along with its determinants, and time to delayed HBsAg seroclearance. Data were used from MSM and PWUD enrolled in the Amsterdam Cohort Studies (1985‐2002) who had anti‐hepatitis B core antibody seroconversion. Potential determinants for standard HBsAg seroclearance, delayed HBsAg seroclearance and chronic HBV were examined using multinominal logistic regression. Time to HBsAg seroclearance was estimated using Kaplan‐Meier curves. A total of 147 incident HBV infections occurred during follow‐up. On initial HBsAg testing after infection (6‐12 months), 42 (29%) were HBsAg‐positive and 105 (71%) were HBsAg‐negative (‘standard HBsAg seroclearance’). Of the 42 initially HBsAg‐positive individuals, 22 subsequently tested HBsAg‐negative (of whom 7 (31.8%) were HBV DNA positive at last visit, suggesting occult HBV). Overall, 15 became HBsAg‐negative and HBV DNA‐negative (‘delayed HBsAg seroclearance’), while 27 remained HBsAg and/or HBV DNA‐positive (‘chronic HBV’). The 5‐year cumulative probability of delayed HBsAg seroclearance was 41.6% for initially HBsAg‐positive individuals. Delayed HBsAg seroclearance and remaining chronically infected were associated with younger age and HIV/hepatitis C virus (HCV)‐co‐infection. In conclusion, delayed HBsAg seroclearance is common in these key adult populations at‐risk for HBV, while proportion developing HBV chronicity (18%) is still higher compared to the general population (~5%). Given the proportion of individuals with occult HBV infection and that HCV direct‐acting antivirals can lead to HBV reactivation, HBV DNA testing in HCV co‐infected MSM/PWUD are warranted prior to treatment initiation.     

Occult HBV infection and YMDD variants in hemodialysis patients with chronic HCV infection

BACKGROUND/AIMS: End-stage renal disease patients on chronic hemodialysis are at risk for both hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Although the prevalence is unknown in hemodialysis patients, occult HBV infection is frequent in subjects with chronic HCV infection. We aimed to investigate (1) the prevalence and clinical impact of occult HBV infection in hemodialysis patients with chronic HCV infection, and (2) the frequency of YMDD variants (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) in this setting. METHODS: Thirty-three anti-HCV and HCV-RNA-positive, HBsAg-negative hemodialysis patients (mean age 36.9+/-10.4 years, 22 male) were admitted to this study. HBV-DNA (Innogenetics kit) and HCV-RNA (Cobas Amplicor HCV kit) were investigated by polymerase chain reaction technique (PCR). YMDD mutation was studied in all HBV-DNA-positive patients by the BOOM method. RESULTS: HBV-DNA was detected in 12 of 33 patients (36.4%) by PCR. Their mean age was 33.0+/-9.0 years. Age, dialysis period (years) and biochemical parameters were not significantly different in patients with and without occult HBV infection. YMDD variants were identified in six of 12 (50%) patients with occult HBV infection. CONCLUSIONS: Occult HBV infection is frequent in hemodialysis patients with chronic HCV infection. YMDD variants are common in this setting.     

Occult hepatitis B in Mexican patients with HIV, an analysis using nested polymerase chain reaction

Hepatitis B virus infection (HBV) with undetectable levels of HBsAg, has been named occult HBV infection and observed in immunosuppressed patients. The aim of this study was to determine the frequency of occult HBV infection in patients with HIV from the West of México, using a combination of serological markers and nPCR. Thirty eight HIV/AIDS patients, 32 men (84.2%) and 6 (5.8%) women, without liver damage related symptoms were studied. HBV coinfection was observed in 10 (26.3%) patients; while only 3 (7.9%) of them were positive to HBsAg. Thus, 7 (18.4%) occult HBV infected patients could be assessed in this population. One (10%) patient with occult HBV infection was positive to anti-HBs, in spite of the reinfection protection attributed to this serological marker. Anti-HBc was detected only in 2 (20%) patients with occult HBV infection. No significant association could be established between occult HBV infection and CD+4 cell count, biochemical, clinical parameters, AIDS stage, or any other risk factor. This study suggest that determination of HBV DNA utilizing highly sensitive techniques, as nPCR, should be performed to detect occult HBV infection, even in the absence of anti-HBc in HIV/ AIDS patients, in order to have a reliable diagnosis, prevent HBV dissemination and acute exacerbation of chronic hepatitis B or even fulminant hepatitis. To our knowledge this is the first study of occult HBV infection in Mexican patients with HIV. However, further studies are necessary in order to determine HBV genotypes and its relationship with evolution and clinical manifestation of the disease.     

Hepatitis B and human immunodeficiency virus co-infection

Hepatitis B and human immunodeficiency virus (HBV and HIV) infection share transmission patterns and risk factors, which explains high prevalence of chronic HBV infection in HIV infected patients. The natural course of HBV disease is altered by the HIV infection with less chance to clear acute HBV infection, faster progression to cirrhosis and higher risk of liver-related death in HIV-HBV co-infected patients than in HBV mono-infected ones. HIV infected patients with chronic hepatitis B should be counseled for liver damage and surveillance of chronic hepatitis B should be performed to screen early hepatocellular carcinoma. Noninvasive tools are now available to evaluate liver fibrosis. Isolated hepatitis B core antibodies (anti-HBc) are a good predictive marker of occult HBV infection. Still the prevalence and significance of occult HBV infection is controversial, but its screening may be important in the management of antiretroviral therapy. Vaccination against HBV infection is recommended in non-immune HIV patients. The optimal treatment for almost all HIV-HBV co-infected patients should contain tenofovir plus lamivudine or emtricitabine and treatment should not be stopped to avoid HBV reactivation. Long term tenofovir therapy may lead to significant decline in hepatitis B surface Antigen. The emergence of resistant HBV strains may compromise the HBV therapy and vaccine therapy.     

Impact of occult HBV infection in HIV/HCV co-infected patients: HBV-DNA detection in liver specimens and in serum samples

Prevalence and impact of occult HBV infection in HIV positive patients is controversial. The aims of this study were to determine the prevalence of occult HBV infection and its impact on histological and virological parameters. 52 HIV/HCV (but HBsAg-negative) co-infected patients, 29 HBsAg and anti-HCV negative chronic hepatitis, and 20 HBsAg positive chronic hepatitis controls were studied. DNA was extracted from frozen biopsies and amplified with primers for S, C and X regions, and for (ccc) HBV-DNA. Sera were tested for HBV-DNA with two quantitative assays (Cobas Amplicor HBV Monitor, and the real-time COBAS (r) Taqman HBV Test, Roche Diagnostics, UK). Occult HBV infection was detected in 7 (13.4%) liver biopsies of the study group, and in none case of the non viral chronic hepatitis group (p=0.04). All serum samples were HBV-DNA negative with Cobas Amplicor HBV monitor assay, while 3 cases were found positive with real time PCR. Statistical analysis didn't show any impact of occult HBV infection on liver histology, CD4+ cells count, HIV and HCV load, and ALT levels. Occult B infection is relatively frequent in HIV/HCV co-infected patients, and is underestimated by common HBV-DNA serological assays. However, it doesn't seem to exert a relevant impact.     

Occult hepatitis B virus infection

Many studies have shown that hepatitis B virus infection may also occur in hepatitis B surface antigen-negative patients. This occult infection has been identified both in patients with cryptogenic liver disease and in patients with hepatitis C virus-related chronic hepatitis, and much evidence suggests that it may be a risk factor of hepatocellular carcinoma development. However, several aspects of this occult infection remain unclear, such as its prevalence and the factor(s) involved in the lack of circulating hepatitis B surface antigen. Moreover, it is uncertain whether the occult hepatitis B virus infection may contribute to chronic liver damage, considering that it is usually associated with a suppressed viral replication. Evidence and hypotheses concerning this fascinating field of biomedical research are reviewed.     

Persistent occult hepatitis B virus infection： Experimental findings and clinical implications

Hepatitis B virus （HBV） is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection （SOI）. The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection （POI） where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.     

Occult and previous hepatitis B virus infection are not associated with hepatocellular carcinoma in United States patients with chronic hepatitis C

Previous studies have suggested that prior exposure to hepatitis B virus (HBV) infection may increase the risk of development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C. The aim of this study was to compare the prevalence of previous or occult HBV infection in a cohort of hepatitis B surface antigen-negative patients with histologically advanced chronic hepatitis C in the United States who did or did not develop HCC. Stored sera from 91 patients with HCC and 182 matched controls who participated in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial were tested for hepatitis B core antibody (anti-HBc), hepatitis B surface antibody, and HBV DNA. Frozen liver samples from 28 HCC cases and 55 controls were tested for HBV DNA by way of real-time polymerase chain reaction. Anti-HBc (as a marker of previous HBV infection) was present in the serum of 41.8% HCC cases and 45.6% controls (P=0.54); anti-HBc alone was present in 16.5% of HCC cases and 24.7% of controls. HBV DNA was detected in the serum of only one control subject and no patients with HCC. HBV DNA (as a marker of occult HBV infection) was detected in the livers of 10.7% of HCC cases and 23.6% of controls (P=0.18). CONCLUSION: Although almost half the patients in the HALT-C Trial had serological evidence of previous HBV infection, there was no difference in prevalence of anti-HBc in serum or HBV DNA in liver between patients who did or did not develop HCC. In the United States, neither previous nor occult HBV infection is an important factor in HCC development among patients with advanced chronic hepatitis C.     

Occult HBV infection in HIV‐infected adults and evaluation of pooled NAT for HBV

The study aimed to determine the prevalence of occult hepatitis B virus infection among HIV‐infected persons and to evaluate the use of a pooling strategy to detect occult HBV infection in the setting of HIV infection. Five hundred and two HIV‐positive individuals were tested for HBV, occult HBV and hepatitis C and D with serologic and nucleic acid testing (NAT). We also evaluated a pooled NAT strategy for screening occult HBV infection among the HIV‐positive individuals. The prevalence of HBV infection among HIV‐positive individuals was 32 (6.4%), and occult HBV prevalence was 10%. The pooling HBV NAT had a sensitivity of 66.7% and specificity of 100%, compared to HBV DNA NAT of individual samples. In conclusion, this study found a high prevalence of occult HBV infection among our HIV‐infected population. We also demonstrated that pooled HBV NAT is highly specific, moderately sensitive and cost‐effective. As conventional HBV viral load assays are expensive in resource‐limited settings such as India, pooled HBV DNA NAT might be a good way for detecting occult HBV infection and will reduce HBV‐associated complications.     

Occult hepatitis B viral DNA in liver carcinomas from a region with a low prevalence of chronic hepatitis B infection

Occult hepatitis B is defined by the presence of hepatitis B viral (HBV) DNA in the serum or liver in persons lacking hepatitis B surface antigen (HBsAg) in the serum. A high prevalence of occult HBV has been reported in hepatocellular carcinoma (HCC) from Asia, but little information is available on the prevalence of occult HBV in HCC from regions with a low prevalence of typical chronic hepatitis B infection. In a retrospective study, 19 cases of primary liver cancer were investigated for the presence of occult HBV DNA by amplification of the surface, core, and X gene. In addition, HBV copy numbers were quantitated by real time polymerase chain reaction, genotyped, and samples tested for covalently closed circular HBV DNA, which is a marker of active viral replication. Occult HBV was found in three of 19 cases (16%). Genotyping was successful in two cases, both of which were genotype A. HBV DNA copy numbers were low, all less than 10 copies/microg liver DNA. No closed circular HBV DNA was detected. Thus, in this study occult HBV was of genotype A and was found in a low percentage of cases of HCC and was associated with low tissue HBV DNA copy numbers and no detectable evidence for viral replication.     

Occult Hepatitis B Infection and its Possible Impact on Chronic Hepatitis C Virus Infection

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

Anti-HBV Drugs: Progress,Unmet Needs,and New Hope

Approximately 240 million people worldwide are chronically infected with hepatitis B virus (HBV), which represents a significant challenge to public health. The current goal in treating chronic HBV infection is to block progression of HBV-related liver injury and inflammation to end-stage liver diseases, including cirrhosis and hepatocellular carcinoma, because we are unable to eliminate chronic HBV infection. Available therapies for chronic HBV infection mainly include nucleos/tide analogues (NAs), non-NAs, and immunomodulatory agents. However, none of them is able to clear chronic HBV infection. Thus, a new generation of anti-HBV drugs is urgently needed. Progress has been made in the development and testing of new therapeutics against chronic HBV infection. This review aims to summarize the state of the art in new HBV drug research and development and to forecast research and development trends and directions in the near future.     

Dual chronic hepatitis B virus and hepatitis C virus infection

Dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are common in HBV or HCV endemic areas. However, several clinical and pathogenetic issues remain unresolved. First, clinical and in vitro studies suggest the interactions between two viruses. The dynamics of the interaction in untreated setting versus treated setting and its influence on the long-term outcomes await further studies. A key issue regarding viral interactions is whether modulation of infection occurs in the same dually infected individual hepatocyte of the liver. Clarifying this issue may help to understand the reciprocal interference between HCV and HBV and provide clues for future immunopathogenetic studies. Second, the prevalence and clinical significance of coexisting occult HBV infection in patients with chronic HCV infection need further investigations. Third, combination therapy of peginterferon alfa-2a and ribavirin appears to be just as effective and safe for the treatment of hepatitis B surface antigen (HBsAg)-positive patients chronically infected with active chronic hepatitis C as it is in patients with HCV monoinfection. Nevertheless, one-third of dually infected patients with nondetectable serum HBV DNA-level pretreatment developed HBV reactivation posttreatment. How to prevent and treat this reactivation should be clarified. Furthermore, about 10% of the dually infected patients lost HBsAg. Underlying mechanisms await further investigations. Finally, the optimal treatment strategies for dually infected patients with hepatitis B e antigen-positive chronic hepatitis B should be identified in future clinical trials.