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 ...     

Clinical significance of occult hepatitis B virus infection

Occult hepatitis B virus(HBV) infection(OBI) is defined as the presence of HBV DNA in the liver(with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative.Until recently,the clinical effect of OBI was unclear on the progression of liver disease;on the development of hepatocellular carcinoma;and on the risk for reactivation or transmission of HBV infection.Several studies suggest a high prevalence of OBI among patients with cryptogenic chronic liver disease,but its role...     

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.     

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

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

HBsAg-negative hepatitis B virus infections in hepatitis C virus-associated hepatocellular carcinoma

This study was conducted to evaluate reports that hepatitis B virus (HBV) DNA sequences can be found in the serum and/or tumour tissue from some hepatocellular carcinoma (HCC) patients who have no detectable hepatitis B surface antigen (HBsAg) in their sera. Such HBV infections would be highly atypical, because prospective studies have shown a clear succession of specific serologic markers during and after most HBV infections. As most HBsAg-negative HCC patients in Japan have hepatitis C virus (HCV) infections, the present study was conducted to determine whether some of these patients actually have unrecognized HBV infections. Thirty newly diagnosed HCC patients from Kurume, Japan, with antibody to the hepatitis C virus (anti-HCV) were studied. None of the 30 had HBsAg detectable in their serum. Of 22 for whom test results for antibodies to the hepatitis B core antigen (anti-HBc) and antibodies to HBsAg (anti-HBs) were available, 14 (64%) had anti-HBc and anti-HBs, four (18%) had anti-HBc alone, and four (18%) had no HBV markers. Nested polymerase chain reaction was used to detect the HBV surface (S), core (C), polymerase (P) and core promoter gene sequences in the HCC tissues and in the adjacent nontumorous liver tissues. HBV DNA was detected in HCC and/or adjacent nontumorous liver in 22 of 30 (73%) patients [detected in both HCC and nontumorous liver in 19/30 patients (63%)]. Among the 22 patients with detectable HBV DNA, more than one HBV gene was detected in 10 (46%). Among the four patients whose sera were negative for all HBV markers, three had HBV DNA in either HCC and nontumorous liver (two cases) or only in the nontumorous liver (one case); HBV DNA could not be detected in tissues from the fourth patient. In 18 of 21 (86%) patients with detectable HBV core promoter sequences, mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found. No deletions were detected in the core promoter gene region of the type reported to be associated with some cases of HBsAg-negative HBV infection. Thus, HBV DNA was detectable in 22 (73%) HBsAg-negative, anti-HCV-positive HCCs, including three (10%) who were also negative for anti-HBc and anti-HBs. HBV mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found in the majority of cases, mutations that have previously been reported in HBV that is integrated in HCC DNA. In serologic surveys to determine etiologic associations of HCC, patients such as those in this study would have been incorrectly designated as having 'HCV-associated HCC,' whereas the data in this study suggest that HBV could have played a role in the development of their HCCs.     

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,intrahepatic 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 canprevent 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 protooncogenic 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.     

Progressive and sufficient decrease of hepatitis B core antibody can predict the disappearance of hepatitis B virus DNA in Japanese patients with hepatitis B surface antigen clearance

The aim of this study was to elucidate the relationships among serum levels of hepatitis B virus (HBV) DNA, periods after hepatitis B surface (HBs) antigen clearance, and the titer of hepatitis B core (HBc) antibody in 200-fold diluted serum. Twelve patients who had clearance of HBs antigen from serum were studied. Five patients had not received any treatment (group A), and seven had received prednisolone withdrawal therapy. The patients in groups A and B were followed up for 86 months and 108 months (median), respectively. Serum HBV was measured by the nested polymerase chain reaction method. In both groups, serum HBV tended to become gradually undetectable after HBs antigen clearance. The positive rate of HBV in the sera 5 years or more after HBs antigen clearance was significantly lower than that in the sera at less than 5 years, both in group A (P = 0.004) and group B (P = 0.010). In both groups, the titer of HBs tended to decline every year after HBs antigen clearance. HBV was still detectable in the sera of some patients for a long period of time after they showed seroconversion to HBs antibody. The results suggest that detection of HBV was difficult in sera with an HBc titer of 30% or lower and at more than 5 years after HBs antigen clearance in both groups. It is important to note that HBV DNA rarely exists in the serum, even when HBs antigen and HBc are both negative. Received: November 22, 1999 / Accepted: April 28, 2000     

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...     

Frequency and Characteristics of Occult Hepatitis B Infection Among Hepatocellular Carcinoma Patients in Japan

Introduction and aim. Occult hepatitis B virus (HBV) infection (OBI) represents a state without detectable hepatitis B surface antigen, but positive for HBV DNA. The correlation between OBI and hepatocellular carcinoma (HCC) carcinogenesis is controversial. We studied the frequency and characteristics of OBI among HCC patients and metastatic liver cancer patients.Material and methods. DNA was obtained from tumor and non-tumor tissues from 75 HCC patients (15 chronic hepatitis B (CHB), 39 chronic hepatitis C (CHC), 21 cryptogenic) and 15 metastatic liver cancer patients who underwent liver resection. HBV DNA and covalently-closed circular (ccc) DNA were detected using real-time polymerase chain reaction (PCR), and four HBV DNA regions were detected by nested PCR. Clinicopathological factors were compared between patients with and without OBI.Results. HBV DNA was detected in 14 (93.3%) CHB, five (22.7%) cryptogenic and four (10.3%) CHC patients. cccDNA was detected in 12 (80.0%) CHB, three (14.3%) cryptogenic and two (5.1%) CHC patients. All CHB, eight (38.1%) cryptogenic and ten (25.6%) CHC patients tested positive with nested PCR. No metastatic liver cancer patients were positive for any HBV DNA regions. OBI patients had shorter prothrombin times (P = 0.0055), and lower inflammation activity score in non-tumor liver (P = 0.0274). There were no differences in anti-HBV antibodies.Conclusions. OBI was detected in 38% of cryptogenic and 25.6% of CHC patients. There was no correlation between OBI and anti-HBV antibodies, but fewer patients with OBI had high inflammatory activity, suggesting that factors other than inflammation may be involved in HCC carcinogenesis in patients with OBI.     

Impact of occult hepatitis B virus infection and prior hepatitis B virus infection on development of hepatocellular carcinoma in patients with liver cirrhosis due to hepatitis C virus

Objective. Although hepatitis B virus (HBV) DNA can be detected in liver or sera of patients without serum hepatitis B surface antigen (HBsAg), its clinical relevance in hepatocarcinogenesis remains controversial. This observational cohort study was conducted to clarify the risk factors, including the presence of serum HBV DNA and hepatitis B core antibody (anti-HBc), for hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV)-related liver cirrhosis (LC). Material and methods. The study comprised 123 patients with LC due to HCV, and negative for HBsAg. The risk factors for HCC development were analyzed by univariate and multivariate analysis. Serum samples were assayed for HBV DNA using real-time polymerase chain reaction. Results. Serum HBV DNA was detectable in 14 patients (11.4%) and serum anti-HBc in 96 (78.0%). During the follow-up period (mean 53.3 months), 80 patients (65.0%) developed HCC. The cumulative HCC development rate was significantly higher in the anti-HBc-positive group than in the anti-HBc-negative group (p=0.0039), but did not differ between the serum HBV DNA-positive and -negative groups (p=0.8570). The multivariate analysis indicated that male gender, alpha-fetoprotein (AFP) 20 ng/ml or greater, average serum alanine aminotransferase (ALAT) 80 IU/l or greater and the presence of anti-HBc were independent risk factors for development of HCC (p=0.038, p=0.013, p=0.020 and p=0.001, respectively). Conclusions. Serum anti-HBc, which indicates a previous HBV infection, has clinical significance in hepatocarcinogenesis in patients with HCV-related LC, but serum HBV DNA does not. Therefore, anti-HBc in serum is a significant predictor for HCC.     

De novo hepatitis B virus infection in hepatocellular carcinoma following eradication of hepatitis C virus by interferon therapy

Epidemiological studies have revealed that hepatocellular carcinoma (HCC) is still observed in hepatitis C virus (HCV)‐positive patients with a sustained response to interferon (IFN) treatment, although a substantial decrease in the incidence of hepatocellular carcinoma (HCC) has been achieved in those patients. Why HCC develops in patients who have a complete clearance of HCV remains unclear. Here, we provided evidence of latent hepatitis B virus (HBV) infection in an initially HCV‐positive chronic hepatitis patient who developed HCC after the complete eradication of HCV by IFN therapy. Although he was initially negative for anti‐hepatitis B surface antigen (HBsAg) or circulating HBV DNA but positive for anti‐hepatitis B core antigen (anti‐HBc) in his sera, he developed HBsAg and HBV DNA during the course of the management of a series of cancers. HBV DNA was detectable in the liver tissues before HBV reactivation and the viral sequences derived from his anti‐HBc‐positive liver showed 100% homology to that from the serum after HBsAg appearance. These findings indicates that HCV‐positive individuals who are positive for anti‐HBc in the absence of HBsAg could have latent HBV infection in their liver tissues and intrahepatic HBV infection may play a pivotal role in the development of HCC after the IFN‐mediated eradication of HCV.     

Occult hepatitis B virus infection in Egypt

The emerging evidence of the potentially clinical importance of occult hepatitis B virus (HBV) infection (OBI) increases the interest in this topic. OBI may impact in several clinical contexts, which include the possible transmission of the infection, the contribution to liver disease progression, the development of hepatocellular carcinoma, and the risk of reactivation. There are several articles that have published on OBI in Egyptian populations. A review of MEDLINE database was undertaken for relevant articles to clarify the epidemiology of OBI in Egypt. HBV genotype D is the only detectable genotype among Egyptian OBI patients. Higher rates of OBI reported among Egyptian chronic HCV, hemodialysis, children with malignant disorders, and cryptogenic liver disease patients. There is an evidence of OBI reactivation after treatment with chemotherapy. The available data suggested that screening for OBI must be a routine practice in these groups of patients. Further studies needed for better understand of the epidemiology of OBI among Egyptian young generations after the era of hepatitis B vaccination.     

Prevalence of occult hepatitis B virus infection

Occult hepatitis B virus(HBV) infection(OBI) is characterized by the persistence of HBV DNA in the liver tissue in individuals negative for the HBV surface antigen.The prevalence of OBI is quite variable depending on the level of endemic disease in different parts of the world,the different assays utilized in the studies,and the different populations studied.Many studies have been carried out on OBI prevalence in different areas of the world and categories of individuals.The studies show that OBI prevalence...     

Occult hepatitis B virus infection: a covert operation

Summary. Detection of occult hepatitis B requires assays of the highest sensitivity and specificity with a lower limit of detection of less than 10 IU/mL for hepatitis B virus (HBV) DNA and <0.1 ng/mL for hepatitis B surface antigen (HBsAg). This covert condition is relatively common in patients with chronic hepatitis C virus (HCV) that seems to exert some influence on the replicative capacity and latency of HBV. Detection of virus‐specific nucleic acid does not always translate into infectivity, and the occurrence of primer‐generated HBV DNA that is of partial genomic length in immunocompetent individuals who have significant levels of hepatitis B surface antibody (anti‐HBs) may not be biologically relevant. Acute flares of alanine aminotransferase (ALT) that occur during the early phase of therapy for HCV or ALT levels that remain elevated at the end of therapy in biochemical nonresponders should prompt an assessment for occult hepatitis B. Similarly, the plasma from patients with chronic hepatitis C that is hepatitis B core antibody (anti‐HBc) positive (±anti‐HBs at levels of <100 mIU/mL) should be examined for HBV DNA with the most sensitive assay available. If a liver biopsy is available, immunostaining for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) should be contemplated and a portion of the sample tested for HBV DNA. This is another reason for optimal collection of a specimen (e.g. two passes with a 16‐guage needle under ultrasound guidance). Transmission of HBV to immunosuppressed orthotopic liver transplant recipients by donors with occult hepatitis B (OHB) will continue to occupy the interests of the transplant hepatologist. As patients with OHB may have detectable HBV DNA in serum, peripheral blood mononuclear cells (PBMC) and/or liver that can be reactivated following immunosuppression or intensive cytotoxic chemotherapy, the patient needs to be either monitored or treated depending on the pretreatment serological results such as an isolated anti‐HBc reaction or a detectable HBV DNA.     

Update on occult hepatitis B virus infection

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

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

Background and Aim: Occult hepatitis B virus (HBV) infection is defined by the detectable serum HBV–DNA in HBV surface antigen‐negative patients. This retrospective study aims to evaluate the therapeutic effects of combined pegylated interferon (PEG–IFN) plus ribavirin (RBV) in patients with concurrent occult HBV/hepatitis C virus (HCV) dual infection. Methods: In total, 126 consecutive chronic hepatitis C (CHC) patients who received combined PEG–IFN and RBV therapy were included. Patients were divided into the occult HBV/HCV dual infection group or the HCV‐monoinfected group according to whether or not they had the detectable serum HBV–DNA. The biochemical and virological responses to combined therapy were compared between these two groups. Serum HCV‐RNA and HBV–DNA were checked before treatment, at the end of treatment as well as at 6‐ and 12‐months' follow up in the occult HBV/HCV group. Result: Six patients were seropositive for HBV–DNA and were included in the occult HBV/HCV dual infection group. There were no statistical differences in the biochemical and virological responses to combined therapy between these two groups. Undetectable serum HBV–DNA was noted at the end of the treatment and the 6‐ and 12‐months' follow up in patients with occult HBV/HCV dual infection. Conclusion: Occult HBV infection in CHC patients is rare. The biochemical and virological responses to combined PEG–IFN and RBV therapy might be similar in CHC patients with or without occult HBV infection. The serum HBV–DNA level was low in patients with occult HBV/HCV dual infection who responded to combined therapy.     

唐山地区献血人群隐匿性乙型肝炎病毒感染分析

目的了解唐山地区无偿献血人群隐匿性乙型肝炎感染情况。方法用ELISA法检测无偿献血者的乙型肝炎血清标志物,对于HBsAg阴性样本,进行HBV核酸检测（NAT）,NAT阳性样本,用罗氏试剂确证HBV DNA载量。结果共检测116 741例血样,证实隐匿性乙型肝炎感染者35例,占总献血人数的0.29‰。其中97.1%隐匿性乙型肝炎感染者样本的HBV DNA滴度低于102IU/ml。在HBV DNA阳性人群中,抗-HBc阳性率较高,占81.5%,抗-HBs阳性或乙型肝炎病毒血清标志物全阴性也可检出HBV DNA分别占55.6%和22.9%。结论唐山地区献血人群中血清HBsAg阴性者存在一定比例的隐匿性HBV感染,其HBV病毒载量均较低,核酸检测能够提高HBV感染的检出率。     

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

AIM To clarify the prevalence of occult hepatitis B virus(HBV) infection(OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma(HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus(HCV) infection. METHODS This prospective cohort study enrolled 174 patients with chronic HCV infection(chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or moredifferent viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome. RESULTS The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively(P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase 40 IU/L, Child-Pugh score and sustained virologic response(SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development. CONCLUSION The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.     

Occult Hepatitis B Virus Infection: 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.     

Pathogenesis of occult chronic hepatitis B virus infection

Occult hepatitis B infection(OBI) is characterized by hepatitis B virus(HBV) DNA in serum in the absence of hepatitis B surface antigen(HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns.Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays;but more frequently it is due to a strong suppression of viral replication and gene expression.OBI is an entity with world-wide diffusion.The failure to detect HBsAg,despite the persistence of the viral DN...