Hepatitis B virus occult infection in subjects with persistent isolated anti-HBc reactivity

Detection of occult hepatitis B virus infection among subjects with isolated hepatitis B core antibodies: Results from a 3-year survey in an Italian tertiary-care hospital

BACKGROUND

Hepatitis B virus (HBV) infection causes hepatitis, liver cirrhosis, hepatocellular carcinoma, and death. This study examines the subjects with isolated anti-HBV core antigen antibody (anti-HBcAg), a pattern characterized by the persistent HBV carriage in the absence of HBV surface antigen (HBsAg) and anti-HBsAg antibody.

METHODS

Based on medical orders, from 2017 to 2019, serological and molecular assays were performed on serum/plasma samples of 33,048 subjects (71.4% Italians, 28.6% foreigners), who referred to the Virology Unit of the University-Hospital of Parma (Northern Italy) for the laboratory diagnosis of HBV infection.

RESULTS

The seroprevalence was 4.6% for HBsAg and 11% for anti-HBcAg. The occurrence of the isolated anti-HBcAg status was 3.1%, with higher frequency in males than in females (66.3% vs. 33.7%, P < 0.0001), in Italians than in foreigners (54.8% vs. 45.2%, P < 0.001), and in outpatients than in inpatients (57.4% vs. 42.6%, P < 0.0001). Foreigners with isolated anti-HBcAg came mostly from Africa (67.9%) and Eastern Europe (26.2%). Among subjects with isolated anti-HBcAg, 14.8% had occult HBV infection, 26.3% hepatitis C virus co-infection, 2% human immunodeficiency virus co-infection, and 3.3% both of these latter co-infections.

CONCLUSIONS

The anti-HBcAg assay accurately evaluates the HBV exposure; subjects with isolated anti-HBcAg antibody should be further analysed for HBV DNA. The HBV infection prevalence in Italy is increasing, due to growing migratory flows from endemic areas.

In silico analysis of mutations associated with occult hepatitis B virus (HBV) infection in South Africa

Occult hepatitis B virus (OBI) infection is defined by the presence of viral DNA in the liver and/or serum in absence of hepatitis B surface antigen (HBsAg). While multiple studies have identified mutations that are associated with OBI, only a small portion of these mutations have been functionally characterized in vitro. Using complementary in silico approaches, the effects of OBI-associated amino acid mutations on HBV protein function in HBV/HIV-positive ART-naïve South Africans were evaluated. Two OBI-associated mutations in the PreS1 region, one in the PreS2 region, and seven in the surface region of subgenotype A1 sequences were identified as deleterious. In subgenotype A2 sequences, 11 OBI-associated mutations in the PreS1 region, seven in the PreS2 region, and 31 in the surface region were identified as deleterious. In the polymerase region, 14 OBI-associated mutations in subgenotype A1 and 71 OBI-associated mutations in subgenotype A2 were identified as deleterious. This study utilized in silico approaches to characterize the likely impact of OBI-associated mutations on viral function, thereby identifying and prioritizing candidates and reducing the significant cost associated with functional studies that are essential for mechanistic studies of the OBI phenotype.

Anti-HBc Screening of Blood Donors in Bangladesh: Relevance to Containment of HBV Propagation

OBJECTIVES

To avoid further transmission of hepatitis B virus (HBV) infection, blood is tested for hepatitis B surface antigen (HBsAg) before transfusion. However, post-transfusion hepatitis B has been detected in clinics after transfusion of HBsAg-negative blood. The study presented here was undertaken to assess if HBsAg-negative blood is free from HBV or not.

METHODS

Sera were collected from 398 blood donors who were negative for HBsAg. Out of 398 blood samples, antibody to hepatitis B core antigen (ant-HBc) was detected in 82 sera samples. HBV DNA was evaluated in HBsAg-negative, anti-HBc-positive sera. HBsAg, hepatitis B e antigen (HBeAg), antibody to HBeAg (anti-HBe), and anti-HBc in the sera were measured by an enzyme-linked immunosorbent assay (ELISA). HBV DNA was quantified by a real time polymerase chain reaction (PCR).

RESULTS

Out of 82 HBsAg-negative, anti-HBc-positive sera samples, HBV DNA were detected in the sera of 7 voluntary blood donors. Out of these 7 subjects, all were negative for HBeAg. The levels of ALT were more than 30 IU/L in 6 of 7 HBVDNA-positive subjects and it was above upper limit of normal (>42 IU/ml) in one subject.

CONCLUSIONS

The present recommendation about blood transfusion of HBsAg-negative blood system is not capable of blocking HBV transmission to blood recipients. Although advanced countries have adopted nucleic acid testing (NAT) for preventing HBV transmission, developing countries may apply anti-HBc testing and ALT estimation before blood transmission.

Are current screening protocols for chronic hepatitis B virus infection adequate?

Chronic hepatitis B virus (HBV) infection screening usually includes only HBV surface antigen (HBsAg) testing; HBV core and surface antibody (anti-HBc, anti-HBs) assays, indicating resolved infection and immunity, are not routinely performed. Yet, serum HBV DNA is measurable in approximately 10% of HBsAg-negative/anti-HBc-positive cases, representing occult HBV infection (OBI). Patient blood samples from 2 Veterans Affairs medical center look-back investigations were screened for HBV infection using HBsAg enzyme immunoassays. Supplementary testing included anti-HBc and anti-HBs enzyme immunoassays. For anti-HBc-positive samples, HBV DNA testing was performed. Background OBI prevalence was further estimated at these 2 facilities based on HBV serology testing results from 1999-2012. Finally, a literature review was performed to determine OBI prevalence in the published literature. Of 1887 HBsAg-negative cohort patients, 98 (5.2%) were anti-HBc positive/anti-HBs negative; and 175 (9.3%), anti-HBc positive/anti-HBs positive. Six of 273 were HBV DNA positive, representing 0.3% of the total tested and 2.2% who were anti-HBc positive/anti-HBs negative or anti-HBc positive/anti-HBs positive. Among 32,229 general population veterans at these 2 sites who had any HBV testing, 4/108 (3.7%) were HBV DNA positive, none of whom were part of the cohort. In 129 publications with HBsAg-negative patients, 1817/1,209,426 (0.15%) had OBI. However, excluding blood bank studies with greater than 1000 patients, the OBI rate increased to 1800/17,893 (10%). OBI is not rare and has implications for transmission and disease detection. HBsAg testing alone is insufficient for detecting all chronic HBV infections. These findings may impact blood donation, patient HBV screening, follow-up protocols for patients assumed to have cleared the infection, and initiation of immunosuppression in patients with distant or undetected HBV.

KASL Clinical Practice Guidelines: Management of chronic hepatitis B

The guideline on the management of chronic hepatitis B (CHB) was first developed in 2004 and revised in 2007 by the Korean Association for the Study of the Liver (KASL). Since then there have been many developments, including the introduction of new antiviral agents and the publications of many novel research results from both Korea and other countries. In particular, a large amount of knowledge on antiviral resistance--which is a serious issue in Korea--has accumulated, which has led to new strategies being suggested. This prompted the new guideline discussed herein to be developed based on recent evidence and expert opinion.

TARGET POPULATION

The main targets of this guideline comprise patients who are newly diagnosed with CHB and those who are followed or treated for known CHB. This guideline is also intended to provide guidance for the management of patients under the following special circumstances: malignancy, transplantation, dialysis, coinfection with other viruses, pregnancy, and children.

Prevalence of a virus similar to human hepatitis B virus in swine

Background

The objective of this study is to established evidence of the existence of a novel member of the hepadnavirus family endemic in swine. Temporarily this virus was designated as swine hepatitis B virus (SHBV). This SHBV can be detected by using human hepatitis B virus diagnostic kits including ELISA, immunohistochemical staining, and transmission electron microscopy (TEM). Also seroprevalence of pig farms in Beijing, China, and pathological features of SHBV infection was determined.

Results

Screened result shows that overall prevalence of HBsAg was 24.8%, closed to that of anti-HBsAg, whereas HBeAg and anti-HBe were barely detectable. The distribution of HBsAg and HBcAg was examined by immunohistochemistry of liver samples. Typical hepatitis pathological change, such as spotty parenchymal cell degeneration, necrosis of hepatocytes and proliferation of fibrous connective tissue were observed during histopathological analysis. Analysis of HBsAg-positive serum with TEM revealed two morphologic forms, 20 nm and 40 nm sized particles, similar to small spherical and Danes particles of HBV. Observation of the ultrastructure of the liver also found HBV-like particles in the nucleus of hepatocytes.

Conclusion

Our research result implies that SHBV could be a causative agent of swine. The discovery of SHBV will unveil novel evolutionary aspects of hepatitis and provides new information for further hepadnavirus research.

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.

Markers for hepatitis A, B and C in methadone maintained patients: an unexpectedly high co-infection with silent hepatitis B

AIMS

To determine the prevalence of hepatitis A, B and C viruses in patients attending a methadone maintenance clinic in New York City.

DESIGN

Cross-sectional.

SETTING

The Adult Services Clinic of Weill Cornell Medical College, an urban hospital-affiliated methadone program.

PARTICIPANTS

Former heroin addicted adults (n = 103) on methadone maintenance therapy.

MEASUREMENTS

Markers for hepatitis A virus [HAV immunoglobulin M (IgM) and imunoglobulin G (IgG)], hepatitis B [hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb)] and hepatitis C virus (HCVAb). Serum alanine aminotransferase (ALT) and quantitative HCV RNA were also obtained. Qualitative detection of HBV DNA and HCV genotype were obtained in a subset of subjects.

FINDINGS

More than 40% of subjects had markers for all three viruses. HCVAb was the most prevalent (83.5%), followed by HBcAb (65.0%), HAV IgG (46.1%) and HBsAb (41.1%). Hepatitis C RNA was detected in 70.6% of HCVAb positive subjects. While no subject had HBsAg, HBV DNA was detected in 26.4% of subjects who underwent this measure; all (n = 20) had HBcAb as their only HBV marker. The presence of HBV DNA did not influence ALT. Subjects with HCV RNA had higher ALTs than those without HCV RNA.

CONCLUSIONS

Most methadone-maintained subjects had at least one marker for viral hepatitis, with 41.8% having markers for HAV, HBV and HCV. A quarter of subjects had silent HBV infection, defined as the presence of HBV DNA in the absence of HBsAg. These subjects should be considered infectious and pose a public health risk.

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

Transfusion-transmitted infections

Although the risk of transfusion-transmitted infections today is lower than ever, the supply of safe blood products remains subject to contamination with known and yet to be identified human pathogens. Only continuous improvement and implementation of donor selection, sensitive screening tests and effective inactivation procedures can ensure the elimination, or at least reduction, of the risk of acquiring transfusion transmitted infections. In addition, ongoing education and up-to-date information regarding infectious agents that are potentially transmitted via blood components is necessary to promote the reporting of adverse events, an important component of transfusion transmitted disease surveillance. Thus, the collaboration of all parties involved in transfusion medicine, including national haemovigilance systems, is crucial for protecting a secure blood product supply from known and emerging blood-borne pathogens.

HIV-related liver disease: infections versus drugs

HIV-infected individuals have myriad causes of hepatotoxicity that range from mild hepatitis to significant liver failure with its associated morbidity and mortality, especially in the setting of chronic viral hepatitis (HCV and HBV). Immune restoration by HAART therapy can contribute liver-related toxicity in HIV-coinfected patients. Clinicians need to be aware of this problem and individualize management in this challenging clinical scenario. Avoidance of potentially hepatotoxic agents or close monitoring during treatment of HIV may prevent liver failure in patients who have HIV. Furthermore, vaccination against hepatitis A virus and HBV in nonimmune HIV individuals may prevent acquisition of hepatitis A virus and HBV infections in patients who have HIV. Finally, treatment of HIV, and, if appropriate, treatment of those who are coinfected with HCV and HBV with close monitoring, may improve the outcome of patients who have HIV and are at risk fo r significant hepatotoxicity during treatment from immune restoration or hypersensitivity reactions.

Occult hepatitis B in HIV-infected patients

Prevalence of hepatitis B virus (HBV) markers, including occult HBV, has not been described in diverse cohorts among HIV-infected patients. The objective of this study was to assess prevalence and significance of active and occult HBV infection in an HIV-positive US cohort. A random sample was taken from 2 prospective multicenter treatment intervention cohorts. The sample population (n = 240) was HIV-1 infected and highly active antiretroviral therapy-naive. Prevalence of HBV serologic markers and quantitative HBV DNA were determined. Serum alanine aminotransferase (ALT) levels were measured to evaluate correlates of hepatocyte injury. A total of 64.6% of subjects demonstrated reactivity for any marker of current or past HBV infection or prior vaccination. Chronic HBV infection characterized by hepatitis B surface antigen (HBsAg) reactivity was present in 7.1% while 15.8% exhibited HB anticore IgG only. Approximately 10% of the latter group was HBV DNA positive by a polymerase chain reaction-based assay. Only patients with a serologic pattern of HBsAg or HB anticore alone reactivity had HBV DNA. Occult HBV was observed in approximately 10% of HIV-infected patients with HB anticore IgG antibody in a geographically representative national cohort. Though viral titers and serum ALT levels were low, screening of this subset of HIV-infected patients may have implications in terms of antiretroviral therapy and risk of immune reconstitution-associated flares.

Replicative homeostasis II: influence of polymerase fidelity on RNA virus quasispecies biology: implications for immune recognition, viral autoimmunity and other "virus receptor" diseases

Much of the worlds' population is in active or imminent danger from established infectious pathogens, while sporadic and pandemic infections by these and emerging agents threaten everyone. RNA polymerases (RNA_pol) generate enormous genetic and consequent antigenic heterogeneity permitting both viruses and cellular pathogens to evade host defences. Thus, RNA_pol causes more morbidity and premature mortality than any other molecule. The extraordinary genetic heterogeneity defining viral quasispecies results from RNA_pol infidelity causing rapid cumulative genomic RNA mutation a process that, if uncontrolled, would cause catastrophic loss of sequence integrity and inexorable quasispecies extinction. Selective replication and replicative homeostasis, an epicyclical regulatory mechanism dynamically linking RNApol fidelity and processivity with quasispecies phenotypic diversity, modulating polymerase fidelity and, hence, controlling quasispecies behaviour, prevents this happening and also mediates immune escape. Perhaps more importantly, ineluctable generation of broad phenotypic diversity after viral RNA is translated to protein quasispecies suggests a mechanism of disease that specifically targets, and functionally disrupts, the host cell surface molecules – including hormone, lipid, cell signalling or neurotransmitter receptors – that viruses co-opt for cell entry. This mechanism – "Viral Receptor Disease (VRD)" – may explain so-called "viral autoimmunity", some classical autoimmune disorders and other diseases, including type II diabetes mellitus, and some forms of obesity. Viral receptor disease is a unifying hypothesis that may also explain some diseases with well-established, but multi-factorial and apparently unrelated aetiologies – like coronary artery and other vascular diseases – in addition to diseases like schizophrenia that are poorly understood and lack plausible, coherent, pathogenic explanations.

Occult hepatitis B virus infection does not affect liver histology or response to therapy with interferon alpha and ribavirin in intravenous drug users with chronic hepatitis C

BACKGROUND

the frequency and the impact of occult HBV infection in patients with chronic hepatitis C infection is still a matter of some controversy.

OBJECTIVES

our aim was to evaluate the prevalence of occult HBV infection and assess its impact on liver biochemistry, HCV viral titre, liver histology and on outcome of therapy in patients with chronic hepatitis C.

STUDY DESIGN

paired liver biopsies and serum samples were collected from 51 patients (84% IVDUS) with HBsAg negative chronic hepatitis C, and tested for HBV-DNA with nested PCR. Liver biopsies were further studied histologically, with morphometric analyses and immunostaining techniques. Twenty-five were treated with alpha Interferon and ribavirin and followed for at least 18 months.

RESULTS

HBV DNA was detected in 29.4% of liver tissue specimens and in only one (1.9%) serum sample. Three liver specimens were positive for surface gene, nine for core gene, three for both and none for the X gene. No significant difference in mean transaminase values, HCV viral titre, HCV genotype, or grading and staging and morphometric analysis was observed in patients with or without HBV DNA. Moreover, all 51 liver specimens were negative for both HBsAg and HBcAg. Sustained response to combination therapy was achieved in 40% of patients with and in 53% of patients without HBV DNA in the liver specimens (P=NS).

CONCLUSIONS

HBV DNA is frequently found in the liver of patients with chronic hepatitis C. However, the lack of any significant impact on HCV viral titre, liver enzymes, histological parameters and response to therapy, suggests that in most cases HBV DNA detected in the liver by PCR may be either an integrated or low level replicative form.

HBV DNA integration and HBV-transcript expression in non-B, non-C hepatocellular carcinoma in Japan

Few studies have examined the etiology of hepatocellular carcinoma (HCC) in patients without hepatitis virus infection. We evaluated the role of occult hepatitis B virus (HBV) infection in the development of HCC in Japanese patients without hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C antigen (anti-HCV). Twenty-one HBsAg negative and anti-HCV negative (non-B, non-C) patients with HCC were studied. HBV DNA in serum and HBV transcripts in liver were examined by polymerase chain reaction (PCR) or reverse transcription and PCR. HBV DNA integration was examined by Southern blot analysis or cassette-ligation-mediated PCR as described previously. p53 mutations were examined by direct sequencing. HBV DNA was not detected in serum from any patients. HBV-related transcripts were detected in 5 of 7 HCCs from patients with antibodies to hepatitis core antigen (anti-HBc) and in 3 of 14 HCCs from patients without anti-HBc (P = 0.0261). HBV DNA was integrated into human genome in two non-B, non-C HCCs. Of the 14 patients without anti-HBc, 5 had a history of excessive alcohol intake. In exons 5 through 8 of the p53 gene, mutations were detected in 2 of 8 HCCs with HBV-transcripts and in 5 of 13 HCCs without such transcripts. p53 mutation at codon 159 was found in 2 of 6 patients with excessive alcohol intake without HBV-transcripts. These results suggested that occult HBV infection might play an important role in hepatocarcinogenesis in non-B, non-C patients with anti-HBc and that excessive alcohol intake might be related to HCC in non-B, non-C patients in Japan.

A novel stop codon mutation in HBsAg gene identified in a hepatitis B virus strain associated with cryptogenic cirrhosis

AIM: HBsAg is the most important serological marker for acute or chronic hepatitis B. Nevertheless, there were reports of HBsAg-negative infection caused by hepatitis B virus in recent years. We had a patient with crytogenic cirrhosis who was negative for HBsAg, positive for anti-HBs and HBeAg. This paper was to explore the pathogenic and molecular basis of the unusual serological pattern.

METHODS: HBV serologic markers were qualitatively and quantitatively determined. HBV DNA in serum was qualitatively tested using routine Polymerase chain reaction(PCR), and the viral level was determined with real-time fluorescence quantitative PCR. HBsAg gene was amplified and cloned. Four clones were sequenced. The new genomic sequences were compared with GenBank on the DNA level as well as the protein level.

RESULTS: The qualitative results of serological markers were HBsAg(-), anti-HBs(+), HBeAg(+), anti-HBe(-) and anti-HBc(+). The quantitative results of serological marker were HBsAg (S/N): 0.77 (cut off of S/N: ≥ 2.00), HBeAg (S/N): 56.43 (cut off S/N: ≥ 2.10), anti-HBc (S/C_O): 2.03 (cut off of S/C_O: ≤ 1.00). The viral level was as high as 1.54 × 10⁹ copies/ml. Sequencing of the HBsAg gene clones revealed a unique point mutation at nucleotide 336 (C to A), which resulted in a novel stop codon at aa 61. The novel HBsAg gene stop mutation had not been described.

CONCLUSION: The lack of detection of HBsAg in the presence of high viral levels of replication may be caused by the existence of viral genomes harboring point mutations which resulted in stop codon upstream of the “a” determinant in HBsAg gene.

Frequent occult hepatitis B virus infection in patients infected with human immunodeficiency virus type 1

The presence of hepatitis B virus (HBV) serological markers was investigated in 170 patients (137 male, 33 female) infected with human immunodeficiency virus (HIV) type 1. Antibodies to the hepatitis B core antigen (anti-HBc antibodies) were detected in 115 (68%) patients. Of these 115, 14 (12%) were hepatitis B surface antigen (HBsAg) positive, 60 (52%) presented anti-HBs antibodies, and 41 (35%) were anti-HBc positive only. All 115 of the anti-HBc positive samples were tested for HBV DNA by using two polymerase chain reaction (PCR) assays that amplify the core and pre-S regions of the HBV genome, respectively. HBV DNA was detected in 23 samples: 7 of 14 (50%) HBsAg-positive samples, 12 of 60 (20%) anti-HBs-positive samples, and 4 of 41 (10%) samples positive for anti-HBc only. Six samples (all HBsAg positive) were positive in both PCR assays and 17 samples were HBV DNA positive in only one assay. The mean viral load in HBsAg-positive patients was higher than that observed in HBsAg-negative patients. A number of patients were receiving treatment with lamivudine, a drug that interferes with both HBV and HIV replication. However, neither the rate of HBV DNA positivity nor HBV load was significantly different between patients treated with lamivudine and those not treated with this drug.

Presence of hepatitis B surface antigen mutant G145R DNA in the peripheral blood leukocytes of the family members of an asymptomatic carrier and evidence of its horizontal transmission

An asymptomatic carrier and all six of his family members were detected positive for HBV DNA in their peripheral blood leukocytes (PBL), by polymerase chain reaction. Direct sequencing of the amplified DNA revealed that the HBV DNA from the carrier and his wife was of subtype ayw. Interestingly, the amplified HBV DNA from the five other members of the family was found to be not only of subtype adw but also contained G to A mutation at nucleotide position 587. This indicates the presence of established vaccine escape mutant of the virus (G145R) and suggests two different sources of infection within the family. Southern blot hybridization of EcoR1 digested DNA from PBL indicated presence of HBV DNA, integrated into cellular DNA and also in the form of free viral DNA. The study not only establishes the persistence of surface mutant G145R HBV DNA, within the PBL of HBsAg negative individuals from the non-vaccinated random population, but also suggests possible horizontal transmission of the mutant among the family members although none of the family members has received immunoprophylaxis against HBV or had clinically apparent disease or any other known risk factors of HBV infection. As all of them were seronegative for HBsAg/antiHBc, the presence of G145R mutant in the PBL signaled possibility of spread of the vaccine escape mutant virus by blood transfusion, unsafe injection practices or through sexual root.

The evolution of hepatitis B virus serological patterns and the clinical relevance of isolated antibodies to hepatitis B core antigen in HIV infected patients

BACKGROUND/AIMS

The evolution of hepatitis B virus (HBV) serological patterns and the clinical relevance of isolated anti-HBc pattern are not well established in HIV infected patients.

METHODS

A cohort of 240 patients was followed for 6.9+/-3.4 years, with iterative HBV serologic assays performed (mean interval of 2.2 years).

RESULTS

Five patients without HBV markers at baseline subsequently developed positive anti-HBs (incidence 0.66/100 patient-year), as did two patients with chronic HBs antigenemia (incidence 1.66/100 patient-year). Only one patient with isolated anti-HBc pattern developed HBs chronic antigenemia. Persistent isolated anti-HBc pattern was observed in 37 patients (13 with detectable blood HBV DNA) and was strongly associated with positive hepatitis C virus (HCV) viremia (hazard ratio=9.5, confidence interval 95%: 4.5-20.0, P<0.0001). Hepatic lesions were more severe in HCV infected patients with persistent isolated anti-HBc pattern than in those without (Knodell score 9.2+/-4.6 versus 6.7+/-5.0, P=0.04). In time updated analysis, this pattern was not associated with an increased risk of hepatotoxicity, by contrast with HCV infection or positive HBs antigenemia.

CONCLUSIONS

In HIV infected patients, HBV serological status must be systematically and regularly assessed, and systematic HBV vaccination must be proposed in those without HBV marker. Isolated anti-HBc pattern must be considered in the management of hepatitis C, but not for antiretroviral therapy.

Characterization of two hepatitis B virus populations isolated from a hepatitis B surface antigen-negative patient

In a study of surface antigen-negative, but weakly hepatitis B virus (HBV) DNA-positive, patients, we were able to amplify and clone whole HBV genomes from the serum of a cirrhotic patient. Sequencing showed that the patient harbored two different HBV populations, one of genotype A and the other of genotype D, with the genotype D genome apparently predominating. The surface antigen of the genotype A virus is heavily mutated, especially in the extracellular << determinant a >> region, with several mutations that have not been previously described. The genotype D virus is a precore mutant. Both genomes possess the common A1762T-G1764A double mutation of the basal core promoter (BCP), and the genotype D virus is also mutated in the << TATA box >> of the large surface antigen promoter. Biological characterization showed that the genotype A genome was fully replication-competent, whereas the genotype D genome replicated poorly. The small surface antigen of the genotype A virus was only very weakly recognized by commercial tests. The small surface antigen of the genotype D virus could be recognized by the tests, but it was mainly retained within transfected cells, probably because of an excess of large surface antigen. In conclusion, the cryptic nature of this double HBV infection is characterized by the predominance of the replication-deficient genotype D virus over the replication-competent genotype A virus.

Long-term clinical impact of occult hepatitis B virus infection in chronic hepatitis B patients

BACKGROUND/AIMS

Long-term clinical outcomes of occult hepatitis B virus (HBV) infection were studied.

METHODS

Fifteen chronic hepatitis B patients were monitored for a median of 4.4 years (range 0.9-15.3) after hepatitis B surface antigen (HBsAg) seroclearance. Serum HBV DNA was measured by real-time detection polymerase chain reaction. Thirteen patients underwent liver biopsies at the end of follow-up and liver histology was evaluated by Ishak score. Liver HBV DNA was also measured for 12 patients.

RESULTS

At the end of follow-up, HBV viremia was absent in 13 (87%) patients, and antibody titers to hepatitis B core antigen showed an inverse correlation with time from HBsAg seroclearance (r=-0.554; P=0.0040). However, all patients retained liver HBV DNA and tested positive for the covalently closed circular HBV DNA replicative intermediate. The hepatic HBV DNA loads had no relation to liver histology. Paired biopsies from 11 patients disclosed that each necroinflammatory score significantly improved after HBsAg seroclearance. Amelioration of liver fibrosis was also evident in eight (73%) patients (P=0.0391 by signed rank test).

CONCLUSIONS

A long-standing but strongly suppressed HBV infection may confer histological amelioration after HBsAg seroclearance.

Significance of isolated hepatitis B core antibody in blood donors from São Paulo

The clinical significance of isolated anti-HBc is still a challenge. To elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. One hundred and twelve isolated anti-HBc seropositive blood donors underwent clinical evaluation and retesting of HBV markers. Those who presented repeatedly reactive isolated anti-HBc, received a single dose of hepatitis B recombinant vaccine to verify anti-HBs early response. A HBV-DNA determination by PCR was done for those who did not test positive to anti-HBs after vaccine. The level of anti-HBc was recorded as a ratio of the sample-to-cut-off values (S:C ratio) in 57 candidates at donation. Comparing true and false-positive anti-HBc results, the different S:C ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. A high percent of false-positive results (16.07%) was verified after anti-HBc retesting. HBV immunity was characterized in 49.11%, either by anti-HBs detection in retesting (15.18%), or after a single dose HBV vaccination (33.93%). HBV-DNA was negative in all tested donors. In conclusion, this algorithm was useful to clarify the meaning of isolated anti-HBc in most of our blood donors.

Hepatitis B virus markers in anti-HBc only positive individuals

Isolated reactivity to hepatitis B virus (HBV) core antigen (anti-HBc) is observed relatively frequently in immunocompromised individuals, intravenous drug abusers (IVDA), and in the presence of HCV infection. The reason for the lack of HBsAg is not clear. The aim of the present study was to investigate which factors (genetic variability of S gene, low-level HBsAg, and immune complexes may be responsible for the failure of HBsAg detection with commercial HBsAg screening assays. Dilution series of two recombinant HBsAg escape mutants and dilutions of serum samples from chronic HBV carriers with multiple insertions in the a determinant and different HBsAg subtypes were tested with a highly sensitive assay that detects wild-type HBsAg (Elecsys HBsAg, Roche Diagnostics, Penzberg, Germany) and two assays that detect HBV wild-type and escape mutants (Murex HBsAg Version 3, Murex and Enzygnost HBsAg 5.0, Dade Behring, Marburg, Germany). Elecsys HBsAg showed in comparison to Murex HBsAg Version 3 and Enzygnost HBsAg 5.0 a reduced sensitivity for escape mutant detection. On the other hand, the best performance for HBsAg subtype detection was obtained with Elecsys HBsAg. In the second part of the study, a selected panel of isolated anti-HBc reactive (n = 104) serum samples (AxSYM Core) was submitted to testing by Elecsys HBsAg, Murex HBsAg Version 3, Enzygnost HBsAg 5.0, and HBsAg detection after immune complex dissociation (ICD) and anti-HBs determination with two different assays (AxSYM Ausab and Elecsys Anti-HBs). To assess the specificity of anti-HBc test results, all the samples were tested by a second anti-HBc assay (Elecsys Anti-HBc). Quantitative HBV DNA detection was undertaken with a commercially available HBV PCR assay (Amplicor HBV Monitor). HCV infection was present in 65.4% of anti-HBc only reactive individuals. Five AxSYM Core positive samples were negative by Elecsys Anti-HBc. Overall, 15 (14.4%) AxSYM Ausab negative samples gave positive results with Elecsys Anti-HBs (median value: 21 IU/ml). No low-level HBsAg carrier was detected among the isolated anti-HBc reactive individuals with Elecsys HBsAg. There was no evidence for the presence of immune complexes. Only one sample was repeatedly reactive by the Murex HBsAg, suggesting that the a mutant form of HBsAg was responsible for the isolated anti-HBc reactivity, however neutralisation assay was not interpretable and HBV DNA PCR was negative. Fifteen (14.4%) anti-HBc only positive individuals were HBV DNA carriers with concentrations ranging from 800 to more than >4,000,000 copies of viral DNA/ml. In conclusion, the most probable explanations for isolated anti-HBc reactivity in our study group are a possible interference of HBsAg synthesis by HCV infection (65.4%) and divergence of results of anti-HBs assays (14.4%). There is no evidence for the presence of low-level HBsAg carriers and immune complexes. HBsAg mutants cannot be excluded definitively by the test strategy used in the present evaluation.

Prevalence of antibodies to hepatitis B core antigen in blood donors in the middle West region of Brazil

The prevalence of antibodies to hepatitis B core antigen in 552 prime blood donors was of 9.4%. The majority (71.2%) has antibodies to hepatitis B surface antigen. The hepatitis B surface antigen was present in 0.7%, all of them antibodies to hepatitis B core antigen positive.

The role of viral load determination for the management of human immunodeficiency virus, hepatitis B virus and hepatitis C virus infection

During the last 5 years, considerable scientific and financial efforts have been made in the development of quantitative nucleic acid detection technology. For detection of human immunodeficiency virus (HIV), quantitative culture is time consuming, cumbersome and requires appropriate laboratory safety equipment. Quantitative determination of p24 antigen by enzyme immunoassay is of limited value due to its relatively poor sensitivity. Therefore, quantitative determination of viral load using nucleic acid amplification techniques is the most accurate, prognostic marker for HIV type 1 infection, independently of the CD4+ cell count. Hepatitis B virus (HBV) is not cultivable in vitro. Serological assays allow an accurate diagnosis and follow-up of acute or chronic infection. Quantification of HBV DNA is used for the monitoring of antiviral therapy, determination of infectivity and for resolution of unclear serological profiles, e.g. isolated anti-HBc reactivity, as well as for patients in which HBV mutants are suspected. Hepatitis C virus (HCV) can only be detected by molecular based assays because no cell culture system, which permits a reliable isolation of clinical specimens, is currently available. Furthermore, early diagnosis and follow-up of infection cannot be achieved with antibody serology. The prognostic relevance of quantitative HCV RNA determination is of limited value for the long-term prognosis of chronic hepatitis C. However, viral load may predict the outcome of antiviral therapy. Genetic diversity is another challenge for HCV RNA quantification.

Prevalence, patterns, and course of past hepatitis B virus infection in intravenous drug users with HIV-1 infection

OBJECTIVE

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) share common routes of transmission. Therefore, markers of either active or past HBV infection are present in many HIV-infected patients, particularly in intravenous drug users (IDUs). The aim of this study was to analyze the serological pattern of past HBV infection (presence or absence of anti-HBs) and the course of past HBV infection (changes in anti-HBs status, and HBV reactivation) in two cohorts of IDUs with and without HIV infection.

METHODS

HBV serum markers were studied in 388 HIV-positive and 197 HIV-negative IDUs. Among them, 263 HIV-positive and 50 HIV-negative patients with past HBV infection (serum HBsAg negative and anti-HBc positive, with or without anti-HBs) were followed-up for a median of 21 and 13 months, respectively, to detect changes in anti-HBs status and HBV reactivation.

RESULTS

The prevalence of HBV infection (either active or past) was higher in HIV-positive than in HIV-negative cases (90% vs 62%, p < 0.001), even when stratified by years of drug use. Most cases (92% of HIV-positive and 89% of HIV-negative) had markers of past infection. Among those patients with past HBV infection, 60% of HIV-positive and 72% of HIV-negative presented serum anti-HBs (p = 0.03). The incidence of anti-HBs loss was 1.8 cases/100 person-year in HIV-positive, and 1.8 cases/100 person-year in HIV-negative patients (RR 1.0, 95% CI 0.1-94, p = NS). Incidence of anti-HBs development was 17.6 cases/100 person-year in HIV-positive and 25.6 cases/100 person-year in HIV-negative IDUs (RR, 1.5, 95% CI, 0.6-3.5, p = NS). Only one HIV-positive patient with markers of past HBV infection developed an active infection (0.2 events/100 person-year).

CONCLUSIONS

HBV infection (either active or past) is particularly frequent in HIV-positive IDUs. Most cases have markers of past infection. Isolated detection of anti-HBc (absence of anti-HBs) is more common in HIV-positive than in HIV-negative IDUs. Despite their progressive immunosuppression, both anti-HBs loss and HBV reactivation are rare in HIV-infected IDUs.

High genetic variability of the group-specific a-determinant of hepatitis B virus surface antigen (HBsAg) and the corresponding fragment of the viral polymerase in chronic virus carriers lacking detectable HBsAg in serum

Chronic carriers of hepatitis B virus (HBV) usually show hepatitis B surface antigen (HBsAg) in their sera, which is considered the best marker for acute and chronic HBV infection. In some individuals, however, this antigen cannot be detected by routine serological assays despite the presence of virus in liver and peripheral blood. One reason for this lack of HBsAg might be mutations in the part of the molecule recognized by specific antibodies. To test this hypothesis, the HBV S gene sequences were determined of isolates from 33 virus carriers who were negative for HBsAg but showed antibodies against the virus core (anti-HBc) as the only serological marker of hepatitis B. Isolates from 36 HBsAg-positive patients served as controls. In both groups, a considerable number of novel mutations were found. In isolates from individuals with anti-HBc reactivity only, the variability of the major hydrophilic loop of HBsAg, the main target for neutralizing and diagnostic antibodies, was raised significantly when compared with the residual protein (22. 6 vs 9.4 mutations per 1000 amino acids; P<0.001) and with the corresponding region in the controls (22.6 vs 7.5 exchanges per 1000 residues; P<0.001). A similar hypervariable spot was identified in the reverse transcriptase domain of the viral polymerase, encoded by the same nucleotide sequence in an overlapping reading frame. These findings suggest that at least some of the chronic low-level carriers of HBV, where surface antigen is not detected, could be infected by diagnostic escape mutants and/or by variants with impaired replication.

Improved detection of hepatitis B virus surface antigen by a new rapid automated assay

The performance of hepatitis B virus (HBV) surface antigen (HBsAg) screening assays is continuously improved in order to reduce the residual risk of transfusion-associated hepatitis B. In a multicenter study, a new automated rapid screening assay, Elecsys HBsAg (Roche Diagnostics), was compared to well-established tests (Auszyme Monoclonal [overnight incubation] version B and IMx HBsAg [Abbott]). Included in the evaluation were 23 seroconversion panels; sera from the acute and chronic phases of infection; dilution series of various HBsAg standards, HBV subtypes, and S gene mutants; and isolated anti-HBV core antigen-positive samples. To challenge the specificity of the new assay, sera from HBsAg-negative blood donors, pregnant women, and dialysis and hospitalized patients and potentially cross-reactive samples were investigated. Elecsys HBsAg showed a higher sensitivity for HBsAg subtypes ad, ay, adw2, adw4, ayw1, ayw2, ayw4, and adr detection in dilution series of different standards or sera than Auszyme Monoclonal version B and/or IMx HBsAg. Acute hepatitis B was detected in 11 to 16 of 23 seroconversion panels between 2 and 16 days earlier with Elecsys HBsAg than with the alternative assays. Elecsys HBsAg and Auszyme Monoclonal version B detected HBsAg surface mutants with equal sensitivity. The sensitivity and specificity of Elecsys HBsAg were 100%. Auszyme Monoclonal version B had a 99.9% specificity, and its sensitivity was 96.6%. IMx HBsAg showed a poorer sensitivity and specificity than the other assays. In conclusion, Elecsys HBsAg permits earlier detection of acute hepatitis B and different HBV subtypes than the alternative assays. By using highly sensitive HBsAg screening assays, low-level HBsAg carriers among isolated anti-HBV core antigen-positive individuals can be detected.

A novel deletion mutant of hepatitis B virus surface antigen

HBsAg is the most important serological marker for acute or chronic hepatitis B. Nevertheless, there are reports of HBsAg-negative virus carriers, either with anti-HBc as the only marker for hepatitis B virus (HBV) infection or even positive for anti-HBs and anti-HBc. We report isolates from a patient, in which a deletion in the HBs-gene was associated with persisting viremia in the presence of anti-HBs. The 62-year-old female, infected most likely by her husband, had detectable markers of chronic active hepatitis B, such as HBsAg, HBeAg, and anti-HBc-IgM, for 2 years. The patient then seroconverted to anti-HBs, although HBeAg and anti-HBc-IgM remained detectable. At this time, semiquantitative polymerase chain reaction showed about 10(4) viral genomes per milliliter of serum. Direct sequencing of the amplified products revealed a major population of DNA molecules with a deletion of nucleotide 31 of the HBs-gene, which up to now has not been described. This deletion led to a frame-shift and introduced a stop-codon after 21 amino acids of the sHBsAg. We suspect that this deletion, and the resulting HBsAg lacking the major epitopes recognized by specific antibodies, could favor ongoing viral replication, despite the presence of anti-HBs. However, because the reading frame of the polymerase was also severely damaged by this deletion, it is assumed that a minor population of intact genomes was present to help in the formation of virus particles.

Seroprevalence of HBV (anti-HBc, HBsAg and anti-HBs) and HDV infections among 9006 women at delivery

Serum samples from 9006 women, who delivered in Switzerland in 1990 and 1991, were collected around the country. Of these women, 62.7% were Swiss and 37.3% originated from foreign countries. Samples were first screened for anti-HBc and those found positive were further tested for HBsAg, anti-HBs and anti-HDV. Anti-HBc was found in 640 of the 9006 women (overall prevalence, 7.1%; Swiss, 3.3%; foreigners, 13.5%). Of these 640 positive samples, 61 (9.5%) were positive for HBsAg (without anti-HBs), 467 (73.0%) positive for anti-HBs (without HBsAg) and 8 (1.3%) positive for both HBsAg and anti-HBs. The remaining 104 were thus anti-HBc positive without HBsAg or anti-HBs. These 104 specimens with the so-called "isolated anti-HBc" reactivity represented 1.2% of the whole population or 16.3% of the 640 anti-HBc positive mothers. All were HBV DNA negative (PCR). Anti-HDV antibody was found in only five women. HBsAg was seen in 38 of the cord-blood samples from the anti-HBc positive mothers. In this large sampling, we observed a relatively high seroprevalence of HBV infection. Cases with isolated anti-HBc reactivity, being HBV DNA negative by PCR, were probably non-infectious at the time of blood collection.

Individuals with antibodies against hepatitis B core antigen as the only serological marker for hepatitis B infection: high percentage of carriers of hepatitis B and C virus

BACKGROUND/AIMS

Several reports have unequivocally demonstrated that some individuals with antibodies against hepatitis B core antigen as the only serological marker for hepatitis B infection are chronic carriers of the hepatitis B virus. Nevertheless, conflicting data exist about the frequency of this phenomenon; its cause is unknown.

METHODS

In a prospective study we tested individuals who were positive for anti-HBc alone for HBV-DNA as well as for coexisting infections with human immunodeficiency virus and hepatitis C virus.

RESULTS

Using polymerase chain reaction with primer pairs from three different regions of the hepatitis B virus genome, we found 54 of 164 individuals (32.9%) with anti-HBc alone to be positive for hepatitis B virus, the majority of them showing very low hepatitis B virus concentrations. 14.3% were human immunodeficiency virus positive; half of them were also hepatitis B virus carriers. Surprisingly, 62 of 153 participants (40.5%) in this study showed antibodies against hepatitis C virus, and about two thirds of the latter were also positive for HCV-RNA. This finding could be confirmed by a retrospective analysis of all people tested for hepatitis B virus markers and anti-HCV in our institution during the 2 years before the prospective study was begun. Again, a high correlation was found between the presence of anti-HCV and anti-HBc alone: 49.2% of individuals with anti-HBc only were anti-HCV positive also, compared to 26.8% of HBsAg carriers and only 10% of individuals showing the serological pattern of past hepatitis B.

CONCLUSIONS

Thus our study of individuals positive for anti-HBc alone revealed a high number of carriers of hepatitis B virus and hepatitis C virus among them; furthermore, we found some evidence that hepatitis C virus infection may favour this unusual hepatitis B virus marker pattern.

High prevalence of hepatitis B, C, and E markers in young sexually active adults from the Central African Republic

The Central African Republic is located in tropical Africa, where both the human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are highly endemic. The exact prevalence of hepatitis C virus (HCV) and hepatitis E virus (HEV) markers in this country is unknown. The aim of the study was to determine, according to HIV and HBV serostatus, the prevalence of these markers in young sexually active adults in the Central African Republic. One hundred and fifty-seven consecutive patients attending the National Centre for Sexually Transmitted Diseases in Bangui were included. The following serological markers were examined: (i) anti-HIV1 and anti-HIV2 antibodies; (ii) markers of HBV infection; (iii) anti-HCV antibodies; (iv) anti-HEV antibodies. Anti-HIV1 antibodies were found in 31 of the 157 patients (20%). The prevalence of anti-HBc antibodies, reflecting exposure to HBV, was 140/157 (89%) and 45 had detectable anti-HBs antibodies. Twenty-two patients (14%) were chronic carriers of hepatitis B surface antigen (HBsAg), but only one was HBe antigen-positive. Anti-HCV antibodies were found in 8 persons (5%) and anti-HEV antibodies in 38 (24%). No difference was found in the prevalence of these markers according to the presence or absence of anti-HIV antibodies. This study confirms the high rate of HIV infection, HBV exposure and chronic carriage of HBsAg in sexually active young adults in the Central African Republic. A high prevalence of HCV markers was found in this population, similar to that reported in neighbouring countries, together with a high rate of HEV markers, suggesting that HEV is endemic in this region.

Detection of HBs antigen in "anti-HBc alone" positive sera

The immunoserological finding "anti-HBc alone" is often observed in defined groups of individuals, such as patients with inflammatory hepatopathies, patients on hemodialyses or with organ transplants, i.v. drug users and homosexuals, but it also occurs in up to 1% of Swiss blood-donors. In order to gain further information about whether "anti-HBc alone" reflects late immunity or points to an ongoing or a recently passed hepatitis B virus infection, 153 serum samples were tested for immune-complex-dissociated HBs-antigen, using acid treatment for complex dissociation. Of the samples tested 31% contained complexed HBsAg, the highest rates being found in individuals with hepatopathies (up to 80%), in i.v. drug users (up to 63%) and in hemodialysis patients (40%). The 153 sera were also tested for HBV-DNA by nested PCR. Sixty (39%) probes yielded positive results, comprising 29 (48%) of 60 sera with immune-complexed HBsAg but only 18 (19%) of 93 probes without complexed HBsAg. The results point to the possibility that at least some of the individuals with "anti-HBc alone" still have an ongoing HBV-infection.