Prevalence and significance of occult hepatitis B in a liver transplant population with chronic hepatitis C

Characterization of occult hepatitis B infection among Iranian liver transplant recipients

Background

The prevalence of occult hepatitis B infection (OBI) among Iranian liver transplant recipient patients has not been explored yet. The present study aimed to determine the OBI prevalence among Iranian liver transplant recipients.

Methods

This study encompassed 97 patients having undergone liver transplantation due to several clinical backgrounds in the Liver Transplantation Center, Tehran, Iran. After serological evaluation, two different types of PCR methods were applied for amplification of HBV DNA, followed by the direct sequencing of whole hepatitis B virus (HBV) surface genes.

Results

At the time of admission, none of the patients were positive for HBsAg. However, 24 (25%), 12 (12.3%), and 5 (5.1%) cases were positive for anti‐HBc, hepatitis C virus (HCV), and hepatitis delta virus (HDV) antibodies, respectively. Moreover, two males were positive for OBI (2.1%). Both were positive for anti‐HBc and negative for anti‐HBs, anti‐HCV, and anti‐HDV. HBV‐related cirrhosis was the underlying reason for their liver transplantation. HBsAg sequences revealed no amino acid substitution.

Conclusions

The prevalence of OBI in the Iranian liver transplantation patients was relatively low. Future longitudinal studies with a larger sample size are suggested to explore the significance of this clinical finding, including the reactivation of cryptic HBV DNA, in liver transplant subjects.

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.

Occult hepatitis B virus infection in patients with chronic liver disease of different etiology in a Brazilian referral center: comparison of two different hepatitis B virus deoxyribonucleic acid amplification protocols: a cross-sectional study

BACKGROUND

Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) in the liver of individuals with undetectable hepatitis B virus surface antigen (HBsAg) in the serum. The actual prevalence of OBI and its clinical relevance are not yet fully understood.

OBJECTIVE

To evaluate the prevalence of HBV DNA in liver biopsies of HBsAg-negative patients with chronic liver disease of different etiologies in a referral center in Brazil and compare two different HBV DNA amplification protocols to detect HBV.

DESIGN AND SETTING

This cross-sectional observational study was conducted at the Liver Outpatient Clinic, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, between January 2016 and December 2019.

METHODS

HBV DNA was investigated in 104 liver biopsy samples from individuals with chronic liver disease of different etiologies, in whom HBsAg was undetectable in serum by nested-polymerase chain reaction (nested-PCR), using two different protocols.

RESULTS

OBI, diagnosed by detecting HBV DNA using both protocols, was detected in 6.7% of the 104 individuals investigated. Both protocols showed a good reliability.

CONCLUSION

In addition to the differences in the prevalence of HBV infection in different regions, variations in the polymerase chain reaction technique used for HBV DNA amplification may be responsible for the large variations in the prevalence of OBI identified in different studies. There is a need for better standardization of the diagnostic methods used to diagnose this entity.

Prevalence of occult HBV infection in Western countries

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

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

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

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

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

The prevalence of occult hepatitis B infection among the blood donors in a tertiary care hospital, Puducherry

Occult hepatitis B infection (OBI) is a cause of concern while screening the blood donors to prevent transfusion-related transmission of infection. This study was conducted to assess the prevalence of OBI using total anti-HBc by ELISA and DNA detection by real time polymerase chain reaction (PCR). The samples included were negative for HBs Ag by ELISA. Out of 1102 samples tested, 156 were positive for total anti-hepatitis B core antigen and 52/156 by real-time PCR. Overall, the prevalence was found to be 4.71% (52/1102). The results indicate that nucleic acid-based testing should be an essential part of screening procedure to prevent missing of OBI.

Occult HBV infection status and its impact on surgical outcomes in patients with curative resection for HCV-associated hepatocellular carcinoma

Background

We sought to clarify the prevalence of occult hepatitis B virus (HBV) infection (OBI) and to determine whether OBI affects the surgical outcomes in curatively resected Japanese patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

Methods

A total of 257 patients with HCV-related HCC who underwent curative surgical resection were enrolled. All enrolled patients were serologically negative for HBV surface antigen and positive for HCV antibody. DNA was extracted from formalin-fixed paraffin-embedded liver tissue. OBI was determined by the HBV-DNA amplification of at least two different sets of primers by TaqMan real-time polymerase chain reaction. Surgical outcomes were evaluated according to overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS).

Results

OBI was identified in 15 of the 257 (5.8%) cases. In the multivariate analyses, the factors significantly correlated with OS were BMI >25 (P=0.0416), portal vein invasion (P=0.0065), and multiple tumors (P=0.0064). The only factor significantly correlated with DSS was T-stage (P=0.0275). The factors significantly correlated with DFS were liver fibrosis (P=0.0017) and T-stage (P=0.0001). The status of OBI did not show any significant correlation with OS, DSS or DFS, but a weak association with DSS (P=0.0603) was observed.

Conclusions

The prevalence of OBI was 5.8% in 257 cases of HCV-related HCC. Although a weak association between DSS and OBI was observed, and statistical analyses were limited by small number of OBI cases, no significant correlation between OBI and surgical outcomes was detected.

Occult HBV infection in HCC and cirrhotic tissue of HBsAg-negative patients: a virological and clinical study

Aim

To evaluate the virological and clinical characteristics of occult HBV infection (OBI) in 68 consecutive HBsAg-negative patients with biopsy-proven cirrhosis and HCC.

Methods

HBV DNA was sought and sequenced in plasma, HCC tissue and non-HCC liver tissue by PCRs using primers for HBV core, surface and x regions. OBI was identified by the presence of HBV DNA in at least two different PCRs.

Results

OBI was detected in HCC tissue of 13 (20%) patients and in non-HCC liver tissue of 3 of these 13. OBI was detected in HCC tissue of 54.5% of 11 anti-HBs- negative/anti-HBc-positive patients, in 29.4% of 17 anti-HBs/anti-HBc-positive and in 5% of 40 anti-HBs/anti-HBc-negative (p < 0.0005). The 13 patients with OBI in HCC tissue more frequently than the 55 without showed Child-B or -C cirrhosis (53.9% vs. 5.5%, p < 0.0001) and BCLC-B or -C stages (46.1% vs. 1.8%, p < 0.0001). The pre-S1, pre-S2 and S region sequences in HCC tissue showed amino acid (AA) substitutions (F19L, P24L, S59F, T131I, Q129H) and deletions (in positions 4,8, 17 and 86) in the S region, AA substitutions (T40S, P124K, L54P, G76A, N222T and I273L) in pre-S1 region and AA substitutions in pre-S2 region (P41H and P66L). In the 3 patients showing OBI also in non-HCC liver tissue the S, pre-S1 and pre-S2 sequencing displayed patterns of mutations different.

Conclusions

The study showed a significant correlation between OBI and the severity of liver damage, several patterns of mutations in the S, pre-S1 and pre-S2 regions in HCC tissue, some at their first description.

Genetic polymorphisms of HLA-DP and isolated anti-HBc are important subsets of occult hepatitis B infection in Indonesian blood donors: a case-control study

BACKGROUND

Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the serum and/or liver in HBsAg-negative individuals. OBI is associated with the risk of viral transmission, especially in developing countries, and with progressive liver disease and reactivation in immunosuppressive patients. The objective of this study was to evaluate the relation of OBI to HLA-DP single nucleotide polymorphisms (SNPs) encoding antigen-binding sites for the immune response to HBV infection. As HLA-DP variants affect the mRNA expression of HLA-DPA1 and HLA-DPB1 in the liver, we hypothesised that high levels of HLA-DPA1 and HLA-DPB1 expression favour OBI development.

METHODS

The study enrolled 456 Indonesian healthy blood donors (HBsAg negative). OBI was defined as the presence of HBV-DNA in at least two of four open reading frames (ORFs) of the HBV genome detected by nested PCR. SNPs in HLA-DPA1 (rs3077) and HLA-DPB1 (rs3135021, rs9277535, and rs2281388) were genotyped using real-time Taqman® genotyping assays.

RESULTS

Of 122 samples positive for anti-HBs and/or anti-HBc, 17 were determined as OBI. The minor allele in rs3077 was significantly correlated with OBI [odds ratio (OR) = 3.87, 95% confidence interval (CI) = 1.58-9.49, p = 0.0015]. The prevalence of the minor allele (T) was significantly higher in subjects with OBI than in those without (59% and 33%, respectively). The combination of haplotype markers (TGA for rs3077-rs3135021-rs9277535) was associated with increased risk of OBI (OR = 4.90, 95%CI = 1.12-21.52 p = 0.038). The prevalence of OBI was highest in the isolated anti-HBc group among the three seropositive categories: anti-HBs <500 mIU/ml, anti-HBs ≥500 mIU/ml, and isolated anti-HBc (29.41%, p = 0.014).

CONCLUSION

Genetic variants of HLA-DP and the presence of anti-HBc are important predictors of OBI in Indonesian blood donors.

TRIAL REGISTRATION

Ref: KE/FK/194/EC; registered 01 March 2013. Continuing approval Ref: KE/FK/536/EC; registered 12 May 2014.

Molecular characterization of occult hepatitis B virus infection in patients with end-stage liver disease in Colombia

Background

Hepatitis B virus (HBV) occult infection (OBI) is a risk factor to be taken into account in transfusion, hemodialysis and organ transplantation. The aim of this study was to identify and characterize at the molecular level OBI cases in patients with end-stage liver disease.

Methods

Sixty-six liver samples were obtained from patients with diagnosis of end-stage liver disease submitted to liver transplantation in Medellin (North West, Colombia). Samples obtained from patients who were negative for the surface antigen of HBV (n = 50) were tested for viral DNA detection by nested PCR for ORFs S, C, and X and confirmed by Southern-Blot. OBI cases were analyzed by sequencing the viral genome to determine the genotype and mutations; additionally, viral genome integration events were examined by the Alu-PCR technique.

Results

In five cases out of 50 patients (10%) the criteria for OBI was confirmed. HBV genotype F (subgenotypes F1 and F3), genotype A and genotype D were characterized in liver samples. Three integration events in chromosomes 5q14.1, 16p13 and 20q12 affecting Receptor-type tyrosine-protein phosphatase T, Ras Protein Specific Guanine Nucleotide Releasing Factor 2, and the zinc finger 263 genes were identified in two OBI cases. Sequence analysis of the viral genome of the 5 OBI cases showed several punctual missense and nonsense mutations affecting ORFs S, P, Core and X.

Conclusions

This is the first characterization of OBI in patients with end-stage liver disease in Colombia. The OBI cases were identified in patients with HCV infection or cryptogenic cirrhosis. The integration events (5q14.1, 16p13 and 20q12) described in this study have not been previously reported. Further studies are required to validate the role of mutations and integration events in OBI pathogenesis.

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 more different 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.

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.

Longitudinal profiles of highly sensitive hepatitis B surface antigen levels: re-evaluation of HBsAg seroclearance

BACKGROUND & AIMS

Serologic profiles after hepatitis B surface antigen (HBsAg) seroclearance in chronic hepatitis B (CHB) have not been well-studied.

METHODS

We employed a highly sensitive HBsAg (hs-HBsAg) assay (lower detection limit 0.5 mIU/ml), 100 times more sensitive than conventional HBsAg measurements. CHB patients achieving HBsAg seroclearance defined by conventional assays were followed up for serum hs-HBsAg, HBV DNA and antibody to HBsAg (anti-HBs) levels at 0 months, 6-12 months and 3-5 years after HBsAg seroclearance. Factors associated with hs-HBsAg detectability were determined.

RESULTS

One hundred and nine patients were recruited; 94 (86.2%) were followed up to years 3-5; and 25 patients (22.9%) were on nucleoside analogue therapy for a median duration of 6.0 (range 1.5-12.7) years before HBsAg seroclearance. Detectable hs-HBsAg was noted in 88 (80.7%), 60 (55.0%) and 20 (21.3%) patients at 0 months, 6-12 months and 3-5 years respectively. At years 3-5, genotype B patients, when compared to genotype C patients, had a higher anti-HBs positive rate (63.2% and 41.1% respectively, P = 0.036). Serum anti-HBs positivity, when compared to persistent anti-HBs negativity, was associated with a lower rate of hs-HBsAg detection (7.4% and 40% respectively, P < 0.001). Multivariate analysis showed anti-HBs negativity at years 3-5 to be independently associated with persistently positive hs-HBsAg (P = 0.007, odds ratio 7.1, 95% confidence interval 1.7-29.3).

CONCLUSION

Serum hs-HBsAg could detect HBsAg presence in a substantial proportion of CHB after HBsAg seroclearance defined by conventional assays, especially among anti-HBs negative individuals. Serum hs-HBsAg could potentially assist differentiating HBsAg-negative CHB from individuals with only past HBV exposure without carrier state.

Role of occult hepatitis B virus infection in chronic hepatitis C

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

High prevalence of occult hepatitis B infection in an African urban population

Occult hepatitis B infection (OBI), the presence of low hepatitis B virus (HBV) deoxyribonucleic acid (DNA) levels in patients without detectable hepatitis B surface antigen (HBsAg), has significant implications for understanding the natural history of hepatitis B infection. We determined the prevalence of OBI in African patients using a sensitive polymerase chain reaction (PCR) assay and describe here the characteristics of OBI in an urban African hospital population. Routine serological testing as well as molecular studies were performed on sera from 314 patients who were part of a previous study from an urban hospital emergency room in Kampala, Uganda, detecting HBV DNA using a nested PCR with amplification of two regions of the HBV genome. HBV viral loads (VL) were determined by real-time PCR (rtPCR) and sequencing performed to determine HBV genotype and S gene mutations. Among 314 subjects tested, 50 (16%) had chronic HBV infection, 94 (30%) had detectable HBV DNA despite testing HBsAg negative (OBI), and 170 (54%) were not infected. VLs of OBI subjects were relatively low although 19 (20%) had VL exceeding 10(4)  IU ml(-) . Subjects with chronic HBV infection had a higher median VL compared to OBI patients (P < 0.001). All chronic HBV sequenced (10) and 83/89 OBI sequences were genotype A, the remaining six being genotype D. S-gene mutations were present in some but not all OBI patients (48%). OBI is more prevalent among African patients than previously thought. This may have implications for clinical management and transfusion-related HBV transmission.

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.

Occult hepatitis B virus infection predicts de novo hepatitis B infection in patients with alcoholic cirrhosis after liver transplantation

BACKGROUND & AIMS

Occult hepatitis B virus infection (OBI) in patients undergoing liver transplantation (LT) is a suspected source of de novo hepatitis B virus (HBV) infection after LT. This study aimed to investigate the prevalence of OBI in liver transplant recipients with alcoholic cirrhosis and demonstrate the association between OBI and de novo HBV infection after LT in these patients.

METHODS

Forty-three patients with alcoholic cirrhosis who were negative for HBsAg before LT were recruited in this retrospective study. DNA was extracted from paraffin-embedded native liver tissues and quantified for HBV DNA by real-time PCR. Correlation between de novo HBV infection after LT (positive HBsAg and/or detectable HBV DNA in serum) and detection of intrahepatic HBV DNA before LT was analysed.

RESULTS

Detectable HBV DNA in the explanted liver was found in 41.9% (18/43) of the patients and was thus defined as OBI, which was correlated with the presence of serum hepatitis B core antibody (P = 0.008). De novo HBV infection occurred in 18.6% (8/43) of the recipients at a median of 10 months after LT. The rate of de novo HBV infection was 38.9% (7/18) in patients with OBI, compared with 4% (1/25) in patients without OBI (P = 0.004). Furthermore, de novo HBV infection was inversely correlated with the presence of hepatitis B surface antibody in recipients with OBI (P = 0.026).

CONCLUSION

With a prevalence of 41.9% in liver transplant recipients with alcoholic cirrhosis, OBI in the native liver can predict de novo HBV infection after LT.

Prevalence of occult hepatitis B virus infection in kidney transplant recipients

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

Prediction of occult hepatitis B virus infection in liver transplant donors through hepatitis B virus blood markers

BACKGROUND

Occult hepatitis B virus infection is defined as detectable HBV-DNA in liver of HBsAg-negative individuals, with or without detectable serum HBV-DNA. In deceased liver donors, results of tissue analysis cannot be obtained prior to allocation for liver transplantation.

AIMS

we investigated prevalence and predictability of occult hepatitis B using blood markers of viral exposure/infection in deceased liver donors.

METHODS

In 50 consecutive HBsAg-negative/anti-HBc-positive and 20 age-matched HBsAg-negative/anti-HBc-negative donors, a nested-PCR assay was employed in liver biopsies for diagnosis of occult hepatitis B according to Taormina criteria. All donors were characterized for plasma HBV-DNA and serum anti-HBs/anti-HBe.

RESULTS

In liver tissue, occult hepatitis B was present in 30/50 anti-HBc-positive (60%) and in 0/20 anti-HBc-negative donors (p<0.0001). All anti-HBc-positive donors with detectable HBV-DNA in plasma (n=5) or anti-HBs>1,000 mIU/mL (n=5) eventually showed occult infection, i.e, 10/30 occult hepatitis B-positive donors which could have been identified prior to transplantation. In the remaining 40 anti-HBc-positive donors, probability of occult infection was 62% for anti-HBe-positive and/or anti-HBs ≥ 58 mIU/mL; 29% for anti-HBe-negative and anti-HBs<58 mIU/mL.

CONCLUSIONS

In deceased donors, combining anti-HBc with other blood markers of hepatitis B exposure/infection allows to predict occult hepatitis B with certainty and speed in one third of cases. These findings might help refine the allocation of livers from anti-HBc-positive donors.

Occult hepatitis B virus infection in liver transplant patients in a Brazilian referral center

Estimates of occult hepatitis B virus (HBV) infection prevalence varies among different studies depending on the prevalence of HBV infection in the study population and on the sensitivity of the assay used to detect HBV DNA. We investigated the prevalence of occult HBV infection in cirrhotic patients undergoing liver transplantation in a Brazilian referral center. Frozen liver samples from 68 adults were analyzed using a nested polymerase chain reaction assay for HBV DNA. The specificity of the amplified HBV sequences was confirmed by direct sequencing of the amplicons. The patient population comprised 49 (72.1%) males and 19 (27.9%) females with a median age of 53 years (range=18-67 years). Occult HBV infection was diagnosed in three (4.4%) patients. The etiologies of the underlying chronic liver disease in these cases were alcohol abuse, HBV infection, and cryptogenic cirrhosis. Two of the patients with cryptic HBV infection also presented hepatocellular carcinoma. Markers of previous HBV infection were available in two patients with occult HBV infection and were negative in both. In conclusion, using a sensitive nested polymerase chain reaction assay to detect HBV DNA in frozen liver tissue, we found a low prevalence of occult HBV infection in cirrhotic patients undergoing liver transplant, probably due to the low prevalence of HBV infection in our population.

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.

Impact of occult hepatitis B virus infection on the outcome of chronic hepatitis C

BACKGROUND & AIMS

Occult hepatitis B virus infection (OBI) frequently occurs in patients with hepatitis C virus (HCV) related chronic hepatitis (CHC), but the influence of OBI on the CHC outcome is still uncertain. This observational cohort study evaluated the clinical evolution of CHC patients according to their OBI status.

METHODS

From 1991 to 2000, 326 hepatitis B surface antigen negative CHC patients were tested for OBI by the analysis of liver biopsy DNA extracts. A total of 128/326 cases (39.2%) tested OBI positive and 198/326 (60.8%) OBI negative. Ninety-four of 326 patients (37 OBI positive, 57 OBI negative) were followed-up for a median time of 11 years (range 5-19 years). During the follow-up, 79/94 patients underwent anti-HCV treatments and 25 [corrected] achieved a sustained virological response that occurred independently of their OBI status

RESULTS

Eighteen patients (13/37 OBI positive, 5/57 OBI negative, p < 0.01) developed hepatocellular carcinoma (HCC). Among the 76 non-HCC individuals, 15 subjects (8/24 OBI positive, 7/52 OBI negative, p < 0.05) developed advanced forms of cirrhosis. Eighteen patients died during follow-up and 2 underwent liver transplantation. OBI positive individuals had a cumulative survival rate significantly shorter than OBI negative individuals (p = 0.003). Liver-related deaths were more frequently found in OBI positive than OBI negative patients (12/37 OBI positive vs. 6/57 OBI negative patients respectively, p < 0.01). Finally, non-response to anti-HCV therapy was significantly associated with lower survival (p = 0.02).

CONCLUSIONS

Among CHC patients, occult HBV co-infected individuals are a category at high risk of progression toward cirrhosis, HCC development, and lower survival.

Viral hepatitis markers in liver tissue in relation to serostatus in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) incidence is increasing in the United States. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major causes of HCC. Hepatitis infection in patients with HCC is generally diagnosed by serology, which is not always consistent with the presence of HBV and HCV in the liver. The relationship of liver viral status to serostatus in hepatocarcinogenesis is not fully understood.

METHODS

HBV and HCV were evaluated in formalin-fixed, paraffin-embedded liver tissue specimens in a retrospective study of 61 U.S. HCC cases of known serologic status. HBV DNA and HCV RNA were detected by PCR, reverse transcription PCR (RT-PCR), and pyrosequencing, and HBsAg and HBcAg were evaluated by immunohistochemistry.

RESULTS

Viral markers were detected in the liver tissue of 25 of 61 (41%) HCC cases. Tissue viral and serologic status were discordant in 27 (44%) cases, including those with apparent "occult" infection. Specifically, HBV DNA was detected in tissue of 4 of 39 (10%) serum HBsAg (-) cases, including 1 anti-HCV(+) case; and HCV RNA was detected in tissue of 3 of 42 (7%) anti-HCV seronegative cases, including two with serologic evidence of HBV.

CONCLUSIONS

Viral hepatitis, including HBV-HCV coinfection, may be unrecognized in up to 17% of patients with HCC when based on serology alone. Further research is needed to understand the clinical significance of viral makers in liver tissue of patients with HCC in the absence of serologic indices.

IMPACT

The contribution of HBV and HCV to the increasing incidence of HCC in the United States may be underestimated.

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

BACKGROUND

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION AND RECOMMENDATIONS

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

Occult hepatitis B: clinical viewpoint and management

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

Occult hepatitis B virus and the risk for chronic liver disease: a meta-analysis

BACKGROUND

The role of occult hepatitis B virus infection as a cause of liver disease is still debated although many studies found a higher prevalence of this condition in subjects than those without liver disease compared. A recent meta-analysis showed an increased risk of hepatocellular carcinoma for occult hepatitis B virus infection.

AIMS

We carried out a meta-analysis of observational studies to summarize the existing evidence and assess quantitatively the association between occult hepatitis B virus infection and chronic liver disease.

METHODS

We searched the available literature on this issue published up to May 2012 using PubMed and EMBASE. All articles that provided enough information to estimate the chronic liver disease risk associated with occult hepatitis B virus infection were selected. Fourteen studies were retrieved.

RESULTS

A total of 1503 subjects with (cases) and 2052 without chronic liver disease (controls) were included. The summary odds ratio for chronic liver disease from all studies was 8.9 (95% confidence interval: 4.1-19.5). The meta-analysis restricted to 7 studies with more precise effect estimate (wt%>8%) provided a lower odds ratio estimate (odds ratio=3.9; 95% confidence interval: 1.7-9.0).

CONCLUSIONS

These findings suggest a relevant association between occult hepatitis B virus infection and chronic liver disease, confirming the hypothesis that hepatitis B virus may play a pathogenic role even in the "occult" status.

Occult Hepatitis B (OBH) in Clinical Settings

CONTEXT

Occult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings.

EVIDENCE ACQUISITION

OHB COULD BE FOUND IN DIFFERENT POPULATION AND CLINICAL BACKGROUNDS INCLUDING: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters.

RESULTS

The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown.

CONCLUSIONS

Monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.

Occult HBV infection

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

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Association between occult hepatitis B infection and the risk of hepatocellular carcinoma: a meta-analysis

BACKGROUND

The association between occult hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) remains controversial.

AIMS

We conducted a meta-analysis of prospective studies and retrospective studies to examine whether occult HBV infection increases the risk of HCC.

METHODS

Two independent reviewers searched databases for eligible studies published in English or Chinese dated from 1966 to 6 April 2010. The odds ratios or the relative risks (RRs) of each study were considered respectively.

RESULTS

We identified 16 eligible studies. A significantly increased risk of HCC was found in subjects with occult HBV infection in comparison with non-infected controls in both retrospective [OR(unadjusted) =6.08, 95% confidence interval (CI)=3.45-10.72] and prospective studies (RR(adjusted) =2.86, 95% CI=1.59-4.13), and occult HBV increased the risk for HCC in both hepatitis C virus (HCV)-infected populations (summary RR=2.83, 95% CI=1.56-4.10) and in non-infected populations (OR(unadjusted) =10.65, 95% CI=5.94-19.08). A higher prevalence of occult HBV was observed in individuals who were positive for anti-HBs and anti-HBc (OR(unadjusted) =1.81, 95% CI=1.06, 3.09).

CONCLUSION

Our findings suggest that occult HBV infection was associated with an increased risk of HCC. Occult HBV may serve as a cofactor in the development of HCV-related HCC, and it may also play a direct role in promoting Non-B and Non-C HCC growth. Suggestive evidence indicates that individuals with a concomitant presence of anti-HBs and anti-HBc had an increased risk of occult HBV infection. However, further studies are needed to clarify these observations.

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

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

Influence of occult hepatitis B virus infection in chronic hepatitis C outcomes

Persistence of hepatitis B virus-DNA in the sera, peripheral blood mononuclear cells or in the liver of hepatitis B surface antigen (HBsAg)-negative patients with or without serological markers of previous exposure (antibodies to HBsAg and/or to HB-core antigen) defines the entity called occult hepatitis B infection (OBI). Co-infection with hepatitis B and hepatitis C viruses is frequent in highly endemic areas. While this co-infection increases the risk of liver disease progression, development of cirrhosis and hepatocellular carcinoma and also increases the rate of therapeutic failure to interferon-based treatments than either virus alone, a potentially negative effect of OBI on clinical outcomes and of therapeutic response to current antiviral regimes of patients with chronic hepatitis C remains inconclusive.

A 2010 update on occult hepatitis B infection

Occult hepatitis B virus infection is a challenging issue whose virological and clinical relevance has been a source of long-lasting debate. By definition, OBI is characterized by the persistence of HBV-DNA in the liver tissue (and in some cases also in the serum) in absence of HBsAg. According to the HBV serological profile, OBI may be antibody (anti-HBc alone or together with anti-HBs) positive (seropositive OBI) or antibody negative (seronegative OBI). OBI is a complex biological entity with possible relevant clinical implications, mainly related to the intrahepatic persistence of viral cccDNA and to a strong suppression of viral replication and gene expression. Clinical observations suggest that OBI carriers may be a source of HBV transmission through blood transfusion or orthotopic liver transplantation (OLT). The state of suppression of viral replication and gene expression may be discontinued when an immunosuppressive status occurs, leading to typical hepatitis B with severe - and some times - fulminant course. The long-lasting persistence of the virus in the liver may provoke a very mild but continuing necro-inflammation that (if other causes of liver damage cohexist) may contribute over time to the progression of the chronic liver damage towards cirrhosis. In addition, OBI is supposed to be an important risk factor to HCC development since it maintains the pro-oncogenic properties typical of the overt infection.

Occult hepatitis B virus infection: a covert operation

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.

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.

Development of up-converting phosphor technology-based lateral-flow assay for rapidly quantitative detection of hepatitis B surface antibody

An up-converting phosphor technology-based lateral-flow (UPT-LF) assay system was developed for rapid and quantitative detection of hepatitis B surface antibody (HBsAb). To evaluate its performance, we compared it with the Abbott Axsym AUSAB (ABBOTT Diagnostics Division, Wiesbaden, Germany) assay and conventional ELISA (Wantai Biological Pharmacy Enterprise, Beijing, China) using 13 standard positive sera and 306 clinical sera. In both laboratory evaluation and clinical application, UPT-LF assay showed the best sensitivity (99.19%) and detection agreement (97.43% for the adjusted agreement) with true results. The concordance rate between UPT-LF and ELISA, as shown by correlative regression analysis, was the highest (R(2)=0.6389), whereas that between UPT-LF and AUSAB was the lowest (R(2)=0.5702). In conclusion, UPT-LF assay for quantitative detection of HBsAb is sensitive and rapid, promising this new assay a bright future.

Hepatitis B virus prevention strategies for antibody to hepatitis B core antigen-positive liver donation: a survey of North American, European, and Asian-Pacific transplant programs

Prophylactic therapy is generally used to prevent reactivated hepatitis B after transplantation of an antibody to hepatitis B core antigen (anti-HBc)-positive liver. To gain insight into current practice, a questionnaire was e-mailed to 89 liver transplant physicians in the United States, Europe, and Asia/Australia and 4 hepatitis B experts. Addressees were asked if they prefer lamivudine or other nucleoside analogs and whether these drugs are used indefinitely. They were also questioned about the use of hepatitis B immune globulin (HBIg), the preferred duration of its administration, and whether treatment strategies differ according to the knowledge of the serologic status of the recipient. Responses were obtained from 78 physicians. All transplant physicians reported the use of nucleoside analog therapy, and 65% prefer lamivudine (58% versus 81% for US and non-US physicians, P = 0.05). Sixty-one percent use HBIg (38% always, 23% sometimes). HBIg was used more frequently in the United States than other parts of the world (69% versus 46%, P = 0.03). Eighty-one percent of transplant physicians use nucleoside analog therapy for an indefinite period, but the duration of HBIg treatment varies widely. Although some centers omit nucleoside analog or HBIg therapy in antibody to hepatitis B surface antigen-positive recipients, 90% will not omit these agents if the recipient is positive for anti-HBc alone. In conclusion, nucleoside analog therapy is nearly always used for anti-HBc-positive livers, and most transplant physicians treat for an indefinite period. Lamivudine continues to be preferred as first-line therapy. Many programs also use HBIg, but there is wide variation in the way this is administered. Further study is needed to determine the most cost-beneficial regimen.