Occult HBV infection in cryptogenic liver cirrhosis in an area with high prevalence of HBV infection

Occult Hepatitis B Virus Infection and Liver Fibrosis in Chinese Patients

BACKGROUND

The impact of hepatitis B surface antigen (HBsAg)-negative/hepatitis B virus (HBV) DNA-positive occult HBV infection (OBI) on the severity of liver fibrosis remains unclear.

METHODS

A total of 1772 patients negative for HBsAg but positive for antibody to hepatitis B core antigen (HBcAg), stratified by the presence or absence of OBI, were selected for long-term carriage leading to elevation of ≥2 of 4 liver fibrosis indexes-hyaluronic acid (HA), laminin, type III procollagen peptide (PCIII), and type IV collagen (CIV)-at testing in a Chinese hospital. Patients were tested for serum viral load, HBV markers, and histopathological changes in liver biopsy specimens.

RESULTS

OBI was identified in 148 patients with liver fibrosis (8.4%), who had significantly higher levels of HA, laminin, PCIII, and CIV than 1624 fibrotic patients without OBI (P < .05). In 36 patients with OBI who underwent liver biopsy, significant correlations were observed between OBI viral load and serum HA levels (P = .01), PCIII levels (P = .01), and pathological histological activity index (HAI) scores (P < .001), respectively; HAI scores and PCIII levels (P = .04); HBcAg immunohistochemical scores and HA levels (P < .001); and HBcAg immunohistochemical scores and PCIII levels (P = .03). Positive fluorescent in situ hybridization results were significantly more frequent in patients with OBIs (80.6% vs 37.5% in those without OBIs). Among patients with OBIs, HBcAg was detected in the liver tissue in 52.8% and HBsAg in 5.6%.

CONCLUSIONS

OBI status appears to be associated with liver fibrosis severity.

Estimates of the prevalence of occult HBV infection in Asia: a systematic review and meta-analysis

PURPOSE

Occult Hepatitis B virus infection (OBI) is of great significance to the transmission of Hepatitis B virus (HBV) and the evolution of the patient's clinical outcome. We conducted a systematic review and meta-analysis to estimate the prevalence of OBI in Asia.

METHODS

Literature search was conducted in PubMed, Cochrane Library database, Web of Science and Embase with the keywords of 'Hepatitis B virus', 'occult infection', 'prevalence'. 70 studies were included in the meta-analysis. Meta-analysis was performed using random-effects models to calculate the pooled prevalence of OBI and 95% confidence interval (CI). The data were analyzed in R 4.1.2.

RESULTS

The overall prevalence of OBI was 4% (95%CI: 0.03-0.06) in Asia. Subgroup analysis based on geographic region showed a prevalence of 3% (95%CI 0.02-0.06) in East Asia, 9% (95%CI 0.05-0.15) in West Asia, 3% (95%CI 0.01-0.11) in Southern Asia and 9% (95%CI 0.05-0.15) in Southeast Asia. Subgroup analysis demonstrated a prevalence of 1% (95%CI 0.00-0.02) in general population, 5% (95%CI: 0.03-0.08) in high-risk population, 9% (95%CI: 0.03-0.22) in the human immunodeficiency virus (HIV)-infected patient, 18% (95%CI: 0.09-0.32) in the hepatopathy patients.

CONCLUSION

Based on the meta-analysis of the prevalence of OBI in different populations, we concluded that the prevalence of OBI in the high-risk population, hepatopathy patients, and HIV-infected patients was higher than that in the general population. A systematic review showed that OBI was associated with disease progression and prognosis. Therefore, these populations should be routinely screened for OBI and promptly intervened to avoid promoting disease progression.

Factors Associated with Liver Enzyme Abnormalities in HIV-HBV and/or HCV Co-infected Patients in Kinshasa, Democratic Republic of the Congo: Multicenter Cross-sectional Study

BACKGROUND AND OBJECTIVE

Liver enzyme abnormalities (LEA) are extremely common and sometimes severe in individuals infected with human immunodeficiency virus (HIV), but data for this disorder are lacking in the developing countries. The objective of this study was to identify factors associated with LEA in HIV-hepatitis B virus (HBV)/hepatitis C virus (HCV) co-infected patients in Kinshasa, Democratic Republic of the Congo.

METHODS

This cross-sectional analytical study included 180 people living with HIV (PLWHIV) mono-infected or co-infected with HBV/HCV between November 10, 2013 and January 10, 2014 in Kinshasa. Sociodemographic, clinical, biological, serological, and immunological data were analyzed. Levels of serum glutamate oxaloacetate transferase (SGOT) and serum glutamate pyruvate transaminase (SGPT) were determined. Antibody levels were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean age of patients was 44.2±11.0 years; female sex was predominant (76.7%). Co-infection, mainly with HBV, but also HCV, was found in 43 (23.9%) patients. Elevated liver enzymes were found in 77 (42.8%) of the patients. No difference was found in the rate of liver enzyme abnormalities between patients with HIV mono-infection or HIV co-infection (46.7% versus 30.2%, respectively; P=0.08). Factors associated with LEA were age ≥50 years (adjusted odds ratio [OR] 2.7; 95% CI 1.4-5.5), duration of HIV infection >3 years (adjusted OR 2.7; 95% CI 1.4-5.5), and CD4 T cells count ≤303 cells/mm³ (adjusted OR 2.2; 95% CI 1.1-4.5).

CONCLUSIONS

Liver enzyme abnormalities are frequent in patients co-infected with HIV-HBV/HCV as well as in HIV patients without co-infection. Diagnosis is determined based on age, immunodeficiency, and length of illness.

Prevalence of occult hepatitis B infection in liver biopsy sample of patients with nonviral liver disease

Aim: To determine the prevalence of occult hepatitis B (HBV) infection (OBI) in patients with nonviral liver disease. Materials & methods: This study included 83 HBsAg-negative patients followed up at a gastroenterohepatology clinic. The presence of HBV DNA was investigated by using an in-house nested-PCR method applied to liver parenchymal biopsy samples obtained from patients who underwent due nonviral chronic liver disease. Results: OBI was detected in 19 (22.9%) of the 83 cases, in 11 (44%) of 25 anti-HBc-positive patients, and 15 (31.9%) of 47 anti-HBc and/or anti-HBs antibodies-positive patients. Conclusion: There is a considerable prevalence of OBI among patients with nonviral chronic liver disease. Therefore, it is suggested that closely monitoring HBV can be useful to prevent or more effectively manage possible OBI-related complications among patients with nonviral chronic liver disease, especially those who are HBsAg seronegative or anti-HBV antibody seropositive.

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.

Prevalence of Risk Factors for Nonalcoholic Fatty Liver Disease in Middle-Aged and Elderly Patients With Cryptogenic Cirrhosis

Aim of the study

To study the prevalence of risk factors for nonalcoholic fatty liver disease (NAFLD) in middle-aged (40-59 years) and elderly patients (≥60 years) with cryptogenic cirrhosis as compared to those with hepatitis B or C virus (HBV or HCV) related cirrhosis.

Methods and materials

Between August 2013 and December 2014, cases (cryptogenic cirrhosis) and controls (HBV/HCV cirrhosis) above 40 years of age were prospectively recruited and assessed for the cause and prevalence of risk factors for NAFLD.

Results

One hundred eighteen cases (male-74%; age 55 (40-74) years; median (range); Child's class A:B:C-46:38:16) and 59 controls (male-80%; age 55.5 (40-69) years; Child's class A:B:C-56:30:14) were enrolled. Obesity (53% v/s 39%, P-0.081), diabetes mellitus (DM) (52% v/s 27%; P-0.002), family history of DM (30% v/s 13%; P-0.016), family history of Obesity (21% v/s 3.5%; P-0.002) and metabolic syndrome (65% v/s 44%; P-0.01) were more among cases than controls. Lifetime weight as obese was also longer in cases than in controls (5.9 ± 6.2 years v/s 3.2 ± 5.1 years, P-0.002). On subgroup analysis, in elderly age group, DM (55% v/s 17%, P-0.006), family history of DM (40% v/s 11%, P-0.025), metabolic syndrome (76% v/s 44%, P-0.017) and family history of obesity (19% v/s 0, P-0.047) were more common in cases as compared to controls, where as in the middle-age group, family history of obesity was the only significant factor (22% v/s 5%, P-0.025). Lifetime weight as obese was longer in cases than controls in both middle and elderly age groups.

Conclusion

Among middle-aged and elderly patients with cirrhosis, there was a higher prevalence of risk factors for NAFLD in those with cryptogenic cirrhosis, compared to those with HBV or HCV cirrhosis.

Controversies in Treating Chronic Hepatitis B Virus Infection: Discordant Serologic Results

Despite effective vaccines and approved therapeutic agents, hepatitis B virus (HBV) remains a prevalent global health problem. Current guidelines rely on a combination of serologic, virological, and biochemical markers to identify the phase in the natural history of chronic HBV infection. Discordant serologic results can occur, which may lead to misclassification. Commonly encountered results that differ from the typical profiles seen in chronic HBV infection are described. For each scenario, the frequency of occurrence, possible explanations, and recommendations for clinical management are discussed. Recognition of discordant serologic findings is crucial for optimal clinical decision.

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.

Hepatitis B virus infection and diabetes mellitus: the Kailuan prospective cohort study in China

BACKGROUND AND AIMS

The effect of hepatitis B virus (HBV) infection on diabetes has remained unclear. We thus conducted a prospective cohort study to investigate the association between different HBV infection status and new-onset diabetes in a Chinese population.

METHODS

We enrolled 55,520 participants with HBV serological markers and diabetes free in 2010 in Kailuan cohort. Cox regression models were used to analyze the relationship between different HBV infection status and incidence of diabetes after adjusting different confounders.

RESULTS

During an average follow-up of 5.6 years, we identified 6008 incident patients with diabetes. Compared to the participants with hepatitis B surface antigen (HBsAg) negative/hepatitis B surface antibody (anti-HBs) negative/hepatitis B core antibody (anti-HBc) negative, those with chronic HBV infection or with HBsAg negative/anti-HBc positive had a higher risk to occur diabetes. The hazard ratios were 1.18 (95% CI 0.99-1.40, p = 0.0588) and 1.22 (95% CI 1.08-1.36, p = 0.0009), respectively. The association between chronic HBV infection, anti-HBc positive and diabetes was different between those with different levels of high density lipoprotein cholesterol, blood pressure, body mass index, and age.

CONCLUSION

The individuals with chronic HBV infection or anti-HBc positive may have an increased risk of diabetes, and the association may be modified by the different status of metabolism related variables and age. Effective management of HBV infection may contribute to the reduction of the burden of both hepatitis B and diabetes.

[Prophylactic Antiviral Treatment in Immunosuppressed Chronic Hepatitis B Patients]

Improved management of chronic hepatitis B patients with oral nucleos(t)ide analogues has increased the number of these patients who are getting older and have other accompanying comorbidities. These comorbidities frequently require various immunosuppression treatments and/or cytotoxic chemotherapy. Not only the patients who are positive for HBsAg, but also the patients who are positive for isolated anti-HBc are at risk for hepatitis B reactivation during immunosuppression. Prophylactic antiviral treatment with oral nucleos(t)ide analogues with high genetic barriers can decrease the risks of HBV reactivation, HBV reactivation- associated hepatitis, and mortality in these patients. It is crucial to screen HBV markers in all of the patients who have to undergo immunosuppression, be administered prophylactic antiviral treatment in the high risk groups, and be monitored for HBV reactivation during and after immunosuppression and/or cytotoxic chemotherapy. This study summarizes the recommendations from the recently updated guidelines from Korea, United States, and Europe.

Hepatitis B Reactivation in Liver Transplant Recipients With Hepatitis B Virus Core Antibody Positive Grafts: a Retrospective Study

BACKGROUND

Liver grafts from hepatitis B core antibody (anti-HBc) positive donors increase the risk of hepatitis B virus (HBV) reactivation in recipients due to posttransplant immunosuppressive therapy.

AIM AND OBJECTIVE

to study the HBV reactivation in liver transplant recipients with anti-HBc-positive donors.

METHODS

This was a retrospective study. Liver transplant recipients who received grafts from anti-HBc-positive donors between January 2013 and December 2017 were included in analysis. Hospital records of all subjects for a 2-year posttransplantation period were studied to observe reactivation of hepatitis B. As per our institute protocol, prophylaxis for HBV was given to subjects with either positive hepatitis B surface antigens or hepatitis B surface antibody (anti-HBs) titre <100 mIU/ml, after transplantation with anti-HBc-positive donor grafts. Recipients with anti-HBs titre >100 mIU/mL were exempted from prophylaxis and kept on regular monitoring for HBV markers.

RESULTS

Of 85 liver transplant recipients, 20 subjects who received anti-HBc-positive grafts were included in analysis. The mean age of the study population was 46 years (range 2-68 years). The most common aetiology of cirrhosis in our study population was cryptogenic followed by ethanol. Among the study population, 16 (80%) transplant recipients had anti-HBs titre less than 100 mu/ml and 4 (20%) subjects had anti-HBs > 100 miu/ml. HBV reactivation occurred in 6 (30%) subjects. Reactivation was seen even in those who received HBV prophylaxis, while none of the subjects with anti-HBs titre >100 miu/ml developed HBV reactivation despite absence of prophylaxis.

CONCLUSION

HBV reactivation can occur even in the presence of target anti-HBs titre (i.e. >10 miu/ml) and HBV prophylaxis during postliver transplantation. However, HBV reactivation is not seen in recipients with anti-HBs titre of >100 miu/ml.

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.

Does persistent anti-HBc positivity influence the prognosis of HBsAg-negative hepatocellular carcinoma? comparative outcomes of anti-Hbc positive versus anti-Hbc negative non-B non-C HCC

BACKGROUND

To compare the presentations and outcomes of anti-HBc seropositive Hepatocellular Carcinoma (HBc-HCC) with anti-HBc seronegative (NHBc-HCC) patients in HBsAg negative Non-HBV Non-HCV (NBNC-HCC) HCC population.

METHODS

515 newly diagnosed HCC patients from January 2011 to September 2016 were retrospectively reviewed. 145 (66.5%) NHBc-HCC and 73 (33.5%) HBc-HCC patients were identified. Patient demographics, disease characteristics, details of treatments, recurrence and survival outcomes were analysed.

RESULTS

A significantly lower proportion of HBc-HCC patients were diagnosed through surveillence (6.8% vs 26.2%, p = 0.001). HBc-HCC patients were less likely cirrhotic (p < 0.001), portal hypertensive (p < 0.001), ascitic (p = 0.008) and thrombocytopenic (p = 0.003). A higher proportion of HBc-HCC patients had treatment with curative intent (46.6% vs 30.3%, p = 0.018) and surgery (39.7% vs 16.6%, p < 0.001). Although HBc-HCC patients had larger median tumor size (74.0 mm vs 55.0 mm, p = 0.016) with a greater proportion of patients having tumors ≥5 cm, there was no difference in the overall median survival (19.0 months vs 22.0 months, p = 0.919) and recurrence rates (38.2% vs 40.9%).

CONCLUSION

Isolated anti-HBc seropositivity in HbsAg negative patients tend to present incidentally with delayed diagnoses resulting in larger tumors, but their long-term survival remain comparable.

Evaluation of elastography combined with serological indexes for hepatic fibrosis in patients with chronic hepatitis B

AIM

To investigate the value of ultrasound elastography combined with serological indexes in diagnosing liver fibrosis and assessing its severity.

METHODS

A total of 338 chronic hepatitis B (CHB) patients were divided into a disease group (patients with hepatic fibrosis) and control group (subjects without hepatic fibrosis). The disease group was further divided into S1-S4 according to the degree of fibrosis. Independent risk factors for hepatic fibrosis were analyzed using multivariate logistic regression. The diagnostic values of hepatic fibrosis from different indicators were compared using receiver operating characteristic (ROC) curves. The combination of elastography and serological indexes was explored to assess the severity of hepatic fibrosis.

RESULTS

The multivariate logistic regression analysis results revealed that shear wave velocity (SWV), hyaluronic acid (HA), type IV collagen (CIV) and aspartate aminotransferase-to-platelet ratio index (APRI) significantly affected the occurrence of hepatic fibrosis. The ROC curve revealed that the accuracy of the diagnosis of hepatic fibrosis for SWV and HA were 87.3% and 84.8%, respectively. The accuracy of SWV combined with HA was 88.9%. The multiple linear regression analysis revealed that SWV, aspartate aminotransferase (AST)/alanine aminotransferase (ALT), HA, CIV, APRI and fibrosis index based on the 4 factor (FIB-4) were screened as statistically significant independent factors. The established regression equation was: Fibrosis level = -4.046 + 1.024 × SWV + 1.170 × AST/ALT + 0.011 × HA + 0.020 × CIV + 0.719 × APRI + 0.379 × FIB-4.

CONCLUSION

SWV combined with serological indexes can improve the accuracy of diagnosis for CHB hepatic fibrosis. Serum indexes can help diagnose the degree of hepatic fibrosis.

Prevalence of occult hepatitis B in a population from the Brazilian Amazon region

In the present study, we evaluated the prevalence of occult hepatitis B (OBI) in a population from the Brazilian Amazon region, identify circulating genotypes, and mutations in the S gene. One hundred eighty-one patients with negative serology for HBsAg and anti-HBs and positive serology for anti-HBc participated in the study. Detection of viral DNA, genotyping by sequencing, and analysis of nucleotide sequences to detect possible mutations were performed. HBV DNA was detected in 14.36% of the patients. Genotyping revealed genotype A in 88.46% of HBV DNA-positive subjects, with subgenotype A1 being the most prevalent (78.26%) followed by subgenotype A2 (21.74%). Genotype F was detected in 11.54% (all of them subgenotype F2). Amino acid substitutions were observed in the amplified S gene in individuals with OBI compared to HBsAg-positive individuals (evident infection). In conclusion, the results show a high prevalence of OBI in the population studied, with a pattern of genotypes A and F that circulate in the Brazilian Amazon region. Amino acid substitutions were detected in part of the S gene in patients with OBI. Further studies on the molecular epidemiology of HBV in this region are important to identify patients considered healthy but who are potential transmitters of the disease.

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.

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.

Characterization of Novel Hepatitis B Virus PreS/S-Gene Mutations in a Patient with Occult Hepatitis B Virus Infection

Objective

The impact of hepatitis B virus (HBV) preS/S-gene mutations on occult HBV infection (OBI) is not fully understood. This study characterized multiple novel HBV preS/S-gene mutants obtained from an OBI patient.

Methods

PreS/S-gene mutants were analyzed by clonal sequencing. Viral replication and expression were analyzed by transfecting HBV genomic recombinants into HepG2 cells.

Results

Twenty-one preS/S-gene mutants were cloned from four sequential serum samples, including 13 mutants that were not previously documented: (1) sI/T126V+sG145R; (2) preS1 nt 3014−3198 deletion; (3) preS1 nt 3046−3177 deletion; (4) preS1 nt 3046−3177 deletion+s115−116 “INGTST” insertion; (5) preS1 nt 3046−3177 deletion+s115−116 “INGTST” insertion+sG145R; (6) preS1 nt 3115−3123 deletion+sQ129N; (7) preS1 nt 3115−3123 deletion+s126−127 “RPCMNCTI” insertion; (8) s115−116 “INGTST” insertion; (9) s115−116 “INGTST” insertion+sG145R; (10) s126−127 “RPCMNCTI” insertion; (11) preS1 nt 2848−2862 deletion+preS2 initiation codon M→I; (12) s122−123 “KSTGLCK” insertion+sQ129N; and (13) preS2 initiation codon M→I+s131−133TSM→NST. The proportion of preS1 nt 3046−3177 deletion and preS2 initiation codon M→I+s131−133TSM→NST mutants increased in the viral pool with prolonged disease. The 13 novel OBI-related mutants showed a 51.2−99.9% decrease in HBsAg levels compared with that of the wild type. Additional N-glycosylation-associated mutations, sQ129N and s131−133TSM→NST, but not s126−127 “RPCMNCTI,” greatly attenuated anti-HBs binding to HBsAg. Compared with the wild type, replication and surface antigen promoter II activity of the preS1 nt 3046−3177 deletion mutant decreased by 43.3% and 97.0%, respectively.

Conclusion

PreS/S-gene mutations may play coordinated roles in the presentation of OBI and might be associated with disease progression. This has implications for HBV diagnosis and vaccine improvement.

Genetic variation of occult hepatitis B virus infection

Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.

Occult hepatitis B virus infection: influence of S protein variants

Background

In occult hepatitis B viral infection (OBI), the persistence of hepatitis B virus (HBV) DNA is associated with a lack of hepatitis B surface antigen (HBsAg). To assess the possible role of HBsAg immune escape variants in OBI patients, variability in the HBV S gene was evaluated for OBI patients as well as chronic HBV infection patients from the same families.

Methods

We selected 17 HBV DNA-positive/HBsAg-negative patients (OBI group) and 15 HBV DNA- and HBsAg-positive patients from OBI families (control group). The S gene was amplified and cloned, and at least 15 clones per patient were sequenced and analyzed.

Results

Although the incidence of stop codon mutations within the S region was higher in the OBI group (13.6 %) than in the control group (1.5 %, P < 0.001), this type of mutation, together with insertion and deletion mutations, was prevalent in only three OBI patients. In the major hydrophilic region (MHR), a median of 0.75 residues were altered in every 100 residues for the OBI patients, whereas 0.95 out of 100 residues were changed in the control group (P = 0.428). Furthermore, some variants that are generally considered immune escape variants, such as mutations at positions s145, s147, and s123, were only observed in less than 5 % of all the clones sequenced, in either OBI or control group.

Conclusions

Our data suggest that HBsAg variants may not play a major role in OBI pathogenesis.

Plasma nuclear factor kappa B and serum peroxiredoxin 3 in early diagnosis of hepatocellular carcinoma

BACKGROUND

Early diagnosis of hepatocellular carcinoma (HCC) is the most important step in successful treatment. However, it is usually rare due to the lack of a highly sensitive specific biomarker so that the HCC is usually fatal within few months after diagnosis. The aim of this work was to study the role of plasma nuclear factor kappa B (NF-?B) and serum peroxiredoxin 3 (PRDX3) as diagnostic biomarkers for early detection of HCC in a high-risk population.

MATERIALS AND METHODS

Plasma nuclear factor kappa B level (NF-?B) and serum peroxiredoxin 3 (PRDX3) levels were measured using enzyme linked immunosorbent assay (ELISA), in addition to alpha-fetoprotein (AFP) in 72 cirrhotic patients, 64 patients with HCC and 29 healthy controls.

RESULTS

NF-?B and PRDX3 were significantly elevated in the HCC group in relation to the others. Higher area under curve (AUC) of 0.854 (for PRDX3) and 0.825 (for NF-?B) with sensitivity of 86.3% and 84.4% and specificity of 75.8% and 75.4% respectively, were found compared to AUC of alpha-fetoprotein (AFP) (0.65) with sensitivity of 72.4% and specificity of 64.3%.

CONCLUSIONS

NF-?B and PRDX3 may serve as early and sensitive biomarkers for early detection of HCC facilitating improved management. The role of nuclear factor kappa B (NF-?B) as a target for treatment of liver fibrosis and HCC must be widely evaluated.

Molecular mechanisms underlying HBsAg negativity in occult HBV infection

Although genomic detection is considered the gold standard test on HBV infection identification, the HBsAg investigation is still the most frequent clinical laboratory request to diagnose HBV infection in activity. However, the non-detection of HBsAg in the bloodstream of chronic or acutely infected individuals has been a phenomenon often observed in clinical practice, despite the high sensitivity and specificity of screening assays standardized commercially and adopted in routine. The expansion of knowledge about the hepatitis B virus biology (replication/life cycle, genetic variability/mutability/heterogeneity), their biochemical and immunological properties (antigenicity and immunogenicity), in turn, has allowed to elucidate some mechanisms that may explain the occurrence of this phenomenon. Therefore, the negativity for HBsAg during the acute or chronic infection course may become a fragile or at least questionable result. This manuscript discusses some mechanisms that could explain the negativity for HBsAg in a serological profile of individuals with HBV infection in activity, or factors that could compromise its detection in the bloodstream during HBV infection.

Occult hepatitis B virus infection among people with a family history of chronic hepatitis B virus infection

The prevalence of occult hepatitis B virus infection (OBI) among people with a family history of chronic hepatitis B virus (HBV) infection is unclear. Serum samples were collected from 747 hepatitis B surface antigen (HBsAg)-negative people with a family history of HBV infection and 579 HBsAg-negative volunteer blood donors. The presence of HBV DNA was evaluated using nested PCR with primers specific for the X, S, and C regions of HBV. The Pre-S1/Pre-S2/ S region PCR products for the OBI group and their family members with chronic HBV infection (control group) were sequenced and compared. The prevalence of OBI was 8.0% (60/747) among HBsAg-negative people with a family history of chronic HBV infection, compared to 2.6% (15/579) among the blood donors (P < 0.05). The prevalence of HBV genotype B infection was lower in the OBI group than in the control group (P = 0.031). The substitution rates in the major hydrophilic region and the "a" determinant seemed to be higher in the OBI group (0.893 vs. 0.507; 1.042 vs. 0.403, respectively), and stop codon mutations more frequent in the OBI sequences (OBI: 2/26, 7.7% vs.

CONTROL

0/31, 0%). However, none of these differences was statistically significant (P = 0.237, 0.199, 0.201, respectively). In summary, the prevalence of OBI among HBsAg-negative people with a family history of chronic HBV infection was significantly higher than that in Chinese blood donors. However, S region mutations and the escape mechanism are not likely to be the major causes of increased prevalence of OBI.

Occult hepatitis B infection in children with chronic liver disease

AIMS

Occult hepatitis B infection (OBI) may adversely affect the outcome of patients with chronic liver disease (CLD). There are no data on OBI and CLD in children. This study determined the prevalence and effect of OBI in HBsAg-negative CLD children.

MATERIALS AND METHODS

CLD children were prospectively evaluated with a demographic, clinical, and investigative proforma. All HBsAg-negative CLD cases were tested for exposure to hepatitis B (total anti-HBc, anti-HBs). Serum hepatitis B virus DNA was measured in exposed (total anti-HBc positive) patients.

RESULTS

A total of 115 HBsAg-negative CLD children (59 boys, age 9.0±3.6 years) were enrolled. The etiology of CLD was known in 94 cases and 21 children had cryptogenic CLD. Of these, 45 (39.1%) had evidence of HBV exposure (23 total anti-HBc positive, 17 total anti-HBc and anti-HBs positive, five only anti-HBs positive without previous vaccination). The anti-HBc-positive children had a higher Child's score than the anti-HBc-negative children [11 (5-13) vs. 7 (5-13); P=0.00]. A total of 4/45 children had seropositive OBI with serum HBV DNA of 8, 36, 133, and 156 IU/ml, respectively. The proportion of total anti-HBc positivity (8/21 vs. 32/94; P=0.8) and OBI (2/21 vs. 2/94; P=0.1) was similar in cryptogenic CLD and known cause CLD.

CONCLUSION

Seropositive OBI is infrequent in Indian children with CLD. The prevalence is similar in cryptogenic and CLD of known etiology.

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.

Mutations associated with occult hepatitis B in HIV-positive South Africans

Occult hepatitis B is characterized by the absence of hepatitis B surface antigen (HBsAg) but the presence of HBV DNA. Because diagnosis of hepatitis B virus (HBV) typically includes HBsAg detection, occult HBV remains largely undiagnosed. Occult HBV is associated with increased risk of hepatocellular carcinoma, reactivation to chronic HBV during immune suppression, and transmission during blood transfusion and liver transplant. The mechanisms leading to occult HBV infection are unclear, although viral mutations are likely a significant factor. In this study, sera from 394 HIV-positive South Africans were tested for HBV DNA and HBsAg. For patients with detectable HBV DNA, the overlapping surface and polymerase open reading frames (ORFs) were sequenced. Occult-associated mutations-those mutations found exclusively in individuals with occult HBV infection but not in individuals with chronic HBV infection from the same cohort or GenBank references-were identified. Ninety patients (22.8%) had detectable HBV DNA. Of these, 37 had detectable HBsAg, while 53 lacked detectable surface antigen. The surface and polymerase ORFs were cloned successfully for 19 patients with chronic HBV and 30 patients with occult HBV. In total, 235 occult-associated mutations were identified. Ten occult-associated mutations were identified in more than one patient. Additionally, 15 amino acid positions had two distinct occult-associated mutations at the same residue. Occult-associated mutations were common and present in all regions of the surface and polymerase ORFs. Further study is underway to determine the effects of these mutations on viral replication and surface antigen expression in vitro.

Impact of occult hepatitis B virus infection on outcome after resection for non-B non-C hepatocellular carcinoma

BACKGROUND

To investigate the clinicopathologic characteristics of patients with both hepatitis B virus-surface antigen and hepatitis C virus antibody negative hepatocellular carcinoma (non-B non-C HCC [NBNC-HCC]) and examine the impact of occult hepatitis B virus infection (OBI) on patients' survival.

METHODS

All patients with OBI were identified from a database of patients with NBNC-HCC who underwent surgical resection between January 1, 2006, and December 31, 2008. Their clinicopathologic and survival characteristics were compared with NBNC-HCC patients without OBI.

RESULTS

Out of the 86 NBNC-HCC patients, 59 patients (68.6%) with OBI. A higher prevalence of hepatitis B core antigen positive rate, low platelet count, portal hypertension, and liver cirrhosis were observed in NBNC-HCC patients with OBI. The 1- and 3-y recurrence free survival rates were 66% and 25% in OBI group and 89% and 70% in the no OBI group, respectively (P < 0.001). The 1-, 3-, and 5-y overall survival rates were 86%, 55%, and 51% in OBI group and 93%, 85%, and 66% in no OBI group, respectively (P = 0.112). Multivariate analysis revealed that OBI (hazard ratio [HR] = 2.122; 95% confidence interval [CI], 1.086-4.149; P = 0.028), liver cirrhosis (HR = 2.411; 95% CI, 1.337-4.345; P = 0.003), and vascular invasion (HR = 5.858; 95% CI, 2.799-12.261; P < 0.001) were independent poor prognostic factors for recurrence free survival of patients with NBNC-HCC.

CONCLUSIONS

NBNC-HCC patients with OBI had a poorer prognosis. OBI can be a useful predictor for recurrence in patients with NBNC-HCC after surgery.

Prevalence and molecular analysis of occult hepatitis B virus infection isolated in a sample of cryptogenic cirrhosis patients in iran

OBJECTIVES

The aims of this study are to investigate the prevalence of occult hepatitis B virus infection among patients with cryptogenic cirrhosis and to analyze the relationship between surface protein variability and occult hepatitis B virus infection, which may be related to the pathogenesis of occult hepatitis B virus infection in cryptogenic cirrhosis. Occult hepatitis B virus infection is a well-recognized clinical entity characterized by the detection of hepatitis B virus DNA in serum and/or liver in the absence of detectable hepatitis B virus surface antigen, with or without any serological markers of a past infection.

METHODS

Sera from patients with cryptogenic chronic liver disease were tested for hepatitis B virus DNA using both real-time and nested PCR. In the detected hepatitis B virus DNA samples, the surface gene was analyzed for mutations.

RESULTS

Hepatitis B virus DNA was detected in 38% of patients, all of whom had a viral load below 10,000 copies/mL. All hepatitis B virus belonged to genotype D. There were no significant associations between occult hepatitis B virus infection status and age, gender, ALT/AST levels, viral load or serologic markers of previous hepatitis B virus infection. There were 14 mutations found in 5 patients; 6 were in the major hydrophilic region, of which 4 were Y134F assigning for the "a" determinant region. All patients who acquired Y134F contained S207R (within HLA-A2-restricted CTL epitope) as a combination.

CONCLUSION

Hepatitis B virus surface antigen variants may arise as a result of natural selection to evade the immune surveillance of the infected host, and subsequently may go undetected by conventional hepatitis B virus surface antigen screening tests. Etiological diagnosis of cryptogenic cirrhosis is significantly underestimated with current serology testing methods alone.

Prevalence and risk factors of hepatitis B and C viruses among hemodialysis patients in Isfahan, Iran

BACKGROUND

The aim of this study was to assess the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) and their associated risk factors among hemodialysis patients in Isfahan, Iran in 2011.

MATERIALS AND METHODS

In this cross-sectional study, a total of 499 chronic hemodialysis patients from eight governmental hemodialysis centers were tested. Demographic information, time duration on hemodialysis, history of blood transfusion, and the number of transfused blood units as risk factors to HBV and HCV infections were calculated. The status of HBsAg and anti-HCV was assessed by serological testing.

RESULTS

The overall prevalence of HBV-positive and HCV-positive among study population was 1.2% and 5.2%, respectively. Age, sex, and time duration on hemodialysis were not statistically significant in HBV- and HCV-patients compared with other hemodialysis patients (P > 0.05). History of blood transfusion and the number of transfused blood units in HBV infected patients were similar to other patients (P > 0.05). The main risk factors in hemodialysis patients infected by HCV were history of blood transfusion and the number of transfused blood units (P < 0.0001).

CONCLUSION

In conclusion, the prevalence of HBV and HCV infections in hemodialysis centers in Isfahan is lower than in some other cities of Iran. History of blood transfusion and the number of blood units transfused might be a risk factor for HCV gaining. However, further studies are needed to assess the role of other demographic and clinical risk factors in these patients.

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.

Hepatitis B virus surface antigen (HBsAg)-positive and HBsAg-negative hepatitis B virus infection among mother-teenager pairs 13 years after neonatal hepatitis B virus vaccination

It is unclear whether a mother who is negative for hepatitis B virus surface antigen (HBsAg) but positive for hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study, using a paired mother-teenager population, aimed to assess whether maternal HBsAg-negative HBV infection ((hn)HBI) is a significant source of child HBV infection (HBI). A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV have been tested, and phylogenetic analysis of HBV isolates has been done. The HBI prevalence was 1.9% (1 (hn)HBI/53) for teenage children of non-HBI mothers, compared with 16.7% (1 (hn)HBI/6) for those of (hn)HBI mothers and 2.9% (1 HBsAg-positive HBV infection [(hp)HBI]/34) for those of (hp)HBI mothers. Similar viral sequences have been found in one pair of whom both the mother and teenager have had (hn)HBI. In comparison with the (hp)HBI cases, those with (hn)HBI had a lower level of HBV load and a higher proportion of genotype-C strains, which were accompanied by differentiated mutations (Q129R, K141E, and Y161N) of the "a" determinant of the HBV surface gene. Our findings suggest that mother-to-teenager transmission of (hn)HBI can occur among those in the neonatal HBV vaccination program.

High prevalence of occult hepatitis B virus infection in children born to HBsAg-positive mothers despite prophylaxis with hepatitis B vaccination and HBIG

BACKGROUND & AIMS

Occult hepatitis B virus (HBV) infection is a well-recognized clinical entity characterized by the detection of HBV DNA in serum and/or liver in the absence of detectable hepatitis B surface antigen (HBsAg). The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. We aimed at determining the prevalence of occult HBV infection in a high risk group of children who developed HBV infection despite immunoprophylaxis.

METHODS

The sera of 75 children born to HBsAg-positive mothers previously immunized by HBIG and prophylaxic vaccine regimen were assayed for HBV DNA by real-time PCR. Subsequently, the samples were tested using a sensitive standard PCR, with an independent set of primers for all HBV genes, and analyzed by direct sequencing.

RESULTS

HBV DNA was detected in 21/75 (28%) children, and ranged between 77 and 9240 copies/ml. All were positive for anti-HBs. Five (24%) children were found to be positive for anti-HBc, while anti-HBc-only positive individuals were not observed. Eight isolates (38%) did not carry any mutation. Thirteen infected children (62%) had at least one mutation in regions known to be involved in functional and/or immune epitope activity. Ten had G145R mutations.

CONCLUSIONS

HBV occult infection seems to be relatively frequent in immunized children born to HBsAg-positive mothers. HBsAg negativity is not sufficient to completely exclude HBV DNA presence. These findings emphasize the importance of considering occult HBV infection in hypo-endemic areas.

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.

Prevalence and virological profiles of hepatitis B infection in human immunodeficiency virus patients

AIM

To determine the prevalence of hepatitis B virus (HBV) in adult human immunodeficiency virus (HIV) patients with CD4+ T-cell count less than 500/mm(3) and without antiretroviral therapy; to describe different HBV-HIV coinfection virological profiles; and to search for factors associated with HBs antigen (HBsAg) presence in these HIV positive patients.

METHODS

During four months (June through September 2006), 491 patients were received in four HIV positive monitoring clinical centers in Abidjan.

INCLUSION CRITERIA

HIV-1 or HIV-1 and 2 positive patients, age ≥ 18 years, CD4+ T-cell count < 500/mL and formal and signed consent of the patient. Realized blood tests included HIV serology, CD4+ T-cell count, quantitative HIV RNA load and HBV serological markers, such as HBsAg and HBc antibody (anti-HBcAb). We performed HBeAg, anti-HBe antibody (anti-HBeAb), anti-HBc IgM and quantitative HBV DNA load in HBsAg positive patients. Anti-HBsAb had been tested in HIV patients with HBsAg negative and anti-HBcAb-positive. HBV DNA was also tested in 188 anti-HBcAb positive patients with HBsAg negative status and without anti-HBsAb. Univariate analysis (Pearson χ(2) test or Fischer exact test) and multivariate analysis (backward step-wise selection logistic regression) were performed as statistical analysis.

RESULTS

Mean age of 491 patients was 36 ± 8.68 years and 73.3% were female. Type-1 HIV was found in 97% and dual-type HIV (type 1 plus type 2) in 3%. World Health Organization (WHO) clinical stage was 1, 2, 3 and 4 respectively in 61 (12.4%), 233 (47.5%), 172 (35%) and 25 patients (5.1%). Median CD4+ T-cell count was 341/mm(3) (interquartile range: 221-470). One hundred and twelve patients had less than 200 CD4+ T-cell/mm(3). Plasma HIV-1 RNA load was elevated (≥ 5 log(10) copies/mL) in 221 patients (45%). HBsAg and anti-HBcAb prevalence was respectively 13.4% and 72.9%. Of the 66 HBsAg positive patients, 22 were inactive HBV carriers (33.3%), 21 had HBeAg positive hepatitis (31.8%) and 20 had HBeAg negative hepatitis (30.3%). HBeAg and anti-HBeAb were indeterminate in 3 of them. Occult B infection prevalence (HBsAg negative, anti-HBcAb positive, anti-HBsAb negative and detectable HBV DNA) was 21.3%. Three parameters were significantly associated with the presence of HBsAg: male [odds ratio (OR): 2.2; P = 0.005; 95% confidence interval (CI): 1.3-3.8]; WHO stage 4 (OR: 3.2; P = 0.01; 95% CI: 1.3-7.9); and aspartate aminotransferase (AST) level higher than the standard (OR: 1.9; P = 0.04; 95% CI: 1.02-3.8).

CONCLUSION

HBV infection prevalence is high in HIV-positive patients. HBeAg positive chronic hepatitis and occult HBV infection are more frequent in HIV-positive patients than in HIV negative ones. Parameters associated with HBsAg positivity were male gender, AIDS status and increased AST level.

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.

Hepatitis B virus S gene escape mutants

Hepatitis B virus (HBV) can be classified into nine immunological subtypes or eight genotypes. The most prevalent genotypes in Asia are genotypes B and C. HBV is transmitted parenteraly and can produce either asymptomatic or symptomatic disease. Although the consequences of acute hepatitis B can be severe, serious sequelae are associated with chronic infections. HBV seroprevalence ranges from intermediate (2%-7%) to high (≥8%) levels in Asia. Several strategies for the control and prevention of HBV infection have been found to be efficacious. They include vaccination and the administration of HBIG, interferon-a and nucleoside/nucleotide analogues. However, these procedures also apply selective pressures on HBV in infected individuals leading to the generation and accumulation of mutations in the S gene. Most of these mutations occur in the major hydrophilic region (MHR) of the S gene. These mutations create public health concerns as they can be responsible for reactivation of hepatitis B and occult hepatitis B infection. The inability to detect occult infections means that these individuals may become blood donors. This suggests that new strategies for donor evaluation and selection may need to be developed to protect the blood supply.

Clinical significance of occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative. Until recently, the clinical effect of OBI was unclear on the progression of liver disease; on the development of hepatocellular carcinoma; and on the risk for reactivation or transmission of HBV infection. Several studies suggest a high prevalence of OBI among patients with cryptogenic chronic liver disease, but its role in the progression to cirrhosis remains unclear. Although OBI has been well documented in human immunodeficiency virus (HIV)-positive patients, especially among those coinfected with hepatitis C virus, further studies are needed to determine its current clinical impact in HIV setting.

Pathogenesis of occult chronic hepatitis B virus infection

Occult hepatitis B infection (OBI) is characterized by hepatitis B virus (HBV) DNA in serum in the absence of hepatitis B surface antigen (HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns. Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays; but more frequently it is due to a strong suppression of viral replication and gene expression. OBI is an entity with world-wide diffusion. The failure to detect HBsAg, despite the persistence of the viral DNA, is due in most cases to the strong suppression of viral replication and gene expression that characterizes this “occult” HBV infection; although the mechanisms responsible for suppression of HBV are not well understood. The majority of OBI cases are secondary to overt HBV infection and represent a residual low viremia level suppressed by a strong immune response together with histological derangements which occurred during acute or chronic HBV infection. Much evidence suggests that it can favour the progression of liver fibrosis and the development of hepatocellular carcinoma.

Chronic hepatitis B in Asia-new insights from the past decade

Chronic hepatitis B virus (HBV) infection is a major health problem in the Asia-Pacific region. In the past decade, much progress has been made in the understanding and management of this disease. The introduction of universal vaccination has significantly reduced the incidence of perinatal infection in most Asia-Pacific countries. As the majority of the adult population have not been immunized at birth, we are still facing a large population of young HBV-infected patients in the coming two decades. The study of long-term longitudinal databases has provided deeper insight into the clinical significance of HBV DNA suppression, hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) seroclearance in chronic hepatitis B. With a better understanding on the natural history of HBV infection, one can now stratify the risk of chronic hepatitis B patients for adverse clinical outcomes and use this to individualize management. The introduction of non-invasive assessment of liver fibrosis can potentially reduce the necessity of liver biopsy. There have also been great advances in the development of antiviral therapy in the past decade. However, the high cost of HBV antiviral drugs poses major challenges to health authorities in many Asia-Pacific countries. Properly performed cost-effective analysis and understanding on the best timing of stopping antiviral drugs will be important to facilitate the most appropriate allocation of resources.

Etiology of liver cirrhosis in Japan: a nationwide survey

BACKGROUND

Little is understood about worldwide changes in the epidemiological distribution of the etiology of liver cirrhosis (LC). The present study examines the etiology of liver cirrhosis in Japan using a nationwide survey.

METHODS

We analyzed data from 33,379 patients with LC at 58 hospitals and presented the findings in a poster symposium regarding the etiology and clinical features of LC in Japan that was included in the program of the 44th Annual Meeting of the Japan Society of Hepatology. We identified the distribution of the etiology of LC and compared the present with previous Japanese findings to estimate the future of etiological changes in LC.

RESULTS

The etiological agents were as follows: hepatitis B virus (HBV) 13.9%, hepatitis C virus (HCV) 60.9%, alcohol 13.6%, primary biliary cirrhosis (PBC) 2.4% and autoimmune hepatitis (AIH) 1.9%. Cirrhosis was considered to be related to nonalcoholic steatohepatitis (NASH) in 2.1% of the patients. The ratio of HCV-related LC was significantly higher among patients with hepatocellular carcinoma (HCC) (P < 0.0001) compared to those without, whereas the ratios of alcohol, PBC, AIH were lower. HCC was evident in 31.5% of NASH-related LC.

CONCLUSIONS

The major etiology of liver cirrhosis in Japan remains HCV. Our survey revealed the prevalence of NASH-related LC in Japan and the frequency of HCC. Future changes in etiology must be considered in establishing preventive or educational strategies, as well as in developing new treatment strategies.

Prevalence of occult hepatitis B virus infection in haemodialysis patients from central Greece

AIM: To assess the hepatitis B virus (HBV)-DNA and the prevalence of occult HBV infection in end-stage renal failure (ESRF) patients from Central Greece.

METHODS: Sera from 366 ESRF patients attending five out of six dialysis units from Central Greece were investigated for HBV-DNA by real-time polymerase chain reaction. Only serum samples with repeatedly detectable HBV-DNA were considered positive. IgG antibodies to hepatitis C virus (anti-HCV) were tested by a third generation enzyme linked immunosorbent assay (ELISA), while IgG antibodies to hepatitis E virus (anti-HEV) were tested by two commercially available ELISAs.

RESULTS: HBV-DNA was detected in 15/366 patients (4.1%) and HBsAg in 20/366 (5.5%). The prevalence of occult HBV infection was 0.9% (3/346 HBsAg-negative patients). Occult HBV was not associated with a specific marker of HBV infection or anti-HCV or anti-HEV reactivity. There was no significant difference in HBV-DNA titres, demographic and biochemical features, between patients with occult HBV infection and those with HBsAg-positive chronic HBV infection.

CONCLUSION: In central Greece, 4% of ESRF patients had detectable HBV-DNA, though in this setting, the prevalence of occult HBV seems to be very low (0.9%).

Reactivation of hepatitis B virus infection with persistently negative HBsAg on three HBsAg assays in a lymphoma patient undergoing chemotherapy

In patients with occult hepatitis B virus (HBV) infection, acute exacerbation may occur when they become immunocompromised. Usually, these patients develop hepatitis B surface antigen (HBsAg) seroreversion during the flare. Here we report on a patient with occult HBV infection, who developed HBV exacerbation after chemotherapy for diffuse large B-cell lymphoma. The resurgence of HBV DNA preceded the elevation of liver enzymes for 20 weeks. Atypically, despite high viraemia, serological tests showed persistently negative HBsAg using three different sensitive HBsAg assays (i.e., Architect, Murex and AxSYM). On comparing the amino acid sequence of the index patient with the consensus sequence, five mutations were found at pre-S1, five at pre-S2 and twenty-three mutations at the S region. Six amino acid mutations were located in the 'a' determinant, including P120T, K122R, M133T, F134L, D144A and G145A. The mutants K122R, F134L and G145A in our patient have not been tested for their sensitivity to Architect and Murex assays by the previous investigators and might represent the escape mutants to these assays.

Evaluating the risk of hepatitis B reactivation in patients with haematological malignancies: is the serum hepatitis B virus profile reliable?

BACKGROUND/AIM

Patients with an occult hepatitis B virus (HBV) infection undergoing deep immunosuppression are potentially at risk of HBV reactivation. In order to assess whether a polymerase chain reaction (PCR) assay for HBV DNA in serum could be used to predict the reactivation of an occult HBV infection, we performed a retrospective study in a cohort of Sicilian patients with oncohaematological diseases.

METHODS

We studied by a highly sensitive ad hoc nested PCR for serum HBV DNA 75 HBsAg-negative oncohaematological patients requiring chemotherapy.

RESULTS

Thirty-three patients (44%) were HBV seronegative (anti-HBc and anti-HBs negative) and 42 patients (56%) were HBV seropositive (anti-HBc and/or anti-HBs positive). Baseline serum HBV DNA was positive in nine out of 33 HBV-seronegative patients and in nine out of 42 HBV-seropositive patients (27.3 vs. 21.4%; P=NS). HBsAg seroconversion was observed in five out of 33 seronegative vs. six out of 42 seropositive patients (15 vs. 14%, P=0.9), and in five out of 18 HBV DNA-positive vs. six out of 57 HBV DNA-negative patients (27.7 vs. 10.6%P=0.11). Hepatitis C virus infection was found in 18 patients (24.3%), although with no correlation to HBV serological status, presence of serum HBV DNA or frequency of HBsAg seroconversion.

CONCLUSIONS

In oncohaematological patients undergoing chemotherapy, highly sensitive serum HBV DNA testing at baseline has a 28% predictive ability to forecast HBsAg seroconversion in HBV DNA-positive patients, and a 90% ability to forecast persistent HBsAg negativity in HBV DNA-negative patients, a better performance than serological tests.

Two HBV DNA+/HBsAg- blood donors identified by HBV NAT in Shenzhen, China

BACKGROUND

In order to further improve blood safety, mini-pool (MP) nucleic acid testing (NAT) was implemented to screen samples negative for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV), anti-human immunodeficiency virus (anti-HIV), syphilis (anti-Treponemal antibody) and with normal ALT.

STUDY DESIGN AND METHODS

From August 2006 to February 2008, 41,301 donations were screened using commercial HIV/HCV RNA and HBV DNA Real-Time PCR NAT assays in pools of 8. Reactive pools were re-tested as individual samples using the appropriate screening test and confirmed using an alternate commercial NAT assay. Donors reactive on both NAT assays were considered 'confirmed' positive for the virus concerned and recalled for additional follow-up testing and counseling.

RESULTS

Of the 41,301 samples screened, no HIV or HCV RNA-positive/seronegative donations were detected but two HBV DNA positive/HBsAg negative blood donors (Donors 1 and 2) were identified. Their respective hepatitis immunological markers were: Donor 1 - anti-HBc positive/anti-HBe positive/HBeAg negative/ALT normal and HBV DNA viral load of 112 IU/ml; Donor 2 - anti-HBc positive/anti-HBe negative/HBeAg negative/ALT normal and HBV DNA viral load 2750 IU/ml.

CONCLUSIONS

MP NAT identified two HBsAg negative donors with presumed occult infection but no HIV or HCV seronegative/NAT positive (yield) donors. The HBV yield rate of 1 in 20,650 (95%CI - 1 in 5663 to 1 in 75,303) is comparatively high, exceeds the predicted rate based on previous modeling for the population and demonstrates the incremental blood safety value of NAT in countries where HBV is highly epidemic. The low viral load of the two yield samples underscores the importance of optimizing the sensitivity of the HBV NAT assay selected for screening.

[Occult hepatitis B: prevalence and clinical characteristics in a population with high endemicity of hepatitis B infection in the western Brazilian Amazon region]

A persistent form of the hepatitis B virus called occult chronic hepatitis B has recently been described. Its prevalence and physiopathology are unknown. The aim of this study was to evaluate the occurrence of this clinical entity among patients in the Brazilian Amazon region. Out of 51 anti-HBc total-positive patients who were tested using the polymerase chain reaction, 17% were positive. We did not find any associations with classical risk factors for hepatitis B virus infection or with biochemical tests, hematological tests or histological patterns. However, the jaundiced and HIV-positive patients showed a statistical association with the presence of hepatitis B virus-DNA. The results demonstrated that occult hepatitis B occurred among our patients, but at prevalence rates lower than expected for this region. We believe that despite the small sample size, the occurrence might have been found to be greater if we had used primers for the S, C and X regions of the hepatitis B virus genome, thereby increasing the sensitivity of the test.