The prevalence of occult hepatitis B infection among the blood donors in a donation center in Beijing

Occult HBV infection (OBI) remains a potential threat for blood safety. The prevalence of OBI was investigated in a blood donation center of Chinese PLA General Hospital to improve HBV blood safety. 229446 samples from blood donors were screened by two different enzyme-linked immunosorbent assay (ELISA) kits. 78 samples were HBV DNA positive among 212134 ELISA nonreactive donor samples. The prevalence of OBI was 0.04% (76/212134). Ten samples of OBI were permitted by the donors' content for further research, and all of these were below 200IU/mL, and six of these were below 20IU/mL(6/10,60%). Genotype B and genotype C was 20% (2/10) and 80% (8/10), respectively. 16 amino acid mutations were detected in the S region of OBI, included three mutations in MHR region of S. The prevalence of OBI is rare in this donation center. These mutations we found may contribute to the multifactorial occurrence of OBI.

Effect of S-region mutations on HBsAg in HBsAg-negative HBV-infected patients

BACKGROUND

Occult HBV infection (OBI) is a special form of hepatitis B virus (HBV) infection that may cause Liver cirrhosis and hepatocellular carcinoma, causing significant harm to patients. Given the insidious nature of OBI, it is usually not easy to be detected. Most of the samples currently studied are concentrated on blood donors, however, patients in this special state have not been fully studied. This project aimed to study the effect of HBV S region mutations on HBsAg in patients with clinical OBI.

METHODS

Collect 107 HBsAg-/HBV DNA + blood samples from Beijing Youan Hospital, Capital Medical University from August 2022 to April 2023. Next, the successfully extracted and amplified HBV DNA S regions were sequenced. Construct mutant plasmids to verify the cell function of the high-frequency mutation sites and explore the possible molecular mechanism.

RESULTS

Sixty-eight HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., sY100C、sK122R、sI126T、sT131P、and sS114T) and TMD (Transmembrane domain) region substitutions (i.e., sT5A、sG10D、sF20S、and sS3N). We constructed a portion of the mutant plasmids and found that sT5A, sF20S, sG10D, sS3N, sI68T, and sI126T single point mutations or combined mutations may decrease HBsAg expression or change the antigenicity of HBsAg leading to detection failure.

CONCLUSIONS

HBsAg-negative patients may show various mutations and amino acid replacement sites at high frequency in the HBV S-region, and these mutations may lead to undetectable Hepatitis B surface antigen (HBsAg), HBsAg antigenic changes or secretion inhibition.

Evaluating the cost-effectiveness of low-level HBV DNA screening in occult hepatitis B infection donors: A study from Shandong Blood Center, China

OBJECTIVE

This study aimed to assess the efficacy of individual-donation nucleic acid testing (ID-NAT) in detecting occult hepatitis B virus infection (OBI) among anti-HBc positive blood donors, compared to minipool nucleic acid testing (MP-NAT).

METHODS

The present study analyzed data from the Shandong Blood Center in China during the period from January 2018 to June 2022, where HBsAg-negative blood donors were screened using the 6-sample minipool nucleic acid testing (6-sample MP NAT) method. NAT-positive samples underwent subsequent anti-HBc and anti-HBs testing. Approximately 5000 samples that passed the nucleic acid mixing test were randomly selected for anti-HBc testing, and over 100 anti-HBc positive samples underwent individual donor nucleic acid testing (ID-NAT). Any HBV DNA positive samples detected by ID-NAT were subsequently confirmed using alternative nucleic acid testing methods.

RESULTS

Among 220,445 HBsAg-negative blood donors, the positivity rate of HBV DNA detection using the 6-sample minipool nucleic acid testing (MP NAT) method was found to be 0.031% (69/220,445). Of the 67 HBV DNA positive samples, 55 (82.09%) and 25 (37.31%) were found to be positive for anti-HBc and anti-HBs, respectively, using the supplementary chemiluminescent microparticle immunoassay (CMIA). Among the 4797 HBsAg-negative/MP NAT-negative samples, 909 (18.95%) tested positive for anti-HBc. Further NAT testing was performed on 164 arbitrarily selected anti-HBc-positive/MP HBV DNA-negative samples, revealing a HBV DNA positivity rate of 1.22% (2/164).

CONCLUSION

Using individual donation nucleic acid testing can significantly increase the detection rate of occult hepatitis B virus infection in anti-HBc-positive blood donors, resulting in a detection rate of 0.22% (1.22 × 0.1895). This rate is 8.10 times higher than the detection rate achieved by mixed testing methods (0.031%) [calculated as (0.22 + 0.031)/0.031]. Therefore, it is recommended to perform single HBV DNA testing on anti-HBc-positive blood donors, discard plasma with weakly positive or negative anti-HBs but positive anti-HBc, or avoid transfusing anti-HBc-positive plasma to recipients with weakly positive or negative anti-HBs to prevent HBV infection.

The role of non-coding RNAs in the diagnosis of different stages (HCC, CHB, OBI) of hepatitis B infection

Despite the availability of an effective hepatitis B virus (HBV) vaccine and universal immunization schedules, HBV has remained a health problem in various stages such as occult hepatitis B infection (OBI), chronic hepatitis B (CHB), and hepatocellular carcinoma (HCC), which is considered one of the possible phases during chronic HBV infection. OBI is defined as the persistence of HBV genomes in hepatocytes of patients with a negative HBV surface antigen (HBsAg) test and detectable or undetectable HBV DNA in the blood. OBI is occasionally associated with infection caused by mutant viruses that produce a modified HBsAg that is undetected by diagnostic procedures or with replication-defective variations. Many aspects of HBV (OBI more than any other stage) including prevalence, pathobiology, and clinical implications has remained controversial. According to a growing body of research, non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been linked to the development and progression of a number of illnesses, including viral infectious disorders. Despite a shortage of knowledge regarding the expression and biological activities of lncRNAs and miRNAs in HBV infection, Hepatitis B remains a major global public health concern. This review summarizes the role of lncRNAs in the diagnosis and treatment of different stages of hepatitis B infection.

Occult infection with hepatitis B virus PreS variants synergistically promotes hepatocellular carcinoma development in a high-fat diet context by generating abnormal ceramides

BACKGROUND

Some occult hepatitis B virus (HBV) infections are resulted from PreS mutations that reduce secretion of envelope protein (HBsAg). We investigated the ceramide amounts and species in hepatocytes infected with PreS variants that were isolated from HBsAg-seronegative patients with hepatocellular carcinoma (HCC) and the ceramide effects on autochthonous HCC development in murine models.

METHODS

HBV PreS/S regions from 35 HBsAg-seronegative HCC patients were sequenced. Hepatocyte cell lines and male C57BL/6J mouse livers were transfected with two PreS variant representatives. The ceramides with variated lengths of fatty acyl chains were quantified. Tumour development was examined in the HBV-transfected mice fed different diet types.

RESULTS

In HBsAg-seronegative HCC patients, nonneoplastic liver tissues harboured HBsAg and replication-competent HBV. The most frequently detected PreS/S variants carried mutations of altered amino acid properties in HBsAg compared with an isolate from one HBsAg-seronegative HCC patient. Hepatocyte infection with PreS variants caused HBsAg retention within the endoplasmic reticulum and generated more amounts of ceramides with C16:0 ceramide elevated the highest. Saturated fatty acids aggravated the PreS variant-infected hepatocytes to generate abnormal amounts and species of ceramides, which with HBV proteins synergistically activated NLRP3 inflammasome in liver inflammatory macrophages. Liver tumours were only detected in HBV-transfected mice fed high-fat diet, with higher tumour loads in the PreS variant-transfected, associated with abnormal ceramide generation.

CONCLUSIONS

HBV PreS mutations which altered amino acid properties of envelope proteins inhibited HBsAg secretion. Hepatocyte infection with PreS variants generated abnormal ceramides which with HBV proteins coactivated NLRP3 inflammasome in liver macrophages to promote autochthonous HCC development.

Antibody to hepatitis B virus core antigen positivity is a predictor of non-alcoholic fatty liver disease severity

Insufficient information is available about co-factors favoring the progression of non-alcoholic fatty liver disease (NAFLD) toward cirrhosis. We aimed to evaluate the impact of a limited alcohol intake and of occult hepatitis B virus (HBV) infection (OBI) on the severity of NAFLD. Three-hundred-seventy-four alcohol non-abusers and HBV surface antigen negative NAFLD patients (223 males; mean age 55.4 years), consecutively admitted to the outpatients clinic of a referral liver unit from January 1st, 2018 to December 31st, 2019, were studied. Anti-HBV core antigen antibody [(anti-HBc), a surrogate marker of OBI] was assessed in all patients. Patients were distinguished between teetotal and moderate alcohol consumers (intake of less than 30 g and 20 g if males or females, respectively). Liver fibrosis was non-invasively assessed by FIB-4 and transient elastography. Uni- and multivariate analyses were performed to identify predictors of advanced fibrosis. Patients had a mean BMI of 28.5 kg/m², and the majority presented metabolic and cardio-vascular comorbidities [258 patients (69%) had insulin resistance/diabetes, 249 (66.6%) dyslipidemia, 200 (53.5%) arterial hypertension]. Multivariate analysis showed that anti-HBc positivity (p = 0.046, OR 2.153) was a factor associated with advanced fibrosis at FIB-4 score testing, whereas moderate alcohol intake was not associated with severe NAFLD both at FIB-4 and transient elastography evaluations. The study showed that a moderate alcohol intake has no impact on NAFLD severity and suggested that OBI might negatively affect the NAFLD outcome.

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.

Comparison of S gene mutations in patients with occult and chronic hepatitis B virus infection

BACKGROUND AND AIM

This study aimed to detect mutations in the HBV S gene and evaluate their relationship to occult hepatitis B virus (HBV) infection (OBI).

METHODS

The study included 32 patients with negative serum HBsAg and HBV DNA who underwent liver biopsy due to different clinical indications defined as the OBI group and 32 patients who underwent liver biopsy due to chronic hepatitis B (CHB) as the comparison group. The HBV S gene region was amplified by Nested PCR, and Sanger sequencing was performed.

RESULTS

At least one amino acid (aa) mutation was detected in the major hydrophilic region (MHR) of the HBV S gene in 14/32 (43.75%) of the patients with OBI and 8/32 (25.0%) with CHB. The genotype of all patients with OBI and CHB was HBV/D. Although 9 (28.1%) of the cases with OBI had sub-genotype HBV/D3, none of the patients with CHB had sub-genotype HBV/D3. Unlike patients with CHB, L15*, D33N, Q51P, V63F, L91I, P108S, T115I, P120L, T125M, Q129H, T189I, L216F, P217L mutations were detected in the HBV S gene in OBI cases. Also, P127T aa polymorphism was frequently detected. Mutation frequency in the HBV S gene in the major hydrophilic region (MHR) was higher in patients with OBI with sub-genotypes HBV/D3 and D2 than those with HBV/D1 and those with serotype HBV/ayw3 compared to those with HBV/ayw2 (p < 0.05).

CONCLUSIONS

Sub-genotypic-specific mutation patterns were seen in the "a" determinant region and T helper cell epitopes of HBsAg, especially in the C-terminus domain; this may be associated with OBI.

May Previous Hepatitis B Virus Infection Be Involved in Etiology and Pathogenesis of Autoimmune Liver Diseases?

INTRODUCTION

Viral infections, especially with hepatotropic viruses, may trigger autoimmune liver diseases (AILDs) and deteriorate their course. However, association of previous hepatitis B virus (HBV) infection (presence of anti-HBc with or without anti-HBs or HBV DNA in serum) with AILDs is poorly studied so far. The aim of the study was to assess the prevalence of previous hepatitis B virus infection markers and its clinical significance in patients with autoimmune liver diseases.

METHODS

The study was based on the data obtained from 234 consecutive HBsAg-negative patients with AILDs [81 with autoimmune hepatitis (AIH), 122 with primary biliary cholangitis (PBC) and 31 with primary sclerosing cholangitis (PSC)] and 131 subjects of the control group without liver diseases. Blood samples of the enrolled patients were tested for anti-HBc and HBV DNA. Samples of liver tissue were examined by standard morphologic protocol and, in anti-HBc positive subjects, for HBV DNA. We assessed estimated risks of AILDs according to anti-HBc positivity and association of anti-HBc positivity with stage of liver fibrosis.

RESULTS

Anti-HBc was detected in 14.5% participants in the control group vs 26.1% (p = 0.016) in patients with AILDs (including 27.1% subjects with PBC (p = 0.021 vs control group), in 29% of PSC and 23.5% in AIH. HBV DNA was detected in three patients with PBC and in one with AIH. Positive anti-HBc test result was associated with higher risk of AILDs-odds ratio (OR) = 2.078 [95% confidence interval (CI) 1.179-3.665], especially in PBC: OR (95% CI) 2.186 (1.165-4.101). Odds of advanced stage of liver fibrosis (F3-F4 by METAVIR) in anti-HBc-positive subjects with PBC were also higher compared to those who had no previous HBV infection: OR (95% CI) 2.614 (1.153-5.926).

CONCLUSIONS

Significant proportions of patients with AILDs are anti-HBc positive, and some of them have OBI. Among patients with AILDs, anti-HBc-positivity is most widespread in the PBC group and in subjects with advanced stage of liver fibrosis. Our data may support the idea of an important role of previous HBV infection in the etiology and pathogenesis of AILDs (namely PBC).

Universal Infant Hepatitis B Virus (HBV) Vaccination for 35 years: moving toward the Eradication of HBV

A universal hepatitis B virus (HBV) vaccination program has been implemented in Taiwan since 1984. 1611 individuals in Taipei were enrolled to monitor long-term efficacy. The prevalences of HBsAg and anti-HBc in the vaccinated birth cohort were lower than those born before 1984 (0.4% vs 7.7%, and 2.2% vs 50.8%, p < .0001; respectively). Three vaccine-failure carriers all were born to HBsAg carrier mothers, probably due to no antiviral intervention during pregnancy. Occult HBV infection was rare in the postvaccination era. High vaccination coverage, comprehensive HBV screening and antiviral agents for pregnant mothers will be essential to eliminate HBV transmission.

Role of core protein mutations in the development of occult HBV infection

BACKGROUND & AIMS

Occult HBV infection (OBI) is associated with transfusion-transmitted HBV infection and hepatocellular carcinoma. Studies on OBI genesis have concentrated on mutations in the S region and the regulatory elements. Herein, we aimed to determine the role of mutations in the core region on OBIs.

METHODS

An OBI strain (SZA) carrying 9 amino acid (aa) substitutions in the core protein/capsid (Cp) was selected by sequence alignment and Western blot analysis from 26 genotype B OBI samples to extensively explore the impact of Cp mutations on viral antigen production in vitro and in vivo.

RESULTS

A large panel of 30 Cp replicons were generated by a replication-competent pHBV1.3 carrying SZA or wild-type (WT) Cp in a 1.3-fold over-length of HBV genome, in which the various Cp mutants were individually introduced by repairing site mutations of SZA-Cp or creating site mutations of WT-Cp by site-directed mutagenesis. The expression of HBcAg, HBeAg, and HBsAg and viral RNA was quantified from individual SZA and WT Cp mutant replicons in transfected Huh7 cells or infected mice, respectively. An analysis of the effect of Cp mutants on intracellular or extracellular viral protein production indicated that the W62R mutation in Cp had a critical impact on the reduction of HBcAg and HBeAg production during HBV replication, whereas P50H and/or S74G mutations played a limited role in influencing viral protein production invivo.

CONCLUSIONS

W62R and its combination mutations in HBV Cp might massively affect HBcAg and HBeAg production during viral replication, which, in turn, might contribute to the occurrence of OBI.

LAY SUMMARY

Occult hepatitis B virus infections (OBIs) have been found to be associated with amino acid mutations in the S region of the HBV, but the role of mutations in the core protein (Cp) remains unclear. In this study, an OBI strain (SZA) carrying 9 amino acid substitutions in Cp has been examined comprehensively in vitro and in vivo. The W62R mutation in Cp majorly reduces HBcAg and HBeAg production during HBV replication, potentially contributing to the occurrence of OBI.

Droplet digital PCR assay as an innovative and promising highly sensitive assay to unveil residual and cryptic HBV replication in peripheral compartment

Droplet digital PCR is an innovative and promising approach for highly sensitive quantification of nucleic acids that is being increasingly used in the field of clinical virology, including the setting of hepatitis B virus (HBV). Here, we comprehensively report a robust and reproducible ddPCR assay for the highly sensitive quantification of serum HBV-DNA. The assay showed a limit of detection of 4 copies/ml (<1IU/ml) by Probit analysis, showed a good linearity (R² = 0.94) and a high intra- and inter-run reproducibility with differences between the values obtained in the same run or in two independent runs never exceeding 0.14logcopies/mL and 0.21logcopies/mL, respectively. By analysing serum samples from chronically HBV infected patients (mostly under antiviral treatment), ddPCR successfully quantified serum HBV-DNA in 89.8% of patients with detectable serum HBV-DNA < 20 IU/mL [equivalent to <112copies/ml] by classical Real-Time PCR assay, with a median (IQR) of 8(5-14)IU/mL [45(28-78)copies/ml], and in 66.7% of patients with undetectable serum HBV-DNA, with a median (IQR) of 5(4-9)IU/mL [28(20-50)copies/ml]. Similarly, by analysing serum samples from patients with a serological profile compatible with occult HBV infection (anti-HBc+/HBsAg-), ddPCR successfully quantified serum HBV-DNA in 40% of patients with a median (IQR) value of 1(1-2)IU/mL [5(5-11)copies/ml], in line with the extremely limited viral replication typically observed in occult HBV infection. Overall, the availability of assays for the highly sensitive quantification of serum HBV-DNA can provide an added value in optimizing the diagnosis of occult hepatitis B infection, improving the therapeutic management of chronically HBV infected patients, also in the light of innovative drugs (upcoming in clinical practise) aimed at achieving HBV functional cure.

Neonatal hepatitis B vaccination protects mature adults from occult virus infection

BACKGROUND

Among elder children/young adults who received hepatitis B virus (HBV) vaccination during infancy, the serological status of HBsAg-negative and anti-HBc-positive [HBsAg(-)/anti-HBc(+)] was frequently reported, indicating potential occult HBV infection (OBI). It is required to define the long-term protection of neonatal vaccination against OBI in their mature adulthood.

METHODS

Building upon the 1983-1990 established Qidong Hepatitis B Intervention Study, we sampled 10% of the 28-35-year-old participants, who remained in the cohort by 2012. Each participant was tested for serological markers of HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc. HBV-DNA and relaxed circular DNA (rcDNA) were determined in some HBsAg(-)/anti-HBc(+) individuals.

RESULTS

Totally, 3615 individuals from the neonatal vaccination group and 3100 individuals from the control group donated blood samples, respectively. In the vaccination group, the prevalence of HBsAg was 1.58% (57/3615), HBsAg(-)/anti-HBc(+) was 4.70% (170/3615), significantly lower than in the control group, which was 7.45% (231/3100) and 19.48% (640/3100) respectively (all p < 0.001). With aging, HBsAg(-)/anti-HBc(+) prevalence increased in the sampled participants from the control group (p_{for trend} < 0.001), but uncertain from the vaccination group. Of HBsAg(-)/anti-HBc(+), HBV-DNA was detected in 13.08% (17/130) from the vaccination group, and in 4.18% (12/287) from the control group. HBV rcDNA was detected in most sera that were tested positive for HBV-DNA.

CONCLUSIONS

OBI occurred in some vaccinated adults. However, neonatal HBV vaccination kept the effective protection against OBI in mature adults.

[Clinical cure strategy for hepatitis B: immunomodulatory therapy]

Chronic hepatitis B virus (HBV) infection remains a major world public health problem. Current guidelines of chronic hepatitis B (CHB) suggest the clinical cure as the ideal thearapeutic goal. Although the optimization of the existing antiviral treatment can make some patients achieve clinical cure, but for most patients with chronic hepatitis B, it is difficult to achieve clinical cure according to the existing antiviral treatment plan. The medical community has begun to work together to seek new treatment strategies, especially the immune intervention measures aimed at restoring the immune response in the liver microenvironment. Notably, immune antiviral response plays a crucial role in HBV clearance, and the clinical cure of chronic hepatitis B is finally achieved through the optimized combination of antiviral and immunomodulatory drugs.

Seroprevalence and genotypic characterization of HBV among low risk voluntary blood donors in Nairobi, Kenya

Background

Hepatitis B virus (HBV) causes significant morbidity and mortality globally primarily due to its ability to cause hepatitis, liver cirrhosis and hepatocellular carcinoma. The Kenya National Blood Transfusion Services screens for Hepatitis B antibodies using the chemiluminescent microparticle immunoassay method. This test does not inform on the genotypic characteristics of the virus or the actual presence of the virus in blood. This study therefore sought to determine the serologic and genotypic profiles of HBV circulating among the voluntary blood donors in Nairobi.

Methods

Blood samples were collected in plain and EDTA vacutainers and tested for the Hepatitis B surface antigen (HBsAg). HBV DNA was then extracted from plasma, its overlapping P/S gene amplified and sequenced. The resulting sequences were used to analyze for the circulating genotypes and mutations within the P and S genes. Bivariate statistical analysis was used to determine the association between demographic factors and HBV infection.

Results

A seroprevalence of 2.3% (n = 7) was reported. The age group 19–28 years was significantly associated with HBV infection. Nine samples were positive for HBV DNA; these included 2 HBsAg positive samples and 7 HBsAg negative samples. Genotype A, sub genotype A1 was found to be exclusively prevalent while a number of mutations were reported in the “a” determinant segment of the major hydrophilic region of the S gene associated with antibody escape. RT mutations including mutation rt181T in the P gene conferring resistance against Lamivudine and other ʟ-nucleoside drugs were detected.

Conclusion

There is a high prevalence of occult HBV infections among these blood donors and therefore the testing platform currently in use requires revision.

The sK122R mutation of hepatitis B virus (HBV) is associated with occult HBV infection: Analysis of a large cohort of Chinese patients

BACKGROUND

Occult HBV infection (OBI) is of great concern due to their complicated diagnosis and potential for public transmission.

OBJECTIVE

The study aimed to determine the clinical prevalence of OBI and if viral immune escape-associated mutations contribute to the occurrence of OBI.

STUDY DESIGN

A total of 91,037 HBV-infected patients with different related illnesses who were admitted to the Fifth Medical Center of Chinese PLA General Hospital from January 2005 to December 2017 were tested for OBI. Serum samples from 62 patients with OBI manifestations (OBI patients) and 124 matched non-OBI patients were sequenced for possible immune escape-associated mutations within the major hydrophilic region of HBV S protein. HBsAg and HBV DNA levels in representative viral strains were measured.

RESULTS

Of the 91,037 tested patients, 487 (0.53 %) were negative for HBsAg but positive for HBV DNA and were defined as OBI patients. The prevalence in different illness categories varied. Immune escape-associated mutations were more frequently detected in OBI patients than in non-OBI patients (59.68 % vs. 35.48 %, P < 0.01), as did the coexistence of multiple mutations (43.55 % vs. 22.58 %, P < 0.01). Specifically, the prevalence rates of sT118 K, sK122R, and sV168A were increased in OBI patients. Strains with sK122R mutants (sK122R, sK122R + D144E, sK122R + C121R + D144E, and sK122R + F134L + D144E) from a follow-up OBI patient all showed significantly lower levels of HBsAg production than a wild-type strain.

CONCLUSIONS

The study clarified the clinical prevalence of OBI, verified the influence of immune escape-associated mutations, and identified the role of the sK122R mutation in multiple OBI patients.

The contribution of more sensitive hepatitis B surface antigen assays to detecting and monitoring hepatitis B infection

BACKGROUND

Hepatitis B surface antigen (HBsAg) remains the main viral marker for screening and monitoring hepatitis B virus (HBV) infection. The quantification limit of most current HBsAg assays is around 0.05 IU/mL. The Lumipulse-G-HBsAg-Quant assay (Fujirebio) claims to obtain a tenfold improvement in sensitivity. This study aimed to assess the performance of this assay in detecting low HBsAg levels in clinical samples.

METHODS

Three panels of stored frozen samples were selected on the basis of HBV-DNA and HBsAg values obtained previously with routine techniques. Panels 1 (n=13) and 2 (n=52) consisted of DNA-positive/HBsAg-negative samples from individuals in the window period and with occult HBV infection respectively. Panel 3 comprised 23 samples with low or discrepant HBsAg screening results. All these samples were tested retrospectively with the DiaSorin and Fujirebio HBsAg assays.

RESULTS

Sixteen out of 65 samples (25 %), initially screened HBsAg negative, were reactive only with the Fujirebio assay (median value= 0.015 IU/mL; IQR= 0.012): three (23 %) samples from panel 1 and 13 (25 %) from panel 2. Thirteen of these 16 (81 %) had HBsAg values below 0.03 IU/mL with the DiaSorin assay. In panel 3, 22 (96 %) samples were quantified successfully with the Fujirebio assay (median: 0.32 IU/mL; IQR: 1.20) and 19 (83 %) with the DiaSorin assay (median: 0.31 IU/mL; IQR: 0.65). Concentrations obtained with the two assays showed good correlations (r=0.893, Spearman).

CONCLUSIONS

HBsAg assays with enhanced analytical sensitivity could improve HBV serological profile interpretation with possible consequences on clinical management of infected patients, and on blood transfusion safety.

The prevalence of occult HBV infection in immunized children with HBsAg-positive parents: a hospital-based analysis

Background and object

The risk of occult HBV infection (OBI) in children whose mothers are HBV carriers has received more widespread attention, but there were few reports to focus on the children with HBsAg-positive parents. In this study, we aimed to investigate the prevalence of OBI in immunized children with HBsAg-positive parents.

Methods

HBV-vaccinated Chinese hospitalized children with HBsAg-positive parents were analyzed in our investigation. Eligible subjects were tested using a standard nested PCR for all HBV genes, and analyzed by direct sequencing.

Results

There were 327 HBsAg-negative children included in the study out of about 9800 involved HBV-vaccinated hospitalized children. The positive rate of OBI was 3.1% (10/327) in the eligible children and 14.1% (46/327) with HBV DNA detectable. No significant differences were found between one and at least two regions positive groups (p > 0.05). The proportions of HBV DNA detectable in children with HBV father-carriers and mother-carriers were similar. The risk factors for HBV DNA-positive children could be male, anti-HBs levels, and anti-HBc positive.

Conclusion

There are 3.1% of OBIs and 14.1% of suspected OBI in vaccinated children with HBsAg-positive parents. The potential risk of suspected OBI in children with HBsAg-positive father should not be ignored. Anti-HBc positivity may be a useful seromarker for suspected OBI screening in vaccinated children. To prevent HBV breakthrough infection, accurate and convenient method is needed to detect OBI timely and exhaustively.

Electronic supplementary material

The online version of this article (10.1007/s12072-020-10055-9) contains supplementary material, which is available to authorized users.

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.

Quantitation of HBV cccDNA in anti-HBc-positive liver donors by droplet digital PCR: A new tool to detect occult infection

BACKGROUND & AIMS

The accurate diagnosis of occult hepatitis B virus (HBV) infection (OBI) requires the demonstration of HBV DNA in liver biopsies of hepatitis B surface antigen-negative individuals. However, in clinical practice a latent OBI is deduced by the finding of the antibody to the hepatitis B core antigen (anti-HBc). We investigated the true prevalence of OBI and the molecular features of intrahepatic HBV in anti-HBc-positive individuals.

METHODS

The livers of 100 transplant donors (median age 68.2 years; 64 males, 36 females) positive for anti-HBc at standard serologic testing, were examined for total HBV DNA by nested-PCR and for the HBV covalently closed circular DNA (HBV cccDNA) with an in-house droplet digital PCR assay (ddPCR) (Linearity: R² = 0.9998; lower limit of quantitation and detection of 2.4 and 0.8 copies/10⁵ cells, respectively).

RESULTS

A total of 52% (52/100) of the individuals studied were found to have OBI. cccDNA was found in 52% (27/52) of the OBI-positive, with a median 13 copies/10⁵ cells (95% CI 5-25). Using an assay specific for anti-HBc of IgG class, the median antibody level was significantly higher in HBV cccDNA-positive than negative donors (17.0 [7.0-39.2] vs. 5.7 [3.6-9.7] cut-off index [COI], respectively, p = 0.007). By multivariate analysis, an anti-HBc IgG value above 4.4 COI was associated with the finding of intrahepatic HBV cccDNA (odds ratio 8.516, p = 0.009); a lower value ruled out its presence with a negative predictive value of 94.6%.

CONCLUSIONS

With a new in-house ddPCR-based method, intrahepatic HBV cccDNA was detectable in quantifiable levels in about half of the OBI cases examined. The titer of anti-HBc IgG may be a useful surrogate to predict the risk of OBI reactivation in immunosuppressed patients.

LAY SUMMARY

The covalently closed circular DNA (cccDNA) form of the hepatitis B virus (HBV) sustains the persistence of the virus even decades after resolution of the symptomatic infection (occult HBV infection). In the present study we developed a highly sensitive method based on droplet digital PCR technology for the detection and quantitation of HBV cccDNA in the liver of individuals with occult HBV infection. We observed that the amount of HBV cccDNA may be inferred from the titer in serum of the IgG class antibody to the hepatitis B core antigen. The quantitation of this antibody may represent a surrogate to determine which patients are at the highest risk of HBV reactivation following immunosuppressive therapies.

Evaluation of clinical sensitivity and specificity of hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency Virus-1 by cobas MPX: Detection of occult HBV infection in an HBV-endemic area

BACKGROUND

Transfusion-transmitted infectious diseases remain a major concern for blood safety, particularly with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Nucleic acid testing (NAT) in donor screening shortens the serologically negative window period and reduces virus transmission. The cobas MPX (Roche Molecular Systems, Inc., Branchburg, New Jersey) is a recently developed multiplex qualitative PCR system that enables the simultaneous detection of HBV, HCV, and HIV with improved sensitivity and throughput using cobas 6800 and 8800 instruments.

OBJECTIVES

The aim of this study was to conduct an evaluation of the clinical sensitivity and specificity of cobas MPX detection of HBV, HCV, and HIV in clinical specimens.

STUDY DESIGN

Among samples referred for HBV, HCV, and HIV-1 quantification at Severance Hospital, Yonsei University College of Medicine, positive samples were selected to evaluate sensitivity. A total of 843 samples was tested using both cobas MPX and COBAS AmpliPrep/COBAS TaqMan Tests for HBV, HCV, and HIV-1 using the cobas 8800 system and a COBAS TaqMan 96 analyzer, respectively. Samples that showed discrepancies were confirmed by nested PCR.

CONCLUSIONS

The cobas MPX achieved excellent sensitivity and specificity for the detection of HBV, HCV, and HIV-1 in clinical samples. We found that the lower limit of detection (LOD) of blood screening by NAT actually improves clinical sensitivity, and occult HBV infection prevalence among healthy employees of the hospital was rather high.

Occult hepatitis B virus infection in Greek patients with congenital bleeding disorders

Occult Hepatitis B Infection (OBI) is a form of chronic HBV infection characterized by low level HBV DNA, without detectable HBV surface antigen (HBsAg). OBI is frequently associated with the presence of anti-HBc and in some cases also with anti-HBs. Patients, who formerly received non-inactivated factor concentrates, can potentially be considered at high risk for OBI, especially since these patients usually are HIV or HCV co-infected. This study aimed to assess the prevalence of occult HBV infection in Greek patients with hereditary bleeding disorders. The study sample comprised of 114 patients from a single haemophilia center. All patients were screened for HBV serum markers and individually tested for HBV DNA using a qualitative PCR. Presence of HBV DNA was further confirmed by quantification of viral load with an ultrasensitive in-house real time PCR. 88 and 21 patients with haemophilia A and B, respectively, 4 patients with von Willebrand Disease and 1 patient with severe factor VII deficiency were screened for the presence of OBI. Anti-HBc were detected in 53 (46.5%) subjects; 18 of them were anti-HBs(-) and 35 anti-HBs(+). Anti-HBe were present in 26 subjects. Two out of 114 patients were HBsAg(+). Of the remaining 112 HBsAg(-) patients tested, two (1.8%) were found HBsAg(-), HBV DNA(+), anti-HBc(+) and anti-HBs(-) and were identified as potential OBI cases. Both cases exhibited very low DNA levels; 38.2IU/mL in patient A and 14.2IU/mL in patient B. Both patients were HBeAg(-), but patient A had HBe antibodies. Patient B was also HIV/HCV co-infected. In conclusion, two cases of OBI with low HBV viraemia were identified among patients with congenital bleeding disorders. Although the incidence in our sample is moderately low (1.8%), close monitoring of these infections is of great clinical significance, especially in patients with co-infections and concomitant immunosuppression.

Occult hepatitis B infection and transfusion-transmission risk

Advances in serology and viral nucleic acid testing (NAT) over the last decades significantly reduced the risk of transfusion-transmitted hepatitis B virus (HBV). The combination of HBsAg testing and NAT efficiently prevents the majority of HBV transmission. However, a specific residual risk remains associated with extremely low viral DNA levels in blood donors with occult HBV infection (OBI) that are intermittently or not detectable even by highly sensitive individual donation (ID) NAT. Studies have reported HBV transfusion-transmission with blood components from donors with OBI that contained low amount of viruses (<200 virions). HBV transfusion-transmission seems to depend on a combination of several factors including the volume of plasma associated with the infected blood components transfused, the anti-HBV immune status of both recipient and donor, and possibly the viral fitness of the infecting HBV strain. Models based on clinical and experimental evidences estimate a residual transmission risk of 3-14% associated with OBI donations testing HBsAg and ID-NAT non-reactive. Anti-HBc testing has the potential to improve further blood safety but it may also compromise blood availability in settings with medium/high HBV prevalence. Pathogen reduction procedures might be considered.

Occult HBV among Anti-HBc Alone: Mutation Analysis of an HBV Surface Gene and Pre-S Gene

PURPOSE

The aim of this study is to investigate the molecular characteristics of occult hepatitis B virus (HBV) infection in 'anti-HBc alone' subjects.

MATERIALS AND METHODS

Twenty-four patients with 'anti-HBc alone' and 20 control patients diagnosed with HBV were analyzed regarding S and pre-S gene mutations. All specimens were analyzed for HBs Ag, anti-HBc, and anti-HBs. For specimens with an anti-HBc alone, quantitative analysis of HBV DNA, as well as sequencing and mutation analysis of S and pre-S genes, were performed.

RESULTS

A total 24 were analyzed for the S gene, and 14 were analyzed for the pre-S gene through sequencing. A total of 20 control patients were analyzed for S and pre-S gene simultaneously. Nineteen point mutations of the major hydrophilic region were found in six of 24 patients. Among them, three mutations, S114T, P127S/T, M133T, were detected in common. Only one mutation was found in five subjects of the control group; this mutation was not found in the occult HBV infection group, however. Pre-S mutations were detected in 10 patients, and mutations of site aa58-aa100 were detected in 9 patients. A mutation on D114E was simultaneously detected. Although five mutations from the control group were found at the same location (aa58-aa100), no mutations of occult HBV infection were detected.

CONCLUSION

The prevalence of occult HBV infection is not low among 'anti-HBc alone' subjects. Variable mutations in the S gene and pre-S gene were associated with the occurrence of occult HBV infection. Further larger scale studies are required to determine the significance of newly detected mutations.

Hepatitis B virus infection assessed 3 to 18 years after vaccination in Cuban children and adolescents born to HBsAg-positive mothers

Thirty-two participants, aged between 3-18 years, born to hepatitis B surface antigen (HBsAg)-positive mothers and vaccinated at birth were analyzed for hepatitis B virus (HBV) infection. Overall, 56% had anti-HB titers ≥10 IU/L; five were positive for antibodies to the core antigen (anti-HBc), and two of these were also positive for HBsAg/DNA. One of the HBsAg/anti-HBc double-negative children presented with an unusual occult infection (HBV DNA-positive). No known vaccine escape mutations were detectable. Our data suggest that the vaccine protected 93.8% of children in this high-risk group against chronic HBV infection. Occult infections should be considered even in countries with low endemicity and high vaccination coverage.

Occult HBV infection in the oncohematological setting

INTRODUCTION

Occult hepatitis B infection (OBI), a virological condition characterized by a low release of Hepatitis B Virus (HBV) from liver cells and low HBV-DNA levels in serum and/or liver tissue of HBsAg-negative subjects, may reactivate in oncohematological patients undergoing immunosuppression by aggressive chemotherapy or hematopoietic stem cell transplantation. The entity of OBI reactivation varies from an increase in HBV replication without liver damage to an active HBV replication followed by liver cell necrosis, frequently severe and in some cases life threatening. Because of a possible severe outcome associated with OBI reactivation (hepatic failure or death due to the discontinuation of chemotherapy), prophylaxis with anti-HBV nucleot(s)ide analogues is recommended in relation to the foreseeable degree of immunosuppression.

MATERIALS AND METHODS

This review article focuses on the clinical impact of OBI in the oncohematological setting and is addressed to all health care workers having in care oncohematological patients or involved in the treatment of HBV infection and OBI prophylaxis.

CONCLUSION

International guidelines have indicated lamivudine prophylaxis in hematopoietic stem cell transplantation and when high-dose corticosteroids or anti-CD20 or anti-CD52 monoclonal antibodies are used. Entecavir or tenofovir should replace lamivudine for patients with advanced liver diseases for whom reactivation of OBI may be life threatening. When anti-CD20 or anti-CD52 sparing schedules or other non-aggressive chemotherapies are used, monitoring may be indicated, but very early treatment with highly effective antiviral drugs (entecavir or tenofovir) should be administered once a reactivation of OBI has occurred.

Poor efficacy of nucleic acid testing in identifying occult HBV infection and consequences for safety of blood supply in Italy

BACKGROUND & AIMS

In Italy, DNA screening of blood donations for hepatitis B virus (HBV) was introduced to prevent the transmission of window period and occult HBV infection. Anti-HBc screening is not recommended in order to avoid shortage of the blood supply. To contain costs, donor samples are generally pooled before testing. We evaluated the safety of this national policy using a prospective repository of donors/recipient pairs.

METHODS

We used highly sensitive nucleic acid testing (NAT) assays to test repository and follow-up samples from donors who were initially classified as negative by minipool NAT assays (6-MP), but were later found to carry occult HBV DNA. When available, we also analysed recipients' pre- and post-transfusion samples, collected in the context of a repository financed by the European Commission (the BOTIA project).

RESULTS

Between 2008 and 2011 6-MP NAT assays identified 18 carriers of occult HBV infection among 12,695 donors; 28 samples from previous donations were available from 13 of these carriers. Highly sensitive HBV DNA detection methods showed that 6-MP HBV DNA screening failed to identify 14/28 (50%) viraemic donations, that were released for transfusion. HBV marker testing of such blood product recipients revealed two cases of transfusion transmitted HBV infection, documented by donor-recipient sequence identity.

CONCLUSIONS

Viraemic blood donations from occult HBV infection carriers remain undetected by current minipool HBV DNA screening, and transfusion transmission of HBV continues to occur in susceptible patients. More effective individual HBV DNA screening and/or tests for antibodies to HBV core antigen should be considered to improve blood safety.

Hepatitis B virus infection in post-vaccination South Africa: occult HBV infection and circulating surface gene variants

BACKGROUND AND OBJECTIVE

The aim of this study was to investigate the prevalence of occult hepatitis B virus (HBV) infection and the HBV surface (S) gene variants circulating in the South African population after nearly two decades of universal hepatitis B vaccination.

STUDY DESIGN

From a previous serosurvey, 201 serum samples with serological evidence of exposure to HBV were identified and these were stratified into post- and pre-vaccine introduction populations. For all samples, HBV DNA was screened and quantified using a real-time PCR assay and results analysed together with HBV serological markers. Where HIV results were available, subset analysis was performed. The HBV S gene was PCR-amplified and sequences analysed for a total of 37 isolates.

RESULTS

The prevalence of occult HBV infection reduced from 70.4% in the pre-vaccine introduction era to 66.0% post-vaccine introduction. There was an association between HIV infection and an increase in prevalence of occult HBV infection within the post-vaccine introduction population, although this was not statistically significant. Furthermore, sequence analysis revealed the following HBV subgenotypes; A1 (n=34), A2 (n=2) and a rare D4 isolate. HBV S gene variants, including diagnostic escape mutants were isolated.

CONCLUSION

There was a decline in the prevalence of occult HBV infection in post-vaccination South Africa, although the disease burden remains significant in the HIV co-infected population. After nearly two decades of a universal hepatitis B vaccination programme, no positive selection of vaccine escape mutants were observed.

Genotyping and virological characteristics of hepatitis B virus in HIV-infected individuals in Sudan

OBJECTIVES

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) share common routes of blood-borne transmission. In HBV mono-infected Sudanese individuals, genotypes D, E, and A circulate. The objective of this study was to molecularly characterize HBV from HBV/HIV co-infected individuals.

METHODS

The polymerase overlapping the S region and the basic core promoter (BCP/PC) of HBV from 32 hepatitis B surface antigen (HBsAg)-positive and 18 HBsAg-negative serum samples were amplified and sequenced.

RESULTS

HBV from 37 samples was successfully genotyped and the genotype distribution was 46.0% D, 21.6% E, 18.9% A, and 13.5% D/E recombinant. Compared to mono-infected individuals, the frequencies of the D/E recombinant and genotype A were higher in HBV/HIV co-infected patients, as was the intra-group divergence of genotype E. BCP/PC mutations affecting hepatitis B e antigen (HBeAg) expression at the transcriptional and translational levels were detected. Two HBsAg-positive individuals had pre-S deletion mutants. The following mutations in the S region could account for the HBsAg negativity: sM133T, sE164G, sV168G, and sS174N. No primary drug resistance mutations were found.

CONCLUSIONS

In HBV/HIV co-infected Sudanese patients, the ratio of genotype A to non-A was higher than that in mono-infected patients. The genotype E intra-group divergence in HBV/HIV co-infected individuals was significantly higher than that in HBV mono-infected patients.

No evidence for occult HBV infection in hepatitis B vaccine non-responders

BACKGROUND AND OBJECTIVE

Although hepatitis B vaccine immunogenicity is high, certain risk factors such as age, tobacco consumption, obesity and genetic background have been associated with low responsiveness to HBV vaccine. We aimed to evaluate the role of occult hepatitis B virus (HBV) infection in non-responder adults to HBV vaccine in a low endemic area for HBV.

MATERIAL AND METHODS

A total of 52 subjects who were non-responder to HBV vaccine were enrolled in the study. HBsAg, anti-HBs and anti-HBc were tested in all subjects. The presence of HBV-DNA was determined in plasma samples by real-time PCR.

RESULTS

A total of 52 cases with median age 34 years were enrolled in the study. 63.5% of patients were male and 36.5% were female. Isolated anti-HBc (HBsAg negative, anti-HBs negative and anti-HBc positive) was detected in 3.8% of cases. HBV-DNA was not detected in our cases.

CONCLUSION

This study showed no evidence of occult HBV infection in our HBV vaccine non-responders even in cases with isolated anti-HBc.

Occult hepatitis B virus infection with positive hepatitis B e antigen

BACKGROUND

Hepatitis B e antigen (HBeAg) is a marker to indicate active replication of hepatitis B virus (HBV). Occult HBV infection (OBI), referred to persistence of HBV DNA in serum and/or liver without detectable serum hepatitis B surface (HBsAg), usually has low HBV DNA levels. The presence of HBeAg in OBI is unusual.

METHODS

We report 2 patients who presented negative for HBsAg but positive for HBeAg and HBV DNA. HBV markers were quantified in the longitudinal sera in a period of 1-2years. The HBV DNA sequences were analyzed in 2 patients' sera and 1 patient's liver.

RESULTS

Both patients were also positive for total anti-HBs and anti-HBc but negative for anti-HBe and anti-HBc IgM. HBV DNA levels were 234-567IU/ml in case 1 and 42-1130IU/ml in case 2. The alignment analysis of the S gene showed that HBV in both patients was genotype C, serotype adr. Cloning analysis of the a determinant of HBsAg showed that the immune escape mutants were predominant in both patients over the follow-up period. The HBV had double mutations (A1762T and G1764A) in the basal core promoter but had no mutation in the pre C/C gene in both patients.

CONCLUSIONS

The patients with negative HBsAg but positive HBeAg may represent a unique type of OBI. Test for HBeAg would be critical to identifying such type of OBI.

Reactivation from occult HBV carrier status is characterized by low genetic heterogeneity with the wild-type or G1896A variant prevalence

BACKGROUND & AIMS

Individuals negative for hepatitis B surface antigen (HBsAg) but positive for antibodies to hepatitis B core antigen (anti-HBc) are at risk of hepatitis B virus (HBV) reactivation under immunosuppressive conditions. We investigated clinical features and viral genetics in patients with reactivation from occult HBV infection triggered by chemotherapy or immunosuppressive therapy.

METHODS

Clinical courses of 14 individuals originally HBsAg-negative but anti-HBc-positive that experienced HBV reactivation were examined. Ultra-deep sequencing analysis of the entire HBV genome in serum was conducted. Prevalence of the G1896A variant in latently infected livers was determined among 44 healthy individuals that were HBsAg-negative but anti-HBc-positive.

RESULTS

In 14 cases, HBV reactivation occurred during (n=7) and after (n=7) termination of immunosuppressive therapy. Ultra-deep sequencing revealed that the genetic heterogeneity of reactivated HBV was significantly lower in patients with reactivation from occult HBV carrier status compared with that in patients from HBsAg carrier status. The reactivated viruses in each case were almost exclusively the wild-type G1896 or G1896A variant. The G1896A variant was detected in 42.9% (6/14) of cases, including two cases with fatal liver failure. The G1896A variant was observed in the liver tissue of 11.4% (5/44) of individuals with occult HBV infection.

CONCLUSIONS

Reactivation from occult HBV infection is characterized by low genetic heterogeneity, with the wild-type G1896 or G1896A variant prevalent.

Hepatitis B virus PreS/S gene variants: pathobiology and clinical implications

The emergence and takeover of hepatitis B virus (HBV) variants carrying mutation(s) in the preS/S genomic region is a fairly frequent event that may occur spontaneously or may be the consequence of immunoprophylaxis or antiviral treatments. Selection of preS/S mutants may have relevant pathobiological and clinical implications. Both experimental data and studies in humans show that several specific mutations in the preS/S gene may induce an imbalance in the synthesis of the surface proteins and their consequent retention within the endoplasmic reticulum (ER) of the hepatocytes. The accumulation of mutated surface proteins may cause ER stress with the consequent induction of oxidative DNA damage and genomic instability. Viral mutants with antigenically modified surface antigen may be potentially infectious to immune-prophylaxed patients and may account for cases of occult HBV infection. In addition, preS/S variants were reported to be associated with cases of fulminant hepatitis as well as of fibrosing cholestatic hepatitis, and they are associated with cirrhosis and hepatocellular carcinoma development.

Virological characteristics of occult hepatitis B virus in a North American cohort of human immunodeficiency virus type 1-positive patients on dual active anti-HBV/HIV therapy

BACKGROUND

Occult hepatitis B virus infection (OBI) is defined as low-level HBV DNA presence in serum, liver and/or peripheral blood mononuclear cells (PBMC) in individuals that lack serum hepatitis B virus surface antigen (HBsAg). HIV+ patients with OBI may be at risk for HBV reactivation, and often receive dual active anti-HBV/HIV therapy, such as lamivudine (LMV).

OBJECTIVES

To determine the presence of OBI in a North American cohort of HIV-1-positive patients.

STUDY DESIGN/METHODS

45 HIV-1-positive, serum HBsAg-negative patients, reactive for antibodies to HBV core antigen (anti-HBc), were tested for HBV DNA in plasma and for HBV DNA and covalently closed circular DNA (cccDNA) in PBMC. Ten patients were re-tested after ∼5-10 years, including genotyping and clonal sequence analysis of the HBV polymerase (P) gene and overlapping HBV surface (S) gene from 8 PBMC samples.

RESULTS

Overall, 42% (19/45) tested HBV DNA positive, especially in PBMC (18/45), including 3/18 that were reactive for HBV cccDNA, compared to 17% (8/45) that were HBV DNA reactive in plasma. In 8 patients on LMV, sequence analysis in PBMC showed that all were HBV genotype C or D. Several carried HBV P region variants at residues associated with anti-HBV drug resistance and overlapping S gene region within the major HBsAg "a determinant".

CONCLUSION

OBI is common in HIV-positive, anti-HBc reactive patients on anti-HBV/HIV therapy, particularly in PBMC. HBV sequence analysis revealed that all had HBV genotype C or D and often had P/overlapping S gene variants possibly associated with dual-active anti-HIV/HBV therapy.

Risk of occult hepatitis B virus infection reactivation in patients with solid tumours undergoing chemotherapy

BACKGROUND

Hepatitis B virus reactivation may occur in occult-infected carriers with haematological malignancies, whereas little data are available in patients undergoing chemotherapy for solid tumours.

AIMS

Evaluation of cancer patients undergoing chemotherapy to investigate occult hepatitis B virus infection and its clinical-virological outcome.

METHODS

Forty-four patients with solid tumours and without liver disease were prospectively enrolled and sampled before starting chemotherapy and between the second and third chemotherapy cycles (time points 1 and 2, respectively); 24 were also sampled 6 months after the end of chemotherapy (time point 3). At each time point, subjects were tested for liver biochemistry, hepatitis B serology and occult infection.

RESULTS

No sample tested positive for virus surface antigen. Twelve subjects (27.3%) were antibody positive to hepatitis B virus. Overall, occult infection was detected in 4 cases (9%), with positive HBV DNA at time points 1 and 2 (one case), at time point 1 only (one case), only at time points 2 and 3 (two cases), respectively. No occult-infected carrier experienced liver biochemistry flares and/or viral surface antigen positivity.

CONCLUSIONS

Occult hepatitis B virus infection may occur in subjects with solid tumours, although the risk of its reactivation under chemotherapy appears to be very low.

HBV transmission from an occult carrier with five mutations in the major hydrophilic region of HBsAg to an immunosuppressed plasma recipient

We describe the case of transmission of an HBsAg-negative hepatitis B infection to an immunosuppressed patient by plasma donation from an HBsAg-negative subject, but with very low serum HBV DNA (about 50 IU/ml) and five mutations in the major hydrophilic region of HBsAg.

Significant increase in HBV, HCV, HIV and syphilis infections among blood donors in West Bengal, Eastern India 2004-2005: Exploratory screening reveals high frequency of occult HBV infection

AIM: To evaluate the prevalence of markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) and human immunodeficiency virus (HIV) among blood donors in Kolkata, Eastern India for two consecutive years and to conduct a pilot study to explore the presence of HBV DNA among hepatitis B surface antigen (HBsAg) negative but anti-HBc positive blood donors.

METHODS: Seroprevalence of HBsAg, anti-HCV and anti-HIV was studied among 113 051 and 106 695 voluntary blood donors screened in 2004 and 2005, respectively. Moreover, a pilot study on 1027 HBsAg negative donors was carried out for evaluating the presence of HBV DNA by PCR on HBsAg negative/anti-HBc positive donors.

RESULTS: A statistically significant increase in the prevalence of HBV (1448 vs 1768, P < 0.001), HIV (262 vs 374, P < 0.001), HCV (314 vs 372, P = 0.003) and syphilis (772 vs 853, P = 0.001) infections was noted among blood donors of Kolkata West Bengal in 2005 as compared to 2004. Moreover, the exploratory study on 1027 HBsAg negative donors revealed that 188 (18.3%) of them were anti-HBc positive out of which 21% were positive for HBV DNA.

CONCLUSION: The findings of this study underscore the significantly increasing endemicity of hepatitis viruses, syphilis and HIV among the voluntary blood donors of our community. The pilot study indicates a high rate of prevalence of HBV DNA among HBsAg negative/anti-HBc positive donors and thus emphasizes the need for a more sensitive and stringent screening algorithm for blood donations.

Prevalence of occult HBV infection in haemodialysis patients with chronic HCV

AIM: To study the prevalence and clinical effects of occult HBV infection in haemodialysis patients with chronic HCV.

METHODS: Fifty chronic hemodialysis patients with negative HbsAg, and positive anti-HCV were included in the study. These patients were divided into two groups: HCV-RNA positive and HCV-RNA negative, based on the results of HCV-RNA PCR. HBV-DNA was studied using the PCR method in both groups.

RESULTS: None of the 22 HCV-RNA positive patients and 28 HCV-RNA negative patients revealed HBV-DNA in serum by PCR method. The average age was 47.2 ± 17.0 in the HCV-RNA positive group and 39.6 ± 15.6 in the HCV-RNA negative group.

CONCLUSION: The prevalence of occult HBV infection is not high in haemodialysis patients with chronic HCV in our region. This result of our study has to be evaluated in consideration of the interaction between HBsAg positivity (8%-10%) and frequency of HBV mutants in our region.

Serological pattern “anti-HBc alone”: Characterization of 552 individuals and clinical significance

AIM: To investigate the prevalence and clinical significance of “anti-HBc alone” in an unselected population of patients and employees of a university hospital in southern Germany.

METHODS: All individuals with the pattern “anti-HBc alone” were registered over a time span of 82 mo. HBV-DNA was measured in serum and liver samples, and clinical charts were reviewed.

RESULTS: Five hundred and fifty two individuals were “anti-HBc alone” (of 3004 anti-HBc positive individuals; 18.4%), and this pattern affected males (20.5%) more often than females (15.3%; P < 0.001). HBV-DNA was detected in serum of 44 of 545 “anti-HBc alone” individuals (8.1%), and in paraffin embedded liver tissue in 16 of 39 patients tested (41.0%). There was no association between the detection of HBV genomes and the presence of biochemical, ultrasonic or histological signs of liver damage. Thirty-eight “anti-HBc alone” patients with cirrhosis or primary liver carcinoma had at least one additional risk factor. HCV-coinfection was present in 20.4% of all individuals with “anti-HBc alone” and was the only factor associated with a worse clinical outcome.

CONCLUSION: In an HBV low prevalence area, no evidence is found that HBV alone causes severe liver damage in individuals with “anti-HBc alone”. Recommendations for the management of these individuals are given.