Molecular characterization of occult hepatitis B cases in Greek blood donors

Longstanding, undiagnosed, highly replicative hepatitis B virus reactivation in the presence of high levels of anti-HBs antibodies

INTRODUCTION

Kidney transplant recipients are among the populations at risk for Hepatitis B Virus (HBV) reactivation, and close monitoring is needed for its early detection.

METHODS

We describe a case of HBV reactivation in a patient who underwent kidney transplantation more than 30 years ago, with a known serological profile of past HBV infection.

RESULTS

Reactivation occurred as a highly replicative infection that went undiagnosed for 7 years due to negative results for HB surface antigen (HBsAg) and high levels of anti-HBs antibodies. Viral genome sequencing showed a high number of mutations in the major hydrophilic region of HBsAg that could explain such a profile.

DISCUSSION

This case highlights the usefulness of frequent and systematic HBV viral load testing in patients at risk of reactivation, with anti-hepatitis B core antibodies, regardless of HBsAg detection, aminotransferases, and anti-HBs antibody levels.

Diagnostic challenges due to hepatitis B virus surface antigen mutations outside the major hydrophilic region

The number of observed cases of occult hepatitis B virus infection (OBI) in eastern India has been increasing. Here, S gene mutations were identified in apparently healthy individuals with OBI, and the S protein variants from these patients were characterized in vitro. Plasma samples from 217 healthy blood donors were collected from three different regions in eastern India and screened for hepatitis B virus (HBV) infection using a nucleic acid amplification test and immunoassays for serological markers. S protein variants found in positive plasma samples were characterized using a liver cell line. Twenty-nine of the 217 plasma samples tested, were positive for HBV DNA and were negative for hepatitis B surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc). Sequencing of the HBV S gene revealed a novel S protein mutation (L173H) in an area outside the major hydrophilic region. Known OBI-associated mutations (S34L, P178R), a mutation resulting in a stop codon at position 196, associated with lamivudine-resistance, the substitution I81T, and a dual mutation (G145A and Q101H) were also identified. S proteins containing these mutations, produced by transfection of human hepatoma (Huh7) cells with recombinant plasmids, were undetectable or gave significantly weaker signals than the wild-type control, despite similar levels of S mRNA production for the mutant and wild-type plasmids. The OBI cases in this study were unexpectedly seronegative. In vitro analysis revealed that the mutations identified here caused the virus to evade immunodetection using commercial immunoassays, thereby rendering a large portion of the population "silently" infected with HBV.

Biomarkers of transfusion transmitted occult hepatitis B virus infection: Where are we and what next?

Blood transfusion is a vital procedure, where transfusion-transmitted infection of hepatitis B virus (HBV) remains an important issue, especially from blood donors with occult hepatitis B virus infection (OBI). Occult hepatitis B virus infection is a complex entity to detect using surrogate blood biomarkers for intrahepatic viral transcriptional activity, requiring a continually refined battery of tests utilised for screening. This review aims to critically evaluate the latest advances in the current blood biomarkers to guide the identification of OBI donors and discuss novel HBV markers that could be introduced in future diagnostic practice. Challenges in detecting low HBV surface antigen levels, mutants, and complexes necessitate ultrasensitive multivalent dissociation assays, whilst HBV DNA testing requires improved sensitivity but worsens inaccessibility. Anti-core antibody assays defer almost all potentially infectious donations but have low specificity, and titres of anti-surface antibodies that prevent infectivity are poorly defined with suboptimal sensitivity. The challenges associated with these traditional blood HBV markers create an urgent need for alternative biomarkers that would help us better understand the OBI. Emerging viral biomarkers, such as pre-genomic RNA and HBV core-related antigen, immunological HBV biomarkers of T-cell reactivity and cytokine levels, and host biomarkers of microRNA and human leucocyte antigen molecules, present potential advances to gauge intrahepatic activity more accurately. Further studies on these markers may uncover an optimal diagnostic algorithm for OBI using quantification of various novel and traditional blood HBV markers. Addressing critical knowledge gaps identified in this review would decrease the residual risk of transfusion-transmitted HBV infection without compromising the sustainability of blood supplies.

Rate of occult hepatitis B virus infection among individuals with tuberculosis in northeastern Iran: A molecular epidemiological study

One third of the world population has a history of exposure to the hepatitis B virus (HBV), and two billion people are infected with latent tuberculosis (TB). Occult hepatitis B infection (OBI) is defined as the presence of replicative-competent HBV DNA in the liver with detectable or undetectable HBV DNA in the serum of individuals testing negative for the HBV surface antigen (HBsAg). Screening with HBV DNA could identify OBI and significantly reduce carriers and complications of chronic hepatitis B (CHB). This study aims to assess HBV serological markers and OBI molecular diagnosis among people with TB in Mashhad, northeastern Iran. We have performed HBV serological markers (HBsAg, HBc antibodies (Ab) and HBs Ab) in 175 participants. Fourteen HBsAg+ sera were excluded for further analysis. The presence of HBV DNA (C, S, and X gene regions) was assessed by the qualitative real-time PCR (qPCR) method. Frequencies of HBsAg, HBc, and HBs Ab were 8% (14/175), 36.6% (64/175), and 49.1% (86/175), respectively. Among these 42.9% (69/161) were negative for all HBV serological markers. The S, C, and X gene regions were positive in 10.3% (16/156), 15.4% (24/156), and 22.4% (35/156) of participants, respectively. The total OBI frequency was estimated at 33.3% (52/156) when based on detecting one HBV genomic region. Twenty-two and 30 participants had a seronegative and seropositive OBI, respectively. Thorough screening of high-risk groups with reliable and sensitive molecular methods could lead to OBI identification and decrease CHB long-term complications. Mass immunization remains critical in preventing, reducing, and potentially eliminating HBV complications.

Occult hepatitis B in blood donation centers

Occult hepatitis B (OHB) is characterized by the presence of hepatitis B virus (HBV) DNA in the blood of individuals who test negative for the hepatitis B surface antigen (HBsAg). OHB in blood donors can lead to HBV transmission through transfusions, yet the prevalence of OHB in Basrah, Iraq, is unknown. This study aimed to determine the prevalence of OHB in blood donation centers in Basrah and investigate the immune response to HBV in OHB-positive donors. We recruited 450 blood donors and categorized them into four groups based on HBV markers: the HBsAg-negative/HBsAb-negative/HBcAb-positive group, the recovery group (HBsAg-negative/HBsAb-positive/HBcAb-positive), the patient group (HBsAg-positive/HBsAb-negative/HBcAb-positive), and the apparently healthy group (negative for all HBV markers). We measured levels of IgG, IgM, complement components (C3 and C4), ALT, AST, and serum ALP in OHB-positive donors. Of the 450 donors, 97 (21.6%) were OHB-positive. IgG levels were significantly higher than IgM levels in OHB-positive donors. Healthy and HBsAg-negative/HBsAb-positive donors had significantly lower C3 levels than patients. IgG levels were significantly higher than IgM in both the patient and recovery groups. C3 levels were higher than C4 levels in all groups. The serum ALP level was significantly higher in the patient group. OHB prevalence in Basrah blood donors is high, indicating the potential for HBV transmission. OHB-positive donors showed an immune response to HBV. Our study provides insights into OHB prevalence and immune response in Basrah, with implications for diagnostic and therapeutic approaches in blood donation centers.

Risk of alanine aminotransferase flare in patients with previous hepatitis B virus exposure on biological modifier therapies-A population-based study

BACKGROUND

It is uncertain whether biological therapies would increase the risk of hepatitis among patients with past hepatitis B virus (HBV) infection. This study aimed to evaluate the risk of alanine aminotransferase (ALT) flare in patients with past HBV infection while using biological therapies.

METHODOLOGY

Patients who received biological therapies for ≥3 months from 2000 to 2019 were identified from a population-based database in Hong Kong. Patients with past HBV infection were compared with a control group without prior HBV exposure. The primary endpoint was development of ALT flare within 5 years of starting biological therapies, defined as ALT >80 IU/L.

RESULTS

There were 2471 and 2394 patients with and without past HBV infection respectively. There was a non-significant increase in risk of ALT flare among the HBV-exposed group (27.6% vs. 23.7%, p = .055). In multivariable analysis, using prednisolone-equivalent dose of >20 mg daily, male sex and concomitant immunosuppressants were risk factors for ALT flare. The risk of ALT flare was significantly higher with anti-CD20 when compared to other biological agents (36.1% vs. 14.5%, p < .01), but was not significantly different among anti-tumour necrosis factor, anti-cytokine, Janus kinase inhibitors and T cell/B cell inhibitors or anti-integrin (15.2% vs. 14.6% vs. 11.7% vs. 11.1%, p = .82). Among patients with documented hepatitis B surface antigen seroreversion, 96% were on anti-CD20.

CONCLUSIONS

Our study further supports the current suggestion of prophylactic anti-viral before starting anti-CD20 in HBV-exposed patients. While other biological therapies appear to have a lower risk for ALT flare, this result needs further confirmation.

Whole genome analysis of hepatitis B virus before and during long-term therapy in chronic infected patients: Molecular characterization, impact on treatment and liver disease progression

Hepatitis B virus (HBV) infection remains a serious public health concern worldwide despite the availability of an efficient vaccine and the major improvements in antiviral treatments. The aim of the present study is to analyze the mutational profile of the HBV whole genome in ETV non-responder chronic HBV patients, in order to investigate antiviral drug resistance, immune escape, and liver disease progression to Liver Cirrhosis (LC) or Hepatocellular Carcinoma (HCC). Blood samples were collected from five chronic hepatitis B patients. For each patient, two plasma samples were collected, before and during the treatment. Whole genome sequencing was performed using Sanger technology. Phylogenetic analysis comparing the studied sequences with reference ones was used for genotyping. The mutational profile was analyzed by comparison with the reference sequence M32138. Genotyping showed that the studied strains belong to subgenotypes D1, D7, and D8. The mutational analysis showed high genetic variability. In the RT region of the polymerase gene, 28 amino acid (aa) mutations were detected. The most significant mutations were the pattern rtL180M + rtS202G + rtM204V, which confer treatment resistance. In the S gene, 35 mutations were detected namely sP120T, sT126S, sG130R, sY134F, sS193L, sI195M, and sL216stop were previously described to lead to vaccine, immunotherapy, and/or diagnosis escape. In the C gene, 34 mutations were found. In particular, cG1764A, cC1766G/T, cT1768A, and cC1773T in the BCP; cG1896A and cG1899A in the precore region and cT12S, cE64D, cA80T, and cP130Q in the core region were associated with disease progression to LC and/or HCC. Other mutations were associated with viral replication increase including cT1753V, cG1764A/T, cC1766G/T, cT1768A, and cC1788G in the BCP as well as cG1896A and cG1899A in the precore region. In the X gene, 30 aa substitutions were detected, of which substitutions xT36D, xP46S, xA47T, xI88F, xA102V, xI127T, xK130M, xV131I, and xF132Y were previously described to lead to LC and/or HCC disease progression. In conclusion, our results show high genetic variability in the long-term treatment of chronic HBV patients causing several effects. This could contribute to guiding national efforts to optimize relevant HBV treatment management in order to achieve the global hepatitis elimination goal by 2030.

Frequency of hepatitis B virus-DNA among hepatitis B surface-Ag negative, anti-hepatitis B core antibody-positive blood donors in Yazd, Iran

BACKGROUND:

The diagnosis of hepatitis B infection in most blood transfusion centers is based on hepatitis B surface (HBs) antigen detection by an enzyme immunoassay method. This study aimed to determine the frequency of hepatitis B core (HBc) antibody, HBs antibody, and hepatitis B virus (HBV) DNA among HBs antigen-negative healthy blood donors of Yazd province, Iran.

MATERIALS AND METHODS:

This cross-sectional study was conducted on 1500 healthy blood donor samples negative for HBs antigen, hepatitis C virus antibody, human immunodeficiency virus antigen/antibody, and rapid plasma regain tests. All samples were screened for HBc antibody test. HBs antibody and real-time polymerase chain reaction were performed for HBc antibody-positive samples.

RESULTS:

HBc antibody was positive in 74 (4.9%) samples and 11 (14.9%) of 74 positive samples for HBc antibody were negative for HBs antibody. Sixty-three (85.1%) positive samples for HBc antibody had HBs antibody titer over 10 IU/L, and 43 (58.1%) had HBs antibody titer over 100 IU/L. There was no hepatitis B DNA-positive sample in the present study.

CONCLUSIONS:

The study results suggest that there is a very low risk for transmission of HBV through blood donors of Yazd, Iran.

Design and Development of a Viral Hepatitis and HIV Infection Screening Program (Hprolipsis) for the General, Greek Roma, and Migrant Populations of Greece: Protocol for Three Cross-Sectional Health Examination Surveys

BACKGROUND

Although infectious diseases are globally on the decline, they remain a major global public health problem. Among them, the hepatitis B virus (HBV) or hepatitis C virus (HCV) and HIV infection are of primary interest. Valid prevalence data on these infections are sparse in Greece, especially for vulnerable populations.

OBJECTIVE

This study aimed to present the design and methods of Hprolipsis, an integrated viral hepatitis and HIV screening program administered to adults (≥18 years) from the general, Greek Roma, and migrant populations. Its aims were to estimate the prevalence of HBV, HCV, and HIV; assess infectious disease knowledge level; design, implement, and assess population-specific awareness actions; and offer individual counseling and referral when indicated and HBV vaccination to susceptible Roma and migrants.

METHODS

Multistage, stratified, random sampling based on the 2011 Census was applied to select the general population sample, and nonprobability multistage quota sampling was used for Roma and migrant sample selection. Trained personnel made home (general population) or community (Roma and migrants) visits. Collected blood samples were tested for Hepatitis B surface Antigen, Hepatitis B core Antibody, Hepatitis B surface Antibody, Hepatitis C Antibody, and HIV 1,2 Antibody. The surveys were conducted during May 2013 and June 2016. To estimate an HCV prevalence of 1.5% with 0.3 precision, the required general population sample size was estimated to be 6000. As migrants constitute 10% of the whole Greek population, the migrant sample size was set to 600. A feasible sample size of 500 Greek Roma was set.

RESULTS

In total, 6006 individuals from the general population (response rate 72%), 534 Greek Roma, and 612 migrants were recruited. Blood test results are available for 4245 individuals from the general population, 523 Roma, and 537 migrants.

CONCLUSIONS

Hprolipsis is the first nationwide survey on HBV, HCV, and HIV. Its results will enhance our understanding of the health needs and disease burden of these diseases in the 3 studied populations. Its implementation provided useful recommendations for future studies, particularly in vulnerable populations.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/13578.

Occult HBV infection in Chinese blood donors: role of N-glycosylation mutations and amino acid substitutions in S protein transmembrane domains

Occult hepatitis B virus infection (OBI) is a low-level asymptomatic phase of HBV infection. Evidence of OBI clinical relevance is emerging but the mechanisms of its occurrence remain unclear. In this study, the molecular characteristics of 97 confirmed OBI from Chinese blood donors were analyzed and relevant mutations were identified. Recombinant HBsAg bearing these mutations were expressed in vitro and the antigenicity and HBsAg secretion properties were analyzed. Results showed that 45 (46.4%) genotype B, 50 (51.5%) genotype C, and 2 (2.1%) genotype D sequences were identified. Two groups of mutations in the S gene were significantly associated with OBI. The first group included mutations creating new N-linked glycosylation sites at positions s116, s123, s130, and s131 + s133 or removing the existing one at s146. Mutations TCT123-125NCT/NFT were associated with reduced antigenicity, while TST116-118NST, GTS130-132NTS, and TSM131-133NSS/NYT/NST were associated with varying levels of impaired HBsAg secretion. N146 mutations had no effect on HBsAg production pattern. The second group included substitutions within the S transmembrane domains TMD1-3. Only mutations C85R, L87R, L88R, and C90R within TMD2 were associated with defective HBsAg production. These mutations appear to be rare and mostly strain specific but they may contribute to the multifactorial occurrence of OBI.

Anti-HBc screening - is it worth the effort? Results of a 10-year surveillance programme covering more than 30 million donations in Germany

BACKGROUND AND OBJECTIVES

Antibodies to hepatitis B core antigen (anti-HBc) testing were added to hepatitis surface antigen (HBsAg) screening in Germany in 2006 to prevent hepatitis B virus (HBV) transmissions by chronically infected donors. We report the results of a national surveillance of anti-HBc-reactive and HBsAg-negative donations and assess the resulting gain in blood safety and the donor loss.

MATERIALS AND METHODS

Donations were tested for anti-HBc, and if reactive, by sensitive individual donation nucleic acid testing (ID-NAT) and for antibodies to HBsAg (anti-HBs). Data from the national anti-HBc surveillance from 2006 to 2015 determined the proportion of anti-HBc-reactive donations stratified for donor type, sex, anti-HBs concentration and NAT-positivity. Donor loss due to anti-HBc-reactive results was quantified.

RESULTS

Of 31 562 556 donations screened, 70 671 were anti-HBc reactive but HBsAg negative (0.22%). The proportion of repeat donors with these test results decreased significantly from 0.25% in 2007 to 0.08% in 2015. In the entire study period, 82 HBV-NAT-positive donations were identified. Of these, 47 donations were only identified by ID-NAT. A total of 54 203 anti-HBc-reactive units were discarded either due to possible infectiousness (NAT positive or anti-HBs concentration <100 IU/l) or because no further testing was performed.

CONCLUSION

Anti-HBc screening has improved blood safety in Germany. HBV-NAT-positive donations were identified after ID-NAT was triggered by the initial reactive anti-HBc result. The observed loss of donations was sustainable for maintaining an adequate blood supply in Germany.

Transfusion-transmissible infections among Serbian blood donors: declining trends over the period 2005-2017

BACKGROUND

The mass migrations experienced by the Western Balkans in the past decades have significantly changed the demographic structures and have probably altered the prevalence of transfusion-transmitted infections (TTIs) among blood donors. However, data on the prevalence of TTIs in the Western Balkans countries remain incomplete. This study reports the prevalence of TTIs among blood donors in Serbia in the period 2005-2017.

MATERIALS AND METHODS

Between January 2005 and December 2017, in the four largest Serbian transfusion centres, mandatory serology tests for screening HBV, HCV, HIV and syphilis infection were used for all blood donations.

RESULTS

Of the total of 1,660,019 blood donations made, 3,377 (0.203%) were positive for one of the TTIs: 1,440 (0.087%), 1,055 (0.064%), 215 (0.013%), and 667 (0.040%) were positive for HBV, HCV, HIV and syphilis, respectively. Serbia showed a declining trend of prevalence of HBV and HCV infection, while prevalence of HIV and syphilis remained unchanged. Prevalence of TTIs varied between different transfusion centres and showed a north-to-south upward trend.

DISCUSSION

The reported prevalence of TTIs among blood donors in Serbia was low and continued to follow a declining trend over the period of study.

Synergistic impact of mutations in Hepatitis B Virus genome contribute to its occult phenotype in chronic Hepatitis C Virus carriers

We characterized occult HBV (OHBV) from hepatitis B surface antigen (HBsAg)-negative chronic HCV carriers of Eastern India to explore the impact of genomic variability of HBV in causing undetectability of HBsAg and low viremia that define the occult phenomenon. Screening of sera samples revealed the presence of OHBV in 17.8% of HCV-infected patients. Determination of full-length OHBV sequences and comparison with that from HBsAg-positive carriers led to the detection of distinct substitutions/mutations in PreS2, S, P and X ORFs and in X-promoter and Enhancer-II of OHBV. These mutations were introduced in wild-type HBV and their effects were evaluated by transfection in Huh7 cells. In vitro assays demonstrated that S-substitutions resulted in antigenically modified HBsAg that escaped detection by immunoassays whereas those in ORF-P caused significant decline in viral replication. Impairment in Enhancer-II and X-promoter activities were noted due to occult-associated mutations that generated reduced pregenomic RNA and intracellular HBV-DNA. Additionally, Enhancer-II mutations altered the small to large surface protein ratio and diminished extracellular HBV-DNA and HBsAg secretion. Further, mutations in PreS2, X and enhancer-II increased Grp78-promoter activity, suggesting that OHBV could trigger endoplasmic reticulum stress. Thus viral mutations contribute synergistically towards the genesis of occult phenotype and disease progression.

Temporal trend of hepatitis B surface mutations in the post-immunization period: 9 years of surveillance (2005-2013) in eastern China

Limited information is available about the temporal trend in the prevalence and evolution of hepatitis B virus (HBV) S-gene mutations in the post-immunization era in China. From 2005 to 2013, 1077 hepatitis B cases under 15 years of age reported through Chinese National Notifiable Disease Reporting System (NNDRS) were successfully sequenced of S-gene in Shandong province, China. A total of 97 (9.01%) cases had amino acid (aa) substitution in the “α” determinant of HBsAg. The yearly prevalence from 2005 to 2013 maintained at a relatively stable level, and showed no significant change (P > 0.05). Multivariate logistic regression analysis demonstrated that the prevalence of “α” mutations was independently associated with the maternal HBsAg status (P < 0.05), and not with surveillance year and hepatitis B vaccination (P > 0.05). The hottest mutation position was aa126 (I126S/N and T126A, 29.63%), and aa 145 (G145R/A, 25.93%). Mutated residue 126 tended to occur less frequent, while that of residue 145 was more frequent with increasing year. Our data showed that there was no increase in the frequency of HBV “α” mutations over time during the post-immunization period. However, long-term vaccination might enhance the change of HBV mutational pattern, and G145 mutation was becoming dominant.

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.

Three-Year Experience in NAT Screening of Blood Donors for Transfusion Transmitted Viruses in Croatia

Background

Croatia implemented individual donation (ID)-NAT testing of blood donors in 2013 for three viruses HBV, HCV, and HIV-1 as a mandatory test for all blood donors. This study assessed the impact of NAT screening 3 years after its implementation.

Methods

A total of 545,463 donations were collected and screened for HBV, HCV, and HIV-1 using the Procleix Ultrio Plus Assay. All initially reactive (IR) NAT samples were retested in triplicate and, if repeatedly reactive (RR), NAT discriminatory assay (dNAT) was performed. ID-NAT positive donations were confirmed by RT-PCR on the COBAS AmpliPrep/TaqMan platform.

Results

Out of 545,463 samples tested, 108 (0.02%) were RR in NAT. There were 82 (75,9%) HBV reactive, 16 (14.8%) HCV reactive, and 10 (9.3%) HIV-1 reactive samples. 51 (47.2%) samples were ID-NAT positive only. Out of these 51 NAT yield cases, 1 window period HIV-1 and 50 occult HBV infections (OBI) were determined. There were only two potential HBV DNA transmissions from OBI donors.

Conclusion

The implementation of NAT screening for three viruses has improved blood safety in Croatia. During the 3-year period, 1 window period HIV-1 and a number of occult HBV donations were identified.

Occult Hepatitis B Virus Infections (Often with Human Herpesvirus 7 Co-Infection) Detected in Pityriasis rosea Patients: A Pilot Study

Background

The etiopathogenesis of Pityriasis rosea (PR), a papulo-squamous skin disease, remains elusive and hypothesized to be caused primarily by human herpesvirus (HHV) 6 or 7 or immune dysfunction.

Aims

The recent increasing incidences of hepatitis B virus (HBV) infections, including asymptomatic occult HBV infections (OBIs), in a densely populated city in India, prompted us to investigate whether PR patients (from varied socioeconomic and immune status) harbor the underlying HBV infections. These cases were also investigated for HHV 6 and 7 infections.

Materials and Methods

DNA from ethylenediaminetetraacetic acid blood samples from PR-diagnosed individuals (n = 13; mostly young adults) and healthy controls (n = 11) were subjected to virus gene-specific polymerase chain reactions (PCRs) for HBV and HHV 6 and 7. PCR products of expected length, when observed, were sequenced (bidirectional) using overlapping primers. Sequences were identified by NCBI BLAST and analyzed by multiple sequence alignment and phylogenetic studies. The blood samples were tested for HBsAg by EIA.

Results

In 5/13 PR samples, only HBV DNA (4/5 being HBsAg negative) was detected, providing first-time evidence that PR may be manifested in asymptomatic HBV carriers. 6/13 cases were HHV 7 (not HHV 6) DNA positive, providing confirmatory molecular genetic evidence for the first time of PR association with HHV 7 from India. Surprisingly, 5/6 HHV 7-positive PR cases were also HBV positive. Overall, 10/13 PR samples showed evidence of HBV infection. 8/13 were OBI, harboring at least one OBI-signature S protein mutation. All healthy controls were HBsAg EIA and PCR negative.

Conclusions

77% of PR patients presented the evidence of underlying HBV infection (genotype D2), suggestive of horizontal HBV transmission. This warrants for mass HBV vaccination. PR patients should be tested for underlying virus infections for appropriate therapy and management.

Current hepatitis B virus infection situation in Indonesia and its genetic diversity

Indonesia has a moderate to high endemicity of hepatitis B virus (HBV) infection. The risk for chronic HBV infection is highest among those infected during infancy. Since 1997, hepatitis B (HepB) vaccination of newborns has been fully integrated into the National Immunization Program. Although HBV infection has been reduced by the universal newborn HepB immunization program, it continues to occur in Indonesia. The low birth dose coverage and the presence of vaccine escape mutants might contribute to this endemicity among children. Although limited information is available for an analysis of occult HBV infection (OBI), several variations and substitutions in the pre-S/S region have been detected in Indonesian HBV strains. Additionally, persistent infection and disease progression of chronic hepatitis B are related to not only viral factors but also the host genome. Indonesia is one of the most ethnically heterogeneous nations, with Javanese and Sundanese as the two highest ethnic groups. This multi-ethnicity makes genomic research in Indonesia difficult. In this article, we focused on and reviewed the following aspects: the current hepatitis B immunization program and its efficacy, OBI, HBV infection among high-risk patients, such as hemodialysis patients, and research regarding the host genome in Indonesia.

Refining the risk estimate for transfusion-transmission of occult hepatitis B virus

BACKGROUND AND OBJECTIVES

We previously published a model to estimate the residual risk (RR) for occult hepatitis B infection (OBI) in the absence of universal anti-HBc testing. To incorporate new information on the epidemiology of OBI, we describe model refinements and estimate a more accurate HBV RR due to OBI in Australia.

MATERIALS AND METHODS

In our original model, the OBI risk, p(OBI), was defined by the rate of 'non-detection' by the HBV DNA screening test in use, p(NAT non-detection), and the average infectivity of blood components from OBI donors, p(transmission). We revised the model by integrating three refinements: that donations with anti-HBs levels of >10 IU/l, or donations solely for manufactured plasma products, be excluded from the risk calculation, and an updated estimate of p(transmission).

RESULTS

Refining our OBI RR model resulted in a more than 10-fold reduction in the reported RR risk to recipients from OBI in our donor population. Based on the use of a common data set, the mean OBI RR risk decreased from 1 in 374 354 donations (95% CI: 1 in 191 940-1 072 681) to 1 in 3 984 033 (95% CI: 1 in 1 146 188-65 268 257) for the refined model.

CONCLUSION

Our model refinements provide a more realistic measure of the HBV RR in the donor population. Unlike the previous model, the new model demonstrates that the risk of HBV due to OBI in the Australian blood donor population is negligible, and further potentially cost-ineffective risk management strategies are not currently warranted.

Naturally Occurring Surface Antigen Variants of Hepatitis B Virus in Tunisian Patients

In Tunisia, the prevalence of naturally occurring surface (S) gene variants of hepatitis B virus (HBV) has not been determined. In the present study, the prevalence of these variants was examined in terms of the clinical and viral state in a series of 99 Tunisian patients with HBV infection. The S genes were amplified and directly sequenced. Genotype D was predominant (98%), 40.4% isolates belonged to subgenotypes D7 and 1 to subgenotype D2. The most common subtype was ayw2 (95.9%). In total, 60.6% of the studied strains harbored S mutations. Several novel mutation patterns were detected. Interestingly, the presence of S mutations was significantly correlated with the D7 subgenotype, low HBV DNA and advancing age (≥35 years), and tended to be higher in liver cirrhosis than in chronic infection. The global prevalence of the major hydrophilic region variants was 12.1%, with substitution S143L/T as the most frequent (4%). Only 33.9% of S substitutions produced amino acid changes in the polymerase gene. In conclusion, a high prevalence of naturally occurring HBsAg variants was observed among Tunisian HBV carriers. Natural viral variability in a geographical region and duration of infection are among the major factors associated with the occurrence of S mutations.

Hepatitis B surface gene variants isolated from blood donors with overt and occult HBV infection in north eastern Egypt

BACKGROUND

Major hydrophilic region in genomic HBV extending from aa99 to aa169, clustered with a highly conformational epitope, is critical to the antigenicity of hepatitis B surface antigen (HBsAg) and may affect the diagnosis of HBV in HBV screening test. So, this study aimed to characterize variants of S gene product of hepatitis B virus (HBV) isolated from patients with overt or occult HBV infection in north-eastern Egypt.

METHODS

The study included sera of two different groups of volunteer blood donors (VBDs), 82 with overt HBV that were positive for HBsAg and anti-HBc and 343 donors negative for HBsAg eligible for donation. Of the latter group, only 44 were positive for anti-HBc. All anti-HBc positive sera were subjected to HBV DNA detection and partial sequence analysis targeting the HBV S gene.

RESULTS

HBV DNA was detected in 22.7 % of HBsAg-/anti-HBc + (10/44 patients) and in 90 % of HBsAg + donors (74/82 patients) with significant statistical difference (P = 0.0001). Phylogenetic analysis showed that HBV strains retrieved from both groups were of genotype D. Amino acid escape mutation T125M was detected in only 2 samples of the occult infection group and in none of the overt group (P = 0.01). Different amino acid substitutions were identified in overt infection group: S143L/T (16.2 %, 12/74) and P120T/S (2.7 %, 2/74). Q129R was significantly more frequent in cases with occult HBV infection (40 %, 4/10) than overt group (6.8 %, 5/74) (P = 0.01).

CONCLUSIONS

HBV genotype D predominated both in patients with overt and occult HBV infection. Different profiles of amino acid substitutions in the major hydrophilic region were seen in these two groups in Egypt.

Investigation of occult hepatitis B virus infection in anti-hbc positive patients from a liver clinic

Occult hepatitis B infection (OBI) is manifested by presence of very low levels (<200IU/mL) of Hepatitis B viral DNA (HBV DNA) in the blood and the liver while exhibiting undetectable HBV surface antigen (HBsAg). The molecular mechanisms underlying this occurrence are still not completely understood. This study investigated the prevalence of OBI in a high-risk Australian population and compared the HBV S gene sequences of our cohort with reference sequences. Serum from HBV DNA positive, HBsAg negative, and hepatitis B core antibody (anti-HBc) positive patients (study cohort) were obtained from samples tested at SEALS Serology Laboratory using the Abbott Architect, as part of screening and diagnostic testing. From a total of 228,108 samples reviewed, 1,451 patients were tested for all three OBI markers. Only 10 patients (0.69%) out of the 1,451 patients were found to fit the selection criteria for OBI. Sequence analysis of the HBV S gene from 5 suspected OBI infected patients showed increased sequence variability in the ‘a’ epitope of the major hydrophilic region compared to reference sequences. In addition, a total of eight consistent nucleotide substitutions resulting in seven amino acid changes were observed, and three patients had truncated S gene sequence. These mutations appeared to be stable and may result in alterations in HBsAg conformation. These may negatively impact the affinity of hepatitis B surface antibody (anti-HBs) and may explain the false negative results in serological HBV diagnosis. These changes may also enable the virus to persist in the liver by evading immune surveillance. Further studies on a bigger cohort are required to determine whether these amino acid variations have been acquired in the process of immune escape and serve as markers of OBI.

Seroprevalence of occult hepatitis B among Egyptian paediatric hepatitis C cancer patients

Occult hepatitis B infection is characterized by the presence of hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). Prevalence of hepatitis C virus (HCV) infections in Egypt is among the highest in the world. In this study, we aim at analysing the rates of occult HBV infections among HCV paediatric cancer patients in Egypt. The prevalence of occult HBV was assessed in two groups of paediatric cancer patients (HCV positive and HCV negative), in addition to a third group of paediatric noncancer patients, which was used as a general control. All groups were negative for HBsAg and positive for HCV antibody. HBV DNA was detected by nested PCR and real-time PCR. HCV was detected by real-time PCR. Sequencing was carried out in order to determine HBV genotypes to all HBV patients as well as to detect any mutation that might be responsible for the occult phenotype. Occult hepatitis B infection was observed in neither the non-HCV paediatric cancer patients nor the paediatric noncancer patients but was found in 31% of the HCV-positive paediatric cancer patients. All the detected HBV patients belonged to HBV genotype D, and mutations were found in the surface genome of HBV leading to occult HBV. Occult HBV infection seems to be relatively frequent in HCV-positive paediatric cancer patients, indicating that HBsAg negativity is not sufficient to completely exclude HBV infection. These findings emphasize the importance of considering occult HBV infection in HCV-positive paediatric cancer patients especially in endemic areas as Egypt.

Subgenotypes and mutations in the s and polymerase genes of hepatitis B virus carriers in the West Bank, palestine

The mutation rate and genetic variability of hepatitis B virus (HBV) are crucial factors for efficient treatment and successful vaccination against HBV. Until today, genetic properties of this virus among the Palestinian population remain unknown. Therefore, we performed genetic analysis of the overlapping S and polymerase genes of HBV, isolated from 40 Palestinian patients' sera. All patients were HBsAg positive and presented with a viral load above 105 HBV genome copies/ml. The genotyping results of the S gene demonstrated that HBV D1 was detected in 90% of the samples representing the most prominent subgenotype among Palestinians carrying HBV. Various mutations existed within the S gene; in five patients four known escape mutations including the common G145R and D144E were found. Furthermore, a ratio of 4.25 of non-synonymous to synonymous mutations in the S gene indicated a strong selection pressure on the HBs antigen loops of HBV strains circulating in those Palestinian patients. Although all patients were treatment-naïve, with the exception of one, several mutations were found in the HBV polymerase gene, but none pointed to drug resistance. The study presented here is the first report to address subgenotypes and mutation analyses of HBV S and polymerase genes in Palestine.

Seroepidemiology and occult hepatitis B virus infection in young adults in Banjarmasin, Indonesia

Hepatitis B virus (HBV) infection remains a public health problem in Indonesia. There has been limited data regarding HBV infection in young adult population. This study aimed to evaluate the seroepidemiology of HBV infection and characterize occult HBV variants in healthy young adults in Banjarmasin, Indonesia, who were born before the implementation of the universal infant hepatitis B vaccination. Serum samples of 195 healthy young adults were tested for HBsAg, anti-HBc, and anti-HBs. The prevalence of HBsAg, anti-HBc, and anti-HBs was 9 (4.6%), 62 (31.8%), and 96 (49.2%), respectively. Seventy four (37.9%) samples were seronegative for all three parameters, indicating the susceptibility to HBV infection. Among 66 samples positive for HBsAg and/or anti-HBc, 13 (19.7%) were HBV DNA positive; of these, four were HBsAg positive and nine were HBsAg negative, and categorized as occult HBV infection. Most occult HBV cases had high-level anti-HBs (>100 IU/l), suggesting that blood with positive anti-HBs and anti-HBc could not be regarded as noninfectious. Thirteen amino acid substitutions were identified: T126S, P127S, Q129R, T131N, M133T, and Y161S in the HBsAg-positive group; P120T, T126I, G145S, Y161F, E164V, and V168F in the occult-HBV group; and T143S in both groups. More studies are required to provide data on the prevalence and characteristics of mutants to ensure reliable diagnosis. The occult HBV infection, combined with the HBsAg prevalence, could indicate the high HBV carriage among young adults in this area. The high percentage of individuals susceptible to HBV infection reiterates the need for catch-up immunization strategies targeted at young adults.

Seroprevalency of transfusion-transmitted infections in first-time volunteer and replacement donors in Tunisia

BACKGROUND

Replacement donors are considered as having a major risk of transmission of infections to recipients mainly by the World Health Organisation.

STUDY DESIGN AND METHODS

Seroprevalency of HBV, HCV, HIV and syphilis were determined in 19,783 whole blood donations collected in the Tunisian National Blood Transfusion Centre during the year 2010 (12,968 [65.55%] replacement donations and 6815 [34.44%] voluntary blood donations). For HBV, HCV and syphilis, we performed a univariate analysis to determine whether age, sex and type of donation were risk factors, then multivariate logistic regression, to see if these factors were independent.

RESULTS

Mean age of donors was 30.1 years (replacement donors 34.5 years, first time non-remunerated donors 34.5 years, P<0.001). The predominant age group was 30-39 years (35.51%) in replacement donors and 20-29 years (54.15%) in first time non-remunerated donors. Male gender was significantly predominant (73.00% men vs 27.00% women, P<10(-6)). There were significantly more men among replacement donors (82.27% vs 55.38%, P<10(-3)). There were more women in the age groups 18-19 and 20-29 years. Only one HIV seropositive donation was noted in a male first time non-remunerated donor aged 18. Replacement type of donation, male sex and age were three independent risk factors for the HBs Ag carriage. For anti-HCV antibodies and TPHA, only replacement type of donation and age were found out to be risk factors and only age was independent.

CONCLUSION

In Tunisia, replacement blood donors were at higher risk of infection transmission, but only for hepatitis B.

Genetic characterization and genotyping of hepatitis B virus (HBV) isolates from donors with an occult HBV infection

BACKGROUND AND OBJECTIVES

Screening of Thai blood donors has resulted in the detection of donors with an occult HBV infection (OBI), where HBsAg is undetectable, but hepatitis B virus (HBV) DNA is present in serum in low concentrations. This study was designed to determine whether the occurrence of OBI in donors was linked to the HBV genotype and possibly to mutations in the surface (S) and core (C) gene regions.

MATERIALS AND METHODS

Mutations in the S and C gene regions in 48 Thai donors with OBI were mapped by sequencing. Genotyping was determined with the INNO-LiPA test and by phylogenetic analysis of sequences from the S and C genes.

RESULTS

The majority of OBI samples were genotype C (81·3%) with 6·3% of samples being genotype B. In addition, two genotype I isolates were identified. Mutations in the S region (100%) were found especially in loop 1 of the major hydrophilic loop (MHL) at positions I110L, T114S, T126I and S113T, whereas mutations in the C region (65%) were within the basal core promoter region (position A1762T/G1764A) and precore region (position G1896A).

CONCLUSION

The majority of OBI samples were HBV genotype C, although genotype I, which is newly emerging in Thailand, was also detected. The study demonstrated that OBI was probably not associated with a particular HBV genotype or with certain mutations in the S and C gene regions. However, mutations in the C gene region which could potentially impair viral replication and HBsAg production and potentially lead to OBI were identified.

Clinical implications of hepatitis B virus mutations: Recent advances

Hepatitis B virus (HBV) infection is a major cause of acute and chronic hepatitis, and of its long-term complications. It is the most variable among DNA viruses, mostly because of its unique life cycle which includes the activity of error-prone enzyme, reverse transcriptase, and the very high virion production per day. In last two decades, numerous research studies have shown that the speed of disease progression, reliability of diagnostic methods and the success of antiviral therapy and immunization are all influenced by genetic variability of this virus. It was shown that mutations in specific regions of HBV genome could be responsible for unwanted clinical outcomes or evasion of detection by diagnostic tools, thus making the monitoring for these mutations a necessity in proper evaluation of patients. The success of the vaccination programs has now been challenged by the discovery of mutant viruses showing amino acid substitutions in hepatitis B surface antigen (HBsAg), which may lead to evasion of vaccine-induced immunity. However, the emergence of these mutations has not yet raised concern since it was shown that they develop slowly. Investigations of HBV genetic variability and clinical implications of specific mutations have resulted in significant advances over the past decade, particularly in regard to management of resistance to antiviral drugs. In the era of drugs with high genetic barrier for resistance, on-going monitoring for possible resistance is still essential since prolonged therapy is often necessary. Understanding the frequencies and clinical implications of viral mutations may contribute to improvement of diagnostic procedures, more proper planning of immunization programs and creating the most efficient therapeutic protocols.

Occult hepatitis B infection in the immigrant population of Sicily, Italy

In Italy, about 7 % of the resident population is represented by immigrants originating from geographic regions at high endemicity for hepatitis B virus infection. This study aims to assess the prevalence of occult HBV infection (OBI) including the identification of HBV-genotypes in a population of immigrants serologically negative for hepatitis B surface antigen (HBsAg). Between May 2006 and May 2010, 339 immigrants were tested for markers of HBV, hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections. HBV-DNA was tested by using nested-PCR assays on three different genetic region. HBV-DNA was detected in plasma samples of 11/339 (3.2 %) patients. Most of them had no serological markers of HBV infection, 3/58 (5.2 %) were anti-HBc-alone, and 4/13 (30.8 %) were anti-HIV positive. HIV positivity was the only factor independently associated with the higher probability of observing OBI (OR = 16.5, p < 0.001). No HCV co-infected patients were found. Genotype D was detected in 9/11 (81.8 %) OBI cases, while the remaining two (18.2 %) were classified as genotype E. Although OBI was found at lower rate than expected among immigrants from highly endemic countries, anti-HBc alone positivity was confirmed as a sentinel marker of occult HBV infection. Nevertheless, a marked heterogeneity of HBV markers was found among HBV-DNA positive subjects. Our finding evidenced the predominance of HBV-genotype D viral strains among OBI cases, also in those from geographical areas where overt HBV infections are mainly sustained by viral genotypes other than D.

Hepatitis B virus nucleic acid amplification testing of Australian blood donors highlights the complexity of confirming occult hepatitis B virus infection

BACKGROUND

We present an analysis of the first 2 years of hepatitis B virus (HBV) nucleic acid testing (NAT) of the Australian donor population.

STUDY DESIGN AND METHODS

Between July 5, 2010, and July 4, 2012, all blood donations were screened for HBV DNA and hepatitis B surface antigen (HBsAg). Donors who tested HBsAg negative but HBV NAT positive were assessed as occult hepatitis B infections (OBI) if reactive for antibodies to HBV core antigen (anti-HBc). Donors who were anti-HBc reactive but with nonrepeatable or nondiscriminated NAT results were assessed as HBV inconclusive pending follow-up testing.

RESULTS

During the study period a total of 2,673,521 donations were screened for HBV. Forty-two chronic OBI infections (5.55/100,000 donors) were identified compared to eight acute serologic window period infections (1.06/100,000 donors). Of the 42 OBI cases, 23 (54.8%) were detected the first time they were screened for HBV DNA while 19 (45.2%) gave one or more HBV NAT-nonreactive results before detection. Of 68 donors initially assessed as HBV inconclusive and available for follow-up, 10 later confirmed as OBI cases while 51 were NAT nonreactive but remained anti-HBc reactive and OBI could not be excluded.

CONCLUSION

This study demonstrated a substantially higher prevalence of OBI compared to acute serologic window period HBV infections in Australian blood donors. Follow-up testing of OBI cases indicates that HBV DNA is often only intermittently detectable in OBI, highlighting the importance of including anti-HBc to optimize the HBV testing algorithm.

Epidemiology and molecular analysis of hepatitis A, B and C in a semi-urban and rural area of Crete

AIM

An observational seroepidemiological study was carried out in a well-defined primary-care district on the island of Crete in order to determine the recent endemicity of viral hepatitis in Cretan-population.

SETTING AND PARTICIPANTS

The setting consisted of a semi-urban group and a remote & rural group. Serum samples were collected from 876 subjects (437 males, 439 females) aged 15 years or above. Subjects were randomly selected from the permanent population of the area that consisted of 5705 individuals. The aim was to measure the prevalence of selected viral-hepatitis markers.

RESULTS

Hepatitis B surface-antigen (HBsAg) was found positive in twenty-nine individuals, (3.3%). Antibodies to hepatitis B virus core-antigen (HBcAb) were detected in 287 subjects (32.8%) and antibodies to hepatitis C virus (anti-HCV) were detected in nineteen subjects (2.2%). Seropositivities for the semi-urban group were: 3.4%, 19.1%, 2.1% and 3.2%, 48.8%, 2.2% in remote & rural group respectively. Virtually, all subjects >45 years old were seropositive for antibodies to hepatitis A, whereas approximately 80% of those in the 15-44 age-group were found to be seropositive.

CONCLUSION

A threefold increase in the HBV exposure and carrier proportion was found in Cretan native-population and in rural-areas compared to older studies carried out in other rural-populations of the island. It is still unknown whether the recent economic crisis or the demographic changes in Cretan-population contributed to these findings. HCV endemicity remains relatively constant, however an alteration of hepatitis C genotypes was observed. Exposure to HAV was found to be higher in remote and rural areas compared to semi-urban areas.

Occult hepatitis B virus infection among Egyptian blood donors

AIM

To identify blood donors with occult hepatitis B virus (HBV) infection (OBI) to promote safe blood donation.

METHODS

Descriptive cross sectional study was conducted on 3167 blood donors negative for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab) and human immunodeficiency virus Ab. They were subjected to the detection of alanine aminotransferase (ALT) and aspartate transaminase (AST) and screening for anti-HBV core antibodies (total) by two different techniques; [Monoliza antibodies to hepatitis B core (Anti-HBc) Plus-Bio-Rad] and (ARC-HBc total-ABBOT). Positive samples were subjected to quantitative detection of antibodies to hepatitis B surface (anti-HBs) (ETI-AB-AUK-3, Dia Sorin-Italy). Serum anti-HBs titers > 10 IU/L was considered positive. Quantitative HBV DNA by real time polymerase chain reaction (PCR) (QIAGEN-Germany) with 3.8 IU/mL detection limit was estimated for blood units with negative serum anti-HBs and also for 32 whose anti-HBs serum titers were > 1000 IU/L. Also, 265 recipients were included, 34 of whom were followed up for 3-6 mo. Recipients were investigated for ALT and AST, HBV serological markers: HBsAg (ETI-MAK-4, Dia Sorin-Italy), anti-HBc, quantitative detection of anti-HBs and HBV-DNA.

RESULTS

525/3167 (16.6%) of blood units were positive for total anti-HBc, 64% of those were anti-HBs positive. Confirmation by ARCHITECT anti-HBc assay were carried out for 498/525 anti-HBc positive samples, where 451 (90.6%) confirmed positive. Reactivity for anti-HBc was considered confirmed only if two positive results were obtained for each sample, giving an overall prevalence of 451/3167 (14.2%) for total anti-HBc. HBV DNA was quantified by real time PCR in 52/303 (17.2%) of anti-HBc positive blood donors (viral load range: 5 to 3.5 x 10(5) IU/mL) with a median of 200 IU/mL (mean: 1.8 x 10(4) ± 5.1 x 10(4) IU/mL). Anti-HBc was the only marker in 68.6% of donors. Univariate and multivariate logistic analysis for identifying risk factors associated with anti-HBc and HBV-DNA positivity among blood donors showed that age above thirty and marriage were the most significant risk factors for prediction of anti-HBc positivity with AOR 1.8 (1.4-2.4) and 1.4 (1.0-1.9) respectively. Other risk factors as gender, history of blood transfusion, diabetes mellitus, frequent injections, tattooing, previous surgery, hospitalization, Bilharziasis or positive family history of HBV or HCV infections were not found to be associated with positive anti-HBc antibodies. Among anti-HBc positive blood donors, age below thirty was the most significant risk factor for prediction of HBV-DNA positivity with AOR 3.8 (1.8-7.9). According to HBV-DNA concentration, positive samples were divided in two groups; group one with HBV-DNA ≥ 200 IU/mL (n = 27) and group two with HBV-DNA < 200 IU/mL (n = 26). No significant difference was detected between both groups as regards mean age, gender, liver enzymes or HBV markers. Serological profiles of all followed up blood recipients showed that, all were negative for the studied HBV markers. Also, HBV DNA was not detected among studied recipients, none developed post-transfusion hepatitis (PTH) and the clinical outcome was good.

CONCLUSION

OBI is prevalent among blood donors. Nucleic acid amplification/HBV anti core screening should be considered for high risk recipients to eliminate risk of unsafe blood donation.

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.

T cell responses and viral variability in blood donation candidates with occult hepatitis B infection

BACKGROUND & AIMS

Occult HBV infection (OBI) is defined by the presence of HBV DNA in the liver and/or serum and negative HBsAg testing. Since the implementation of highly sensitive HBV DNA screening, OBI is also detected in healthy blood donors. The aims of this study were to investigate HBV-specific immune responses and genetic variability in donors with OBI, established by HBV DNA in serum.

METHODS

HBV-specific T-cell responses to HBV antigens were tested in 34 OBI donors by IFN-γ ELISpot, cytometric bead array, and intracellular cytokine staining. As comparison populations, 36 inactive HBV carriers, 22 donors with spontaneously resolved HBV infection, 24 vaccinated donors, and 25 seronegative donors were also included. Surface, pre-S, and pre-c/core genes from 44 genotype D isolates (24 OBI and 20 HBsAg-positive) were sequenced.

RESULTS

The immune response of OBI donors to the 3 HBV antigens was 29-41%, similar to the response in subjects with resolved HBV infection and higher than that in HBsAg-positive subjects. On sequence analysis, OBI donors presented a higher HBsAg mutation rate than HBsAg-positive subjects. Mutations were clustered in the major hydrophilic region of HBsAg, and no stop codons or relevant mutations that could affect antigen formation or detection were observed.

CONCLUSIONS

Our results suggest that immune response can suppress viral replication to low levels and HBsAg expression to undetectable levels in OBI blood donors. Relevant mutations were not found in the genomic HBsAg coding region. Hence, the fact that HBsAg was not detected in OBI is likely due to low HBsAg production, rather than to a failure of laboratory reagents.

Hepatitis B virus genotype, HBsAg mutations and co-infection with HCV in occult HBV infection

BACKGROUND

The association between mutations in the hepatitis B surface antigen (HBsAg) gene and the occurrence of occult HBV (OBI) in patients has not been studied adequately to determine if the two are correlated. The current study was aimed to investigate HBsAg mutations, the genotype of HBV and co-infection with HCV in OBI in the central part of Iran to determine any possible associations.

MATERIAL AND METHODS

In this study, 3700 plasma samples were examined for the presence of HBsAg, anti-HBc and HBV-DNA. All HBsAg(-)/anti-HBc(+)/HBV-DNA(+) samples were regarded as OBI. The genotype of HBV was identified using Gap-PCR and RT-PCR was used to determine possible co-infection with HCV. Finally, direct sequencing was performed to analyse mutations within the surface antigen gene of HBV in occult versus acute HBV infection.

RESULTS

Of the 3700 patient samples analysed, 352 (9.5%) cases were determined to be HBsAg(-)/anti-HBc(+) in which HBV-DNA was detected in 57 (16.1%), these latter patients were classified as OBI. All of the patients studied carried the D genotype. Direct sequencing of the S-gene from occult and acute HBV patients revealed one silent and one glycine to arginine mutation but the acute HBV patients showed an additional mutation (alanine to threonine). All the mutations were outside the range of the α-determinant. Furthermore, none of the OBI patients were co-infected with HCV.

CONCLUSIONS

The absence of conformational mutations in the α-determinant of HBsAg confirmed that this antigen could be detected by commercial Elisa kits and therefore was not responsible for false negatives during blood screening. However, it can be concluded that suitable amounts of HBsAg were not expressed by HBV in the OBI patients to be detected by Elisa. Low level expression of HBsAg might be related to the D genotype of the virus. Furthermore, our results suggest that OBI is not related to co-infection with HCV.

An overview of occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI), alternatively defined as occult hepatitis B (OHB), is a challenging clinical entity. It is recognized by two main characteristics: absence of HBsAg, and low viral replication. The previous two decades have witnessed a remarkable progress in our understanding of OBI and its clinical implications. Appropriate diagnostic techniques must be adopted. Sensitive HBV DNA amplification assay is the gold standard assay for detection of OBI. Viral as well as host factors are implicated in the pathogenesis of OBI. However, published data reporting the infectivity of OBI by transfusion are limited. Several aspects including OBI transmission, infectivity and its relation to the development of chronic liver diseases and hepatocellular carcinoma have to be resolved. The aim of the present review is to highlight recent data on OBI with a focus on its virological diagnosis and clinical outcome.

The status of humoral immunity in occult HBV infection in south-eastern Iranian patients

BACKGROUND

Occult hepatitis B infection (OBI) is characterized as a form of hepatitis in which, despite of absence of detectable HBsAg, HBV-DNA is present in patient's peripheral blood. The aim of this study was to investigate components of humoral immunity during OBI as a possible measure of how patients respond to Hepatitis B viral infections.

MATERIAL AND METHODS

In this study, HBsAg-/anti-HBc+/HBV-DNA+ samples were assigned as OBI cases and SRID techniques were performed to measure levels of circulating antibodies (IgG, IgM and IgA) as well as C3, C4. In addition, complement system function was assessed by CH50.

RESULTS

Our results showed that the serum levels of IgG and C4 were significantly lower in OBI patients, while IgM and C3 were higher in patients when compared to healthy controls. Serum levels of IgA and CH50 were not significantly different between OBI patients and controls.

DISCUSSION

Based on these results, it could be concluded that although OBI patients produced elevated levels of IgM there may be a problem converting and progressing this response to generate enough IgG to overcome HBV infection.

Occult hepatitis B virus infection in Thai blood donors

BACKGROUND

An evaluation by the National Blood Center, the Thai Red Cross Society, of two commercial multiplex nucleic acid tests (NATs; the Chiron PROCLEIX ULTRIO test and the Roche Cobas TaqScreen MPX test) for screening Thai blood donors for hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency virus Type 1 identified 175 HBV NAT-reactive/hepatitis B surface antigen (HBsAg)-negative donors. The classification of the HBV infection of these donors was confirmed by follow-up testing.

STUDY DESIGN AND METHODS

Index samples were tested for HBV serologic markers and HBV viral loads were determined. Donors were followed for up to 13 months and samples were tested with both NAT assays and for all HBV serological markers.

RESULTS

Of 175 HBV NAT-yield donors, 72 (41%) were followed. Based on the follow-up results, the majority of donors who were followed had an occult HBV infection (66.7%), followed by donors with a primary, acute infection (26.4%). The majority of donors in this latter group (20.8%) were in the window period. Three donors (4.2%), who were anti-HBs positive, had a reinfection or breakthrough infection.

CONCLUSION

The majority of donors detected during routine screening, who were HBsAg negative and NAT reactive, had an occult HBV infection, thus validating the decision to introduce NAT for blood donations in Thailand.

Serologic and molecular characteristics of hepatitis B virus among school children in East Java, Indonesia

Universal childhood hepatitis B vaccination was introduced in Indonesia in 1997; by 2008, coverage was estimated to be 78%. This study aimed to investigate the serologic status and virologic characteristics of hepatitis B virus (HBV) among the children in East Java. A total of 229 healthy children born during 1994-1999 were enrolled in this study. Overall, 3.1% were positive for hepatitis B surface antigen (HBsAg) and 23.6% were positive for antibody to HBsAg (anti-HBs). HBV DNA was detected in 5 of 222 HBsAg-negative carriers, which were suggested to be cases of occult HBV infection. A single amino substitution (T126I) in the S region was frequently found. HBV infection remains endemic, and the prevalence of anti-HBs remains insufficient among children in East Java, Indonesia.

Development of a new ultra sensitive real-time PCR assay (ultra sensitive RTQ-PCR) for the quantification of HBV-DNA

Background

Improved sensitivity of HBV-DNA tests is of critical importance for the management of HBV infection. Our aim was to develop and assess a new ultra sensitive in-house real-time PCR assay for HBV-DNA quantification (ultra sensitive RTQ-PCR).

Results

Previously used HBV-DNA standards were calibrated against the WHO 1^st International Standard for HBV-DNA (OptiQuant^® HBV-DNA Quantification Panel, Accrometrix Europe B.V.). The 95% and 50% HBV-DNA detection end-point of the assay were 22.2 and 8.4 IU/mL. According to the calibration results, 1 IU/mL equals 2.8 copies/mL. Importantly the clinical performance of the ultra sensitive real-time PCR was tested similar (67%) to the Procleix Ultrio discriminatory HBV test (dHBV) (70%) in low-titer samples from patients with occult Hepatitis B. Finally, in the comparison of ultra sensitive RTQ-PCR with the commercially available COBAS TaqMan HBV Test, the in-house assay identified 94.7% of the 94 specimens as positive versus 90.4% identified by TaqMan, while the quantitative results that were positive by both assay were strongly correlated (r = 0.979).

Conclusions

We report a new ultra sensitive real time PCR molecular beacon based assay with remarkable analytical and clinical sensitivity, calibrated against the WHO 1^st International standard.

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%).

Association of exon 9 but not intron 8 VDR polymorphisms with occult HBV infection in south-eastern Iranian patients

BACKGROUND AND AIM

Occult hepatitis B infection (OBI) is characterized as a form of hepatitis in which, despite the absence of detectable hepatitis B surface antigen (HBsAg), hepatitis B virus DNA (HBV-DNA) is present in a patient's peripheral blood. Investigators believe that divergent genetics and immunological parameters vary between resistant individuals and patients with OBI. Vitamin D3 and its known receptor appear to be involved in antiviral immune responses. Therefore, because OBI is a form of viral infection, the aim of this study was to investigate the association between polymorphisms in intron 8 and exon 9 of the vitamin D receptor (VDR) with OBI.

METHODS

In this experimental study, the plasma samples of 3700 blood donors were collected and tested for HBsAg and anti-HBs using ELISA. The HBsAg(-)/anti-HBc(+) samples were selected and screened for HBV-DNA using polymerase chain reaction (PCR). HBV-DNA-positive samples assigned as OBI cases and PCR-restricted fragment length polymorphism.

RESULTS

The results of the current study demonstrated that 352 (9.5%) of 3700 blood samples were HbsAg(-)/anti-HBc(+). HBV-DNA was detected in 57/352 (16.1%) of HBsAg(-)/anti-HBc(+) samples. Our results showed a significant difference in the T/T allele of exon 9 of VDR, but any differences were also observed in the other examined alleles.

CONCLUSION

The polymorphisms in the T/T allele of exon 9 of VDR is possibly associated with OBI, thus it can be concluded that VDR and its functional polymorphisms are likely to be related to sensitivity and resistance of the immune system to HBV in OBI patients.

Hepatitis B virus genotypes and evolutionary profiles from blood donors from the northwest region of China

Hepatitis B virus (HBV) is prevalent in China and screening of blood donors is mandatory. Up to now, ELISA has been universally used by the China blood bank. However, this strategy has sometimes failed due to the high frequency of nucleoside acid mutations. Understanding HBV evolution and strain diversity could help devise a better screening system for blood donors. However, this kind of information in China, especially in the northwest region, is lacking. In the present study, serological markers and the HBV DNA load of 11 samples from blood donor candidates from northwest China were determined. The HBV strains were most clustered into B and C genotypes and could not be clustered into similar types from reference sequences. Subsequent testing showed liver function impairment and increasing virus load in the positive donors. This HBV evolutionary data for China will allow for better ELISA and NAT screening efficiency in the blood bank of China, especially in the northwest region.