Reactivation of occult hepatitis B virus infection following cytotoxic lymphoma therapy in an anti-HBc negative patient

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.

[Hepatitis B vaccines-history, achievements, challenges, and perspectives]

Die ersten Impfversuche gegen das Hepatitis-B-Virus (HBV) erfolgten 1970, noch bevor die Natur des dafür verwendeten „Australia-Antigens“ bekannt war. Bald darauf wurde dieses Antigen als Hüllprotein des HBV erkannt (HBV Surface Antigen, HBsAg), dann aus HBV-haltigem Plasma gereinigt und später gentechnisch in Hefezellen hergestellt. Die hohe Wirksamkeit des HBsAg-Impfstoffs wurde vielfach bewiesen, insbesondere bei Neugeborenen von HBV-infizierten Müttern, die sonst fast immer chronische HBV-Träger werden. Auch bei älteren Kindern und Erwachsenen schützt die Impfung und wird seit 1984 weltweit angewendet, was zu einer ungefähr 10-fachen Abnahme der HBV-Infektionen bei den Geimpften geführt hat.

Es gibt dennoch verschiedene Herausforderungen bei der Hepatitis-B-Impfung. Bei Neugeborenen von hochvirämischen Müttern kann die Impfung versagen. Bei verringerter Immunkompetenz kann die Bildung schützender Antikörper ausbleiben, aber auch bei Risikofaktoren wie höherem Alter, Rauchen oder Übergewicht. Frühe Impfstudien belegten, dass Impfstoffe mit dem HBsAg-Subtyp adw2 auch gegen HBV mit anderen HBsAg-Subtypen schützen, neuere Beobachtungen zeigen aber, dass die Schutzwirkung gegen heterologe Subtypen schwächer ist. Gelegentlich werden auch Escape-Mutationen beobachtet.

Die meisten jetzigen Impfstoffe beruhen auf dem Kenntnisstand vor 40 Jahren und könnten wesentlich verbessert werden. Eine Einbeziehung der bislang fehlenden PräS-Domänen der HBV-Hülle in die Impfstoffe würde die wichtigsten schützenden T‑ und B‑Zellepitope einbringen. Die Expression in Säugerzellkulturen verbessert die native Faltung der neutralisierenden HBsAg-Epitope und die Verwendung von regional vorherrschenden HBsAg-Subtypen würde die Schutzwirkung erhöhen. Optimale Adjuvanzien oder Epitopträger könnten die Immunogenität auch für eine HBV-Immuntherapie steigern.

Evolution and phenotypic characterization of whole HBV genome in compliant patients experiencing unexplained entecavir treatment failure

Entecavir treatment failure can be observed in compliant patients despite an absence of detectable resistance mutations by Pol/RT Sanger sequencing. We hypothesized that these unexplained treatment failures could rely on other mechanisms of viral resistance, especially on mutations selected outside of the Pol/RT domain. Partial virological response to entecavir was observed in three patients treated with immunosuppressive drugs, without selection of Pol/RT resistance mutations. Mutations selected in the whole HBV genome during entecavir treatment and potentially associated with resistance were searched for using deep sequencing and characterized using a phenotypic resistance assay. Mutations Q206K (pre-core/core), Q120K (pre-S1/pre-S2, T-cell epitope) and A300E (spacer domain) were selected during entecavir treatment in patient #1 but were not associated with an increased level of resistance to entecavir or an increase in HBV replication capacity. Core promoter mutations T1753G, A1762T and G1764A were present as major mutations before and after treatment in patient #1. HBs Ag immune escape mutations were present as major mutations before and after treatment in patients #2 (sK122R, sT126I, sP127S and sG145R) and #3 (sM133I). We demonstrated that PVR to entecavir does not require selection of any resistance mutation in the whole HBV genome. Our results demonstrate that major mutations can be selected outside of the Pol/RT domain before or during entecavir treatment. These mutations could contribute to entecavir treatment failure by other mechanisms than an increased level of resistance.

Japan Society of Hepatology Guidelines for the Management of Hepatitis B Virus Infection: 2019 update

The Drafting Committee for Hepatitis Management Guidelines established by the Japan Society of Hepatology published the first version of the Guidelines for the Management of Hepatitis B in 2013 (first English version in 2014), and has since been publishing updates to the Guidelines as new drugs become available, with the latest original Japanese version being Version 3.1. Herein, the Drafting Committee publishes the second English version that contains all the changes made since the first English version of the guidelines was published in 2014. This 2019 version covers: (i) the nucleos(t)ide analogs, tenofovir disoproxil fumarate and tenofovir alafenamide; (ii) updates to treatment recommendations and management of drug-resistant hepatitis B virus that reflect the new availability of these drugs; and (iii) new information about hepatitis B virus reactivation with each update. This latest update also contains information about treatment goals, indications for treatment and cessation of nucleos(t)ide analog therapy, most of which were covered by the first version.

Ultra-high sensitivity HBsAg assay can diagnose HBV reactivation following rituximab-based therapy in patients with lymphoma

BACKGROUND & AIMS

HBV reactivation is a risk in patients receiving anti-CD20 antibodies for the treatment of lymphoma. The purpose of this post hoc analysis was to evaluate the efficacy of an ultra-high sensitivity HBsAg assay to guide preemptive antiviral treatment in patients with lymphoma and resolved HBV infections using prospectively stored samples from an HBV DNA monitoring study.

METHODS

HBV reactivation (defined as HBV DNA levels of ≥11 IU/ml) was confirmed in 22 of 252 patients. A conventional HBsAg assay (ARCHITECT, cut-off value: 0.05 IU/ml) and an ultra-high sensitivity HBsAg assay employing a semi-automated immune complex transfer chemiluminescence enzyme technique (ICT-CLEIA, cut-off value: 0.0005 IU/ml) were performed at baseline, at confirmed HBV reactivation and monitored after HBV reactivation.

RESULTS

Baseline HBsAg was detected using ICT-CLEIA in 4 patients; in all of whom precore mutants with high replication capacity were reactivated. Of the 6 patients with HBV DNA detected below the level of quantification at baseline, 5 showed HBV reactivation and 3 of the 5 had precore mutations. Sensitivity for detection by ARCHITECT and ICT-CLEIA HBsAg assays at HBV reactivation or the next sampling after HBV reactivation was 18.2% (4 of 22) and 77.3% (17 of 22), respectively. Of the 5 patients undetectable by ICT-CLEIA, HBV reactivation resolved spontaneously in 2 patients. All 6 patients reactivated with precore mutations including preS deletion could be diagnosed by ICT-CLEIA HBsAg assay at an early stage of HBV reactivation. Multivariate analysis showed that an anti-HBs titer of less than 10 mIU/ml, HBV DNA detected but below the level of quantification, and HBsAg detected by ICT-CLEIA at baseline were independent risk factors for HBV reactivation (adjusted hazard ratios, 15.4, 31.2 and 8.7, respectively; p <0.05).

CONCLUSIONS

A novel ICT-CLEIA HBsAg assay is an alternative method to diagnose HBV reactivation.

CLINICAL TRIAL NUMBER

UMIN000001299.

LAY SUMMARY

Hepatitis B virus can be reactivated in lymphoma patients receiving anti-CD20 antibodies such as rituximab. Currently, reactivation requires the monitoring of HBV DNA, but monitoring of the surface antigen (HBsAg) could provide a relatively inexpensive, quick and easy alternative. We assessed the performance of an ultra-high sensitivity HBsAg assay and showed that it could be effective for the diagnosis and monitoring of HBV reactivation.

Laboratory Diagnosis and Monitoring of Viral Hepatitis

Many microbes, toxins, autoimmune diseases, and neoplastic diseases may cause liver inflammation; however, 5 viruses whose main pathogenesis is liver disease are referred to as hepatitis A, B, C, D, and E viruses. These viruses cause a significant burden of global illness. With the exception of hepatitis A virus, all may cause chronic infection potentially leading to cirrhosis and hepatocellular carcinoma. Excellent serologic and nucleic acid detection methods are available for determining the precise cause and, in some cases, the duration of infection. Diagnostics are critical for identifying individuals needing treatment and for monitoring the treatment success.

Hepatitis B Virus Infection Among Patients With Chronic Kidney Disease Who Attended an Educational Program in Japan

The rate of hepatitis B infection among hemodialysis patients is high. However, it is not clear if this rate reflects the infection rate among patients with chronic kidney disease (CKD). Therefore, we evaluated the rate of hepatitis B infection among patients with CKD. This is an important clinical issue when considering the risk of infection to medical staff when performing invasive procedures in this clinical population. A retrospective, observational study was conducted among stable, non-dialysis patients with CKD who attended a CKD educational program at our hospital, between August 2012 and October 2017. We collected patients' background and markers of hepatitis infection (HBsAg, HBcAb and HBsAb, as well as HBV-DNA when available) from medical records. The data from 496 patients (373 men and 123 women, with a mean age of 69.3 ± 13.0 years and mean level of creatinine of 3.15 ± 1.72 mg/dL, AST of 21.6 ± 10.5 IU/L, and ALT of 17.3 ± 12.5 IU/L), were included in the analysis. The rate of positive testing for hepatitis B virus infection was as follows: HBsAg, 1.6%; HBsAb, 16.5%; and HBcAb, 21.4%. Of the patients with a negative HBsAg test, 20.1% tested positive for HBcAb. Of the 66 patients in whom HBV-DNA testing was performed, 10.6% tested positive. The rate of hepatitis B virus infection was specifically higher among patients ≥71-years-old. In patients with CKD, the rate of HBsAg positivity is high. Rate of HBcAb positivity is higher particularly in older individuals.

Patterns of serologic markers of hepatitis B virus infection and the risk of transmission among pregnant women in southwestern Nigeria

Hepatitis B virus (HBV) infection is a major health concern in developing countries that has a high morbidity and mortality rate. Vertical transmission of HBV from mother to child has been identified as a major factor leading to chronicity with attendant liver conditions, especially in poor socioeconomic settings. This study aims to evaluate the prevalence of serological HBV markers among pregnant women in Ibadan southwestern Nigeria and to determine the implications for perinatal HBV transmission. This study revealed the presence of varied HBV serological patterns of infection or immunity among pregnant women in Ibadan, Nigeria, and thus the risk of mother to child transmission.

Chronologic changes in serum hepatitis B virus DNA, genotypes, surface antigen mutants and reverse transcriptase mutants during 25-year nationwide immunization in Taiwan

We investigated breakthrough infection and hepatitis B virus (HBV) genetic changes in immunized subjects after 25 years of a universal infant immunization. Specifically, serum HBV DNA, genotypes, surface antigen mutants and nucleoside analog-resistant (NAr) mutants were assessed in 2853 subjects (<25 years old) surveyed in 2009, and these data were compared with the data from previous serosurveys. A comparison across different age-stratified groups using the 2009 data revealed a significant increase in the seropositive rate of anti-HBc (5.51% vs 12.38%, P=.001) and HBV DNA (1.13% vs 3.96%, P=.007) between those 17-22 and 23-24 years of age, possibly due to selective infant immunization in 1984-1986. Well-characterized NAr mutants, potential NAr mutants and surface "a" determinant mutants were detected in none, 15 (45.5%) and nine (27.3%) of 33 HBV DNA-positive subjects, respectively. Of 15 immunized, HBV DNA-positive young adults (18-24 years), three (20%) carried "a" determinant mutants. Amongst 1176 HBsAg-negative subjects evaluated for occult HBV infection, those seropositive for anti-HBc had a higher seropositive rate for HBV DNA (10/110, 9.1% vs 7/1066, 0.66%; P<.001) and "a" determinant mutants (4/110, 3.6% vs 0/1066; P<.001) than those seronegative for anti-HBc. Overall, the HBsAg-positive subjects in six serosurveys showed no significant increase in genotype C frequency in the comparison between the vaccinated and unvaccinated cohorts (25/98, 25.5% versus 14/79, 17.7%, P=.188). Over the 25-year programme, there was no increase in the prevalence of genotype C in HBsAg carriers and no increase in breakthrough HBV infection or surface mutant prevalence beyond adolescence. Nucleic acid amplification should still be considered the primary screening method for occult hepatitis B detection in high-risk recipients.

Risk factors and outcomes of hepatitis B virus reactivation in hepatitis B surface antigen negative patients with hematological malignancies

AIM

Current guidelines recommend all patients scheduled to receive chemotherapy should be screened for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B virus core antigen (anti-HBc) status. However, still, more research is needed to identify the risk factors for hepatitis B virus (HBV) reactivation. We retrospectively investigated the incidence, risk factors and outcome of HBV reactivation in HBsAg negative patients with hematological malignancies.

METHODS

Seven hundred and thirty-eight HBsAg negative patients with hematological malignancies were included in the study. HBV reactivation was defined as reverse seroconversion of HBsAg (HBsAg reappearance). Risk factors, cumulative incidence and overall survival of HBV reactivation were analyzed.

RESULTS

Reactivation occurred in 23 of the 738 (3.1%) enrolled patients. As expected, the reactivation rate of the anti-HBc positive group was significantly higher than that of the anti-HBc negative group (5.4% vs 0.8%). Multivariate analysis indicated that loss of antibody to the hepatitis B surface antigen (anti-HBs) was an independent risk factor. Patients with acute lymphoblastic leukemia and multiple myeloma showed significantly higher reactivation rate than those with other diseases. The cumulative incidence of HBV reactivation after starting chemotherapy in the anti-HBc positive subgroup was 0.3% at 1 year, 1.7% at 2 years and 10.5% at 3 years.

CONCLUSION

Close monitoring of HBV markers, including anti-HBs, should be performed for longer than 24 months. Further study is needed to establish a strategy to prevent HBV reactivation after chemotherapy in HBsAg negative patients with hematological malignancies.

Age-dependent decrease of anti-HBs titers and effect of booster doses using 2 different vaccines in Palestinian children vaccinated in early childhood

Immunization against hepatitis B virus (HBV) has proven to be highly effective and led to significant reduction of new infections worldwide. However, protective immunity measured by anti-HBs titers may decrease to critical levels in the years after basal immunization, particularly in case of exposure to HBV variants different from the vaccine strain. We tested 400 Palestinian children between one and 19 years of age for their anti-HBs titer, challenged the immune memory of those with low or absent anti-HBs with 2 types of hepatitis B vaccines and determined thereafter the anti-HBs titer. At the age of one, 92.2% of the children presented with protective anti-HBs titers (≥ 10 mIU/ml) with the majority having ≥ 100 mIU/ml. Protective immunity was still high at ages 2 (87.5%) and 4 (95%), declining by age 5 and 6 (from 69.2% to 66.7%) and down to an average of 39.8% between the ages of 7 and 19. 160 children with a nonprotective or low immune response challenged with either the yeast-derived Engerix-B or the mammalian cell-derived preS1-containing Sci-B-Vac vaccine showed an anamnestic immune response. 92.4% and 85.9% of the children challenged with one dose Sci-B-Vac and Engerix-B presented with anti-HBs titers >100 mIU/ml respectively. Our results reveal that vaccine-induced protective anti-HBs titers against HBV decrease rapidly beyond the age of 6 in Palestinian children, but can be strongly enhanced with a single booster vaccine dose, independent of brand and antigen composition. Our data suggest that a booster vaccine dose against HBV during school years may be useful.

Hepatitis B Reactivation During Immunosuppressive Therapy or Cancer Chemotherapy, Management, and Prevention: A Comprehensive Review-Screened

CONTEXT

Due to the close relationship between the immune system and the hepatitis B virus (HBV) replication, it is essential to monitor patients with current or past HBV infection under any type of immunosuppression. Cancer chemotherapy, immunosuppressive therapies in autoimmune diseases, and immunosuppression in solid organ and stem cell transplant recipients are the major reasons for hepatitis B virus reactivation (HBVr). In this review, the challenges associated with HBVr are discussed according to the latest studies and guidelines. We also discuss the role of treatments with different risks, including anti-CD20 agents, tumor necrosis factor-alpha (TNF-α) inhibitors, and other common immunosuppressive agents in various conditions.

EVIDENCE ACQUISITION

Through an electronic search of the PubMed, Google Scholar, and Scopus databases, we selected the studies associated with HBVr in different conditions. The most recent recommendations were collected in order to reach a consensus on how to manage patients at risk of HBVr.

RESULTS

It was found that the positive hepatitis B surface antigen (HBsAg), the high baseline HBV DNA level, the positive hepatitis B virus e antigen (HBeAg), and an absent or low hepatitis B surface antibody (HBsAb) titer prior to starting treatment are the most important viral risk factors. Furthermore, rituximab, anthracycline, and different types of TNF-α inhibitors were identified as the high-risk therapies. By analyzing the efficiency of prophylaxis on the prevention of HBVr, it was concluded that those with a high risk of antiviral resistance should not be used in long-term immunosuppressants. Receiving HBV antiviral agents at the commencement of immunosuppressant therapy or chemotherapy was demonstrated to be effective in decreasing the risk of HBVr. Prophylaxis could also be initiated before the start of therapy. For most immune suppressive regimes, antiviral therapy should be kept up for at least 6 months after the cessation of immunosuppressive drugs. However, the optimal time of prophylaxis keeping should be increased in cases associated with rituximab or hematopoietic stem cell transplants. According to the latest studies and guidelines from different bodies, recommendations regarding screening, monitoring, and management of HBVr are outlined.

CONCLUSIONS

Identification of patients at the risk of HBVr before immunosuppressive therapy is an undeniable part of treatment. Starting the antiviral therapy, based on the type of immunosuppressive drugs and the underlying disease, could lead to better management of disease.

Reactivation of occult hepatitis B virus infection in patients with rheumatic diseases: pathogenesis, risk assessment and prevention

Over the past decade, reactivation of occult hepatitis B virus (HBV) infection has garnered much attention from rheumatologists owing to a number of reports which have indicated the potential risk of biologics in causing this previously ignored infectious complication. Hepatitis due to reactivation of occult HBV infection occurs only occasionally but with high mortality upon occurrence, placing us in a clinical dilemma "to address or not to address?" In this review, we discuss how biological and other immunosuppressive therapies increase the risk of developing reactivation of occult HBV infection and attempt to solve this clinical quandary.

Risk of Reverse Seroconversion of Hepatitis B Virus Surface Antigen in Rituximab-Treated Non-Hodgkin Lymphoma Patients: A Large Cohort Retrospective Study

Rituximab causes hepatitis B virus (HBV) reactivation in HBV surface antigen (HBsAg)-seronegative patients with CD20-positive B-cell non-Hodgkin lymphoma (CD20 NHL), especially for those seropositive to the antibody of core antigen (anti-HBc). Clinical hepatitis usually develops after reverse seroconversion of HBsAg (HBV-RS), indicated by the reappearance of HBsAg in serum. Because of the relatively high prevalence of anti-HBc seropositivity in unvaccinated HBsAg-seronegative adults in an HBV hyperendemic area, we aimed to investigate additional factors influencing the development of rituximab-associated HBV-RS.Between January 2000 and December 2010, unvaccinated HBsAg-seronegative adults with CD20 NHL who had received rituximab-containing therapy but not anti-HBV agents were enrolled. Patients with and without HBV-RS were compared in terms of clinical factors and treatments including the number of cycles of rituximab therapy, and transplantation. Competing risk regression was used to identify the factors associated with HBV-RS.For the 482 patients enrolled, the serological status of anti-HBc was available in 75.9%, with a seropositivity rate of 86.6%. At the last follow-up, a total of 33 (6.85%) patients had HBV-RS, with 95.8% anti-HBc seropositive, 78.9% anti-HBs seropositive, and none anti-HCV seropositive. HBV-RS patients have received more cycles (≥6) and prolonged durations of rituximab therapy, and hematopoietic stem cell transplantation. The overall survival was not different between patients with and those without HBV-RS. At the time of HBV-RS, a total of 25 (78.1%) patients had hepatitis flare, especially when HBV-RS appeared during/after induction therapy (100%, 10 of 10). Three (9.1%) patients had fulminant hepatitis, resulting in death in 1 (3%) patient. A higher rituximab cycle intensity was associated with a higher rate of hepatitis flare at the time of HBV-RS. When death in the absence of HBV-RS was considered as the competing risk, the univariate and multivariate regression analyses showed that several factors were independently associated with the development of HBV-RS, including anti-HCV seronegativity, histological subtype of posttransplant lymphoproliferative disorders, ≥6 cycles of rituximab therapy, and succeeding hematopoietic stem cell transplantation.The findings of our study identify additional factors influencing the development of rituximab-associated HBV-RS in HBsAg-seronegative adults with CD20 NHL.

Prophylactic vaccination against hepatitis B: achievements, challenges and perspectives

Large-scale vaccination against hepatitis B virus (HBV) infection started in 1984 with first-generation vaccines made from plasma of chronic carriers containing HBV surface antigen (HBsAg). Thereafter, it was replaced in most countries by second-generation vaccines manufactured in yeast cells transformed with gene S encoding HBsAg. Both generations of vaccines have been applied for universal neonate and early childhood vaccination worldwide and have led to a 70-90 % decrease in chronic HBV carrier rates. However, 10-30% of newborns from HBsAg/HBeAg-positive mothers cannot be protected by passive/active vaccination alone and become chronic HBV carriers themselves. Asymptomatic occult HBV infections are frequent even in those who have protective levels of anti-HBs. Suboptimal protection may be due to heterologous HBsAg subtypes that are present in 99% of HBV carriers worldwide. Second-generation vaccines contain partially misfolded HBsAg and lack preS1 antigen that carries the major HBV attachment site and neutralizing epitopes. Third-generation vaccines produced in mammalian cells contain correctly folded HBsAg and neutralizing epitopes of the preS antigens, induce more rapid protection, overcome nonresponse to second-generation vaccines and, most importantly, may provide better protection for newborns of HBV-positive mothers. PreS/S vaccines expressed in mammalian cells are more expensive to manufacture, but introduction of more potent HBV vaccines should be considered in regions with a high rate of vertical transmission pending assessment of health economics and healthcare priorities. With optimal vaccines and vaccination coverage, eradication of HBV would be possible.

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.

Therapy of occult hepatitis B virus infection and prevention of reactivation

Occult hepatitis B virus infection (OBI) is highly prevalent worldwide. In some cases, it is a consequence of infection with variant viruses mutated in the S gene and producing a surface antigen not recognized by diagnostic kits. In most cases, OBI is due to a strong inhibition of hepatitis B virus (HBV) activities exerted by host defense mechanisms. OBI may reactivate in patients undergoing immunosuppressive therapy and/or chemotherapy with the possibility of a consequent development of acute hepatitis that may lead to hepatic failure. Hematological malignancies and therapeutic schedules including rituximab are the conditions most frequently associated with OBI reactivation. However, this event may occur in a large number of additional clinical and therapeutic settings. Identification of patients prone to undergo reactivation is of great importance for promptly starting a proper antiviral therapy that may stop the HBV reactivation and prevent its clinical sequelae.

Cytokine and chemokine responses in the acute phase of hepatitis B virus replication in naive and previously vaccinated blood and plasma donors

BACKGROUND

Blood and plasma donor screening for hepatitis B virus (HBV) DNA, HBV surface antigen (HBsAg), and antibodies to surface (anti-HBs) and core (anti-HBc) antigens allows identification of individuals who acquired HBV despite previous HBV vaccination.

METHODS

Of 14 HBV acute infection donor panels (HBV-DNA-positive/anti-HBc-negative), 6 donors were previously vaccinated (anti-HBs+). We investigated the differences in viral kinetics and immune responses in vaccinated and nonvaccinated individuals. Serial specimens were characterized for HBV DNA and serological markers and 39 cytokines.

RESULTS

The rate of viral load increase was blunted, and virus was cleared more rapidly in vaccinated individuals (P = .004). In unvaccinated individuals, induced protein 10 (IP-10), interleukin 10 (IL-10), macrophage inflammatory protein 1β (MIP-1β), and soluble interleukin 2Rα (sIL-2Rα) levels were commonly elevated at the time of peak viremia. In contrast, vaccinated individuals had earlier peaks in IL-10 and IP-10 responses that occurred at much lower viral loads and coincided with anamnestic anti-hepatitis B surface (HBs) responses and clearance of viremia.

CONCLUSION

There is earlier engagement of innate and adaptive immunity in infected subjects with previous vaccination, possibly explaining suppressed viremia in vaccine breakthrough infections. Although breakthrough infections occur in partially protected vaccine recipients, vaccination likely contributes to early control of replication, limiting immune activation and preventing development of clinically significant acute and chronic HBV infection.

Medical virology of hepatitis B: how it began and where we are now

Infection with hepatitis B virus (HBV) may lead to acute or chronic hepatitis. HBV infections were previously much more frequent but there are still 240 million chronic HBV carriers today and ca. 620,000 die per year from the late sequelae liver cirrhosis or hepatocellular carcinoma. Hepatitis B was recognized as a disease in ancient times, but its etiologic agent was only recently identified. The first clue in unraveling this mystery was the discovery of an enigmatic serum protein named Australia antigen 50 years ago by Baruch Blumberg. Some years later this was recognized to be the HBV surface antigen (HBsAg). Detection of HBsAg allowed for the first time screening of inapparently infected blood donors for a dangerous pathogen. The need to diagnose clinically silent HBV infections was a strong driving force in the development of modern virus diagnostics. HBsAg was the first infection marker to be assayed with a highly sensitive radio immune assay. HBV itself was among the first viruses to be detected by assay of its DNA genome and IgM antibodies against the HBV core antigen were the first to be selectively detected by the anti-μ capture assay. The cloning and sequencing of the HBV genome in 1978 paved the way to understand the viral life cycle, and allowed development of efficient vaccines and drugs. Today’s hepatitis B vaccine was the first vaccine produced by gene technology. Among the problems that still remain today are the inability to achieve a complete cure of chronic HBV infections, the recognition of occult HBV infections, their potential reactivation and the incomplete protection against escape mutants and heterologous HBV genotypes by HBV vaccines.