Role of silent hepatitis B virus in chronic hepatitis B surface antigen(-) liver disease

Comparison of High-Throughput Fully Automated Immunoanalyzers for Detecting Hepatitis B Virus Infection

CONTEXT.—

High-throughput automated immunoanalyzers for hepatitis B virus serologic markers have been introduced but have not been compared to existing systems.

OBJECTIVE.—

To compare hepatitis B surface antigen, hepatitis B surface antibody, and total hepatitis B core antibody analyses between our Architect i2000 platform and newer high-throughput fully automated immunoanalyzers.

DESIGN.—

From May to June 2018, a total of 932, 914, and 1055 samples tested for hepatitis B surface antigen, hepatitis B surface antibody, and total hepatitis B core antibody, respectively, with the Architect i2000 system for routine testing in our center were tested again with Alinity i, Atellica IM, and Cobas e801 systems.

RESULTS.—

Total concordance rates among the systems were 98.0%, 89.5%, and 93.0% for hepatitis B surface antigen, hepatitis B surface antibody, and total hepatitis B core antibody, respectively. Cohen's κ values exceeded 0.8. The correlations between serum hepatitis B surface antibody levels quantified by all 4 systems were high (r > 0.85). The hepatitis B surface antibody averages were greater for the Alinity i, Atellica IM, and Cobas e801 than for the Architect i2000 (P < .001).

CONCLUSIONS.—

Alinity i, Atellica IM, and Cobas e801 automated immunoanalyzers performed well when compared with the existing Architect i2000 system with regard to detection of hepatitis B viral infection. However, the new systems have higher titer and positivity rates for hepatitis B surface antibody and are more sensitive. Notably, the Atellica IM has a lower positive rate for total hepatitis B core antibody than does the Architect i2000.

Favorable effect of corticosteroids in treating acute-on-chronic liver failure underlying chronic hepatitis B

Acute-on-chronic liver failure (ACLF) occurs in the presence of a chronic liver disease or cirrhosis, and often results from exacerbation of chronic hepatitis B (CHB). The efficacy of corticosteroid treatment in ACLF patients with underlying CHB remains unclear. We report the case of a 50-year-old woman who experienced ACLF due to CHB exacerbation and was treated with a combination of corticosteroids and nucleot(s)ide analogue (NUC). The patient showed rapid decompensation due to CHB exacerbation. Three months of antiviral therapy produced no improvement in liver function. Combination therapy with corticosteroids and NUC was started, which did result in improvement of liver function. This case shows that the combined therapy of corticosteroids and NUC can be effective in treating ACLF due to CHB exacerbation.

Efficacy of lamivudine prophylaxis in preventing hepatitis B virus reactivation in patients with resolved infection undergoing allogeneic SCT and receiving rituximab

PURPOSE

Hepatitis B virus (HBV) reactivation during immunosuppressive therapy is common in patients with hematological malignancies, even in case of resolved infection. Prophylaxis of HBV reactivation is universally recommended in stem cell transplant (SCT) recipients and patients treated with anti-CD20 agents (i.e., rituximab). Despite its well-established favorable safety profile, lamivudine (LAM) use in prophylaxis has been debated because of the possible emergence of resistant viral strains. The aim of this study was to investigate the efficacy of LAM in preventing HBV reactivation in allogeneic SCT recipients with a resolved HBV infection.

METHODS

Patients who received first allogeneic SCT in years 2009-2016 were evaluated. Sixty-three patients with resolved infection received LAM prophylaxis and were included in the study. Baseline and post-SCT characteristics were recorded, including rituximab exposure, length of LAM prophylaxis, and time from transplant to the last clinical and virological follow-up.

RESULTS

Overall, 39 patients (62%) were male, 39 (62%) had acute myeloid leukemia, 38 (60%) received transplant from haploidentical donor, 29 (53%) received myeloablative conditioning, and 15 (24%) received rituximab post-transplant. Median clinical follow-up was 24 months after SCT (range 0.3-97); median virological follow-up 16 months (range 0.3-78), and median length of LAM prophylaxis of 14.5 months (range 0.3-78). No patient experienced HBV reactivation while on LAM prophylaxis. One patient experienced reactivation 8 months after discontinuing prophylaxis.

CONCLUSIONS

In this high-risk population, LAM prophylaxis was effective in preventing HBV reactivation in patients with resolved infection. It should be considered a reasonable first-line prophylactic agent to be administered in this setting.

Prevention of Hepatitis B reactivation in the setting of immunosuppression

Advances in the treatment of malignant and inflammatory diseases have developed over time, with increasing use of chemotherapeutic and immunosuppressive agents of a range of drug classes with varying mechanism and potency in their effects on the immune system. These advances have been met with the challenge of increased risk of hepatitis B virus (HBV) reactivation in susceptible individuals. The magnitude of risk of HBV reactivation is associated with the individual’s HBV serological status and the potency and duration of immunosuppression. Individuals with chronic hepatitis B (CHB) and previously infected but serologically cleared HBV infection are both susceptible to HBV reactivation. HBV reactivation in the setting of immunosuppression is a potentially life threatening condition leading to liver failure and death in extreme cases. It is important to recognize that HBV reactivation in the setting of immunosuppression is potentially preventable. Therefore, identification of patients at risk of HBV reactivation and institution of prophylactic antiviral therapy prior to initiation of immunosuppression is essential.

Identification of occult hepatitis B virus (HBV) infection and viral antigens in healthcare workers who presented low to moderate levels of anti-HBs after HBV vaccination

BACKGROUND

Worldwide, healthcare workers (HCWs) show different levels of response to hepatitis B virus (HBV) vaccine. One of the factors associated with vaccine unresponsiveness may be the existence of current or past HBV infection. Regardless of the presence of HBsAg (overt infection), occult HBV infection (OBI, defined as presence of HBV DNA in the absence of HBsAg) might also account for some non- or hypo-response cases.

METHODS

Sera from 120 HBsAg-negative HCWs with low and moderate levels of anti-HBs, <10 IU/mL (group I) and <100 IU/mL (group II) respectively, were selected and were examined for OBI by sensitive real-time PCR regardless of HBV serological profiles. Direct sequencing on surface genes was carried out in OBI-positive cases.

RESULTS

Four (3.3%) were positive for OBI. All were negative for anti-HBc. Two of the positive cases had moderate levels of anti-HBs (>10 to <100 IU/mL). No significant differences were found between the two groups in terms of risk factors or serological data. No mutations were found in surface proteins of OBI cases.

CONCLUSION

OBI in these subjects might be due to other factors rather than presence of "a" determinant mutations. Healthcare workers with inadequate to moderate levels of anti-HBs (<100 IU/mL) following vaccination, regardless of their serological profile for HBV, should be tested for the presence of HBV DNA by sensitive molecular tests. Anti-HBc is not a reliable marker for suspicion of OBI, especially in high-risk group individuals.

Hepatitis B virus reactivation and hepatitis in diffuse large B-cell lymphoma patients with resolved hepatitis B receiving rituximab-containing chemotherapy: risk factors and survival

Introduction

Hepatitis B virus (HBV) reactivation has been reported in B-cell lymphoma patients with resolved hepatitis B (hepatitis B surface antigen [HBsAg]-negative and hepatitis B core antibody [HBcAb]-positive). This study aimed to assess HBV reactivation and hepatitis occurrence in diffuse large B-cell lymphoma (DLBCL) patients with resolved hepatitis B receiving rituximab-containing chemotherapy compared with HBsAg-negative/HBcAb-negative patients to identify risk factors for HBV reactivation and hepatitis occurrence and to analyze whether HBV reactivation and hepatitis affect the survival of DLBCL patients with resolved hepatitis B.

Methods

We reviewed the clinical data of 278 patients with DLBCL treated with rituximab-containing therapy between January 2004 and May 2008 at Sun Yat-sen University Cancer Center, China. Predictive factors for HBV reactivation, hepatitis development, and survival were examined by univariate analysis using the chi-square or Fisher’s exact test and by multivariate analysis using the Cox regression model.

Results

Among the 278 patients, 165 were HBsAg-negative. Among these 165 patients, 6 (10.9%) of 55 HBcAb-positive (resolved HBV infection) patients experienced HBV reactivation compared with none (0%) of 110 HBcAb-negative patients (P = 0.001). Patients with resolved hepatitis B had a higher hepatitis occurrence rate than HBsAg-negative/HBcAb-negative patients (21.8% vs. 8.2%, P = 0.013). HBcAb positivity and elevated baseline alanine aminotransferase (ALT) levels were independent risk factors for hepatitis. Among the 55 patients with resolved hepatitis B, patients with elevated baseline serum ALT or aspartate aminotransferase (AST) levels were more likely to develop hepatitis than those with normal serum ALT or AST levels (P = 0.037, P = 0.005, respectively). An elevated baseline AST level was an independent risk factor for hepatitis in these patients. Six patients with HBV reactivation recovered after immediate antiviral therapy, and chemotherapy was continued. HBcAb positivity, HBV reactivation, or hepatitis did not negatively affect the survival of DLBCL patients.

Conclusions

DLBCL patients with resolved hepatitis B may have a higher risk of developing HBV reactivation and hepatitis than HBsAg-negative/HBcAb-negative patients. Close monitoring and prompt antiviral therapy are required in these patients.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

Discrepancy between serological and virological analysis of viral hepatitis in hemodialysis patients

BACKGROUND AND AIM

Viral hepatitis is a health threat for hemodialysis (HD) patients and it may be transmitted during treatment. Some patients categorized to have viral hepatitis were found to be non-viremic. To clarify the discrepancy between the serological tests in HD patients, we conducted the study.

METHODS

A total of 1681 HD patients was included. Blood samples were analyzed for hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody (anti-HCV). Detection of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA were performed in either HBsAg (+) or anti-HCV (+) samples. HBV DNA/HCV RNA was also measured in a subset of HBsAg (-) and anti-HCV (-) patients. Liver function tests were analyzed and compared with the serological and virological tests.

RESULTS

The serological tests showed that 230 patients (13.7%) were HBsAg (+) and 290 (17.3%) were anti-HCV (+). We were unable to detect HBV DNA in 97 of 230 (42.2%) HBsAg (+) patients, and HCV RNA could not be found in 76 of 290 (26.2%) anti-HCV (+) patients. In 167 HBsAg (-) patients, only one showed a trace amount of HBV DNA. None of 151 anti-HCV (-) patients showed detectable HCV RNA. The prevalence rate of viral hepatitis remains high in Taiwanese HD patients: 13.7% for HBV and 17.3% for HCV. However, virological analysis showed 42.2% non-viremic rate for HBsAg and 26.2% non-viremic rate for anti-HCV.

CONCLUSIONS

The findings might challenge the presently suggested principles of bed and machine dedication and the diagnosis of viral hepatitis in HD patients.

Cross-sectional study of hepatitis B virus infection in rural communities, Central African Republic

Background

As most data on hepatitis in resource-poor countries relate to urban communities, surveys in the rural environment are necessary to determine the ‘true’ prevalence of these viral infections. We undertook a survey to determine the prevalence of hepatitis B virus (HBV) infection in an apparently healthy rural population in the Central African Republic (CAR).

Methods

The cross-sectional study was based on dried blood spots (DBS) from 273 people recruited in four prefectures (Lobaye, Nana-Mambéré, Ouham and Ouaka). Eluates from DBS were tested with commercial ELISA kits to detect markers of HBV infection. DBS were directly used for DNA extraction, followed by PCR and genotyping based on preS/S gene sequences.

Results

The overall prevalence of HBc antibodies was 27.1% (Lobaye 29%, Nana-Mambéré 28%, Ouaka 29% and Ouham 23%) and that of HBsAg was 10.6% (Lobaye 9%, Nana-Mambéré 9%, Ouaka 19% and Ouham 8%), with no statistically significant difference among the surveyed communities. Nineteen sequences obtained from 74 anti-HBc-positive patients all belonged to genotype E. Risk factor analysis of HBV infection pointed to sexual transmission of the virus.

Conclusion

The prevalence of HBV is high in rural communities in the CAR and comparable to that observed in urban areas. In addition, genotype E is prevalent in these areas. These findings underline the importance of instituting a programme of active HBV surveillance and vaccination of the population.

Occult Hepatitis B (OBH) in Clinical Settings

CONTEXT

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

EVIDENCE ACQUISITION

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

RESULTS

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

CONCLUSIONS

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

HBsAg variants: diagnostic-escape and diagnostic dilemma

A wide variety of commercial assays is available for the detection of hepatitis B surface antigen (HBsAg). Clearly, the sensitivity of an assay to detect a variant is dependent on the anti-HBs usage. Thus, it is not surprising that there are examples of variants that cannot be detected by all assays. Data from Europe, Asia and Africa about HBsAg variants which are not recognized by either monoclonal or polyclonal antibodies specific for wild-type group 'a' determinant, but positive by DNA polymerase chain reaction (PCR) in chronic patients and from vaccinated children are increasing. This would impose a challenge for public health issues of hepatitis B virus. In this review we tried to summarize the discrepancies between results of HBsAg assays and to explain some rationales for these inconsistencies.

Mutations in TP53 and CTNNB1 in Relation to Hepatitis B and C Infections in Hepatocellular Carcinomas from Thailand

Hepatocellular carcinoma (HCC) may develop according to two major pathways, one involving HBV infection and TP53 mutation and the other characterized by HCV infection and CTNNB1 mutation. We have investigated HBV/HCV infections and TP53/CTNNB1 mutations in 26 HCC patients from Thailand. HBV DNA (genotype B or C) was detected in 19 (73%) of the cases, including 5 occult infections and 3 coinfections with HCV. TP53 and CTNNB1 mutations were not mutually exclusive, and most of TP53 mutations were R249S, suggesting a significant impact of aflatoxin-induced mutagenesis in HCC development.

Expression of Hepatitis B Virus Surface Antigen Containing Y100C Variant Frequently Detected in Occult HBV Infection

Small hepatitis B virus surface protein (S-HBsAg) variant Y100C has been associated with HBsAg-negative phenotype. To determine whether Y100C substitution yields impaired HBsAg or small amounts of HBsAg that may reduce HBsAg detection by commercial anti-HBsAg antibodies, two eukaryotic expression plasmids, one containing a wild-type S and the other an S gene from a Y100C variant, were constructed and their levels of HBsAg compared by ELISA after transfection of HuH7 cells. Unexpectedly, the extracellular HBsAg levels detected with Y100C plasmid were higher than those observed with the wild-type plasmid, but without statistical significance. We concluded that the Y100C substitution alone did not play a role in reducing HBsAg amounts or HBsAg affinity by commercial ELISA assay. Further studies on in vitro replication fitness with the complete genome of HBV isolates displaying or not Y100C substitution may elucidate whether this mutation affects HBV replication and consequently HBsAg production.

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

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

Occult hepatitis B virus infection in patients with chronic liver disease due to hepatitis C virus and hepatocellular carcinoma in Brazil

BACKGROUND

The prevalence and consequences of occult HBV infection in patients with chronic liver disease by HCV remain unknown.

AIMS

To evaluate the prevalence of occult HBV infection in a population of HCV-infected patients with hepatocellular carcinoma.

METHODS

The serum samples were tested for HBV DNA by nested PCR and liver tissue analysis was carried out using the immunohistochemical technique of 66 HBsAg-negative patients: 26 patients with chronic hepatitis by HCV (group 1), 20 with hepatocellular carcinoma related to chronic infection by HCV (group 2) and 20 with negative viral markers for hepatitis B and C (control group).

RESULTS

Occult HBV infection was diagnosed in the liver tissue of 9/46 (19.5%) HCV-infected patients. Prevalence of occult B infection was evaluated in the HCV-infected patients with and without hepatocellular carcinoma, and there were seven (77.7%) of whom from group 2, conferring a 35% prevalence of this group. No serum sample was positive for HBV DNA in the three groups.

CONCLUSION

Occult infection B is frequently detected in liver tissue of HCV-infected patients, especially in cases of hepatocellular carcinoma. However large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population.

Efficient hepatitis C antigen immunohistological staining in sections of normal, cirrhotic and tumoral liver using a new monoclonal antibody directed against serum-derived HCV E2 glycoproteins

Detection and localization of Hepatitis C Virus (HCV) in liver tissue is useful for diagnostic purposes as well as to elucidate the mechanisms by which the virus participates in hepatocarcinogenesis. However, so far, a sensitive method for HCV detection at the cellular level is lacking. We describe here the application of a novel antibody, D4.12.9, developed against serum-derived HCV RNA-positive particles, for the detection of E2 proteins by immunohistochemistry in fixed, archived specimens including liver biopsies of HCV-infected patients and surgical specimens of hepatocellular carcinoma. We demonstrate that D4.12.9 is a powerful tool for sensitive and specific detection of HCV, independently of viral genotype. This approach has applications to diagnosis as well as exploratory pathological studies.

Clinical impact of occult HBV infections

HBV infection in the absence of HBsAg has been a matter of debate for years, but its existence and clinical relevance are now supported by many publications, editorials and reviews. HBV DNA without HBs antigenemia was detected in the following clinical situations: (1) Chronic, presumably viral, hepatitis unrelated to HCV, atypical alcoholic hepatitis and hepatocellular carcinoma (HCC); (2) viral reactivation following immunosuppression; (3) Transmission through transplantation, transfusion or experimental transmission to chimpanzees. Occult HBV infections are not restricted to areas of high HBV endemicity. Indeed, such cases have been described in Western countries including France. It is now established that occult HBV infection among non-HCV patients suffering from chronic hepatitis varies from 20% to 30% in Europe, and in the context of HCV infection it varies from 20% in France up to 80% in Japan. The percentage of occult HBV infections among non A-E cases depends on several parameters: (1) The method of detection, including PCR primer selection; (2) patient recruitment; (3) patients from countries highly endemic for HBV are more likely to develop occult HBV infections; (4) prevalence may also vary depending on the nature of biological material tested, with a higher proportion for liver compared to serum specimen. The mechanisms leading to HCC in occult HBV infection seem similar to those overt cases, patients with low-grade but diagnosable HBV replication that retains its pro-oncogenic properties. During the course of HCV infection, occult HBV infection may worsen liver damage induced by HCV and reduce the response to HCV antiviral treatment. Occult HBV infection is a frequent phenomenon and HBV DNA testing with highly sensitive PCR in the clinical setting is therefore becoming of paramount importance.

The relationship between HBV-DNA levels and cirrhosis-related complications in Chinese with chronic hepatitis B

We studied the hepatitis B virus (HBV)-DNA levels below which the development of cirrhosis-related complications became unlikely in chronic hepatitis B (CHB). Seventy-nine Chinese CHB patients with cirrhosis-related complications and 158 age-, sex- and HBeAg status-matched patients without complications were enrolled. The precore and core promoter mutations were detected by the Line Probe assay (LiPA). HBVDNA levels were determined by Digene assay and Cobas Amplicor Monitor test. Patients with complications had higher HBVDNA levels than those without complications (P = 0.02). HBeAg-positive patients with complications had similar alanine transferase (ALT) and HBVDNA levels and frequency of precore mutations, but higher frequency of core promoter mutations (P = 0.003), compared with those without complications. Anti-HBe-positive patients with complications had higher ALT and HBVDNA levels (P < 0.01) but similar frequency of precore and core promoter mutations, compared with those without complications. Anti-HBe patients (24.5%) with complications had HBVDNA levels <10(4) copies/mL. The major factor for the development of cirrhotic complications was viral loads but cirrhotic complications continued to develop in patients with HBVDNA levels below 10(4) copies/mL.

HBsAg-negative hepatitis B virus infections in hepatitis C virus-associated hepatocellular carcinoma

This study was conducted to evaluate reports that hepatitis B virus (HBV) DNA sequences can be found in the serum and/or tumour tissue from some hepatocellular carcinoma (HCC) patients who have no detectable hepatitis B surface antigen (HBsAg) in their sera. Such HBV infections would be highly atypical, because prospective studies have shown a clear succession of specific serologic markers during and after most HBV infections. As most HBsAg-negative HCC patients in Japan have hepatitis C virus (HCV) infections, the present study was conducted to determine whether some of these patients actually have unrecognized HBV infections. Thirty newly diagnosed HCC patients from Kurume, Japan, with antibody to the hepatitis C virus (anti-HCV) were studied. None of the 30 had HBsAg detectable in their serum. Of 22 for whom test results for antibodies to the hepatitis B core antigen (anti-HBc) and antibodies to HBsAg (anti-HBs) were available, 14 (64%) had anti-HBc and anti-HBs, four (18%) had anti-HBc alone, and four (18%) had no HBV markers. Nested polymerase chain reaction was used to detect the HBV surface (S), core (C), polymerase (P) and core promoter gene sequences in the HCC tissues and in the adjacent nontumorous liver tissues. HBV DNA was detected in HCC and/or adjacent nontumorous liver in 22 of 30 (73%) patients [detected in both HCC and nontumorous liver in 19/30 patients (63%)]. Among the 22 patients with detectable HBV DNA, more than one HBV gene was detected in 10 (46%). Among the four patients whose sera were negative for all HBV markers, three had HBV DNA in either HCC and nontumorous liver (two cases) or only in the nontumorous liver (one case); HBV DNA could not be detected in tissues from the fourth patient. In 18 of 21 (86%) patients with detectable HBV core promoter sequences, mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found. No deletions were detected in the core promoter gene region of the type reported to be associated with some cases of HBsAg-negative HBV infection. Thus, HBV DNA was detectable in 22 (73%) HBsAg-negative, anti-HCV-positive HCCs, including three (10%) who were also negative for anti-HBc and anti-HBs. HBV mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found in the majority of cases, mutations that have previously been reported in HBV that is integrated in HCC DNA. In serologic surveys to determine etiologic associations of HCC, patients such as those in this study would have been incorrectly designated as having 'HCV-associated HCC,' whereas the data in this study suggest that HBV could have played a role in the development of their HCCs.

Absence of hepatitis B virus DNA in patients with hepatitis C and non-A-E hepatitis in the State of São Paulo, Brazil

Occult hepatitis B virus (HBV) infection has been reported as cases in which HBV DNA was detected despite the absence of any HBV serological markers or in cases in which anti-HBc antibody was the sole marker. The aim of the present study was to determine, using the polymerase chain reaction (PCR), whether HBV infection occurs in hepatitis C and non-A-E hepatitis patients without serological evidence of hepatitis B infection in Sao Paulo State. Two different populations were analyzed: 1) non-A-E hepatitis patients, including 12 patients with acute and 50 patients with chronic hepatic disorders without serological evidence of infection with known hepatitis viruses; 2) 43 patients previously diagnosed as hepatitis C with positive results for anti-HCV and HCV RNA. Among hepatitis C patients, anti-HBc was detected in 18.6% of the subjects. Three different sets of primers were employed for HBV DNA detection by nested PCR, covering different HBV genes: C, S and X. HBV-DNA was not detected in any sample, whereas the positive controls did produce signals. The lack of HBV DNA detection with these pairs of primers could be due to a very low viral load or to the presence of mutations in their annealing sites. The latter is unlikely as these primers were screened against an extensive dataset of HBV sequences. The development of more sensitive methods, such as real time PCR, to detect circular covalent closed DNA is necessary in order to evaluate this question since previous studies have shown that cryptic hepatitis B might occur.

Molecular and serological evaluation of surface antigen negative hepatitis B virus infection in blood donors from Venezuela

Surface antigen negative hepatitis B virus (HBV) infection was evaluated in Venezuela, by molecular characterization of blood samples positive for antibodies to core antigen (anti-HBc) and negative for surface antigen (HBsAg) in blood donors (residual infections). HBV DNA was found in 11/258 samples (4.3%), and was significantly associated with high levels of anti-HBc antibodies (>25 UI/ml, P < 0.05), while no correlation was found between the presence of HBV DNA and the levels of anti-HBs. Synonymous and non-synonymous mutations were found in the HBV surface region (but not vaccine escape mutants) and in the precore/core region (precore mutants in 2/7 samples and 33-45 bp deletions near the N-terminal core region in 4/19 samples). While HBV genotype F prevails among HBsAg positive samples from blood donors in Venezuela, residual infection isolates were mainly genotypes A and D. Phylogenetic analysis of viral surface and core region revealed discrepancies in genotype designation in 6/9 samples, suggesting the presence of mixed infection or recombination. In conclusion, HBV residual infection in Venezuela does not seem to be frequently observed in HBV genotype F. This type of infection is frequently associated with variants exhibiting mutations in the surface gene that might be affecting the correct recognition by commercial tests, with precore mutants and with core internal deletions. These variants do not seem to cause severe liver disease, and on the contrary, were found circulating at low viremia.

Cloning and expression of surface antigens from occult chronic hepatitis B virus infections and their recognition by commercial detection assays

Occult hepatitis B virus (HBV) infections show little or no serological markers of viral infection, including the absence of hepatitis B surface antigen (HBsAg) which is the main marker of ongoing HBV infection. Such infections can be important in the context of blood and/or organ donations. To study whether mutations contribute to HBsAg seronegativity, S gene sequences from such patients were amplified and cloned. Sequencing revealed 12 clones from seven different patients which contained potentially important mutations. The sequences were subcloned into an expression vector and mutant HBsAgs were expressed in cell culture. The capacity of three HBsAg detection assays to recognise the mutant HBsAgs was studied. Three categories were found: mutant HBsAgs that are not recognised by the assays, those that are recognised as well as wild-type (WT) antigen and an intermediate category where detection of the mutant HBsAgs is reduced with respect to WT. Most of the isolates fall into the second category. Mutations can therefore contribute to HBsAg seronegativity in occult HBV infections, but in most cases the explanation is probably the low level of viral replication.

Occult hepatitis B virus infection does not affect liver histology or response to therapy with interferon alpha and ribavirin in intravenous drug users with chronic hepatitis C

BACKGROUND

the frequency and the impact of occult HBV infection in patients with chronic hepatitis C infection is still a matter of some controversy.

OBJECTIVES

our aim was to evaluate the prevalence of occult HBV infection and assess its impact on liver biochemistry, HCV viral titre, liver histology and on outcome of therapy in patients with chronic hepatitis C.

STUDY DESIGN

paired liver biopsies and serum samples were collected from 51 patients (84% IVDUS) with HBsAg negative chronic hepatitis C, and tested for HBV-DNA with nested PCR. Liver biopsies were further studied histologically, with morphometric analyses and immunostaining techniques. Twenty-five were treated with alpha Interferon and ribavirin and followed for at least 18 months.

RESULTS

HBV DNA was detected in 29.4% of liver tissue specimens and in only one (1.9%) serum sample. Three liver specimens were positive for surface gene, nine for core gene, three for both and none for the X gene. No significant difference in mean transaminase values, HCV viral titre, HCV genotype, or grading and staging and morphometric analysis was observed in patients with or without HBV DNA. Moreover, all 51 liver specimens were negative for both HBsAg and HBcAg. Sustained response to combination therapy was achieved in 40% of patients with and in 53% of patients without HBV DNA in the liver specimens (P=NS).

CONCLUSIONS

HBV DNA is frequently found in the liver of patients with chronic hepatitis C. However, the lack of any significant impact on HCV viral titre, liver enzymes, histological parameters and response to therapy, suggests that in most cases HBV DNA detected in the liver by PCR may be either an integrated or low level replicative form.

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Health and economic impact of posttransfusion hepatitis B and cost-effectiveness analysis of expanded HBV testing protocols of blood donors: a study focused on the European Union

BACKGROUND

Residual risk of posttransfusion hepatitis B (PT-HB) may be reduced through implementation of HBV NAT or the new, enhanced-sensitivity HBsAg assays in routine donor testing. However, there are some doubts about the cost-effectiveness of these new safety measures, because hepatitis B acquired in adulthood is not regarded as a severe disease in western countries.

STUDY DESIGN AND METHODS

A computer model was designed to estimate the health outcomes and associated costs of patients with PT-HB. Results from this model and estimations of the residual risk of HBV transmission, the risk reduction yielded by the new assays, and their cost were used to calculate the cost-effectiveness of including the new HBsAg assays or single-sample HBV NAT in the routine screening of blood donors.

RESULTS

The model predicts that 0.97 percent of patients with PT-HB die of liver disease (54% of them due to fulminant hepatitis). The mean loss of life expectancy was 0.178 years per patient, and the present value of the lifetime costs of treating PT-HB was 4160 euros per patient. Single-donor HBV NAT or the new HBsAg assays would increase the life expectancy of blood recipients by 16 (95% CI, 8-40) or 14 (95% CI, 7-28) years, respectively, per every 10 million donations tested. The projected cost per life-year gained was 0.79 (95% CI, 0.15-1.85) million euros for the enhanced-sensitivity HBsAg assays and 5.8 (95% CI, 1.9-13.1) million euros for single-donation HBV NAT, both compared with current HBsAg assays. If single-donation HBV NAT is compared with the new HBsAg assays, its cost- effectiveness ratio increases to 53 (95% CI, 16-127) million euros.

CONCLUSION

PT-HB has few health or economic repercussions. Single-donation HBV NAT would provide a small health benefit at a very high cost. Instead, in some circumstances, the cost-effectiveness of enhanced-sensitivity HBsAg assays would be within acceptable ranges for new public health interventions.

Occult hepatitis B

Worldwide, chronic hepatitis B virus (HBV) infection is the primary cause of cirrhosis and hepatocellular carcinoma and is one of the ten leading causes of death. Traditionally, people with chronic HBV infection have been identified with blood tests for HBV antigens and antibodies. Recently, another group of patients with chronic HBV infection has been identified by sensitive, molecular testing for HBV DNA. Members of this group are often referred to as having occult hepatitis B because they are HBV-DNA positive, but hepatitis B surface antigen negative. Occult hepatitis B occurs in a number of clinical settings. In this review, we examine occult hepatitis B in people co-infected with hepatitis C, in whom occult hepatitis B has been associated with advanced fibrosis and diminished response to interferon alpha. Although much more research is needed, existing reports justify a heightened awareness of the medical importance and means of testing for occult hepatitis B.