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1.
Occult hepatitis B virus infection(OBI), characterized as the persistence of hepatitis B virus(HBV) surface antigen(HBs Ag) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant "α" determinant of S protein are "hot spots" that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBs Ag or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.  相似文献   

2.
Occult hepatitis B virus infection: implications in transfusion   总被引:11,自引:0,他引:11  
Allain JP 《Vox sanguinis》2004,86(2):83-91
Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.  相似文献   

3.
Occult hepatitis B infection(OBI) is characterized by hepatitis B virus(HBV) DNA in serum in the absence of hepatitis B surface antigen(HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns.Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays;but more frequently it is due to a strong suppression of viral replication and gene expression.OBI is an entity with world-wide diffusion.The failure to detect HBsAg,despite the persistence of the viral DN...  相似文献   

4.
Occult HBV infection (OBI) is defined as persistence of HBV genomes (with detectable or undetectable serum HBV DNA) in the liver of serum HBsAg negative individuals. It represents the HBsAg negative phase of the natural history of HBV infection in individuals with self-limited acute hepatitis B or in HBsAg carriers or chronic hepatitis B patients who lose HBsAg either naturally or after antiviral therapy and maintain lifelong anti-HBc in serum (with or without anti-HBs and\or anti-HBe). Rarely it may occur as primary “occult” infection when caused by minute viral amounts unable to induce humoral immune response. HBsAg negative infections stem from lifelong intrahepatic persistence of HBV-ccc-DNA under the host’s immune control and may lead to HBsAg positive reactivation after immunosuppressive therapies or epigenetic modifications. HBV reactivation can be avoided by pre-emptive antiviral therapy with nucleos(t)ide analogs. OBI in chronic liver disease of other etiologies may contribute to the development of hepatocellular-carcinoma.  相似文献   

5.
Background: Gaps remain in the detection of nucleic acid test (NAT) yield and occult hepatitis B virus (HBV) infection (OBI) by current HBV surface antigen (HBsAg) assays. The lack of detection may be due to HBsAg levels below current assay detection limits, mutations affecting HBsAg assays or HBsAg levels, or the masking of HBsAg by antibody to HBsAg (anti-HBs). In this study, we evaluate the incremental detection of NAT yield and OBI from five diverse geographic areas by an improved sensitivity HBsAg assay and characterize the samples relative to the viral load, anti-HBs status, and PreS1–S2–S mutations. Included is a comparison population with HBV DNA levels comparable to OBI, but with readily detectable HBsAg (High Surface–Low DNA, HSLD). Methods: A total of 347 samples collected from the USA, South Africa, Spain, Cameroon, Vietnam, and Cote D’Ivoire representing NAT yield (HBsAg(−), antibody to HBV core antigen (anti-HBc)(−), HBV DNA(+), N = 131), OBI (HBsAg(−), anti-HBc(+), HBV DNA(+), N = 188), and HSLD (HBsAg(+), anti-HBc(+), HBV DNA(+), N = 28) were tested with ARCHITECT HBsAg NEXT (HBsAgNx) (sensitivity 0.005 IU/mL). The sequencing of the PreS1–S2–S genes from a subset of 177 samples was performed to determine the genotype and assess amino acid variability, particularly in anti-HBs(+) samples. Results: HBsAgNx detected 44/131 (33.6%) NAT yield and 42/188 (22.3%) OBI samples. Mean HBV DNA levels for NAT yield and OBI samples were lower in HBsAgNx(−) (50.3 and 25.9 IU/mL) than in HBsAgNx(+) samples (384.1 and 139.5 IU/mL). Anti-HBs ≥ 10 mIU/mL was present in 28.6% HBsAgNx(+) and 45.2% HBsAgNx(−) OBI, and in 3.6% HSLD samples. The genotypes were A1, A2, B, C, D, E, F, and H. There was no significant difference between HBsAgNx(−) and HBsAgNx(+) in the proportion of samples harboring substitutions or in the mean number of substitutions per sample in PreS1, PreS2, or S for the NAT yield or OBI (p range: 0.1231 to >0.9999). A total of 21/27 (77.8%) of HBsAgNx(+) OBI carried S escape mutations, insertions, or stop codons. HSLD had more PreS1 and fewer S substitutions compared to both HBsAgNx(−) and HBsAgNx(+) OBI. Mutations/deletions associated with impaired HBsAg secretion were observed in the OBI group. Conclusions: HBsAgNx provides the improved detection of NAT yield and OBI samples. Samples that remain undetected by HBsAgNx have exceptionally low HBsAg levels below the assay detection limit, likely due to low viremia or the suppression of HBsAg expression by host and viral factors.  相似文献   

6.
Immune control of various infectious diseases, particularly viral, was shown to be more efficient for females than males. Response to viral vaccines (HAV, HBV) was higher in females. Data on hepatitis B virus (HBV) markers accumulated over 15 years in blood donors was stratified according to sex, including HBsAg, HBV viral load and levels of anti-HBs in areas where genotypes B and C (China), genotype D (Iran, Lebanon, Tunisia) and genotype E (Ghana, Burkina Faso, Gabon) were prevalent. HBsAg was screened by either ELISA or rapid tests, anti-HBc and anti-HBs by ELISA, HBV DNA load by a standardized method across sites. In Ghanaian children less than 5 years, HBV DNA load was significantly lower in females than in males (p = 0.035). In China, Ghana, Burkina Faso and Gabon blood donors, median HBsAg prevalence was ~5% and 3% in China, ~8.5% and 4.5% in Gabon, ~16% and 11% in Burkina Faso and ~11% and 7% in Ghana for male and female donors, respectively (p < 0.001). In HBsAg+ Ghanaian blood donors, distribution and median viral load were not significantly different between sexes; occult hepatitis B infections (OBI) were significantly more frequent in males. In Chinese blood donor anti-HBc+ and anti-HBs+, anti-HBs levels tended to be higher in males but vaccinated donors’ anti-HBs+ only, while anti-HBs levels were females > males. In areas where genotypes B-E are dominant, the prevalence of chronic HBV infection (HBsAg+) seems better controlled before age 16–18 by females infected vertically or horizontally. OBIs appear considerably more frequent in men, suggesting lower efficacy of HBV infection control. Female blood donors appear significantly safer from HBV than males, and their donation should be encouraged.  相似文献   

7.
This study was carried out to determine the incidence of hepatitis B virus (HBV) infection in the young generation born after mandatory implementation of hepatitis B vaccination since 1992. Repeat blood donors born between 1992 and 1997 were enrolled, who gave blood at least twice during the past 3 years. Donors were tested for HBV infection markers of HBsAg, anti‐HBc, anti‐HBs and viral DNA by immunoassays (EIAs) and nucleic acid tests (NAT). A total of 14 937 pre‐donation screening qualified young repeat donors aged 18‐23 years were tested with 9 (0.06%) being HBsAg by EIA and 10 (1:1494) HBV DNA positive by Ultrio NAT (10.4 IU/mL), respectively. HBV DNA was further detected in 1:192 (9/1732) anti‐HBc+ repeat donors with Ultrio Plus NAT (3.4 IU/mL). Most cases were identified as occult HBV infection (OBI). Of 14 937 repeat donors, 20.9% were anti‐HBc+ positive, while approximately 50% of 12 024 repeat donors were anti‐HBs negative or had levels <100 IU/L. HBsAg+ or OBI strains were classified as wild type of genotype B or genotype C. Incident HBV infection in repeat donors was approximately 1:18.5 person‐years (1.1%/year) but significantly less frequent in donors with confirmed HBV vaccination (2.4%‐3.3%) than those unsure of vaccination status (10.5%; = .0023). Hepatitis B virus vaccination appears largely protective of HBV infection, but incidence of infections increases in young adults with mostly undetectable or low anti‐HBs or occasionally high anti‐HBs. A boost of hepatitis B vaccine for adolescents prior to age 18 years may reduce HBV infection, and implementation of more sensitive NAT in blood donation screening may improve HBV safety in blood transfusion.  相似文献   

8.
Occult hepatitis B virus(HBV) infection(OBI) is defined by the presence of HBV DNA in the liver tissue of individuals who test negative for hepatitis B surface antigen(HBsAg).Patients who have recovered from acute hepatitis B can carry HBV genomes for a long time and show histological patterns of mild necro-inflammation,even fibrosis,years after the resolution of acute hepatitis,without showing any clinical or biochemical evidence of liver disease.At least in conditions of immunocompetence,OBI is inoffensiv...  相似文献   

9.
Occult hepatitis B infection (OBI) is characterized by serum hepatitis B surface antigen (HBsAg) negative and hepatitis B virus (HBV) DNA positive (HBsAg‐/HBV DNA+). Occult hepatitis B infection in community‐based populations has been scarcely investigated, and OBI outcomes remain unclear, especially in Wuwei, a region located in Northwest China. This region is one of the areas in China that has the highest prevalence of chronic HBV infection. A prospective study was performed in the general population of 2 towns of Wuwei from June 2011 to May 2014. A questionnaire was used to collect demographic and medical data, and serum samples were collected from the participants and stored until analysis. DNA was detected using quantitative PCR (qPCR) or nested PCR, the HBV DNA from HBV DNA‐positive or possible positive (below the detection limit) subjects was extracted and amplified by nested PCR, and the PCR products were sequenced. Sequence analysis was performed using the Mega 6.0 program and CLC sequence viewer software. Hepatitis B virus DNA was detected in 90 of 3,080 HBsAg‐negative subjects, and the prevalence of OBI in the study population was 2.92% (90/3,080, 95% CI: 2.33%‐3.51%). Hepatitis B virus genomes in 51 of 80 objects (63.75%) contained mutations in the “a” determinant of HBsAg. After 2 years follow‐up, 42 of 90 HBV DNA of OBI subjects remained positive, and the natural clearance rate of OBI subjects was 53.3%. Occult hepatitis B infection prevalence in this cohort was much lower than chronic HBV infection in the same region. HBV DNA was cleared in most OBI subjects during the 2 year period. Our data suggest that some OBI may represent a late stage of resolving the HBV infection process.  相似文献   

10.
《Annals of hepatology》2018,17(4):541-543
Occult hepatitis B infection (OBI) is the presence of hepatitis B virus (HBV) DNA in the liver and/or serum (< 200 IU/mL) in HBsAg-negative patients with or without serologic markers of previous viral exposure. The clinical significance of OBI is of concern in post-transfusional hepatitis B infection, hepatitis B reactivation, chronic liver disease and hepatocellular carcinoma (HCC). The diagnosis of OBI relays on the use of highly sensitive and specific laboratory techniques. Herein, comments derived from a study analyzing the frequency and characteristics of OBI in HCC Japanese patients are stated. While OBI and other causes of HCC have been highly studied in Asia and Europe, research in Latin America in these topics is limited. Several findings such as population risk groups with high prevalence of overt and OBI infection, HBV genotype F in Argentinean HCC patients, and the clinical impact of the foreign A-D genotypes suggest the need of further investigation. Additionally, alcoholism, obesity, NASH and type 2 diabetes may override the presence of OBI. Therefore, OBI diagnosis is essential. It is known that anti-HBc alone is a predictive signal of potential OBI and given the fluctuations of the HBV infection markers, testing for HBsAg and anti-HBc at baseline and follow-up is recommended. In conclusion, OBI and other causes involved in the epidemiology of HCC in Latin America are unexplored risk factors. Genome-based research is required to decipher the role of gene-environmental interactions associated with chronic liver disease. Novel algorithms to detect OBI supported by basic/applied/clinical research are also needed.  相似文献   

11.
Although a universal newborn hepatitis B (HB) immunization programme has been implemented in China, hepatitis B virus (HBV) breakthrough infection, including HB surface antigen (HBsAg)‐positive infection and occult HBV infection (OBI), still occurs during infancy or childhood. Obtaining the actual prevalence of HBV infection in general children is important for preventing and controlling the spread of HB. Accordingly, we investigated the prevalence of overt infection and OBI in community children and compared the serological and virological characteristics of OBI and HBsAg carrier children to clarify the mechanisms related to OBI. In total, 6 706 community children <12 years of age were included from a population‐based HBV seroepidemiological investigation in Northwest China. The HBsAg carrier rate in community children was 1.60% (107/6706), and the anti‐HBs positive rate was 57.35% (3846/6706). Additionally, 1192 HBsAg‐negative children were examined for OBI using nested PCR. The prevalence of OBI in local children was 1.26% (15/1192), and the predominant OBI genotypes were C and D. The 15 OBI children and 29 HBsAg‐positive children from the same population did not have a statistical significant difference in age, gender, alanine aminotransferase (ALT), proportion of anti‐HBs or anti‐HBc, viral genotypes or mutations. Children with chronic overt infection had higher viral loads than OBI children (P=.004). These results suggested that HBV overt and occult infection of children was more serious in underdeveloped north‐west regions. HBV neonatal immunization and catch‐up programmes should be strengthened and supplemented. None of specific viral mutations or genotypes related to OBI were found. OBI may be a specific stage of HBV infection.  相似文献   

12.
Occult hepatitis B virus (HBV) infection (OBI) is characterized by presence of HBV DNA in blood or liver tissue without detectable HBV surface antigen (HBsAg), with or without antibodies to hepatitis B core antigen (anti-HBc) or antibodies against HBsAg (anti-HBs). A molecular and serological characterization was done of OBI in blood donors from Yucatan, Mexico. HBV DNA was found in 24 (6.4%) of the 372 evaluated samples. Anti-HBs was present in 15/24 samples (62.5%), and no significant difference was observed between HBV DNA positivity and anti-HBs levels. HBV genotype H was detected in 66.7% of samples, followed by genotypes D (20.8%) and F (8.3%). Amino acid substitutions were identified in the core region of nine samples, and most of these changes were located in immunodominant epitopes. No precore stop codon 28 mutant (W28Stop) was identified among the analyzed HBV isolates. In conclusion, genotype H is the main circulating HBV strain among OBI blood donors from Yucatan, Mexico. Mutations in the core region may contribute to viral persistence.  相似文献   

13.
In 2008,the European Association for the study of the liver(EASL) defined occult hepatitis B virus infection (OBI) as thepresence of hepatitis B virus(HBV) DNA in the liver(with detectable or undetectable HBV DNA in the serum) of individuals testing hepatitis B surface antigen(HBsAg) negative by currently available assays.Several aspects of occult HBV infection are still poorly understood,including the definition itself and a standardized approach for laboratory-based detection,which is the purpose of this ...  相似文献   

14.
目的观察原发性肝癌患者血清HBV标志物模式及HBV DNA水平。方法采用化学发光法检测151例PHC、132例慢性乙型肝炎和140例乙型肝炎肝硬化患者血清乙型肝炎病毒标记物;采用聚合酶链反应检测血清HBV DNA水平。结果在151例原发性肝癌患者中,HBV感染率达97.4%(147/151),HBV DNA阳性率为74.8%(113/151),平均水平为5.6±1.1 lgcopies/ml;HBsAg(+)、HBeAb(+)、HBcAb(+)90例(59.6%),其血清HBVDNA检出率为76.7%,平均水平为5.1±0.9lgcopies/ml;HBsAg(+)、HBeAg(+)、HBcAb(+)38例(25.2%),血清HBVDNA检出率100.0%,平均水平为6.4±0.9 lgcopies/ml。结论 PHC患者HBV感染率高,HBV与PHC发生有十分密切的关系。随着慢性乙型肝炎和乙型肝炎肝硬化病情的进展,血清HBeAg自发性发生血清学转换和HBV DNA载量下降,要警防原发性肝癌的发生。  相似文献   

15.
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...  相似文献   

16.
There are approximately 2 billion HBV-infected individuals worldwide, and approximately 1.87% to 7% of these individuals are copositive for HBsAg and HBsAb.Our study detected hepatitis B virus pgRNA (HBV RNA) levels in HBsAg and HBsAb copositive patients and then analyzed the correlation with HBV DNA, HBsAg, ALT, and AST levels. A total of 149 HBsAg and HBsAb copositive patients were identified from 66,617 outpatients.HBV RNA, HBV DNA, HBsAg, ALT, and AST serum levels were significantly different in different natural phases of HBV infection (immune tolerance phase, immune clearance phase, low replication phase, and reactivation phase) with statistical significance (P < .01). HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels. HBV RNA and HBV DNA levels were significantly increased in the HBeAg-positive group (66 patients) compared with the HBeAg-negative group (83 patients) (P < .01). In the HBeAg-positive group, HBV RNA levels were positively correlated with HBV DNA and HBsAg levels. In the HBeAg-negative group, HBV RNA levels were positively correlated with HBV DNA. Serum HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels.HBV RNA could be used as a virological indicator for antiviral therapy in HBsAg and HBsAb copositive hepatitis B patients.  相似文献   

17.
BackgroundScreening blood donors for the presence of hepatitis B virus surface antigen (HBsAg) has been the backbone of blood safety. However, occult hepatitis B infection (OBI) in donors can be missed when only HBsAg screening is used. Nucleic acid testing (NAT) is capable of detecting OBI among donors. The aim of our study was to analyse the sensitivity of NAT for detecting OBI.ResultsOf the 18 samples studied, nine were NAT-reactive at a dilution of <1:4 and five out of these showed presence of antibody to core antigen (IgG+IgM). Antibody to surface antigen was present in only two of the nine NAT-reactive samples, one with antibody to core antigen and the other without. Six had a viral load in the range from <10 to 38 IU/mL whereas the viral load in the remaining three samples was not determined. Among the other nine samples which were NAT-reactive at dilutions ≥1:4, antibody to core antigen (IgG+IgM) was present in seven.DiscussionOur study showed that ID-NAT testing along with HBsAg screening could detect most potentially HBV infectious donors (including those with OBI). NAT screening for HBV on diluted samples could compromise blood safety because samples with a low viral load will escape detection.  相似文献   

18.
Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.  相似文献   

19.
While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.  相似文献   

20.
The visualization of intrahepatic hepatitis B virus (HBV) DNA by in situ hybridization (ISH) has uncovered some interesting aspects of HBV life cycle at the single-cell level. In the current study, we intend to evaluate the reliability and robustness of this assay in the real-world clinical scenario and its relationship with currently available clinical biomarkers in chronic hepatitis B (CHB) patients.In this cross-sectional study, 94 CHB patients and 10 patients with non-HBV related liver diseases were enrolled. Liver biopsies and routine histopathology analysis were performed. Intrahepatic HBV DNA and viral antigens (HBsAg and HBcAg) were detected by ISH and immunohistochemistry (IHC), respectively. The basic biochemical and virological parameters such as alanine transaminase, serum HBV DNA, and serum HBsAg were measured.The HBV DNA-ISH assay showed 55.8% (53/94 cases) positive rate in CHB patients, no false positive was found in non-HBV related hepatitis. The IHC of HBsAg and HBcAg showed a positive rate of 94.7% (89/94 cases) and 19.5% (17/87 cases), respectively. Quantification of HBV DNA-ISH signal showed a significant correlation with serum HBV DNA (rs = 0.6223, P < .0001). In addition, the staining pattern of HBV DNA in situ in the context of collagen deposition informed the histopathological progression of chronic liver disease.The application of this ISH assay in evaluating intrahepatic viral replication in real-world CHB patients showed favorable performance. It can be a complementation to conventional liver histopathology examination and IHC detection of viral antigens. This methodology provides an intuitive assessment of virological and pathological state of CHB patients, and further supports clinical diagnosis and management.  相似文献   

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