Diagnostic strategy for occult hepatitis B virus infection

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 ...     

Clinical significance of occult hepatitis B virus infection

Occult hepatitis B virus(HBV) infection(OBI) is defined as the presence of HBV DNA in the liver(with or without detectable HBV DNA in serum) for individuals testing HBV surface antigen negative.Until recently,the clinical effect of OBI was unclear on the progression of liver disease;on the development of hepatocellular carcinoma;and on the risk for reactivation or transmission of HBV infection.Several studies suggest a high prevalence of OBI among patients with cryptogenic chronic liver disease,but its role...     

Pathogenesis of occult chronic hepatitis B virus infection

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...     

An overview of occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI), alternatively defined as occult hepatitis B (OHB), is a challenging clinical entity. It is recognized by two main characteristics: absence of HBsAg, and low viral replication. The previous two decades have witnessed a remarkable progress in our understanding of OBI and its clinical implications. Appropriate diagnostic techniques must be adopted. Sensitive HBV DNA amplification assay is the gold standard assay for detection of OBI. Viral as well as host factors...     

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.     

Occult hepatitis B virus infection in Egypt

The emerging evidence of the potentially clinical importance of occult hepatitis B virus (HBV) infection (OBI) increases the interest in this topic. OBI may impact in several clinical contexts, which include the possible transmission of the infection, the contribution to liver disease progression, the development of hepatocellular carcinoma, and the risk of reactivation. There are several articles that have published on OBI in Egyptian populations. A review of MEDLINE database was undertaken for relevant articles to clarify the epidemiology of OBI in Egypt. HBV genotype D is the only detectable genotype among Egyptian OBI patients. Higher rates of OBI reported among Egyptian chronic HCV, hemodialysis, children with malignant disorders, and cryptogenic liver disease patients. There is an evidence of OBI reactivation after treatment with chemotherapy. The available data suggested that screening for OBI must be a routine practice in these groups of patients. Further studies needed for better understand of the epidemiology of OBI among Egyptian young generations after the era of hepatitis B vaccination.     

Long-term clinical impact of occult hepatitis B virus infection in chronic hepatitis B patients

BACKGROUND/AIMS: Long-term clinical outcomes of occult hepatitis B virus (HBV) infection were studied. METHODS: Fifteen chronic hepatitis B patients were monitored for a median of 4.4 years (range 0.9-15.3) after hepatitis B surface antigen (HBsAg) seroclearance. Serum HBV DNA was measured by real-time detection polymerase chain reaction. Thirteen patients underwent liver biopsies at the end of follow-up and liver histology was evaluated by Ishak score. Liver HBV DNA was also measured for 12 patients. RESULTS: At the end of follow-up, HBV viremia was absent in 13 (87%) patients, and antibody titers to hepatitis B core antigen showed an inverse correlation with time from HBsAg seroclearance (r=-0.554; P=0.0040). However, all patients retained liver HBV DNA and tested positive for the covalently closed circular HBV DNA replicative intermediate. The hepatic HBV DNA loads had no relation to liver histology. Paired biopsies from 11 patients disclosed that each necroinflammatory score significantly improved after HBsAg seroclearance. Amelioration of liver fibrosis was also evident in eight (73%) patients (P=0.0391 by signed rank test). CONCLUSIONS: A long-standing but strongly suppressed HBV infection may confer histological amelioration after HBsAg seroclearance.     

Role of occult hepatitis B virus infection in chronic hepatitis C

The development of sensitive assays to detect small amounts of hepatitis B virus(HBV) DNA has favored the identification of occult hepatitis B infection(OBI), a virological condition characterized by a low level of HBV replication with detectable levels of HBV DNA in liver tissue but an absence of detectable surface antigen of HBV(HBs Ag) in serum. The gold standard to diagnose OBI is the detection of HBV DNA in the hepatocytes by highly sensitive and specific techniques, a diagnostic procedure requiring liver tissue to be tested and the use of non-standardized non-commercially available techniques. Consequently, in everyday clinical practice, the detection of anti-hepatitis B core antibody(antiHBc) in serum of HBs Ag-negative subjects is used as a surrogate marker to identify patients with OBI. In patients with chronic hepatitis C(CHC), OBI has been identified in nearly one-third of these cases. Considerable data suggest that OBI favors the increase of liver damage and the development of hepatocellular carcinoma(HCC) in patients with CHC. The data from other studies, however, indicate no influence of OBI on the natural history of CHC, particularly regarding the risk of developing HCC.     

无偿献血人群隐匿性乙型肝炎病毒感染调查

目的 调查无偿献血人群隐匿性乙型肝炎病毒感染(OBI)情况。方法 2021年1月～2021年12月我站无偿献血者血液样本107397份,采用两种ELISA法检测试剂盒进行HBsAg的初次筛查,采用核酸检测(NAT)法对两次HBsAg结果均为阴性的样本进行HBV DNA检测。对血清HBsAg阴性而HBV DNA阳性样本进行HBV血清学标志物检测,并采用实时荧光定量聚合酶链式反应(PCR)法检测核酸和病毒基因分型。结果 在筛查的107397例无偿献血人群血样本中,经血清标志物检测后确认为OBI者29例(0.27‰);血清抗-HBc阳性者12例(35.3%),抗-HBe/抗-HBc阳性者8例(23.5%),抗-HBs/抗-HBc阳性者6例(17.7%),抗-HBs/抗-HBe/抗-HBc阳性者3例(8.8%);19～29岁年龄段献血人群OBI感染率为0.09‰,30～39岁人群为0.32‰,40～49岁人群为0.39‰,50～55岁年龄段献血人群OBI感染率为0.41‰,且该年龄段重复献血者OBI感染率为0.31‰;血清抗-HBs/抗-HBc阳性和抗-HBs/抗-HBe/抗-HBc OBI献...     

隐匿性乙型肝炎病毒感染者临床特点和肝组织病理学检查

目的了解血清肝炎病毒标志物阴性、肝功能反复异常患者中HBV隐匿性感染的比例及其临床和病理学特点。方法对27例血清肝炎病毒标志物阴性、肝功能反复异常患者采用免疫组化法检测肝组织HBsAg、HBcAg和HCVAg，并进行常规的病理学检查。结果肝组织HBsAg和（或）HBcAg阳性9例（33．3％）；HBsAg和（或）HBcAg及HCVAg阳性10例（37．0％）；全阴性8例（29．6％）。在HBV隐匿性感染的19例患者中，慢性肝炎8例，肝硬化11例。结论HBV和HCV感染为血清肝炎病毒标志物阴性患者肝功能反复异常的主要原因之一，尤其是HBV感染。这种HBV隐匿性感染与慢性肝炎、肝硬化的发生关系密切，应引起重视。     

Prevalence of occult hepatitis B virus infection in haemodialysis patients from central Greece

AIM:To assess the hepatitis B virus(HBV)-DNA and the prevalence of occult HBV infection in end-stage renal failure(ESRF)patients from Central Greece. METHODS:Sera from 366 ESRF patients attending five out of six dialysis units from Central Greece were investigated for HBV-DNA by real-time polymerase chain reaction.Only serum samples with repeatedly detectable HBV-DNA were considered positive.IgG antibodies to hepatitis C virus(anti-HCV)were tested by a third generation enzyme linked immunosorbent assay(ELIS...     

隐匿性乙型肝炎病毒感染

大量研究通过对肝组织和血清乙型肝炎病毒（HBV）DNA或转录体的检测，证实隐匿性HBV感染是所谓“隐源性肝炎”及其它慢性肝病的常见病因。现就其发生率、形成机制、临床意义、诊断、治疗等方面作一综述。     

Influence of occult hepatitis B virus infection in chronic hepatitis C outcomes

Persistence of hepatitis B virus-DNA in the sera,peripheral blood mononuclear cells or in the liver of hepatitis B surface antigen(HBsAg) -negative patients with or without serological markers of previous exposure(antibodies to HBsAg and/or to HB-core antigen) defines the entity called occult hepatitis B infection(OBI).Co-infection with hepatitis B and hepatitis C viruses is frequent in highly endemic areas.While this co-infection increases the risk of liver disease progression,development of cirrhosis and ...     

Genetic variation of occult hepatitis B virus infection

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.     

Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients

AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico.METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson’s χ² and/or Fisher’s exact test.RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05).CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV.     

献血员隐匿性乙型肝炎病毒感染的分子流行病学

目的 了解献血员中隐匿性HBV感染的发生率,从S基因变异角度探讨隐匿性HBV感染可能的分子机制.方法 收集经血站筛查HBsAg阴性的合格献血员血浆594份,ELISA法检测HBV血清学标志物,套式PCR检测血清HBV DNA.对筛查出的隐匿性HBV感染者再次用雅培试剂定量检测HBV血清学标志物,并对其S区进行测序,发现可能与HBV隐匿性感染有关的变异位点.随机收集11例HBsAg阳性的HBV感染者作为阳性对照,对其S区进行测序,比较其与隐匿性HBV感染之间的关系.结果 在594例献血员中有15例为隐匿性HBV感染,隐匿性HBV感染的发生率为2.5％.未发现HBV血清学标志物检测结果与隐匿性HBV感染有相关性.15例隐匿性HBV感染者中有10例进行了S区测序,结果HBV均有不同程度的变异,其中3例在“a”决定簇内出现氨基酸突变,分别为1126T(1例)、T140I(2例).与隐匿性HBV感染者相比,阳性对照在“a”决定簇内仅出现了1例T131N变异.结论 常规检测HBsAg阴性的献血员中存在隐匿性HBV感染,且这些病毒可能存在变异.     

隐匿性乙型肝炎病毒感染者血清表面抗体性质鉴定

目的 了解隐匿性HBV感染者抗-HBs的特性及其与HBsAg的结合能力.方法 对2例抗-HBs阳性的隐匿性HBV感染者进行长期随访,使用多种试剂盒对患者血清进行多次HBsAg检测,利用不同血清型HBsAg对患者血清进行中和反应,了解血清中抗体亚型情况.PCR扩增S基因构建真核表达质粒,分析S基因变异情况,并将质粒转染HepG2细胞,取培养上清液及转染细胞分别混合进行HBsAg检测.使用患者血清及抗-HBs阳性血清(对照组)对部分HBsAg阳性克隆上清液进行中和反应.不同组间数据比较采用t检验.结果 多种试剂盒进行的多次检测结果均表明患者血清HBsAg为阴性;HBsAg的3种不同血清型(adr、adw、ay)均能够中和患者血清中大部分抗-HBs(82.1%～100.0%).S基因序列分析表明核苷酸同源性和氨基酸同源性分别为95.13%～97.79%和92.04%～95.58%;培养上清液和转染细胞裂解液中HBsAg定量分别为对照组的48.1%和59.3%,上清液/细胞裂解液比值分别为0.85和0.38.中和试验结果显示转染上清液中HBsAg定量较混合前有所降低,但是仍然可以检测到,而对照组检测不到HBsAg,差异均有统计学意义(F值分别为353.6和645.2,P值均<0.01).结论 抗-HBs阳性隐匿性HBV感染者体内HBsAg的抗原性及分泌能力有所下降,抗HBs主要针对不同血清型HBsAg的共同表位,但可能与疫苗注射产生的抗-HBs有所不同.

Abstract：

Objective To investigate the properties of HBsAb in occult hepatitis B virus infection and its affinity to different serotypes of hepatitis B virus surface antigen (HBsAg). Methods Long-term follow-up was conducted in 2 HBsAb positive patients with occult hepatitis B virus infection. HBsAg was detected using multiple diagnostic kits and the HBsAb subtype was determined by performing neutralization experiments with different serotypes of HBsAg. The viral S gene was PCR-amplified and mutation analysis was conducted. Plasmids expressing HBsAgs were constructed by inserting these PCR products into an eukaryotic expression vector and were then transfected into HepG2 cells. The cell culture supernatant and cellular extracts were detected for HBsAg respectively. Neutralization experiments were carried out in the cell culture supernatant from HBsAg plasmids transfected HepG2 cells and serum samples from these patients and others who had been confirmed to be positive for HBsAb. Results Multiple tests using various diagnostic kits showed that the 2 patients were negative for HBsAg and the three different serotypes of HBsAg (adr, adw, ay) could neutralize 82.1%-100% of HBsAb existed in the 2 patients. Sequence analysis of S gene cloned from these patients revealed that the homology to reference strain were 95.13%-97.79% and 92.04%-95.58% respectively at the nucleotide and amino acid levels. Quantitation of HBsAg showed that the expression levels of HBsAg from the two patients were 41.1% and 22.6% respectively of that of control HBsAg in cell culture supernatant and 48.1% and 59.3% respectively in cellular extract, and the supernatant/cell lysate ratios were 0.85 and 0.38 respectively. In neutralization experiments, HBsAg could be totally absorbed by control serum, whereas could only be partially neutralized by HBsAbs from the two patients (F = 353.6 and 645.2, P < 0.01). Conclusion Both the antigenicity and the ability of HBsAg secreted outside of the cells are decresed in these HBsAb-positive patients with occult HBV infection. The HBsAbs are mainly specific for common epitopes among different serotypes of HBsAg and are probably different as compared with those produced by vaccine inoculation.     

未抗病毒治疗人类免疫缺陷病毒感染者隐匿性乙型肝炎的调查及其临床特点

目的 观察未经抗病毒治疗(ART)的人类免疫缺陷病毒(HIV)感染者和普通人群隐匿性乙型肝炎流行状况,评估HIV感染者合并隐匿性乙型肝炎的临床特点.方法 通过酶联免疫分析法检测未经ART治疗的HIV感染者和普通人群血浆HBsAg、抗-HBs、HBeAg、抗-HBe和抗-HBc水平,筛查出HBsAg阴性的HIV感染者(感染组)249例,健康体检者HBsAg阴性者121例(健康组),再采用罗氏COBASAmpliPrep/COBAS TaqManHBVTest,version2.0试剂盒检测外周血HBV DNA水平.统计分析用STATA 10软件处理本实验各组数据.用Fisher's精确概率检验、秩和检验.结果 感染组HBV DNA阳性者24例,隐匿性乙型肝炎占9.7％;健康组HBV DNA阳性者4例,隐匿性乙型肝炎占3.3％,两组比较,P=0.035,差异有统计学意义.感染组24例HBVDNA阳性者,HBV DNA载量最低者血中能测到,但在检测值水平以下,(即＜20 IU/ml),最高者3.22×105 IU/ml.大于100 IU/ml占37.5％(9/24),20 ～ 99 IU/ml占16.7％ (4/24),＜20IU/ml,但可测出HBV DNA占45.8％ (11/24).HIV感染者抗-HBc(+)/抗-HBs(+)组、抗-HBc(+)/抗-HBs(-)组、抗-HBc(-)/抗-HBs(+)组、抗-HBc(-)/抗-HBs(-)组DNA阳性率分别为7.3％ (8/110),20.8％ (11/53),14.3％ (3/21),3.1％(2/64),抗-HBc(+)/抗-HBs(-)组分别与抗-HBc(+)/抗-HBs(+)组、抗-HBc(-)/抗-HBs(-)组两组比较,P值分别为0.018和0.003,差异有统计学意义.四组间HBV DNA病毒载量比较,P=0.805,差异无统计学意义.感染组HBV DNA(+)组与HBV DNA(-)组比较,CD4计数(Z=1.902,P=0.0586)和ALT水平(Z=1.401,P=0.1611)差异无统计学意义.结论 在未经ART治疗HIV感染者中,隐匿性乙型肝炎高于普通人群,HIV感染者抗-HBc(+)/抗-HBs(-)组隐匿性乙型肝炎最高.     

MiR-122 in hepatitis B virus and hepatitis C virus dual infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the most common causes of chronic liver diseases and hepatocelluar carcinomas. Over the past few years, the liver-enriched microRNA-122 (miR-122) has been shown to differentially regulate viral replication of HBV and HCV. It is notable that the level of miR-122 is positively and negatively regulated by HCV and HBV, respectively. Consistent with the well-documented phenomenon that miR-122 promotes HCV accumulation, inhibition of miR-122 has been shown as an effective therapy for the treatment of HCV infection in both chimpanzees and humans. On the other hand, miR-122 is also known to block HBV replication, and HBV has recently been shown to inhibit miR-122 expression; such a reciprocal inhibition between miR-122 and HBV suggests an intriguing possibility that miR-122 replacement may represent a potential therapy for treatment of HBV infection. As HBV and HCV have shared transmission routes, dual infection is not an uncommon scenario, which is associated with more advanced liver disease than either HBV or HCV mono-infection. Thus, there is a clear need to further understand the interaction between HBV and HCV and to delineate the role of miR-122 in HBV/HCV dual infection in order to devise effective therapy. This review summarizes the current understanding of HBV/HCV dual infection, focusing on the pathobiological role and therapeutic potential of miR-122.