丽水地区无偿献血者中隐匿性乙型肝炎病毒感染调查与分析

目的 隐匿性乙型肝炎感染一直是困扰献血中健康血清筛查的一个重要因素,通过高度灵敏的Nest-PCR检测方法对献血者中的OBI进行调查,了解该地区隐匿性HBV感染情况和基因分析.方法 共收集10080例献血者血浆,进行进口雅培HBsAg试剂和北京万泰抗-HBc及抗-HBs试剂平行检测,采用高灵敏度的Nest-PCR进行核酸检测和基因调取.结果 10080例无偿献血者中,共检出雅培（超敏）HBsAg阳性108例（阳性率1.07％）,抗-HBC单独阳性767例（阳性率7.67％）.10080例献血者中筛查出25例血浆HBsAg检测阴性HBV DNA检测阳性的隐匿性HBV携带者.隐匿性HBV感染者的发生率为0.25％.HBV基因C型12例（48％）,基因B型13例（52％）,未发现其他基因型.基因B型和基因C型之间没有明显的统计区别（P＞0.05）,序列分析显示其中5例在HBsAg“a”表位（aa124～aa147）存在突变（20％）.结论 我国无偿献血中存在较高比例的隐匿性乙型肝炎感染,且不同地区的基因型与突变情况存在差异.     

Detection of hepatitis B virus DNA in the serum of Canadian hepatitis B surface antigen negative,anti-HBc positive individuals,using the polymerase chain reaction

Continuing hepatitis B virus (HBV) infection is normally associated with the presence of hepatitis B surface antigen (HBsAg) in the serum. In spite of sensitive screening assays for HBsAg, rare cases of post-transfusion HBV infection are still observed. Antibody to hepatitis B core antigen (anti-HBc) often indicates remote HBV infection but DNA hybridisation and more sensitive polymerase chain reaction (PCR) assays have demonstrated that some HBsAg negative individuals, positive for anti-HBc, have continuing HBV replication. To determine the incidence of ongoing HBV infection in a Canadian HBsAg negative, anti-HBc positive population we studied three groups with this combination of HBV markers: Group A, 36 patients referred for investigation of raised serum aminotransferases; Group B, 21 Canadian Red Cross blood donors; Group C, seven vaccinees in an Ottawa Health Care Student hepatitis B vaccination programme. The PCR was carried out using a nested PCR reaction with primers specific for the pre-core region of HBV. Seven of 36 (19%) patients in Group A had detectable HBV DNA whereas none of Group B or C were positive. This data indicates that in some HBsAg negative patients with ongoing hepatic inflammation, continuing HBV replication may persist. This was not observed in any healthy blood donors or health care students investigated. Larger studies are required, but this data would suggest that, in Canada, the addition of anti-HBc testing for all blood donors for detection of low level HBV replication would not be indicated. © 1994 Wiley-Liss, Inc.     

抗-HBc单项阳性患者中的隐匿性HBV感染

目的 研究抗-HBc单项强阳性患者中的隐匿性HBV感染发生率并分析发生原因.方法 收集183例血清学检测抗-HBc单项强阳性（A≤0.1）患者血清标本,采用实时定量PCR进行HBV DNA含量检测.对于DNA定量阳性的标本,PCR扩增HBV pre-S/S区基因,并进行克隆测序.结果 183例血清标本中3例HBV DNA定量结果大于103拷贝/ml,占1.6%.这3例标本中有2例得到pre-S/S区测序结果,2例标本均存在S基因＂a＂决定簇内Q129R/P点突变,且突变株与野生型共存.结论 抗-HBc单项阳性患者中存在隐匿性HBV感染,HBsAg血清免疫学方法的漏检与HBV S基因突变有关,同时与循环中HBsAg量低于检测限也有一定关系.HBV隐匿感染不仅可以造成临床诊断失误,更为严重的是献血员HBV隐匿感染造成血液的污染.     

Surface antigen-negative hepatitis B virus infection in Dutch blood donors

Hepatitis B virus (HBV) surface antigen (HBsAg) is a reliable marker for HBV infection, but HBsAg-negative forms of HBV infection occur. The introduction of HBV DNA screening of Dutch blood donors, which were not preselected for absence of HBV core antibodies, enabled the characterization of HBsAg-negative HBV infection in healthy persons and a comparison of the HBV genomes involved. The screening of 4.4 million Dutch blood donations identified 23 HBsAg-negative, HBV DNA-positive persons. Serological testing of the index donations, follow-up samples and archived earlier samples was performed to determine the nature of each HBV DNA-only case. Despite low viral loads HBV DNA could be sequenced in 14 out of 23 donors, allowing HBV genotyping and the analysis of mutations in the HBV surface gene. Four types of HBsAg-negative HBV infection were detected: infection in the early stage before occurrence of HBsAg; suppressed infection after vaccination; HBV genotype G infection with decreased HBsAg production; and chronic occult (HBsAg negative) HBV infection. In the donors with occult HBV genotype D infection the HBV surface gene showed multiple “escape” mutations in the HBsAg a-determinant and CTL epitopes, while in an occult genotype A case the surface gene showed no mutations. HBsAg-negative forms of HBV infection in healthy blood donors explain the ongoing transmission of HBV via blood transfusion, if donor screening is limited to HBsAg. The screening of blood donors for HBV DNA and HBV core antibodies seems to cover all stages and variants of HBV infection.     

衢州市无偿献血者中隐匿性HBV感染的基因型别及突变类型分析

目的 了解衢州市无偿献血者隐匿性乙肝病毒感染情况及病毒的分子生物学特征.方法 对衢州市中心血站24 178例无偿献血者血液用北京万泰和Sorin公司生产的ELlSA试剂盒进行HBV的初检和复检,对HBsAg阴性标本进行HBV DNA检测,从而检出隐匿性乙肝病毒感染者,再对HBV DNA 阳性标本进行 S 基因片段序列分析和氨基酸突变分析,从而了解本市无偿献血者隐匿性乙肝病毒感染情况和病毒分子生物学特征,探讨隐匿性乙肝病毒感染的可能机制.结果 24 178例无偿献血者标本中,158例HBsAg阳性,24 020例HBsAg阴性标本中,15例HBV DNA阳性,隐匿性HBV感染比例为0.62‰（15/24 020）,其中基因C型9例（60％）,基因B型6例（40％）;S基因“a”表位氨基酸突变分析显示有11例隐匿性HBV感染病毒株在“a”表位发生突变.结论 衢州市无偿献血者中存在一定比例隐匿性乙肝病毒感染,隐匿性乙肝病毒感染与病毒基因突变有相关性.     

Occult hepatitis B virus infection.

The detection of HBV DNA without HBsAg with or without the presence of HBV antibodies outside the acute phase window period defines occult HBV infection. This condition has been described in hepatocellular carcinoma (HCC), chronic hepatitis B, healthy HBV carriage and recovered infection, chronic hepatitis C and individuals without serological markers of HBV. The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. Occult HBV in blood donors has a wide range of potential origins within the natural history of the infection. It may originate from recovered infections with anti-HBs and persistent, low-level, viral replication, escape mutants undetected by the HBsAg assays or healthy chronic carriage. The last situation is mostly found with anti-HBc only. Over time, antibody markers may become undetectable leaving HBV DNA as the only marker of the infection. In all cases, the viral load is low, mostly below 10(4) IU/ml, often below 100 IU/ml. At these levels, nucleic acid testing (NAT) in pools is likely to be largely ineffective. Is occult HBV transmissible by transfusion? Carriers of anti-HBs or anti-HBc only were shown infectious in immunosuppressed organ or bone marrow transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components are infectious, even in low titre. Donations carrying anti-HBc only and HBV DNA can be infectious and this is a threat where anti-HBc is not screened. Anti-HBc screening identifies most occult HBV infection but not all. HBV NAT needs either extreme sensitivity or to be performed on individual donations to eliminate HBV DNA-containing units.     

Assessment of hepatitis B surface antigen negative blood units for HBV DNA among replacement blood donors in a hospital based blood bank in Nigeria

BackgroundHepatitis B virus infection is one of the greatest threats to blood safety all over the world. The laboratory algorithm based on only the detection of hepatitis B surface antigen (HBsAg) leaves a gap for infected HBsAg negative donors to donate blood during the “window period” (WP) and late stages of infection.ObjectiveTo estimate the frequency of the presence of HBV deoxyribonucleic acid (DNA) in HBsAg negative blood units screened using two different assays for HBsAg in a high endemic region.MethodsFrozen serum aliquot of 100 replacement blood donors who donated blood units that were HBsAg negative were retrieved and tested for HBV DNA. Sample positive for HBV DNA was sequenced by Sanger''s method, genotyped and the viral load was determined.ResultsOne sample (1%) was positive for HBV DNA. The HBV viral load of the sample was 768,000 IU/ml. The partial S-gene of the Hepatitis B virus isolated was genotype E using the NCBI viral genotyping tool.ConclusionsThere is still a risk of HBV infected blood unit escaping detection when donor testing is limited to HBsAg screening. The use of NAT which can substantially reduce HBV infected blood donors from the donor pool should be considered.     

献血人群隐匿性乙型肝炎病毒感染的流行病学和血清学研究

目的了解广州地区献血人群隐匿性乙型肝炎病毒感染（OBI）的流行病学和血清学情况。方法对广州地区199631例无偿献血者标本同时用ELISA法检测HBsAg、紫外-乳酸脱氢酶法检测ALT、核酸扩增技术（NAT）联合检测HBV/HCV/HIV及HBV单项鉴别试验,对HBsAg阴性HBV DNA阳性者进行随访,用荧光定量PCR检测病毒载量,用ELISA法检测乙肝两对半。结果 199631例标本中共检出104例HBsAg阴性HBV DNA阳性者,经随访有54例为OBI,OBI检出率为0.027%,年龄以46～55岁组检出率最高（P〈0.01）,外地身份证的献血者检出率高于广州市身份证者（P〈0.01）,OBI检出率与性别和献血次数无关（P〉0.05）。104例HBsAg阴性HBV DNA阳性的标本ALT均正常,病毒载量均〈1000IU/ml,平均值为162IU/ml。随访标本中,除6例ALT异常外其余均正常,54例OBI标本病毒载量均〈1000IU/ml,平均值为122IU/ml,乙肝两对半中抗-HBc阳性率明显高于其他项目（P〈0.01）。结论 HBsAg阴性献血者中存在OBI,有必要在献血者中开展核酸检测。     

Genotype, phylogenetic analysis, and transmission pattern of occult hepatitis B virus (HBV) infection in families of asymptomatic HBsAg carriers

Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in the serum in absence of hepatitis B surface antigen (HBsAg). Studies were conducted to screen for occult HBV infection among family members of HBV carriers, incidentally detected positive for HBV infection with a view to assess the pattern of virus transmission among them. Nested PCR assay, employing independent sets of primers to surface and core genes, was used for detection of HBV DNA in serum samples from 28 index cases with asymptomatic HBV infection, and in serum samples from 72 HBsAg negative/anti-HBc positive family members. HBV DNA was detected in 15 HBsAg negative family members of 10 HBsAg positive index patients and was studied in detail. Direct sequencing of S gene region of 25 isolates (10 index cases and 15 contacts) and phylogenetic analysis with data base sequences revealed that genotypes A, C, and D and subtype adw2, adr, and ayw3 were present among them. Evidence of transmission from outside family sources was found in addition to intrafamilial transmission among individuals with occult infection. Mutations in the major hydrophilic loop (MHL) of the S gene region were also detected, including the 'vaccine escape' mutation G145R in three cases. Although majority of the occult infection was associated with low viral load, 3/15 (20%) cases were with higher viral load and potential infectivity. These cases are especially notable in diagnostic, blood banking, and transplantation services.     

Molecular characterization of occult hepatitis B cases in Greek blood donors

The use of sensitive nucleic acid testing for hepatitis B virus in blood donors revealed a number of HBV DNA(+) cases among HBsAg(?) donors, a status known as occult HBV infection. The purpose of this study was the serological and molecular characterization of occult HBV infection in Greek blood donors. A prospective study was undertaken in order to identify occult HBV infection cases in blood donors. As part of the routine screening of blood donations in Greece, blood units were screened individually by a multiplex HIV‐1/HCV/HBV nucleic acid assay. Initially reactive samples were retested with discriminatory assays. HBV DNA(+)/HBsAg(?) samples were tested further for HBV serological markers and HBV DNA was quantified by real‐time PCR. Molecular characterization was performed by sequencing the envelope and polymerase genes of HBV. Preliminary screening revealed 21 occult cases with the following patterns: anti‐HBc only: 7 donors, anti‐HBc/anti‐HBs: 7 donors, anti‐HBc/anti‐HBe: 5 donors, anti‐HBc/anti‐HBs/anti‐HBe: 2 donors. In all cases, the HBV DNA load was <351 IU/ml. Sequencing was successful in 10 donors (classified within genotype D) revealing several amino acid substitutions related to diagnostic escape and antiviral resistance. HBsAg diagnostic failure and low viral replication in occult HBV infection carriers could possibly be attributed to multiple changes in envelope and polymerase regions, respectively. J. Med. Virol. 81:815–825, 2009. © 2009 Wiley‐Liss, Inc.     

Multiple surface antigen mutations in five blood donors with occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen (HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia (<10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An unusually large number of amino acid mutations was present in the immunodominant a-determinant of HBsAg (respectively 3, 6, 7, 10, and 10 mutations). Comparison of the HBV genomes in two donors to a consensus HBV genotype D sequence showed a most prominent hotspot of genetic variation in HBV nucleotides 480-570, encoding the HBsAg a-determinant. The phylogenetic comparison of separate donor HBV genes to the HBV genes of 11 reference strains (genotypes A-H) showed the donor HBV surface genes to form an outgroup, while the HBV polymerase, core and X genes closely cluster with the HBV genotype D reference strain. Maybe the HBV strains in this study represent a natural end-stage of seemingly cleared HBV infection, in which HBV maintains a low level of possibly non-infectious replication, after sacrificing its immunologically offending surface antigen, thus avoiding final clearance by the immune system.     

奉贤地区HBsAg阴性的HBV自然感染母亲对新生儿影响的研究

目的　为揭示HBsAg阴性的乙型肝炎病毒 (HBV)自然感染孕妇的宫内感染及其危险因素。方法　采用多聚酶链反应 (PCR)技术结合酶联免疫吸附法 (ELISA) ,对奉贤地区 131例HBsAg阴性的HBV自然感染孕妇外周血 ,及其分娩后的脐带血进行HBV血清学标志物 (HBVM)和HBVDNA检测。结果　HBsAg阴性的HBV自然感染孕妇宫内的感染率 (除外单一抗 -HBs阳性 )为 5 2 6 7% ;脐血中不同HBVM组合的HBVDNA检出率依次为 :抗 -HBe( )、抗 -HBc( ) >抗 -HBs( )、抗 -HBe( )、抗 -HBc( ) >抗 -HBs( )、抗 -HBe( ) >抗 -HBs( )、抗 -HBc( ) >抗 -HBs( ) ;脐血HBVDNA总检出率为 16 79%。结论　HBsAg阴性的HBV自然感染孕妇也可能发生宫内感染。提议HBsAg阴性的HBV自然感染孕妇和新生儿有进行自动和被动免疫接种的必要性     

Screening for hepatitis B virus in healthy blood donors by molecular DNA hybridization analysis.

A DNA molecular hybridization technique employing a purified adw subtype hepatitis B virus (HBV) cloned DNA of 3.2 kilobase pairs as a probe was used to screen for the presence of HBV DNA in blood samples collected from 486 apparently healthy blood donors. Eighteen of 104 (17.3%) hepatitis B surface antigen (HBsAg) carriers and 7 of 382 (1.8%) HBsAg-negative individuals had circulating HBV DNA in their sera. Among the seven individuals who were positive for HBV DNA but negative for HBsAg, three had antibodies against both HBsAg (anti-HBsAg) and hepatitis B core antigen, one had only anti-HBsAg, one had both anti-hepatitis B core antigen and anti-hepatitis B e antigen and two were negative for all the above HBV markers. The results suggest that the absence of HBsAg in otherwise apparently healthy individuals may not be enough to ensure lack of circulating HBV.     

The prevalence and significance of occult hepatitis B virus in a prospective cohort of HIV-infected patients

BACKGROUND: Occult hepatitis B virus (HBV) is defined as low-level HBV DNA without hepatitis B surface antigen (HBsAg). Prevalence estimates vary widely. We determined the prevalence of occult HBV at the University of Cincinnati Infectious Diseases Center (IDC). METHODS: Patients in the IDC HIV database (n = 3867) were randomly selected using a 25% sampling fraction. Samples were pooled for HBV nucleic acid extraction. Pools were tested for HBV DNA by a real-time polymerase chain reaction (PCR) assay to co-amplify core/surface protein regions. The PCR assay was run on all individual samples from each DNA pool. DNA samples were tested for HBV serologic markers. RESULTS: A total of 909 patients without known HBV were selected. The mean CD4 count was 384 cells/mm. Forty-three patients were HBV DNA. Twelve of 43 were DNA/HBsAg (95% confidence interval for database: 0.58% to 1.90%). Five of 12 were negative for all serologic markers. Alanine aminotransferase, aspartate aminotransferase, and HBV DNA titers were elevated in HBsAg patients versus occult patients and versus HIV-monoinfected patients. No other significant differences were detected. No occult HBV patient was on treatment with anti-HBV activity. CONCLUSIONS: Forty-three percent of those with HBV were not previously identified as HBV, indicating the need for ongoing screening in high-risk populations. Occult HBV may occur in persons with all negative serologic markers, representing a challenge for identification.     

绍兴市无偿献血者中隐匿性HBV感染的基因型别及突变类型分析

目的 了解绍兴市无偿献血者隐匿性乙肝病毒感染情况及病毒的分子生物学特征.方法 应用ELISA的方法对绍兴市中心血站8692例无偿献血者进行筛查,对HBsAg阴性标本进行HBV DNA检测,从而检出隐匿性乙肝病毒感染者,再对阳性标本进行序列分析和氨基酸突变分析,从而了解绍兴市无偿献血者隐匿性乙肝病毒感染情况和病毒分子生物学特征,探讨隐匿性乙肝病毒感染的可能机制.结果 在总共8692例无偿献血者标本中,共计H BsAg（-）8644例,在8644例HBsAg（-）标本中,有8例HBV DNA阳性,隐匿性HBV感染比例为0.92‰（8/8692）,其中基因C型6例（75％）,基因B型2例（25％）;氨基酸突变分析显示有7株OBI病毒株在“a”表位发生特异性突变.结论 绍兴市无偿献血者中存在一定比例隐匿性乙肝病毒感染,隐匿性乙肝病毒感染与病毒基因突变有相关性.     

输血后乙型肝炎病毒感染的前瞻性研究

目的　了解输血后所致乙型肝炎病毒 (HBV)感染现状 ,以及通过检测乙型肝炎病毒表面抗原筛选献血员的效果。方法　用酶联免疫吸附测定 (ELISA)和聚合酶链反应 (PCR)分别检测了受血者和供血者血清中HBV M和HBVDNA。结果　在 5 83份供血者血中HBV M阳性 32 6份 ,HBVDNA阳性 5 7份。 136份受血者输血后 39份血清HBV M阳转 ,阳转率为 2 8 6 8% ;2 3份HBVDNA阳性 ,阳性率为 16 9%。结论　经检测乙型肝炎病毒表面抗原筛选献血员后仍有输血后乙型肝炎病毒感染的可能。     

供受者感染乙肝病毒对造血干细胞移植后肝炎复发及愈后的影响

目的分析移植前供、受者感染乙肝病毒对造血干细胞移植后肝炎复发及愈后的影响。方法对上海第一人民医院2006年1～11月移植前供、受者感染乙肝病毒的23例恶性血液病患者,进行移植前后肝功能、乙肝免疫标记物、HBVDNA等检测,并结合临床综合分析。血清丙氨酸氨基转移酶（ALT）、γ谷氨酰转肽酶（GGT）采用速率法,血清总胆红素（TBIL）采用终点比色法检测;乙肝病毒血清标志物采用酶免疫测定（EIA）;HBVDNA测定采用聚合酶链反应（PCR）试剂盒。结果①9例HBV感染的自体移植患者移植后3例发生乙型肝炎,其中2例为移植前HBsAg阳性,乙肝发作时3例HBVDNA及肝功能指标均明显增高;②14例HBV感染的供、受者移植后5例患者发生乙型肝炎,HBVDNA及肝功能指标均明显增高;③移植前HBsAg或HBVDNA阳性移植后发生乙肝相关性肝损的几率显著高于阴性组（X^2分别为8.44、9.07,均大于X0.005^2,P〈0.005）;④移植前HBsAg或HBVDNA阳性对移植预后均无影响（X^2分别为2.58、0.24,均小于X0.05^2,P〉0.05）;⑤1例患者异体移植后41d,乙肝合并戊肝,发生急性黄疸性肝炎,第46天重症GVHD死亡。结论移植前HBsAg和HBVDNA阳性均是HBV感染和再激活的高危因素,移植要密切监测免疫标志物和HBVDNA。移植前HBsAg和HBVDNA阳性不影响患者的生存,要注意非常见肝炎的多重感染。     

Detection of an acute asymptomatic HBsAg negative hepatitis B virus infection in a blood donor by HBV DNA testing.

The issue of HBV DNA screening on blood donations is controversially discussed since the economic impact of post-transfusion hepatitis B is expected to be relatively low. We report on a case of HBsAg negative unapparent acute HBV infection, which was detected by HBV NAT testing on 96-member maxi-pools with a commercially available NAT assay, which has a detection threshold of 3 IU/mL of plasma. The presence of an HBsAg escape mutant could be excluded by sequencing the amplified DNA. Follow-up testing showed the presence of an acute HBV infection (anti-HBc-IgM positive) and finally anti-HBs seroconversion. Although the reduction of the diagnostic window with NAT screening on maxi-pools may be relatively low, it may help to improve the residual risk of blood donation, especially in asymptomatic HBV infection, where the HBsAg positive period may be very short and low levels of circulating surface antigen are present. It would also permit to detect occult HBV infection in chronic carriers who are HBsAg negative. Since the viral load in chronic isolated anti-HBc positive carriers is low, there is a potential risk for failure of HBV DNA detection with pool-PCR in blood donors. Anti-HBc screening would reduce the residual risk.     

Latent HBV infection in single blood donors

A total of 14,366 one-time blood donors were examined; 984 (6.8%) donors of them were found to have anti-HBc. All anti-HBc-positive samples were tested for HBsAg, IgM anti-HBc, HBeAg, anti-HBe, and specific DNA-HBV by polymerase chain reaction (sensitivity 400 coplml or higher). Anti-HBc in combinations with HBsAg, anti-HBe, IgM anti-HBc was detected in 29 (2.9%), 3 (0.3%), 5 (0.5%) donors, respectively. Specific HBV DNA was identified in 29 donors with HBs-antigenemia and in 9 anti-HBc positive donors in the absence of serum HBsAg. The activity of AIAt was correlated with neither HBsAg nor HBV DNA. Thus, latent HBV infection is 0.9% of anti-HBc-positive one-time blood donors and tests for anti-HBc may be useful in identifying persons who need a more meticulous study for HBV DNA.     

Correlation between HBV DNA detection by polymerase chain reaction and Pre-S1 antigenemia in symptomatic and asymptomatic hepatitis B virus infections

The presence of hepatitis B virus (HBV) genome in sera from 73 symptomatic and asymptomatic HBsAg carriers was studied by the polymerase chain reaction (PCR) with primers specific for the S and C regions. Pre-S proteins of the HBV envelope were detected in serum by a specific monoclonal antibody in a double immunoradiometric assay. Out of twenty-five symptomatic patients with chronic active hepatitis (14 with HBeAg and 11 with anti-HBe), all were positive for HBV DNA by PCR, while 14/14 HBeAg and 2/11 (18%) of the anti-HBe patients were positive by dot blot hybridization. All but one anti-HBe patient (96%) carried Pre-S1 proteins. Among the asymptomatic HBsAg carriers, HBV DNA was detected by PCR in 14/14 (100%) HBeAg positive patients and in 25/34 (73%) anti-HBe positive patients. Pre-S1 proteins were found, respectively, in 14/14 (100%) and 11/22 (50%) of the same cases tested in parallel. The 20 healthy blood donors devoid of HBV markers and with normal transaminases tested were found negative for HBV DNA using PCR. Out of 12 patients who recovered from acute hepatitis B, all were found negative by PCR analysis after a mean follow up of 1 year after seroconversion to anti-HBs. When serial samples from 2 patients (one with acute hepatitis B, the other with chronic hepatitis B) were tested for the presence of HBV DNA and of Pre-S1 proteins, both markers showed parallel development.(ABSTRACT TRUNCATED AT 250 WORDS)