HBsAg和HBsAb同时阳性慢性HBV感染者血清病毒PreS/S区基因序列分析及临床意义探讨

目的：分析HBsAg和HBsAb同时阳性慢性HBV感染者的血清病毒PreS/S区基因序列,探讨其临床意义。方法：收集HBsAg和HBsAb同时阳性慢性HBV感染者32例,其中HBV DNA阳性者12例（实验组）,其余20例为HBV DNA阴性。另外选取HBsAg阳性、HBsAb阴性和HBV DNA阳性的慢性HBV感染者12例（对照组）。采用聚合酶链反应（PCR）法体外扩增两组患者HBV PreS/S基因序列并测序分析,比较两组间PreS/S基因变异情况,结合临床资料探讨其临床意义。结果：实验组与对照组在性别、年龄、HBeAg阳性率、HBsAg滴度及HBV DNA水平上差异均无显著性意义（P〉0.05）。两组基因型分布亦相似（P〉0.05）。实验组与对照组在PreS1区、PreS2区、S区、MHR（主要亲水）区及＂a＂表位区各区域的核苷酸替换率相当（P〉0.05）。实验组中1例患者的PreS区有一长约144bp的片段缺失,位于PreS/S区nt285~428位（PreS1区末端及PreS2区起始部）。结论：HBsAg和HBsAb同时阳性的现象与PreS/S区基因突变无明显的相关性,HBsAb的出现对HBsAg和HBsAb同时阳性且HBV DNA亦阳性的患者不具有保护作用。     

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.     

乙型肝炎病毒表面抗原基因的克隆及序列分析

目的克隆并鉴定乙型肝炎病毒表面抗原基因,为下一步构建该重组腺病毒载体以及进一步研究腺病毒载体的包装及在乙型肝炎病毒基因治疗中的作用。方法参照人 HBV adr 亚型序列,设计和合成 S 基因特异引物。应用 PCR 技术,从含有 HBsAg 的 HBV DNA 中扩增目的 DNA,通过 TA 连接将其克隆人 pGEM-T easy 载体,经限制性内切酶 BglⅡ/SalⅠ鉴定后,进一步测序鉴定。结果从乙肝表面抗原阳性(HBsAg )血清中成功提取 HBV DNA,并以此 DNA 为模板,成功扩增出 S 基因,测序结果与 GenBank 中注册的相应序列比对,核苷酸序列的同源性高达92％～99％,预测氨基酸序列同源性亦达82％。结论从 HBsAg 阳性血清中成功克隆出 S 基因序列,为进一步构建重组腺病毒及后续实验奠定了基础。     

HBsAg与抗-HBs同时阳性慢性乙肝患者HBV基因全序列分析

目的 报告HBsAg与抗-HBs同时阳性慢性乙肝患者基因序列变化特点.方法 对三例HBsAg与抗-HBs同时阳性慢性乙肝患者血清中HBV DNA基因全序列进行PCR扩增、测序,并对测序结果及S区氨基酸进行分析.结果 测序结果发现三例患者血清中HBV S区氨基酸均发生替换突变,并且,三例患者中HBV DNA发生碱基替换的位点大部分相同,且替换后碱基基本相同.结论 HBsAg与抗-HBs同时阳性慢性乙型肝炎患者常发生S区氨基酸序列突变,双阳现象的出现亦可能与S区外其他位点碱基突变有关.     

慢性HBV感染者肝脏HBV cccDNA含量相关因素分析

目的探讨慢性HBV感染者肝组织中HBV cccDNA含量与血清病毒标志物、HBV DNA及肝脏病理分级的关系,为临床评价抗病毒治疗效果及疗程确定提供理论依据。方法以2007年5月-2008年2月住院的30例慢性HBV感染者为研究对象,应用实时荧光定量聚合酶链反应（RT-PCR）方法检测患者肝组织中HBV cccDNA、肝组织总HBV DNA（HBV tDNA）和血清HBVDNA,同时用化学发光免疫分析法检测HBsAg、HBeAg定量,分析感染者肝组织内HBV cccDNA与肝组织内HBV DNA、血清HBVDNA、HBsAg及HBeAg定量水平之间的关系,并比较肝组织中HBV cccDNA含量与肝脏病理炎症和纤维化分级的关系。采用Pear-son简单相关和Spearman等级相关法进行相关性分析。结果 30例慢性HBV感染者肝组织中均可检出HBV cccDNA,范围在3.15×103～1.06×107拷贝/mg;肝组织cccDNA定量与肝组织总HBV DNA定量呈正相关（r=0.375,P〈0.05）,与血清HBV DNA无相关性（r=0.174,P〉0.05）;肝组织中HBV cccDNA水平与血清HBsAg定量呈高度正相关（r=0.562,P〈0.001）,而与血清HBeAg定量无相关性（r=0.152,P〉0.05）。肝组织cccDNA定量与肝组织炎症活动度（G）及纤维化程度（S）无相关性（r=0.082,P〉0.05）。结论慢性HBV感染者肝组织内HBV cccDNA成稳定的中等水平复制;血清HBV DNA载量不能直接代表其肝组织中的HBV cccDNA水平;血清HBsAg定量可作为反映肝组织中HBV cccDNA水平的指标。     

HBsAg和HBsAb双阳性检测结果的初步分析

目的对临床检测中少见的HBsAg和HBsAb双阳性结果进行分析,寻找可能的产生原因。方法对3家医院初筛HBsAg和HBsAb双阳性的81份血标本进行同种和不同种试剂盒复检,并检测HBsAg145位氨基酸变异（G145R变异）、HBVDNA基因型和血清型分析。结果81份双阳性标本经复检有30例（37％）仍然为双阳性;对30例复检双阳性标本应用不同试剂盒再次检测,HBsAg／HBsAb仍为双阳性者18例（22．2％）;18例双阳性标本G145R检测全部为阴性;其中8例HBV DNA阳性血清的基因型分布为B型2例和C型6例,血清型分布为adw2例、adr5例和ayr1例,与9份对照血清的检测结果比无显著性差异。结论HBsAg和HBsAb双阳性检测结果大多数与操作或试剂的质量有关,少数可能为S基因变异或不同血清型的再次感染等有关。     

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.     

乙型肝炎相关性肝脏疾病肝移植术后乙肝病毒复发的预防

目的通过乙型肝炎相关性肝脏疾病患者在拉米夫定联合乙型肝炎高效免疫球蛋白（HBIG）治疗下供肝植入前后受体乙型肝炎标志物变化，HBV基因序列变化检测，探讨其预防受体HBV再感染的效果。方法采用MEIA法、PCR-微流芯片法，基因测序法检测21例受体手术前后血清HBV—M、HBV—DNA定量、HBV—YMDD、HBVS基因α决定簇变异，同时采用ELISA法检测供体血清HBV—M。结果术前21例受体HBsAg、HBeAg／HBeAb、HBcAb阳性，16例HBV-DNA阳性，1例HBV．DNA阴性，4例HBV．DNA未测，术后19例患者HBV-M变成HBsAb或HBsAb、HBcAb阳性，1例为HBsAg、HBeAg、HBcAb阳性，1例为HBsAg、HBeAb、HBcAb阳性，其中19例HBV-DNA阴性，2例HBV-DNA阳性，无一例术前、后出现HBV．YMDD、HBVS基因α决定簇变异，供肝HBV-M均阴性。结论拉米夫定联合HBIG预防肝移植术后乙肝复发疗效确切，乙肝低或无复发可能与供体HBV-M阴性及受体无HBVS基因d决定簇变异有关，术前受体HBV-DNA结果与术后乙肝复发相关性未显示。     

HBsAg/HBsAb双阳性慢性乙型肝炎患者HBV S基因免疫逃逸相关变异分析

目的分析HBsAg/HBsAb双阳性慢性乙型肝炎患者HBV S基因主要亲水区免疫逃逸相关位点变异特点。方法收集89例HBsAg/HBsAb双阳性和148例HBsAg单阳性的慢性乙型肝炎患者血清及临床资料,提取患者血清HBV DNA,扩增患者HBV S基因并进行测序,应用DNASTAR Lasergene Meg Align软件对主要亲水区已有文献报道的46个免疫逃逸相关位点及新增N-糖基化变异进行比对分析。结果 2组患者在年龄、ALT、TBIL、HBV DNA载量和HBe Ag阳性率方面差异均无统计学意义(P均0.05)。HBsAg/HBsAb双阳性患者HBV S基因主要亲水区变异的总检出率为31.46%,明显高于HBsAg单阳性患者的18.92%(P0.05),其中s L110I/S、s T113N/S、s T131I/N/P和s S143L/M/T的变异检出率明显高于单阳性组;双阳性患者多位点联合变异检出率亦明显高于单阳性患者(20.22%vs.6.08%,P0.05)。双阳性患者新增N-糖基化变异检出率高于单阳性患者(7.87%vs.2.03%),差异具有统计学意义(P0.05)。结论 HBsAg/HBsAb双阳性患者比HBsAg单阳性患者的HBV S基因免疫逃逸相关变异种类更多,单位点和多位点联合变异检出率更高,并且新增N-糖基化变异检出率也更高,这些变异可能是引起慢性乙型肝炎患者HBsAg/HBsAb双阳性共存的驱动因素之一。     

人类免疫缺陷病毒感染者合并隐匿性乙型肝炎病毒感染的现状调查

目的 调查分析上海地区HIV感染者中隐匿性HBV感染的流行现状.方法 对上海市公共卫生临床中心就诊的HIV感染者在尚未接受抗病毒治疗前采集血标本,检测HBsAg、抗-HBs、HBeAg、抗-HBe、抗-HBc,抗-HCV,CD4+T细胞计数,使用巢式PCR法检测HBV S区.结果 105例(男92例,女13例)HBsAg阴性的HIV感染者中32例(男27例,女5例)HBV DNA阳性;16～30岁年龄组22例,其中5例HBV DNA阳性,31～49岁年龄组44例,其中15例HBV DNA阳性,50～75岁年龄组39例,其中12例HBV DNA阳性;32例中有27例至少一项HBV血清学标志物阳性,5例均阴性.47例合并HCV感染者中有14例HBV DNA阳性,阳性率29.8%;58例未合并HCV感染的HIV感染者中18例HBV DNA阳性,阳性率为31.0%.CD4+T细胞计数平均值145.1个/μ(4～623个/μ1),75例CD4+T细胞<200个/μ1的患者中有26例HBV DNA阳性,约占34.7%,30例CD4+T细胞>200/μ1患者中有6例HBV DNA阳性,阳性率为20.0%.以上各项之间两两相比差异均无统计学意义.结论 HIV感染者中存在隐匿性HBV感染,且与HIV感染者性别、年龄、HBV标志物、是否合并HCV感染及CD4+T细胞计数无明显相关.     

不同HBV标志物模式的乙型肝炎患者HBV表面大蛋白的检测及与HBVDNA水平的相关性

目的通过检测乙型肝炎病毒标志物（HBVM：HBsAg／抗-HBs、HBeAg／抗一HBe、抗一HBc）不同模式的乙型肝炎患者血清中乙型肝炎病毒外膜大蛋白（HBV—LP）、乙型肝炎病毒前s1抗原（HBVpreSl）、HBVDNA,探讨HBV—LP与HBVDNA及HBVM模式间的关系,研究HBV—LP用于乙型肝炎患者临床诊治的意义。方法采用酶联免疫吸附试验（ELISA）对HBV—LP、HBVpreS1和HBVM进行检测;采用荧光定量PCR方法对HBVDNA进行检测。结果乙型肝炎患者大蛋白检测结果与HBVDNA检测结果差异无统计学意义（X^2=1．97,P〉0．05）。HBV—LPA值随HBVDNA拷贝数的增加呈上升趋势,二者之间存在良好的相关性（r=0．565,P〈0．01）,在不同HBVDNA拷贝数组别间,HBV—LPA值差异有统计学意义（F=9．23,P〈0．01）。结论HBV—LP是反应HBV感染者体内病毒复制程度的良好的血清免疫学指标,血清中的HBV—LP与HBVDNA具有较好的相关性,特别是可作为HBeAg阴性患者体内监测病毒复制及预后判断的良好的血清学指标。     

Virological analysis, genotypes and mutational patterns of the HBV precore/core gene in HBV/HCV-related hepatocellular carcinoma

We investigated the replicative profile of hepatitis B (HBV) and hepatitis C (HCV) viruses and the mutational pattern of the HBV precore/core (pre-C/C) domain in hepatocellular carcinoma (HCC). Thirty-eight consecutive patients with HCC were included in the study - 18 of them with HBV/HCV co-infection and 20 with HBV single infection. Twenty-three additional patients with co-infection, without HCC were recruited as the control group. Replication activity was evaluated by detecting and quantitating both HBV and HCV genomes. The HBV pre-C/C region, encompassing the pregenome encapsidation signal involved in viral replication, was analysed by direct sequencing. HBV viraemia levels were significantly lower (P = 0.04) in patients with co-infection in comparison with single-infected HCC, whereas two different HBV viraemia profiles were detected in co-infection with or without circulating HCV. HBV genotype D was prevalent in the three groups and HCV genotype 1b was found to be the infecting strain in all patients. Lower variability in the pre-C/C region was found in co-infection in comparison with HBV single infection (P = 0.0004). A synonymous T1936C mutation was found in all co-infected HCC cases not related to the presence or absence of circulating HCV, and a hypermutated pre-C strain, characterized by the same mutational pattern, was identified in three HCC cases. The mutational pattern of the pre-C/C region was closely related to HBV replication efficiency, and specific HBV mutations selectively associated with HCV co-infection could be linked with accelerated HBV/HCV-related disease progression.     

慢性乙型肝炎病毒基因型与BCP区变异的临床研究

为了研究乙型肝炎病毒 (HBV)基因型与C基因启动子 (BCP)基因变异的关系 ,对 6 9例慢性乙型肝炎患者分别用聚合酶链反应 (PCR)—限制性片段长度多态性 (RFLP)技术和PCR微板核酸分子杂交技术 ,进行基因分型及HBVBCP基因变异检测。在 6 9例慢性乙型肝炎患者中 ,各基因型发生的BCP区A176 2T/G176 4A双突变分别为C型 18例 (4 3 9% )B型 3例 (16 7% )D型 2例 (2 0 % )。C型的BCP双突变率明显高于B型 ,两者相比有显著性差异(P <0 0 5 )。故可以认为乙型肝炎病毒基因型与BCP区双突变存在有一定的相关性。推测A176 2T/G176 4A双突变可能是造成C型患者比B型存在更严重肝损害的原因之一     

HBV/HCV重叠感染的研究进展

HBV是一种嗜肝DNA病毒,HBV DNA和HBV特异P蛋白由核壳包裹成为核心颗粒,再由脂蛋白外膜包裹成完整的病毒颗粒。HCV是黄病毒科病毒,为单股正链RNA。HBV和HCV均由肠道外途径传播,2种病毒常可由相同途径发生感染。归纳了HBV/HCV重叠感染的发病机制、与隐匿性HBV感染和肝细胞癌以及器官移植、HBV疫苗之间的关系,同时介绍了重叠感染的治疗。指出存在于患者体内的HBV和HCV在病毒学方面相互干扰,在病变方面相互叠加。     

HBV vaccination in liver transplant recipients: not an effective strategy in the prophylaxis of HBV recurrence

Anti-HBs immunoglobulins (HBIG) and lamivudine are main options to prevent hepatitis B virus (HBV) reinfection after liver transplantation. Although they are very effective, development of mutant viruses and high cost of treatment are main limitations for their application. Additionally there is an uncertainity for the duration of that prophylaxis regimen and its mostly applied indefinitely. Recently, post-transplant HBV vaccination is reported to be a cheaper alternative prophylaksis strategy, that enables discontinuation of HBIG. To investigate the efficacy of HBV vaccination in patients transplanted for HBV cirrhosis, we administered double course of double dose recombinant HBV vaccine (Genhavac B; containing HBV pre-S1, pre-S2, and S gene products). Vaccination has been started 1 month after HBIg discontinuation, and lamivudine (100 mg/day) was given throughout the study. The first cycle consisted of 0, 1- and 6-month schedule, and, in nonresponders, second cycle 0, 1-, 2-month schedule. Fourteen patients included into the study. Only one patient seroconverted (an anti-HBs titre of 37 IU/L) after the first cycle. No other patient responded to second cycle. HBV vaccination in the post-transplantation setting does not seems like an effective strategy in the prophylaxis of HBV recurrence.     

乙型肝炎病毒母婴传播阻断的共识与争议

慢性乙型肝炎因其严重的不良临床结局如肝硬化或肝细胞癌而成为严重的公共卫生问题,而母婴传播是导致慢性HBV感染的最主要原因。尽管HBV阳性孕妇所生的新生儿在出生后24h之内应用了乙型肝炎疫苗和乙型肝炎免疫球蛋白（HBIG）进行联合免疫阻断,仍然有大约10％左右的新生儿感染了HBV,特别是高病毒载量的孕妇。本文将就HBV母婴传播的特点、目前在阻断措施方面达成的共识和存在的争议进行论述。     

乙型肝炎患者检测肝组织HBV-DNA的意义

为了探讨提高乙型肝炎病毒微量检出率的有效途径。采用PCR分别检测血清及肝穿刺组织HBVD-NA，血清检出总阳性率为41.7%，肝组织检出总阳性率为72.9%。在血清HBsAg阴性的病例中PCR血清检出阳性率为26.7%。肝组织检出阳性率为66.7%。早此可见PCR检测灵敏。准确、特别对血清HBVM难以检测的微量HBVDNA更有价值。两种标本来源相比肝组织较血清为优。     

Molecular and Serological Characterization of Hepatitis B Virus (HBV)-Positive Samples with Very Low or Undetectable Levels of HBV Surface Antigen

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.     

肝癌患者血清中乙型肝炎病毒基因分型及临床意义

目的:探讨血清中乙型肝炎病毒(HBV)基因型及HBV DNA水平与肝细胞癌的关系。方法:应用巢式聚合酶链反应扩增乙型肝炎病毒与基因,用末端标记方法对PCR产物标记并直接测序,测序结果和GenBank中登录的标准基因型序列相比较,应用荧光定量PCR法检测HBV DNA水平。对61例肝癌、65例慢性乙型肝炎、10例乙型肝炎病毒携带者进行了检测。结果:136例中B基因型59例(43.4%)、C基因型77例(56.6%),随着病情加重,C基因型比例逐渐增高;不同基因型HBV感染的肝癌患者间HBV DNA水平差异有显著意义,P<0.05;在慢性乙型肝炎患者中,HBV DNA水平差异无显著性意义。结论:本地区乙型肝炎病毒以B、C基因型为主,乙型肝炎病毒C基因型及高水平的HBV DNA感染与肝癌的发生相关。     

靶向HBV C区RNAi对HBV复制和HBeAg表达的抑制作用

目的观察靶向HBVC基因区的RNA干扰（RNAi）对HBV复制的抑制作用。方法选择HBV基因组C区的Nt2021-2049作为靶序列,合成相应的正、反义寡核苷酸,退火后形成双链,克隆人shRNA表达质粒,将得到的质粒与HBV质粒共转染HepG2细胞,观察HepG2细胞中HBV的受抑情况。结果病毒复制及HBeAg的表达明显受到抑制。结论所选靶区通过RNAi可有效抑制HBV复制。