中国广东地区乙型肝炎病毒基因亚型的分布

目的调查中国广东地区乙型肝炎病毒(HBV)基因型,主要是基因亚型的分布情况.方法应用聚合酶链反应-限制性片段长度多态性法以及序列测定法,对广东地区417例慢性HBV感染者血清进行研究.结果广东地区流行的HBV基因型主要为B型和C型,其中B型为Ba亚型,未发现Bj亚型的存在.C亚型有C1和C2两个亚型,其中C1占63%,C2占37%.结论广东地区流行的HBV基因型以Ba和C1亚型为主,C2亚型较少,Bj亚型极为罕见.     

乙型肝炎病毒基因型及亚型与YMDD、前C和C基因启动子变异的关系

目的 探讨乙型肝炎病毒(HBV)基因型及亚型与YMDD变异的关系,以及前C基因区终止密码变异(A1896)、基本核心启动子(BCP)区T1762/A1764变异在Ba、C1和C2三种基因亚型中的发生情况.方法 采用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)法对211例服用拉米夫定后发生YMDD耐药变异的患者HBV进行基因型、基因亚型、A1896及T1762/A1764变异检测.结果 211份标本中B基因型占50.7%(1071211),C基因型占49.3%(104/211),与广东地区对照人群HBV基因型分布情况相比无统计学差异(χ2=0.508,P=0.476).进一步亚型分析发现,107份B基因型全部为Ba亚型;C基因型有C1和C2两种亚型,其中C1亚型占64.4%(67/104),C2亚型占35.6%(37/104),与广东地区对照人群C基因亚型分布情况相比也无统计学差异(χ2=0.043,P=0.836).A1896变异在Ba亚型中的分布最高(41/107,38.3%),C2亚型次之(13/39,33.3%),C1亚型最低(9/65,13.8%),变异在不同基因亚型中的分布有统计学差异(χ2=11.839,P=0.03).T1762/A1764变异在C1亚型中的分布最高(34/65,52.3%),C2亚型次之(17/39,43.6%),Ba亚型最低(23/107,21.5%),T1762/A1764变异在不同基因亚型中的分布有统计学差异(χ2=18.384,P＜0.001).结论 HBV基因型及亚型并不影响YMDD变异的发生,但3种基因亚型发生A1896及T1762/A1764变异的模式存在明显不同.     

福州市乙肝病毒基因型和基因亚型的分布及其与前C、C基因启动子变异的关系

目的 研究福州市乙肝病毒基因型和亚型分布及其与T1762/A1764、A1896变异的关系,为完善预防、诊断、治疗病毒感染的策略和方法提供科学依据. 方法 应用型特异性引物PCR法检测HBsAg阳性血清的基因型,应用PCR-RFLP方法检测基因亚型、T1762/A1764变异和A1896变异. 结果 282份HBsAg阳性血清样品中103份未能成功分型,其余179份样品中B基因型122份(68.2%),C基因型54份(30.2%),B C型3份(1.7%),未检测到其他基因型.随机选取的100份B基因型样品中,Ba亚型71份(71.0%),Bj亚型8份(8.0%),未能分亚型者21份(21.0%).54份C基因型样品中Ce亚型 31份(57.4%),Cs亚型 14份(25.9%),Ce Cs 1份(1.9%),未能分亚型者8份(14.8%).T1762/A1764变异标本9份(8.7%),Ce亚型变异率最高(29.2%),Ba亚型次之(3.3%),Cs和Bj亚型未检测到变异株,T1762/A1764变异在不同基因型和亚型间的分布差异有统计学意义(P＜0.05).A1896变异标本10份(10.0%),Ba亚型变异率最高(14.0%),Cs亚型次之(10.0%),Ce亚型最低(4.0%),不同基因型和亚型中的变异差异无统计学意义(P＞0.05).HBeAg阳性和阴性样品中的基因型和亚型分布差异无统计学意义(P＞0.05). 结论 福州市乙肝病毒以B、C基因型为主,Ba、Ce亚型占优势,HBV各基因型和亚型发生T1762/A1764、A1896变异的模式不同.     

乙型肝炎病毒基因型与YMDD变异的关系

目的:了解乙型肝炎病毒(HBV)基因型与YMDD变异之间的关系.方法:多对型特异性引物PCR扩增法对238例经拉米夫定治疗的慢性乙型肝炎患者进行HBV基因分型,直接序列分析;采用基因芯片检测YMDD及前C/BCP区变异.结果:238例患者中,检测出B基因型190例(79.8%),C基因型41例(17.2%),BC混合型7例(3.0%);发生YMDD变异44例,变异率为18.5%,其中B基因型33例,变异率为17.4%,C基因型8例,变异率为19.5%,BC混合型3例,变异率为42.4%,C基因型YMDD变异的发生率与B基因型相比,差异无显著性意义(P＞0.05).44例YMDD变异者中,30例同时存在L528M变异,7例联合前C区(nt 1 896)变异,13例联合BCP区(nt 1 762/1 764)双重突变.结论:本地区慢性乙型肝炎患者中,优势基因型为B型和C型,经拉米夫定治疗后YMDD变异的发生率在B型和C型差异无显著性意义,同时伴有L528M及前C/BCP区多重变异.     

慢性乙型肝炎病毒感染者病毒YMDD的自然变异

目的 了解慢性HBV感染患者外周血HBV YMDD自然变异情况及其影响因素.方法 采用引物特异性实时荧光PCR法检测慢性HBV感染者外周血HBV YMDD变异情况,并对影响YMDD自然变异检出率的可能因素进行单因素及多因素分析.根据不同资料分别采用χ~2检验、Fisher's确切概率法、t检验、秩和检验及Logistic回归分析进行统计学处理. 结果在196例未经抗病毒治疗的慢性HBV感染者中,检出存在YMDD自然变异株感染者21例(10.70%),其中YVDD阳性20例,YIDD阳性例1变;变异毒株占总病毒株超过50%者1例,25%～500者5例,9%～25%者15例.B基因型HBV感染病例中YMDD变异株的检出率(20.00%,12/60)显著高于C基因型HBV感染病例(7.38%,9/122),χ~2=6.28,P<0.05.患者性别、年龄、HBeAg状态、HBVDNA载量、疾病状态、病毒感染时间对YMDD自然变异株的检出率无显著影响. 结论 在未经抗病毒治疗的慢性HBV感染者中存在HBV YMDD自然变异;YMDD自然变异的发生率与患者性别、年龄、HBeAg状态,HBV DNA载量、疾病状态、感染时间无显著相关性.B基因型较C基因型HBV更易出现YMDD自然变异.     

巢式PCR—RFLP法对江西省乙型肝炎病毒Bj和Ba基因亚型的初步鉴定

随着HBV基因型研究的深入,研究表明,HBV基因亚型和基因型一样,也具有明显的地域分布,如日本以Bj亚型为主,中国以Ba基因亚型为主[1].那么,在以B基因型HBV感染为主的江西省[2]是否也以Ba基因亚型为主呢?本研究采用Sugauchi等[3] 的巢式PCR-RFLP法检测江西省HBV基因亚型的分布情况, 以期进一步了解HBV基因亚型与临床相关性.     

拉米呋定联合苦参素治疗慢性乙型肝炎临床分析

[目的]观察拉米呋定联合苦参素治疗慢性乙型肝炎(CHB)的疗效及对慢性肝炎病毒P基因(YMDD)变异的影响。[方法]收集乙型肝炎病毒(HBV)HBeAg、HBV-DNA阳性的CHB患者106例,分为拉米呋定联合苦参素(Ⅰ)组、苦参素(Ⅱ)组、拉米呋定(Ⅲ)组。分别检测血清HBeAg、抗-HBe、HBV-DNA、肝脏生化指标和YM-DD变异。[结果]治疗12个月时,Ⅰ组HBeAg/抗-HBe转换率为44.4%,优于Ⅲ组(P<0.05),HBV-DNA阴性率及YMDD变异率较Ⅲ组低(P<0.05)。[结论]拉米呋定联合苦参素在一定程度上提高CHB疗效并可减少YM-DD变异。     

乙型肝炎病毒基因型研究进展

1988年Okamoto等[1]通过对18株不同血清型乙型肝炎病毒(HBV)DNA进行全序列分析,将HBV分为A、B、C、D四种基因型。目前,根据HBV全基因组核苷酸序列差异≥8%或S基因序列差异≥4%,将HBV分为8个基因型,分别命名为A~H。每种基因型又可分为不同亚型,如A基因型可进一步分为A1(Aa)、A2(Ae)、A3(Ac)亚型;B基因型分为B1(Bj)、B2(Ba)、B3、B4和B5亚型;C基因型分为C1(Cs)、C2(Ce)、C3、C4和C5亚型;D基因型分为D1、D2、D3和D4亚型;F基因型分为F1和F2亚型等[2-6]。一、HBV基因型的地域和种族分布HBV基因型的分布具有明显的种族和…     

拉米夫定耐药变异株在急性HBV感染者中的流行调查

目的:调查YMDD变异株在急性HBV感染(AHB)中的流行情况,为指导AHB的防治提供依据.方法:收集HBV感染者321例(HBV DNA≥1.0×107copies/L),其中未开始治疗的AHB患者100例和拉米夫定治疗(100 mg/d)不同时期的CHB患者221例.采集外周血标本,用荧光标记杂交双探针PCR融解曲线法(FH-PCR-MC)检测血清HBV YMDD及其变异,统计分析HBVYMDD变异在两组中的分布.结果:在AHB组,只检出HBV YMDD野生型,未检出变异型.而在CHB组,YMDD变异检出率为63.4%,其中YIDD占52.1%,YVDD占37.9%,YIDD+YVDD混合变异占10.0%:1年内、1-2年、2-3年、3-4年和4年以上疗程YMDD变异率分别为45%,66%,77%,75%和40%,YMDD变异检出率在两组中差异显著(X2=112.3,P=0.00).结论:目前在用拉米夫定治疗的CHB患者中仍有较高比率的YMDD变异株存在,但尚未发现该变异株在AHB患者中流行.     

乙肝患者拉米夫定治疗过程中YMDD耐药突变株的变化

目的探讨乙肝患者拉米夫定治疗过程中YMDD变异与HBV基因型、HBV DNA含量及治疗时间的关系。方法采用实时PCR法和基因测序法分别对107例拉米夫定治疗的慢乙肝患者进行HBV DNA含量和HBV基因分型、YMDD变异检测。结果 107例慢乙肝患者中,B型19例（17.8%）,C型81例（75.7%）,B、C混合型7例（6.5%）,未发现A、D、E、F、G、H等其他基因型;共25例（23.4%）发生YMDD变异,其中B型、C型和B、C混合型YMDD变异的发生率分别为26.3%、22.2%、28.6%。各基因型患者YMDD变异的发生率及Y IDD、YVDD的变异类型均无统计学差异（P〉0.05）。血清HBV定量水平低、中、高度组产生YMDD变异株的时间有统计学差异（P〈0.05）。结论 YMDD变异与HBV基因型无明显相关性;治疗前血清HBV DNA含量越高,拉米夫定治疗期间发生YMDD变异的时间越早;出现YMDD变异患者肝组织内处于不同的炎症及纤维化状态。     

B protein of factor XIII: differentiation between free B and complexed B

Plasma factor XIII is a complex of A and B proteins noncovalently linked in a tetramer, A2B2, Enzyme-linked immunosorbent assays (ELISA) were developed to measure the separate factor XIII proteins and the complex. All of the A protein in plasma is in the zymogen complex. The B assay measures the total amount of B protein in plasma (both free B and complexed B). This was confirmed by nondenaturing gel electrophoresis and immunoblotting, which showed two bands for B in plasma with this antibody. Two assays were developed to measure A2B2 complex specifically. One assay used a monoclonal antibody to B to bind antigen and measured B protein in the zymogen complex only and hence the concentration of the complex. The specificity of this antibody was also shown by immunoblotting. In the second assay, the capture antibody was to B and the tag antibody was to A. These two assays gave identical results for the concentration of A2B2 (0.07 mumol/L, 21.6 micrograms/mL in normal plasma). Thus, for the first time, differentiation and quantitation of free B and complexed B in plasma was possible. The assays were used to measure factor XIII proteins in plasma from normal controls, homozygous-deficient factor XIII patients, and their heterozygous relatives. The normal concentration of A in plasma is 0.13 to 0.16 mumol/L (approximately 11 micrograms/mL), all of which is in A2B2. The total B concentration is 0.26 to 0.28 mumol/L (approximately 21 micrograms/mL), half of which is complexed. The free B concentration is 0.13 mumol/L (approximately 10 micrograms/mL). Homozygous-deficient patients have essentially no A protein, but their free B concentration is 0.11 mumol/L. Heterozygotes have decreased A2B2, but their free B is 0.11 mumol/L. These results indicate that the concentration of free B is remarkably constant and does not depend on the concentration of A2 or A2B2.     

Subgenotype reclassification of genotype B hepatitis B virus

ABSTRACT: BACKGROUND: Nine subgenotypes from genotype B have been identified for hepatitis B virus (HBV). However, these subgenotypes were less conclusive as they were often designated based on a few representative strains. In addition, subgenotype B6 was designated twice for viruses of different origin. METHODS: All complete genome sequences of genotype B HBV were phylogenetically analyzed. Sequence divergences between different potential subgenotypes were also assessed. RESULTS: Both phylogenetic and sequence divergence analyses supported the designation of subgenotypes B1, B2, B4, and B6 (from Arctic). However, sequence divergences between previously designated B3, B5, B7, B8, B9 and another B6 (from China) were mostly less than 4%. In addition, subgenotype B3 did not form a monophyly. CONCLUSION: Current evidence failed to classify original B5, B7, B8, B9, and B6 (from China) as subgenotypes. Instead, they could be considered as a quasi-subgenotype B3 of Southeast Asian and Chinese origin. In addition, previously designated B6 (from Arctic) should be renamed as B5 for continuous numbering. This novel classification is well supported by both the phylogeny and sequence divergence of > 4%.     

B safe, B sorted: results of a hepatitis B vaccination outreach programme

The risk of hepatitis B among men having sex with men (MSM) is high, with core antibody rates ranging from 5% to 81%. We describe an outreach, hepatitis B vaccination programme aiming to raise awareness of hepatitis B and increase vaccination uptake. The 13-week programme used an ultra rapid vaccination schedule. Follow-up was defined as complete if the client was core antibody positive, had adequate surface antibody levels following prior vaccination or received three vaccine doses. One hundred and fifty clients were screened for hepatitis B and syphilis. Three cases of untreated syphilis (early latent) and one case of e-antigen-positive hepatitis B were detected. With the aid of text-message reminders, a vaccination completion rate of 76.6% was achieved, with 82.5% completing follow-up. In conclusion, this programme succeeded in reaching MSM not routinely accessing services. Text messaging was an acceptable and effective method of follow-up, resulting in high vaccination completion rates.     

Prevalence of hepatitis B virus genotype B in Vietnamese patients with chronic hepatitis B

Purpose  Hepatitis B virus (HBV) genotypes can affect treatment response to interferon-based therapy and disease outcomes in patients with chronic hepatitis B (CHB). Little data exist to characterize HBV genotypes in Vietnamese, one of the largest minority groups in the United States and also one with one of the highest CHB and liver cancer disease burdens. The goal of this study was to compare the distribution of HBV genotypes in Vietnamese and Chinese patients. Methods  We performed a cross-sectional study of 567 consecutive patients of Vietnamese (n = 478) or Chinese (n = 89) descent, with HBV genotype mutation analysis performed between 7/2,005 and 6/2,008 at a community gastroenterology clinic and a university-affiliated liver clinic in the United States. Results  There were no significant differences between the Vietnamese and Chinese groups in mean age (45 and 44 years), gender (58% and 61% male), HBeAg status (64% and 65% negative), median alanine aminotransferase (33 and 41 U/L), and log₁₀ HBV DNA (4.9 and 5.0 log₁₀ IU/ml), or the prevalence of precore/basic core promoter mutations (72% and 71%), respectively. Vietnamese patients had a much higher prevalence of HBV genotype B and a lower prevalence of genotype C than Chinese patients: 74% and 25% vs. 55% and 43% (P = 0.001). Conclusions  Chinese patients with CHB often carry either B or C genotype. Vietnamese patients with CHB mostly have HBV genotype B. Additional studies are needed to further characterize the clinical significance of HBV genotype in the natural history and treatment outcomes of CHB in Vietnamese patients.     

To B or not to B

Recent data from mouse models suggest that some phenotypes of X-linked lymphoproliferative disease (XLP) result from impaired T:B-cell interactions.Hislop and colleagues now provide evidence that this may contribute to abnormal responses to Epstein-Barr virus (EBV) in XLP.     

Hepatitis B Antigen and Prevention of Post-Transfusion Hepatitis B

Abstract. Screening for hepatitis B antigen (HB_sAg) in the serum of blood donors and exclusion of antigen-positive blood units have reduced the frequency of post-transfusion hepatitis but several cases of hepatitis B still occur in association with transfusions. One explanation for this is probably that HB_sAg is not an indicator of infectivity. Thus healthy carriers of the antigen seem to have low infectivity while carriers with chronic liver disease as well as donors incubating hepatitis B probably present a great risk.     

Group B streptococcal polyarthritis complicating hemophilia B

We report a case of polyarticular group B streptococcal infection in an HIV-negative 46-year-old alcoholic with factor IX deficiency. Septic arthritis occurs infrequently in the hemophilic population despite their chronic joint disease; indications for diagnostic arthrocentesis in these individuals are discussed. The group B streptococcus often behaves as an opportunist in adults.