HBcAg18-27V/I变异体与严重乙型肝炎活动的关系

目的探讨人白细胞抗原(HLA)-A2限制性细胞毒T淋巴细胞(CTL)表位HBcAg18-27V/I变异体与乙型肝炎活动的关系。方法收集77例严重乙型肝炎活动(SHB)患者和88例慢性乙型肝炎(CHB)患者的血标本,提取其中的HBV DNA,PCR扩增测序HBcAg18-27表位编码区、HBV基因型并鉴定HLA-A2。随访SHB患者至少3个月,在随访时间点留取血标本,提取其中的HBV DNA,PCR扩增测序HBcAg18-27表位编码区,并收集单个核细胞(PBMC)行五聚体染色检测HBcAg18-27表位特异性CD8+记忆T细胞的频数。结果 SHB组HBcAg18-27V的检出率为23.4%(18/77)、CHB组为4.5%(4/88),两组相比,P<0.01。随访存活的10例HBcAg18-27V SHB患者(1例PCR扩展阴性),其中4例HLA-A2阳性患者HBcAg18-27V变异为HBcAg18-27I,而5例HLA-A2阴性者随访后仍检测到HBcAg18-27V。HBcAg18-27V特异性CD8+记忆T细胞的频数高于HBcAg18-27I者。结论在HLA-A2阳性的SHB患者中,发生HBcAg18-27V向HBcAg18-27I表位漂移是HBcAg18-27V诱导的CTL免疫反应的结果;而CTL免疫反应在清除HBcAg18-27V病毒的同时,也参与了HBV相关SHB活动的发生。     

急性乙型肝炎患者特异性核心抗原细胞毒性T淋巴细胞频率的变化及其意义

目的 动态观察急性乙型肝炎(AHB)患者外周血HBcAg18-27表位特异性细胞毒性T淋巴细胞(CTL)、血清ALT、HBV DNA、HBsAg和淋巴细胞亚群的变化,探讨HBV特异性CTL频率的消长在病毒清除以及肝脏损伤中的作用.方法 分别选取AHB、慢性乙型肝炎(CHB)患者外周血,根据人类白细胞抗原(HLA)-A0201结果分为两组:HLA-A0201阳性患者作为HBV特异性CTL检测组、HLA-A0201阴性患者作为特异性抗原表位对照组.用HLA-A0201限制性表位HBcAg18-27五聚体复合物通过流式细胞技术,动态定量检测外周血中HBV特异性CTL频率和T、B淋巴细胞与自然杀伤细胞(NK)和NKT淋巴细胞;以速率法检测血清ALT水平;荧光定量PCR检测HBV DNA水平; Abbott微粒子化学发光技术检测HBV血清学标志物.计量资料采用均数±标准差((x)±s)表示或中位数(P25-P75)描述,组间比较采用方差分析或非参数检验(KruskalWallis检验和Mann-Whitney U检验);两种计量指标的关系采用Pearson相关分析.结果 AHB患者入院第1、2、3周外周血HBcAg表位特异性CTL频率分别为2.11%(0.20%～3.64%)、3.56%(1.05%～5.91%)、2.03%(0.33%～3.58%),高于入院第4、5、6周的0.99%(0.12%～2.16%)、0.29%(0.05%～0.76%)、0.39%(0.05%～0.46%),也显著高于CHB的0.11%(0.06%～0.29%),z值分别为-3.258,-4.041,-3.259,P值均＜0.01.AHB患者HBcAg表位特异性CTL峰值延迟于血清HBV DNA、HBsAg和ALT等指标的峰值;在AHB患者中,HBcAg表位特异性CTL高频率患者的血清HBsAg消失时间早于CTL频率较低的患者[(1.75±1.04)周与(4.33±3.51)周,t=-2.018,P＜0.05].CD3+CD8+T淋巴细胞频率的峰值出现在入院后第2周,并与HBcAg表位特异性CTL峰值相重叠,两者动态变化规律呈相关性(r=0.420,P＜0.01).AHB患者早期外周血NK、NKT淋巴细胞数量显著低于正常对照组和CHB患者,但随着病情好转而逐渐恢复,AHB患者外周血NK细胞数量变化与HBcAg特异性CTL动态变化呈负相关(r=-0.435,P＜0.01).结论 急性HBV感染者高频率的HBcAg表位特异性CTL与HBsAg的更早消失有密切关系,动态监测外周血中HBcAg特异性CTL频率变化,可以作为预测HBV感染后临床转归的参考指标;AHB患者外周血CD8+T淋巴细胞数量的变化,可以间接反应AHB患者体内HBcAg特异性CTL频率的改变.

Abstract：

Objective This report aims to investigate the dynamical changes of HBcAg18-27 epitope specific cytotoxic T lymphocytes(CTL), alanine aminotransferase (ALT), HBV DNA and HBsAg in peripheral blood of acute hepatitis B patients, and to explore the roles of HBcAg18-27-specific CTLs in virus clearance and liver injury. Methods Acute hepatitis B (AHB) and chronic hepatitis B (CHB) patients were divided into two groups according to results of HLA-A0201. Patients with positive HLA-A0201 were classified into HBcAg-specific CTL group and those with negative HLA-A0201 were referred as control group.The specific CTLs were stained with HLA-A0201 limited HBcAg18-27 epitope MHC-Pentamer and the frequencies of CTLs, T, B, NK and NKT cells were detected by flow cytometry (FCM). The serum ALT, HBV DNA and HBsAg were examined using speed analysis, quantitative PCR and abbott chemiluminescent technology. Results The frequencies of HBcAg18-27-specific CTLs in AHB patients were higher in the early three weeks as compared to the late three weeks. The apex time of HBV-specific CTL frequencies lagged behind those of HBV DNA, HBsAg and ALT. The loss of HBsAg in patients with high frequencies of HBVspecific CTL was earlier than that in patients with low frequencies (t = 2.018, P ＜ 0.05). In the second week the peak frequencies of CD3+CD8+ cells overlapped with that of HBcAg18-27-specific CTLs and with a positive correlation between (r = 0.420, P ＜ 0.05). During the early stages of AHB, the frequencies of NK and NKT cells were found significantly lower than that of control group and CHB group and the levels were back to normal after recovery. Moreover, a negative correlation existed between the frequencies of NK cells and the dynamic changes of HBcAg18-27-specific CTLs (r = -0.435, P ＜ 0.01) in AHB group. The frequencies of HBcAg18-27-specific CTLs were significantly higher as compared to CHB group in the first three weeks (z = -3.258, -4.04, and -3.259, P ＜ 0.01). Conclusion The early loss of HBsAg was closely related to the high frequencies of HBcAg18-27 specific CTLs in AHB patients. HBcAg-specific CTL frequencies in peripheral blood could be used to predict clinical outcome after HBV infection. The frequencie of CD8+ T cells can reflect the changes of frequencies of HBcAg-specific CTL. during acute HBV infection.     

人白细胞抗原-A*0201限制性丙型肝炎病毒细胞毒性T淋巴细胞表位的鉴定

目的 鉴定人白细胞抗原(HLA)-A*0201限制性HCV-CTL表位.方法 基于RANKpep和SYFPEITHI细胞表位预测软件预测结果,选择合成6条候选CTL表位.研究候选CTL表位肽与T2细胞表达的HLA-A*0201分子的亲和力,进一步采用酶联免疫斑点实验(ELISPOT)和细胞内细胞因子染色(ICS)实验研究HLA-A*0201高亲和力肽在HLA-A*0201阳性HCV感染者的外周血单个核细胞(PBMC)中刺激CTL反应情况.结果 在6条候选CTL表位肽中,肽C_181(LLSCLTTPV)和NS2_172(VLQAGLIRV)与HLA-A*0201分子有高亲和力,其亲和力随肽浓度增加而升高.在10例HLA-A*0201阳性HCV-1b感染者每1×105PBMC中,肽C_181和NS2_172刺激后,特异性分泌IFN-γ细胞的斑点形成细胞数(SFC)分别为0～19和0～20.肽C_181和NS2_172特异性IFN-γ+CD8+T淋巴细胞占CD8+T淋巴细胞的比例分别为0.006%～0.065%和0.005%～0.080%.结论 肽C_181(LLSCLTTPV)和NS2_172(VLQAGLIRV)为HLA-A*0201 限制性HCV-CTL表位.     

HLA-肽复合物研究HBV/C区变异对HLA-A2限制性表位的影响

目的 探讨乙型肝炎病毒(HBV)C区热点变异S87G和(或)197L对细胞毒T细胞表位形成的影响。方法以我国C基因型HBV DNA参照序列为标准(EMBL：Y18855-18858)，在计算机预测197L和(或)S87G变异对HLA-A*0201限制性表位影响的基础上，利用基因T程制备的HLA-A*0201轻链、重链多肽在体外只能与相应表位短肽形成稳定复合物的特点，对预测到的可疑表位肽段进行验证。结果197L时，肽段HBcAg96105(KLRQLLWFHI)的DC50比正常(KIRQLLWFHI)时大5倍以上；S87G无影响；197L、S87G没有协同作用。人工合成该短肽在体外不能与HLA-A*0201轻、重链多肽形成稳定复合物。结论HBV／C基因197L和(或)S87G变异时，没有新的HLA-A*0201限制表位产生。     

人白细胞抗原-A*0201限制性丙型肝炎病毒细胞毒性T淋巴细胞表位的鉴定

Objective To identify human leucocyte antigen (HLA)-A* 0201-restricted hepatitis C virus (HCV)-cytotoxic T lymphocyte (CTL) epitopes. Methods Based on the prediction results of RANKpep and SYFPEITHI prediction programs, six candidate CTL epitopes were selected and synthesized. The affinity of candidate CTL epitopes to HLA-A* 0201 molecules of T2 cells was explored. Subsequently, enzyme-linked immunosorbent spot (ELISPOT) assay and intracellular cytokine staining (ICS) were utilized to determine whether candidate CTL epitopes could induce the recall positive response in peripheral blood mononuclear cells (PBMC) of HLA-A* 0201 positive HCV-1b-infected patients. Results Among six candidate CTL epitopes, peptides C_181(LLSCLTTPV) and NS2_172 (VLQAGLIRV) had high affinity to HLA-A* 0201 molecules. Moreover, the affinity was proportional to the concentration of peptide. Furthermore, among ten HLA-A* 0201 positive HCV-1b-infected patients, the frequencies of C_181 and NS2_172-specific interferon (IFN)-γ-producing cells were 0-19 spots forming cells (SFC)/1 × 105 PBMC and 0-20 SFC/1 × 105 PBMC, respectively.The percentages of C_ 181 and NS2_172-specific IFN-γ+ CD8+ T lymphocytes in total CD8+ T lymphocytes were 0.006%-0.065% and 0.005%-0.080%, respectively. Conclusion Peptides C_181 (LLSCLTTPV) and NS2_172 (VLQAGLIRV) are identified as novel HLA-A* 0201-restricted HCV-CTL epitopes.     

胰岛人类白细胞抗原-A2限制性T淋巴细胞表位体外筛选方法的建立

目的 应用表位多肽与人类白细胞抗原(HLA)Ⅰ类分子结合力和解离率分析建立新型T淋巴细胞表位体外筛选方法.方法 采用基于矩阵算法的SYFPEITHI和BIMAS数据库预测6种胰岛细胞自身抗原[包括谷氨酸脱羧酶65(GAD65)、胰岛素瘤相关抗原2(IA-2)、前胰岛素原(PPI)、胰岛特异性葡萄糖6-磷酸酶催化亚基相关蛋白(IGRP)、胰岛淀粉样多肽(IAPP)、神经胶质纤维酸性蛋白(GFAP)]的表位序列,根据预测的结合力指数和已有数据分析筛选并合成15个HLA-A2限制性候选表位多肽.采用HLA-A2转基因的T2细胞检测候选肽与HLA-A2的分子结合力,通过多肽/HLA复合物解离率实验分析复合物的稳定性.采用单因素方差分析进行数据统计.结果 T2细胞肽结合力分析显示,15个候选表位多肽中,IGRP152～160、IGRP215～223、IGRP228-236、PPI2～10、胰岛素B10～18、IA-2172～180、GFAP143～151与HLA-A2的分子结合力＞80%.肽/HLA复合物解离率分析显示,上述结合力较强的7个表位多肽中,胰岛素B10-18、IGRP228～236、GFAP143～151、IA-2 172～180 4 h解离率低于20%.结论 本实验建立的候选多肽结合力与解离率相结合的T淋巴细胞表位体外筛选方法有助于减少研究中目标肽数量,推进1型糖尿病T淋巴细胞诊断方法的研究.     

乙型肝炎患者HBV X蛋白特异性CTL表位变异分析

目的 比较急性乙型肝炎、慢性乙型肝炎与慢性重型乙型肝炎HBV X 蛋白特异性CTL表位变异差异,探讨乙型肝炎重症化和慢性化的可能机理.方法 对393例乙型肝炎患者的血清样本进行HLA-A2分型;用巢式PCR扩增血清HBV前S/S基因与X基因并对PCR产物进行序列测定;根据HBV前S/S基因序列,用VirusBlast软件鉴定患者感染的HBV基因型;用Vector NTI软件对目前已知的6个HLA-A2限制性X蛋白特异性CTL表位序列分析,对患者各个表位变异的差异进行卡方检验.结果 190例(48.35%)患者HLA-A2阳性,其中急性乙型肝炎(AHB)67例,慢性乙型肝炎(CHB)52例,慢性重型乙型肝炎(CSHB)71例.CTL表位变异分析结果如下:对三组所有患者进行比较时,X92-100表位变异发生频数三组患者比较有非常显著性差异(P＜0.01);对三组中HBV C基因型患者进行比较时,X92-100和X115-123表位变异发生频数三组患者比较有显著性差异(P＜0.05);对三组中HBV B基因型患者进行比较时,各表位变异发生频数三组患者比较无显著差异.结论 某些HBV X蛋白特异性CTL表位在AHB、CHB和CSHB患者间变异有明显差异且受病毒基因型影响,CTL表位变异可能与乙型肝炎的重症化和慢性化机制相关.     

ELISPOT检测HLA-A0201转基因小鼠对恶性疟原虫红前期候选抗原的CTL应答

用恶性疟原虫红前期多表位候选抗原PfCP-3^tcl（含有1个HLA A*0201限制的CTL表位YLNKIQNSL）免疫人白细胞抗原复合体（HLA）A*0201（HLA-A*0201）转基因小鼠，再用鼠γ干扰素（IFN-γ）酶联免疫吸附斑点法（ELISPOT）检测该转基因小鼠特异性CTL应答，尝试在转基因实验动物中建立评价恶性疟原虫红前期候选抗原CTL应答的方法。结果显示该候选抗原中含有的CTL表位在转基因小鼠体内激发出了特异性的CTL应答，表明该CTL表位在转基因小鼠体内能够正确地加工和递呈。     

慢性乙型肝炎患者HBV核心区与聚合酶区特异性CTL表位变异分析

目的比较急性乙型肝炎、慢性乙型肝炎与慢性重型乙型肝炎患者HBV C蛋白和Pol蛋白特异性CTL表位变异的差异,以探讨乙型肝炎重症化和慢性化的可能机理。方法对516例乙型肝炎患者的血清进行HLA-A2和A11分型;用巢式PCR扩增血清HBV C基因与Pol基因并对PCR产物进行序列测定;根据HBV S基因序列,用VirusBlast软件鉴定患者感染的HBV基因型;用Vector NTI软件对目前已知的HLA-A2限制性的4个C蛋白和5个Pol蛋白特异性CTL表位与HLA-A11限制性的1个C蛋白表位进行序列分析。结果 247例（47.86%）患者HLA-A2阳性,其中AHB 67例,CHB 109例,CSHB 71例;220例（42.64%）患者HLA-A11阳性,其中AHB 67例,CHB 107例,CSHB 46例;CTL表位变异分析结果如下：①在3组HLA-A2阳性患者,表位变异发生率无显著性差异（P〉0.05）;②在三组HLA-A2阳性HBV B基因型患者,P455-463和P816-824表位变异有极显著性差异（P〈0.01）;③在三组HLA-A2阳性HBV C基因型患者,各表位变异无显著性差异;④在三组HLA-A11阳性患者,C88-96表位变异发生率有显著性差异（P〈0.05）,三组HBV C基因型患者,表位变异发生率有极显著性差异（P〈0.01）,而在HBV B基因型患者,各表位变异无显著性差异（P〉0.05）。结论某些HBV C蛋白和Pol蛋白特异性CTL表位在AHB、CHB和CSHB患者间变异有明显差异,并且受感染病毒基因型的影响。CTL表位变异可能与乙型肝炎的重症化和慢性化机制相关。     

乙型肝炎病毒特异性细胞毒性T淋巴细胞应答与不同临床感染状态的关系

目的 分析人类白细胞抗原(HLA)-A0201限制性的特异性CTL,研究急性肝炎急性期和慢性乙型肝炎活动期患者T淋巴细胞对特异性抗原表位免疫应答的差异.方法 收集HLA-A0201阳性的5例急性肝炎急性期和6例慢性乙型肝炎活动期患者的外周血单个核细胞(PBMC),酶联免疫斑点技术(ELISPOT)测定针对HBV聚合酶区(Pol575-583)、包膜区(Env348-357)和核心区(Core18-27)3个CD8+T淋巴细胞表位肽特异性CTL的数量和功能.数据采用t检验.结果 经Pol575-583、Env348-357和Core18-27三条抗原肽刺激,急性乙型肝炎急性期患者组斑点形成细胞数(SFC)分别为110±13、165±17和185±20;慢性乙型肝炎活动期患者组SFC分别为22±4、23±5和30±5,两组差异有统计学意义(t值分别为10.9、15.2和8.0,均P<0.05).急性乙型肝炎急性期患者各抗原肽特异性CTL的应答能力Pol575-5830.05).非特异性HLA-2402限制性Core117-125刺激也出现SFC增加,但与阴性对照组比较,差异无统计学意义(P>0.05).结论 急性感染者HBV特异性CTL应答水平显著高于慢性HBV感染者,慢性乙型肝炎患者体内的多克隆CTL数量和功能低下.     

Geographic distribution, virologic and clinical characteristics of hepatitis B virus genotypes in China

The significance of hepatitis B virus (HBV) genotypes for the heterogeneity of chronic HBV infection and severity of liver disease is not well understood. The aim of this study was to determine the distribution and virologic characteristics of HBV genotypes in China and possible association with the diversity of liver disease. The study includes 1096 chronic HBV carriers from nine provinces in China. We collected clinical and laboratory data and analysed the HBV strains in sera by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequencing techniques. The most common HBV genotypes were B (41%) and C (53%), while genotypes A and D were also found. A North-South divide was identified in genotype B and C distribution - genotype C was predominant in northern China, while genotype B was more prevalent in southern provinces. Patients with genotype B were younger than those with genotype C, and had a lower prevalence of HBeAg - 65%vs 72%, respectively (P = 0.03). However, the severity of liver disease did not differ significantly between patients infected with genotype B or C - neither when comparing liver function tests (1024 patients), nor hepatic inflammation and fibrosis (264 patients). Amongst 47 patients with genotype D (by PCR-RFLP), 37 (79%) were infected with a new subtype (designated Dc), having a recombination fragment from genotype C precore/core region. This is the first large-scale HBV genotype study from China and convincing documentation of the North-to-South gradient of genotypes C vs B in this country. HBV DNA recombination over the surface and precore/core genes increases the diversity of HBV strains and may have diagnostic and clinical implications.     

YMDD mutations and genotypes of hepatitis B virus in northern China

The objective of this research was to determine the relationship between YMDD mutations and the genotypes of hepatitis B virus (HBV) during lamivudine treatment. HBV genotypes were determined by nested PCR with 6 pairs of HBV genotype-specific primers (A to F) in serum specimens from 142 hepatitis B patients receiving lamivudine antiviral therapy. YMDD mutations were detected by fluorescent hybridization bioprobe PCR and melting curve assay (FH-PCR-MC). Among 142 serum specimens, 13 samples were genotype B (9.2%), 125 samples were genotype C (88%), 4 samples were genotype D (2.8%), and 80 YMDD mutations were found. The YMDD mutation rates were 69.2 and 54.4% in genotype B and genotype C, respectively. There was no significant difference in the YMDD mutation rate between genotypes B and C. Nine genotype B sera with YMDD mutations were found, including 2 YIDD mutations and 7 YVDD (M + V) mutations. Sixty-eight genotype C sera with YMDD mutations were found, including 34 mutations I (M + I) and 17 mutations V (M + V). There was a significant difference in the YMDD mutation types between genotypes B and C. Our results suggested that the YMDD mutation rate was 56.3% in patients treated with lamivudine for 2-4 years. YIDD was the main mutation type. The YMDD mutation rate showed no significant difference between HBV types B and C (P > 0.05), while the YMDD mutation types showed a significant difference between HBV types B and C in Northern China (chi2 test = 4.6, P < 0.05).     

徐州地区汉族人及慢性乙型肝炎HLA-A基因多态性的研究

探讨慢性乙型肝炎与HLA-A位点的等位基因多态性.用PCR-SSP方法对徐州地区汉族正常组和慢性乙型肝炎组的HLA-A基因多态性进行分析.HLA-A＊0201-17出现的频率在慢性乙型肝炎组为45.57%,高于正常组的29.69%,P=0.002＜0.05,RR=1.983,（95%CI：1.227-3.080）,具有统计学意义.HLA-A＊0201-17与慢性乙型肝炎较高的相关性,可能为易感基因.     

Hepatitis B virus core and core-related antigen quantitation in Chinese patients with chronic genotype B and C hepatitis B virus infection

BACKGROUND AND AIMS: Hepatitis B virus (HBV) core-related antigen (HBcrAg) and HBV core antigen (HBcAg) assays were developed for the measurement of serum HBV load. The aim of this study was to assess the clinical utility of these assays in Chinese patients with chronic genotype B and C HBV infection. METHODS: One hundred and ninety-three chronic hepatitis B patients were enrolled. Serum HBcrAg and HBcAg were measured by chemiluminescence enzyme immunoassay, and HBV-DNA was measured by using a sensitive polymerase chain reaction assay. The data were analyzed in patients with HBV genotype B (HBV/B) and genotype C (HBV/C). The HBcrAg/HBcAg ratio was calculated and compared between patients with and without hepatitis B e antigen (HBeAg). RESULTS: The concentrations of HBcrAg and HBcAg showed significant positive correlation with the HBV-DNA concentration in both HBV/B (r = 0.79, P < 0.001, and r = 0.77, P < 0.001, respectively) and HBV/C (r = 0.87, P < 0.001, and r = 0.90, P < 0.001, respectively). The cut-off for a positive HBcAg corresponded to approximately 4.5 log copies/mL, and that for a positive HBcrAg result corresponded to 3-4 log copies/mL. The HBcrAg/HBcAg ratio was higher in patients with HBeAg than in those without HBeAg. CONCLUSIONS: The HBcrAg assay and HBcAg assay are clinically useful in viral quantitation of HBV/B and HBV/C. A combination of these assays would be a valuable tool for analyzing the clinical status of HBV infection.     

山西省HBV基因型及亚型分布调查

目的了解山西省乙型肝炎病毒(HBV)的基因型及亚型分布情况。方法对136例乙型肝炎表面抗原(HBsAg)阳性者血清采用PCR-PFLP结合基因型特异性引物-PCR法进行HBV基因型及亚型检测。结果 136例HBV感染者的血清标本经PCR-PFLP分析,B基因型18例,均为Ba亚型,占13.2%;C基因型113例,占83.1%,除4例未分型外均为Ce亚型;D基因型5例,占3.7%。经型特异性引物-PCR分析,18例HBV B基因型中有4例为B/C基因型混合感染;5例经PCR-PFLP确定的D基因型病毒经型特异性引物法分析有2例扩增出E基因型条带。C、B基因型病毒感染者的平均年龄分别为(39.5±13.1)岁和(30.5±14.1)岁,差异有统计学意义(P<0.05);与B基因型相比,C基因型病毒感染者的HBeAg阴转率减慢。结论山西省HBV基因型主要为C(Ce),有少量的B(Ba)和D基因型,且存在B/C混合基因型,且可能存在D和E基因型病毒的重组体;与B基因型比较,感染C基因型病毒更难被机体清除,疾病更易慢性化。     

基因芯片技术检测西藏拉萨地区的乙型肝炎病毒基因型

目的:研究西藏拉萨地区乙型肝炎病毒基因型的分布与特点.方法:采集92份西藏拉萨地区乙型肝炎患者的血清,参照GenBank中HBV DNA序列设计寡核苷酸探针并制备HBV基因分型芯片,利用套式PCR扩增HBV S基因部分片段,结合基因芯片、DNA测序和BioEdit软件进行基因分型检测,并对其与乙肝标志物、DNA含量、性别和民族之间的关系进行分析.结果:在92例血清标本中,套式PCR检测73例HBV DNA阳性可进行基因分型检测.其中B型13例(17.8%),C型18例(24.7%),D型39例(53.4%)和B/D混合基因型3例(4.1%).统计学分析3种基因型分布在不同乙肝标志物阳性、不同DNA含量和不同性别之间无差异,但与民族存在统计学差异(x~2=7.179,P<0.05).B型以汉族为主(9/13),而C、D型以藏族为主(12/18、28/39).将基因芯片分型的B、C、D型和B/D混合型进行DNA序列分析,表明两种分型方法的结果完全一致.结论:PCR结合基因芯片技术可用于HBV基因分型.西藏拉萨地区HBV基因型包括B、C、D和B/D混合型,其中以D型为主.     

拉米夫定治疗无良好应答患者乙型肝炎病毒P区突变与基因型的关系

目的 观察拉米夫定治疗后无良好应答的慢性乙型肝炎患者HBV P区变异情况与基因型的关系.方法 对631例拉米夫定治疗后无良好应答的慢性乙型肝炎患者进行研究.通过荧光定量PCR或核酸测序确定HBV基因型,直接测序观察P区突变,实时荧光定量PCR方法检测患者病毒载量,比较不同基因型患者的HBV DNA水平及HBV P区变异情况.计量资料采用成组设计资料t检验,计数资料采用x~2检验或Fisher精确检验.结果 631例慢性乙型肝炎患者中,B基因型HBV感染者272例,C基因型感染者359例,C基因型感染者患者年龄为(39.1±11.4)岁,明显大于B基因型感染患者的(33.7±9.7)岁(t=-6.55,P<0.01).C基因患者病毒载量为(5.96±1.22)log_(10)拷贝/ml,高于B基因型患者的(5.58±1.21)log_(10)拷贝/ml,t=-2.01,P<0.05.A181V/T变异在C基因型的发生率高于B基因型(0.4%比5.3%,χ~2=12.23,P<0.01),M204I/V,L180M、T184A/G/I/S、S202G/I和V173L变异发生率在B、C基因型之间差异无统计学意义(P值均>0.05).M204I在B基因型的发生率为20.6%,高于C基因型的13.9%(χ~2=4.91,P<0.05);M204V和M201Ⅳ变异在B、C基因型中的发生率差异无统计学意义(χ~2值分别为1.70和2.21,P值均>0.05).拉米夫定耐药发生率在B、C基因型间差异无统计学意义(χ~2=0.00,P>0.05).结论 拉米夫定常见耐药位点在B、C基因型之间无明显差异,但是C基因HBV感染患者病毒载量高于B基因型HBV感染患者;M204I变异在B基因型中出现频率高于C基因型,拉米夫定加用或改用阿德福韦酯后可能会使A181V/T变异在C基因型出现的概率高于B基因型;年龄、免疫因素和非常见位点的变异或许是影响拉米夫定疗效的重要因素.