肝炎患者中TT病毒DNA及其IgG抗体的检测

目的：了解肝炎患中TTV的感染情况，方法：应用Nested-PCR对137份甲－庚型肝炎、31份非甲－庚型肝炎及104份献血员进行TTV DNA检测，同时用ELISA法检测抗TTVIgG。结果：TTV基因检出率分别为甲－庚型肝炎20．44％，非甲－庚型肝炎29．03％，献血员13．46％，抗TTVIgG检出率分别为甲－庚型肝炎27．74％，非甲－庚型肝炎35．48％，献血员14．42％；甲－庚型肝炎、非甲－庚型肝炎与献血组相比TTV DNA及抗TTV IgG均存在显性差异（P＜0．01）。结论：肝病中存在TTV感染，TTV存在健康携带状态。     

应用聚合酶链反应检测南京地区TT病毒感染

目的：了解南京地区ＴＴ病毒感染情况。方法：采用巢式ＰＣＲ方法检测血甭标本中ＴＴＶ－ＤＮＡ。结果：１６３例病毒性肝炎患者血清标本中,ＴＴＶ－ＤＮＡ总检出率为２１．５％（３５／１６３）,其中甲型肝炎１３．３％（４／３０）,乙型肝炎２１．３（１６／７５）,丙型肝炎２０．０％（３／１５）,戊型肝炎５．３％（１／１９）,非甲－庚型肝炎４５．８％（１１／２４）。结论：南 地区丰硕 导致非甲－庚型肝炎的重要病因     

36例非甲、乙、丙、丁、戊型病毒性肝炎患者的血清病原学检测

目的：对非甲－戊型病毒性肝炎患者的血清病原学进行探讨。方法：用酶联免疫吸附法（ELISA）和PCR法检测36例非甲－戊型病毒性肝炎患者血清的病毒标记物。结果：庚型肝炎病毒抗体（抗－HGV）阳性率为19％,庚型肝炎病毒核糖核酸（HGVRNA）阳性率为36％;抗巨细胞病毒免疫球蛋白M（抗－CMVIgM)和抗EB病毒免疫球蛋白M（抗－EBVIgM)均阳性;输血后肝炎相关病毒DNA（TTVDNA）阳性率为31％,TTVDNA阳性者的PCR产物与日本株N22的同源性为95％。结论：TTV、TGV感染在乌鲁木对地区病毒性肝炎患者中占有相当比例,并同时存在不明致病因子感染,应当引起方式工作者的重视。     

供血员、血液透析及非甲～庚型肝炎患者中TTV的感染状况

了解供血员,血液透析及非甲－庚型肝炎患者中输血传播病毒的感染状况,方法对４０份供血员标本,２７例血液透析及６０例散发性非甲－庚型肝炎患者血清标本,采用ＰＣＲ方法检测ＴＴＶ－ＤＮＡ,分析ＴＴＶ的感染状况。结果：４０份供血员血清中,有５例检出ＴＴＶ－ＤＮＡ阳性,检出率为１２．５％;血液透析患者中ＴＴＶ的检出率为２２．２％（６／２７）,而６０例散发性非－庚型肝炎患者血清中,无１例检出ＴＴＶ－ＤＮＡ。在１     

TT病毒DNA PCR-ELISA检测方法的建立

目的:建立检测TT病毒(TTV)DNA快速、敏感、特异的PCR-ELISA方法。方法:将生物素标记的PCR产物与地高辛标记的特异性探针杂交。通过酶免疫显色反应测出A值,判断TTV感染情况。优化反应条件,与PCR电泳结果比较,测定方法的敏感性,并检测325份正常人群、甲～庚型肝炎、非甲～庚型肝炎血清标本,确定该方法的特异性。结果:本实验的最佳杂交时间为45min,最佳探针浓度为4pmol/mL。该方法的检测阈值为50fg/μL TTV DNA,其灵敏度是PCR电泳法的10倍,检测TTV在正常人群、甲～庚型肝炎、非甲～庚型肝炎血清标本中的阳性率分别为2.4%、29.3%、25.0%,与PCR电泳检出结果差异无显著性(P>0.05)。结论:PCR-ELISA是一种快速、敏感、特异的检测方法,可用于临床TTV感染的诊断。     

HBsAg阳性肝病患者血清TTV抗体的检测

输血传播病毒(TTV)最早由Nishizawa等于1997年从1例不明原因的输血后非甲～庚型肝炎患者血清中发现。尽管在许多原因不明的重症肝炎和不明原因的ALT升高患者血清和肝组织中能够检测到TTV DNA，但关于TTV的致病性和在其他病毒性肝炎(甲～庚型)中的作用以及TTV是     

2000年2月份全国疾病监测点35种法定传染病疫情动态分析

本研究通过对我国部分地区的自然人群和非甲非戊型肝炎病人进行HGV和TTV感染的分子流行病学研究,探讨这两种病毒在我国肝炎发病尤其是在非甲非戊型肝炎中的作用和地位.用建立的PCR方法检测血清标本中的HGV RNA和TTV DNA,对调查的自然人群和非甲非戊型肝炎病人血清标本进行检测.HGV RNA采用反转录PCR(RT-PCR)检测,TTV DNA则采用巢式PCR方法检测.结果表明,HGV在自然人群中HGV RNA携带率为0.6%～1.1%,TTV的病原携带率则高达7.1%～12.4%;非甲非戊型肝炎病人中HGV和TTV的阳性率分别为7.9%和28.1%.在所检测的非甲非戊肝炎病人中HGV和TTV的总感染率为35.9%(包括了HGV和TTV的混合感染).因此,HGV在自然人群中感染率低,而且在非甲非戊型肝炎病人中约为10%的病人是由HGV的感染所致,HGV不是非甲非戊型肝炎病人的主要病因.TTV DNA在自然人群中的携带率约为10%,类似于HBV DNA的携带率.虽然在非甲非戊型肝炎病人中TTV DNA的阳性率为28%,但仍然有高达60%的病人病因不明,TTV感染也不是非甲非戊型肝炎病人的主要致病病原.     

我国部分地区人群中TT病毒感染的分子流行病学

目的　了解我国不同地区和人群中 TTV DNA的感染情况。方法　采用巢式 PCR方法检测血清标本 TTVDNA。结果　在 2 1 4例各型病毒性肝炎患者中 ,检出 TTV DNA阳性 5 7例 ,阳性率为 2 6.64%。在甲～戊型肝炎、非甲～戊型肝炎、有偿献血者和正常人群中 ,TTV DNA流行率分别为 2 5 .97% ( 4 0 /1 5 4)、2 8.3 3 % ( 1 7/60 )、3 9.2 9% ( 2 2 /5 6)和 1 7.86%( 1 0 /5 6) ,四组差异亦无显著性 ( P>0 .0 5 ) ;我国北京、沈阳、南京、合肥和深圳的非甲～戊型肝炎患者中 TTV DNA流行率为 2 9.5 7% ( 68/2 3 0 ) ,与上述甲～戊型肝炎组比较差异亦无显著性 ( P>0 .0 5 )。结论　我国不同地区人群中存在 TTV DNA感染 ,各型病毒性肝炎患者和正常人群中 TTV DNA流行率较高。     

新疆地区献血者HGV和TTV感染的流行病学分析

目的：研究分析庚型肝炎病毒（HV）和输血传播病毒（TTV）在新疆地区献血中的感染状况，方法：采用酶联免疫吸附试验（ELISA）法检测抗－HGV IgG、逆转录聚合酶链反应（RT－PCR）技术检测HGV RNA，聚合酶链反应（PCR）技术检测TTV RNA，对1997年维吾尔族献血和321名汉族献血的血清标本进行了检测分析。结果：518名研究对象中抗－HBV IgG的阳性检险率为6．5％（34／518）。维吾尔族和汉族血抗－HBV IgG阳性率分别为11．2％（22／197）和3．7％（12／321），X^2=10．9，P＜0．005，维吾尔族有偿献血，无偿献血抗－HBV IgG阳性率分别为13．5％（21／156）、2．4％（1／41），X^2＝4．0，P＜0．05；汉族有偿献血、无偿献血抗－HGV IgG阳性率分别为7．5％（8／106）和1．9％（4／215），X^2＝6．4，P＜0．05，维吾尔族和汉族抗－HGV阳性献血HGV RNA阳性率分别为77．3％（17／22）和66．7％（8／12），X^2=0．5，P＞0．05。维吾尔族和汉族献血TTV DNA阳性率分别为25．7％（9／35）和13．0％（6／46），X^2＝2．1，P＞0．05，抗－HGV阳性和阴性献血中TTV DNA阳性率分别为35．3％（12／34）和14．0％（7／50），X^2=5．2，P＜0．05。结论：新疆地区存在HGV和TTV感染，有偿献血为HGV感染的高危人群，抗－HGV阳性献血有更高的TTV DNA检出率，这种重叠感染的机制有待进一步研究分析。     

萍乡地区两株TTV分子克隆和核苷酸序列分析

目的探讨TTV感染与临床肝炎关系,分析TT病毒株基因结构特点。方法运用套式PCR方法,检测两例非甲～非庚型肝炎血清中TTV－DNA,克隆测定TTV部分基因序列,分析其基因变异情况。结果两侧有ALT异常,TTV－DNA克隆序列结果表明,与日本株（AB008394）同源性为75．4％和76．8％,与日本株（NA004）同源性为88．6％和83．8％,与中国深圳株（SZ11和SZ2）同源性分别是73．9％、83.2％、75.7％和74.3％。结论萍乡地区正常人群中存在TTV感染者,类似HBsAg的所谓“慢性携带状态”。在本地流行株可能是G2亚型,该研究对萍乡地区病毒性肝炎诊断和防治具有重要意义。     

聚合酶链反应斑点杂交法检测TT病毒感染

目的研究ＴＴ病毒在肝炎发病中的作用机制及其临床病理特征。方法采用聚合酶链反应（ＰＣＲ）技术将地高辛素标记到ＴＴ病毒ＤＮＡ上,制备成地高辛素探针,建立斑点杂交方法,并与套式ＰＣＲ方法进行比较。结果此探针具有一定的特异性和较高的敏感性,采用斑点杂交方法对２９１例各种肝炎血清标本进行检测,ＴＴ病毒阳性率为１３．７％（４０／２９１）,其中甲～戊型肝炎为５．３％（９／１７０）,庚型肝炎为１５．０％（３／２０）,非甲～戊型肝炎阳性为２７．７％（２８／１０１）。斑点杂交与套式ＰＣＲ方法相符率为９８．３％（２８６／２９１）。结论ＴＴ病毒在各型肝炎中均有感染,且斑点杂交方法作为ＴＴ病毒的检测方法是可行的。     

Detection of TT virus DNA in patients with non-A to G liver diseases]

A novel single-stranded DNA virus, TT virus(TTV), has been reported recently. We detected TTV viral sequences by polymerase chain reaction using primers derived from nucleotide sequences of ORF1 and the 5' noncoding region of ORF2. Using primers of the 5' noncoding region, TTV DNA was detected in 21 of 25(84%) healthy individuals, suggesting that most TTV strains detected by these primers are almost harmless. In contrast, using primers of ORF1, which detect genotype 1a TTV that was reported to be a causative agent of posttransfusion hepatitis, TTV DNA was detected in only 3 of 25 healthy subjects and 3 of 27 acute and 9 of 72(12%) chronic non-A to G hepatitis patients. Whether these TTV strains actually cause hepatitis remains to be determined.     

Prevalence of TT virus in serum and peripheral mononuclear cells from a CAPD population.

BACKGROUND: A novel virus named TT virus (TTV) has been isolated recently from patients with posttransfusional hepatitis of unknown etiology. The prevalence of TTV in several groups at risk has been reported, however, there is no information about the prevalence of TTV in patients on continuous ambulatory peritoneal dialysis (CAPD) without blood transfusions or hemodialysis antecedents. OBJECTIVE: To study the incidence of TTV in serum and peripheral blood mononuclear cells (PBMC) of CAPD patients. DESIGN: TTV DNA was detected by polymerase chain reaction, using primers from the open reading frames (ORF) 1 and 2, in serum and PBMC from 22 CAPD patients who had not received blood transfusions or hemodialysis therapy prior to CAPD. As controls, sera from 20 patients with chronic viral hepatitis (10 with HBV and 10 with HCV) and 20 healthy donors were included in the study. RESULTS: TTV DNA was detected in the serum of 5 of 22 (22.7%) CAPD patients with both sets of primers. Four of the 5 (80%) patients with TTV DNA in their serum were TTV positive in their PBMC with primers from ORF1 and ORF2. Five of 20 (25%) patients with chronic viral hepatitis (2 patients with HBV and 3 with HCV) and 4 of 20 (20%) healthy donors were TTV DNA positive in serum. No relation was found between TTV infection and the underlying kidney disease, previous surgery, and abnormal alanine aminotransferase levels. CONCLUSION: We have found a relatively high prevalence of TTV that is similar to that found in healthy donors and in patients with chronic viral hepatitis.     

Detection of TT virus in healthy volunteer]

A novel DNA virus, TT virus(TTV), has been reported in Japanese patient with non A to G posttransfusion hepatitis. We sought to determine whether TTV infection occurs in healthy volunteer, and to compared with DNA extraction methods and polymerase chain reaction(PCR) primer for TTV in diagnostic system. Using a nested PCR assay, serum sample of healthy volunteer serve our laboratory in Japan were examined for the presence of TTV DNA. Twenty of 90(22%) healthy volunteer were detected to have TTV sequences in their serum. Also, we found that DNA extraction methods with a modified phenol-chloroform method. Our result suggested that detection of TTV DNA are high ratio of adults in Japan and were necessary to take care of selected using diagnostic systems.     

Quantitative and genotypic analysis of TT virus infection in Chinese blood donors

BACKGROUND: The TT virus (TTV) is a member of a newly described family of human viruses related to the C ircoviridae viruses. Its association with specific diseases has not been established, and screening of blood donors has not been implemented. To date, 16 genotypes have been identified. STUDY DESIGN AND METHODS: Sera from 471 healthy blood donors (aged 11-58 years) were randomly selected and tested for TTV by the use of two sets of primers: NG59d/NG61d/NG63d primers and T801/T935 primers. Quantitative competitive PCR (QC-PCR) was developed to measure the TTV DNA concentration among the blood donors. Sequencing of a part of the genome was performed to identify the various genotypes. Several samples showed a mixed genotype infection. RESULTS: TTV was detected in 251 (53.3%) of 471 healthy Hong Kong blood donors by the use of NG59d/NG61d/NG63d primers. The prevalence of the virus increased steadily with age (p = 0.03). TTV DNA was detected in 90 percent (90 of a randomly selected 100) of samples by the use of T801/T935 primers. TTV DNA concentration was also measured by QC-PCR in the blood donors who were positive for TTV DNA in the first round of the heminested PCR. TTV titers ranged from 4.8 x 10(2) copies per mL to 6 x 10(4) copies per mL, with a median value of 1.2 x 10(4) copies per mL. Sequencing and phylogenetic analysis of a 223-bp fragment from open reading frame 1 showed three main genotypes (G1 [60.7%], G2 [24.3%], and G3 [14%]) and a new genotype 17 (G17), with the latter bearing 60-percent nucleotide homology with other genotypes deposited at GenBank. In addition, a new TTV subtype, G2f, was found. CONCLUSION: The prevalence of TTV is high in healthy Chinese blood donors. Three main genotypes (G1, G2, and G3) were detected. In addition, a new TTV genotype, tentatively designated as G17, and a new subtype, G2f, were identified.     

Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevance to hepatitis

BACKGROUND: A novel transfusion-transmissible human DNA virus, TT virus (TTV), has been discovered recently. An attempt was made to determine the incidence and clinical outcome of TTV infection in recipients of blood transfusion. STUDY DESIGN AND METHODS: Serial serum samples collected as part of a prospective study of posttransfusion hepatitis were examined for TTV DNA by a nested PCR assay. RESULTS: Among 150 adults undergoing cardiac surgery, posttransfusion specimens from 59 individuals were positive for TTV DNA. Pretransfusion sera were found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after transfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfected with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, with persistently normal levels in 34 of the 38 patients with TTV infection alone. In 8 other patients who subsequently developed well-documented non-A-G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patients followed for more than 1 year, TTV viremia persisted in every case. CONCLUSION: In this population, TTV is transmitted by transfusion to approximately 30 percent of patients who undergo cardiac surgery. Most of the infections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.     

深圳市一般人群HGV和TTV感染的研究

为探讨深圳市一般人群中HGV和TTV感染状况及其影响因素。方法采用随机抽样法选取研究对象 ,对HGV感染的检测先用ELISA法检测样本中的抗 -HGV ,对其中阳性样本再用反转录PCR(RT -PCR)进行检测 ;TTVDNA则采用巢式PCR方法检测。结果表明 ,深圳市一般人群中HGVRNA和TTVDNA阳性率分别为 2 33%和 14 77% ,男女阳性率HGVRNA为 2.45%和2.20% ,TTVDNA阳性率为 17.86%和 12.0%。年龄组间HGVRNA及TTVDNA阳性率差异均无显著性 ;单因素和Logistic回归分析未显示肝炎病史、近期手术史、注射史、拔牙史及乙型肝炎疫苗接种史等因素与HGV及TTV感染有关 ;HBsAg、抗 -HBS和抗 -HBc与HGV及TTV感染无统计学意义。不同职业人群中HGVRNA阳性率以中学生和教师较高 ;TTVDNA阳性率则以税务干部和教师高于其他人群 ,因此证明 ,深圳市一般人群中HGV和TTV感染率较高 ,但其流行因素有待进一步研究。     

输血传播病毒感染与丙型肝炎病毒感染的相互影响

目的了解输血传播病毒(TTV)与丙型肝炎病毒(HCV)重叠感染的发生率,探讨TTV感染与HCV感染的相互影响。方法采用酶联免疫吸附试验(ELISA)法检测血清中人类免疫缺陷病毒(HIV)、乙型肝炎病毒(HBV)、HCV、庚型肝炎病毒(HGV)及TTV标志物,应用巢式聚合酶链反应(n-PCR)技术检测血清TTV DNA,用速率法或终点法检测血清肝功能指标,用放射免疫法检测血清肝纤维化指标,用超声诊断仪检查肝胆脾形态及动态指标;应用SPSS 11.0软件分析比较肝功能检测结果、肝纤维化指标检测结果及肝脾形态和动态指标改变的差异。结果TTV/HCV重叠感染占TTV感染的69.6%(39/56),占HCV感染的61.9%(39/63)。TTV、HCV感染与TTV/HCV重叠感染肝功能检测结果差异有统计学意义(P<0.05);肝纤维化指标检测结果差异有统计学意义(P<0.05)。结论TTV/HCV重叠感染存在很高的发生率,感染者肝损程度较重,临床进程加快,有肝纤维化趋势。