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方法检测血清标本中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：南京地区存在TTV感染,TTV是导致非甲－庚型肝炎的重要病因,TTV可能存在非血源性传播途径。     

血清中输血传播病毒检测及临床意义的探讨

目的 研究血清中输血传播病毒（TTV）抗体的检测及其临床意义。方法采用间接ELISA法检测88例患者及20例献血员血清中TTV抗体。结果88例患者中11例血液透析患者、35例乙型肝炎患者、26例丙型肝炎患者、4例庚型肝炎患者和12例非甲-庚型肝炎患者以及20例献血员TTV抗体阳性率分别为27．3％、20．0％、7．8％、0．0％、25．0％与5．0％。结论 在正常人群中TTV健康携带者较为常见;血液透析患者与非甲-庚型肝炎患者是TTV感染的高危人群;乙型及丙型肝炎患者常重叠TTV感染。     

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。     

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     

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。     

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     

72例肝炎患者TT病毒DNA检测及部分基因序列分析

目的 了解肝炎患者中的TTV的感染情况并对部分分离株进行基因分型。方法 设计通用引物，采用半套式聚酶链反应检测肝炎患者血清标本中TTVDNA，并对部分PCR产物进行直接测序和序列分析。结果 在72例不同肝炎患者血清中，共检出TTVDNA阳性血清39份，总检出率为54.16%.其中,在非甲-非庚型肝炎患者中,TTVDNA阳性率为87.5%;在甲-庚型肝炎患者TTVDNA的阳性率(50.0%).对4株TTV序列分析结果显示,它们与日本分离株TA278、NA004、TKB555、PT3最高的同源性分别为97.7%、99.1%、96.8%、91%。经系统发育分析。其中有1株属G1型，有3株属G2型。结论 本次研究的肝炎人群中，TTV感染率较高，。感染的TTV颁发于G1及G2两个不同的基因型，TTV可能是非甲-非庚肝炎致病因素之一。     

TT病毒国内外研究进展

TTV是 1997年由日本学者真弓忠发现的一种新病毒 ,被认为是一种有可能引起输血后肝炎的新的DNA病毒 ,称输血传播病毒 ,也称TT病毒。本文介绍了TTV的发现、自然史追踪、病原学、检测、致病性、传播途径、病理表现和在非甲 -庚型肝炎患者中的检出率。众多的研究结果表明 ,它可能是导致非甲 庚型肝炎的重要病原。有些研究还认为 ,TTV可能是导致肝炎慢性化的病原之一 ,也是导致爆发型肝炎或肝衰竭的重要因素之一。但仍有一些研究者认为 ,TTV感染不一定致病 ,其致病性尚待进一步研究证实。现已证实 ,TTV还存在非血液传播的途径 ,肠道传播是重要的 ,我国已证实有肠道传播型TTV引起的集体病毒性肝炎流行。     

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。     

献血者TT病毒DNA及其IgG抗体的检测

目的　观察献血者输血传播病毒 (TTV)的感染情况。方法　应用 Nested- PCR对 388例献血者、16 8例非肝炎住院患者进行 TTV DNA检测 ,同时用 EL ISA法检测抗 TTV Ig G。结果　 TTV基因检出率分别为献血组 15 .46 % ,对照组 2 4.40 % ;5 5 6例受检血清中 TTV DNA总的阳性检出率为 18.17% ,抗 TTV Ig G检出率分别为献血组 13.14% ,对照组 2 7.98% ;献血组与对照组相比 TTV DNA及抗 TTV Ig G均存在显著性差异 (P<0 .0 5 )。结论　献血者存在TTV感染 ,TTV存在健康携带状态。     

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。     

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.     

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.     

中国南通地区TT病毒ORF2基因的克隆及序列分析

用巢式聚合酶链反应 (nest PCR)的技术从南通地区某肝癌患者血清中检出输血传播病毒(TTV) ,并在PUC1 8上对其开放读码框 2 (ORF2 )基因进行了克隆。序列分析表明 ,该序列与国内外发表的TT病毒AB0 0 8394(日本株 )、AF0 791 73(中国株 )对应位置核苷酸同源性为 98%和 97% ,对 1 80例献血者及 62例各型肝病及 1 8例非甲～庚型肝炎血清进行检测 ,TT病毒阳性率在 9%～ 47%之间。     

TT virus(TTV) infection in patients with acute hepatitis]

A novel DNA virus, TT virus(TTV), has been reported in patients with posttransfusion hepatitis of unknown etiology. However association between TTV and acute hepatitis has not been shown. We investigated the prevalence of TTV in acute hepatitis. TTV-positive rates in acute hepatitis A, B, C, cytomegalovirus infection, Epstein-Barr virus infection, and acute hepatitis of unknown etiology were 15.3%, 21.8%, 60.0%, 0%, 10.0%, 22.6%, respectively. There were no significant differences in TTV prevalence between each etiology and healthy blood donors(20.8%). Clinical data were similar between patients with or without TTV. In this study we could not find any difference in the prevalence of TTV between acute hepatitis with known etiologies and that with unknown etiology. TTV did not affect the clinical features of acute hepatitis with known etiologies.     

Prevalence of the newly described human circovirus, TTV, in United States blood donors

BACKGROUND: A novel nonenveloped single-stranded circular DNA virus (TTV) was recently identified. The prevalence of TTV in blood donors in the United States is, however, still unclear. STUDY DESIGN AND METHODS: Viral DNA was detected in US blood donors from five cities by using two sets of TTV primers: NG059/NG061/NG063 primers, which amplified the conserved region of strains 1 and 2, and T801/T935 primers, which amplified the 5' end region of the TTV sequence. A TTV antibody assay system was based on the detection of the truncated open reading frame (ORF)-1 (amino acids 1-411) from type 1b. The truncated ORF-1 was expressed as a fusion protein in Escherichia coli, and the fusion protein was used as the antigen in the antibody assay system. RESULTS: Viremia was detected in 21 (8. 4%) of 250 donors by use of NG059/NG061/NG063 primers and 104 (41. 6%) of 250 by use of T801/T935 primers. There was little correlation among the assays, which suggests the preferential detection of different strains with the different primers. TTV antibody was detected in 38 of 100 donors: 32 (84%) of 38 with concurrent TTV viremia and 6 (16%) of 38 without TTV viremia. TTV viremia and/or TTV antibody-positive samples were detected in 52 (52%) of 100 of US blood donors. CONCLUSION: Evidence of infection or exposure to TTV appears to be common among blood donors in United States.     

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。     

瑶族无偿献血者人细小病毒B19与TTV重叠感染分析简

目的 了解广东瑶族无偿献血者人细小病毒B19及TTV重叠感染现状,探讨HPV B19与TTV感染相关性.方法 采用ELISA法检测HPV B19 IgG和抗-TTV IgG,并采用PCR法对部分血样进行HPV B19 DNA及TTV DNA检测.结果 376例无偿献血者血液标本中,检出HPV B19 IgG阳性110例,阳性率29.26％,检出抗-TTV IgG阳性176例,阳性率46.81％.147例血样检出HPV B19 DNA 10例,阳性率6.80％,检出TTV DNA 12例,阳性率8.16％.两者阳性检出率差异有统计学意义（x2=21.279,P＜0.05）. 67例抗-TTV IgG阳性中HPV B19的检出率为35.82％,43例HPV B19 IgG阳性中TTV的检出率为53.49％,两者检出率差异无统计学意义（x2=3.341,P＞0.05）.在阴性血液中,HPV B19总阳性检出率为36.25％,TTV总阳性检出率为53.85％,两者阳性率比较差异有统计学意义（x2＝5.633,P＜0.05）.结论 广东瑶族无偿献血者存在较高的HPV B19与TTV重叠感染,目前尚未在献血人群中开展HPV B19及TTV筛查,存在输血传播的风险.