HGV和TTV不是我国非甲非戊型肝炎的主要病因

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HGVRNA和TTVDNA ,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。HGVRNA采用反转录PCR(RT -PCR)检测 ,TTVDNA则采用巢式PCR方法检测。结果表明 ,HGV在自然人群中HGVRNA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。TTVDNA在自然人群中的携带率约为 10 % ,类似于HBVDNA的携带率。虽然在非甲非戊型肝炎病人中TTVDNA的阳性率为 2 8% ,但仍然有高达 6 0 %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。     

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。     

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.     

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。     

套式PCR技术检测肝癌和肝硬化患者TTV DNA

目的 了解肝癌和肝硬化患者中TTV DNA感染状况。方法 采用套式PCR技术检测TTV DNA及血清稀释法检测血清TTV DNA的滴度。结果 山东肝癌25例标本中8例TTVDNA阳性,阳性率为32．0％;广州肝癌16例中6例TTV DNA阳性,阳性率为37．5％;广西肝癌65例中28例TTV DNA阳性,阳性率为43．1％。16例肝硬化标本中6例TTV DNA阳性,阳性率为37．5％。结论 研究证实中国肝癌和肝硬化患者中存在35．7％的TTV DNA感染,这种TTV DNA感染是否对肝癌和肝硬化有促进作用,尚待进一步研究证实。     

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。     

TTV病毒检测方法的建立及在维吾尔族人群中的应用

目的建立TTV-DNA聚合酶链反应方法并应用于新疆地区不同人群TTV感染的检测。方法根据已报道的TTV基因序列(DDB）序列号：AB008394)．通过引物设计软件SQNCE和OLIGO在其ORF1区设计一对PCR引物,扩增产生一个315bp的扩增片段,产物经Bg1Ⅱ酶切分别产生一个219bp和96bp的酶切片段。结果用建立的PCR方法检测临床标本,在15例维吾尔族转氨酶升高的非甲～非庚型肝炎患血清标本中检测到6份TTVDNA阳性,表明新羞地区存在TTV感染．维吾尔旗人群中有较高的TTV感染率。结论我们建立的TTV DNA-PCR灵敏度高、特异性好,可用于各类人群TTV-DNA的检测。     

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。     

徐州地区TTV感染的流行病学研究

为了探讨徐州地区正常人群中输血传播病毒 (TTV)感染情况及其流行病学特征。用随机整群及分层随机法抽取研究对象 ,在国内首次采用酶联免疫吸附试验 (ELISA)法检测该人群血清中TTVIgG抗体。结果表明 ,对 1268名不同年龄的正常人群调查表明 ,徐州地区正常人群中TTVIgG的总阳性率为 5.36 % ,男女性阳性率分别为 3.81%和 6.67% ,女性略高于男性。年龄、职业、城乡之间TTVIgG阳性率差异无显著性意义。但有手术史和输血史者中TTVIgG阳性率最高 ,分别为 27.27%和 11.48% ,显著高于其它因素者。结果表明 ,徐州地区正常人中TTV感染率与HBV感染率基本相同 ,有手术史和输血史者TTV感染率较高 ,进一步证实血液是TTV传播的重要因素之一 ,同时也提示TTV可能与HBV感染相类似 ,存在“健康携带状态”。     

维持性血液透析患者经血液传播嗜肝病毒感染状况

目的：探讨血液透析（血透）患者HBV,HCV,HDV,HGV和TTV等经血液传播的肝炎病毒感染状况。方法;对80例长期维持性血透患者和12位血透工作人员应用ELISA法检测HBV两对半及HCV,HDV抗体;逆转录－套式PCR检测血清HGV RNA;巢式PCR检测TTV DNA。结果：80例患者中,经血液传播肝炎病毒感染51例（63.8%),其中HBV阳性21例（22.5％）,未检出HDV,HGV阳性15例（18.7％）,TTV阳性28例（35％）。二重或二重以上感染18例（22.5％）,其中二重感染12例（15.2%) ,三重感染4例（5％）,四重感染2例（2.5％）。HBV单独感染8例（10％）,合并HCV感染4例（5％）,合并TTV感染4例（5％）;与HGV和TTV三重感染3例（3.8％）,与HCV,HGV和TTV四重感染2例（2.5％）。HCV单独感染10例（12.5％）,合计TTV感染1例（1.2％）;与HGV和TTV三重感染1例（12.5％）。HGV单独感染8例（10％）,合并TTV感染2例（2.5％）。TTV单独感染15例（18.8％）。12例工作人员HBV,HCV,HDV和HGV检测均阴性,1例TTV阳性。与非输血组相比,输血 组除HDV外,HGV,HBV,HCV和TTV的感染率明显增加,均P＜0.05。结论：血液透析患者经血液传播性肝炎病毒感染严重,重叠感染率高,其高发生率与输血有关。     

TT virus (TTV) in Japanese haemophiliacs]

This study aimed to evaluate the prevalence and characteristics of infection with a novel virus designated TT virus (TTV) in Japanese haemophiliacs. TTV DNA was measured in 60 haemophiliacs by semi-nested PCR. HCV RNA, HGV RNA and HIV antibody were also tested. TTV DNA was detected in 35 haemophiliacs (58.3%). There were no differences in the backgrounds or characteristics between TTV DNA-positive and-negative haemophiliacs, except that levels of IgG and IgM in TTV DNA-positive patients were higher than those in TTV DNA-negative patients. In patients infected with TTV type 2, which is rare in Japan, the rate of coinfection with HCV of imported types was high. These indicate that TTV type 2 in Japanese haemophiliacs might have a foreign origin.     

Frequency of hepatitis G virus and transfusion-transmitted virus infection in type II diabetes mellitus

The hepatitis G virus (HGV) and transfusion-transmitted virus (TTV) are recently defined hepatitis viruses that the pathogenic roles in liver diseases are still not clear. It has been well known that some hepatitis virus, such as hepatitis C, might have an affinity to pancreatic islet cells. To investigate the relationship between the newly defined hepatitis viruses and diabetes mellitus (DM), we studied the prevalence of TTV and HGV in a type 2 diabetic patient population. Serum samples of 60 patients with DM and 45 healthy volunteers as control were taken. HGV RNA and TTV DNA was investigated by polymerase chain reaction. HGV was detected in none of diabetic patients (0%) and only one in control group (2.2%). However, TTV DNA was detected in 16 patients with DM (26%) and in five controls (11%). TTV was more prevalent in diabetic patients, but the difference between groups was not statistically significant (p > 0.05). These results revealed that TTV is more common in diabetic patients than in controls. At present, we don't know if this result is only a coincidence or a sign of potential association between TTV and DM. Further studies are certainly needed to elucidate a potential relationship.     

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.     

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。     

TT virus infection in an area of high-endemicity for hepatitis C]

TT virus (TTV) was recently identified as a candidate for a new hepatitis virus. In the present study, the clinical features and transmission routes of TTV infection were analyzed in an area highly endemic for hepatitis C virus (HCV) infection, and compared to those in an area not endemic. In conclusion, the prevalence of TTV infection was as high as 58% in the high-endemicity area for HCV infection. The main transmission route for TTV appeared to be different from that of HCV and HGV. TTV infection showed a reciprocal association with HCV infection, and had limited pathogenetic effect on hepatitis.     

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.     

Similar frequency of TT virus infection in patients with liver enzyme elevations and healthy subjects

TT virus (TTV) is a novel DNA virus that has been identified in patients with post-transfusional hepatitis of unknown aetiology. However, its pathogenic role in liver injury remains unclear. To determine its frequency and clinical impact in cryptogenic liver diseases, we investigated the TTV prevalence in patients with liver enzyme elevations of unknown aetiology and in healthy subjects. Fifty-four patients (33 male, 21 female) who have been followed up for elevated ALT/AST levels of unknown aetiology and 118 healthy subjects (99 male and 19 female) were included in the study. TTV DNA was investigated by the polymerase chain reaction. Other possible causes of transaminase elevation were excluded in detailed biochemical and serological tests. A liver biopsy was performed in 45 patients. TTV DNA was detected in 46 patients with liver enzyme elevations (85.1%) and in 94 healthy subjects (79.6%). There was no statistical difference between the groups (p = 0.51). Histological examination of the liver revealed no specific change in TTV DNA positive patients that could be attributed to this virus infection. These results showed that TTV is a common virus in patients with liver enzyme elevation of unknown aetiology and even among healthy subjects in our geographical area. TTV infection is therefore widespread in the general population and does not seem to be associated with liver damage.