TT肝炎病毒及5种输血相关病毒感染云南省静脉吸毒者的分子流行病学调查研究

目的 :旨在探讨云南省静脉吸毒者 (intravenous drug users,IVDUs)的 HIV、HBV、HCV、HGV、HTL V和 TTV等6种病毒的感染现状及其 TTV核酸序列的特征。方法 :用选自云南省某戒毒所 15 8名 IVDUs的血清标本 ,用取自于 TTVDNA的基因组开放读码框架 1区 (ORF1 )合成的引物经半套式 PCR法检测 TTV DNA,并对 TTV DNA阳性标本全部进行了核酸序列分析和分子进化基因分析 ;还同步测试了 HIV、 HBV、 HCV、 HGV和 HTL V等 5种病毒感染的标志物 (分别用PA法、 PAH法、EIA法、WB法和 PCR法 )。结果 :TTV DNA阳性为 31/ 15 8(19.6 % ) ,抗 - HIV、 HBs Ag、抗 - HBs、抗- HBc、抗 - HCV、HGV- RNA和抗 - HTL V等 5种病毒的 7项标志物测试出阳性分别为 34 / 15 8(2 1.5 % )、 6 / 15 8(3.8% )、 98/15 8(6 2 .0 % )、 76 / 15 8(4 8.1% )、 136 / 15 8(86 .1% )、 6 5 / 15 8(4 1.1% )和 0 / 15 8(0 )。 31例 TTV DNA阳性者均合并上述5种病毒之一种以上的共同感染 ;31例 TTV DNA阳性者经测序和构建绘制分子进化同源序列树状图进行种系发生学分析表明 ,2 7/ 31(87.1% )为 TTV基因型 型中的 G1a、G1b、G1c、G1d型的四个基因亚型 ;4/ 31(12 .9% )为 TTV基因型2型中的 G2 a、 G2 b、 G2 c型的 3个基因亚型。结论

荧光定量PCR检测TTV方法学建立及临床应用

目的 建立一种灵敏度高、特异性好、操作简便的荧光实时定量PCR技术。方法 设计针对TT型肝炎病毒(TTV)基因保守序列非转录区的一对引物和一条荧光基团双标记探针。将PCR扩增所得的产物片段克隆 ,作为定量检测的标准品。对 36例丙肝患者及 12 3例不同血清标志物阳性的乙肝患者、16 6例健康体检者血清中TTVDNA定量检测 ,评估TTVDNA在不同人群中检出阳性率的差异显著性。结果 该方法检测TTVDNA的灵敏度高于普通套式PCR ELISA方法 ,线性范围为 10 2～ 7拷贝 /ml;批间CV为 13.2 %～ 16 .0 % ,批内CV为 6 .5 %～ 11.3%。健康体检者、丙肝患者、乙肝患者三组人群阳性检出率无显著性差异 ;且乙肝患者 (TTVDNA +)血清ALT水平与TTVDNA载量无显著相关性 (P >0 .0 5 ) ;乙肝患者血清ALT异常与正常两组TTVDNA阳性检出率无显著性差异 (P >0 .0 5 )。结论 该方法操作简单、灵敏度高、特异性好、结果数据化 ,适合于临床实验室进行临床标本的TTVDNA定量检测。

TT virus infection in patients with chronic hepatitis B and response of TTV to lamivudine

AIM: To investigate the responses of TT virus (TTV) and hepatitis B virus (HBV) to a long-term lamivudine therapy.METHODS: Sixteen patients infected with both TTV and HBV were treated with lamivudine 100 mg daily for 30 months. Blood samples were drawn at the beginning of the therapy and subsequently at month 3, 6, 9, 12 and 30.Serum TTV was quantified by real time PCR and serum HBV was detected by hybridization assay and nested polymerase chain reaction.RESULTS: TTV infection was detected in 100 % of HBV-infected patients. Loss of serum TTV DNA after one year of treatment occurred in 1/16 (6 %) patients. At the end of therapy, TTV DNA was positive in 94 % of them. The decline of HBV viremia was evident at 3 months after therapy and the response rate was 31%, 44 %, 63 %, 50 % and 50 %at month 3, 6, 9, 12 and 30, respectively.CONCLUSION: TTV replication is not sensitive to lamivudine and is highly prevalent in HBV-infected patients.

TT virus and hepatitis G virus infections in Korean blood donors and patients with chronic liver disease

AIM:To determine the prevalences of TTV and HGV infections among blood donors and patients with chronic liver disease in Korea,to investigate the association of TTV and HGV infections with blood transfusion,and to assess the correlation between TTV and HGV viremia and hepatic damage. METHODS:A total of 391 serum samples were examined in this study.Samples were obtained from healthy blood donors(n=110),hepatitis B surface antigen(HBsAg)-positive donors(n=112),anti-hepatitis C virus(anti-HCV)-positive donors(n=69),patients with type B chronic liver disease (n=81),and patients with type C chronic liver disease(n=19). Trv DNA was detected using the hemi-nested PCR.HGV RNA was tested using RT-PCR.A history of blood transfusion and serum levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were also determined. RESULTS:TTV DNA was detected in 8.2%of healthy blood donors,16.1%of HBsAg-positive donors,20.3%of anti- HCV-positive donors,21.0%of patients with type B chronic liver disease,and 21.1%of patients with type C chronic liver disease.HGV RNA was detected in 1.8%of healthy blood donors,1.8%of HBsAg-positive donors,17.4%of anti-HCV-positive donors,13.6%of patients with type B chronic liver disease,and 10.5%of patients with type C chronic liver disease.The prevalence of TTV and HGV infections in HBV- or HCV-positive donors and patients was significantly higher than in healthy blood donors(P<0.05), except for the detection rate of HGV in HBsAg-positive donors which was the same as for healthy donors.There was a history of transfusion in 66.7%of TTV DNA-positive patients and 76.9%of HGV RNA-positive patients(P<0.05).No significant increase in serum ALT and AST was detected in the TTV or HGV-positive donors and patients. CONCLUSION:TTV and HGV infections are more frequently found in donors and patients infected with HBV or HCV than in healthy blood donors.However,there is no significant association between TTV or HGV infections and liver injury.

Response of TT virus to IFN plus ribavirin treatment in patients with chronic hepatitis C

AIM:TT virus (TTV) is a newly described DNA virus related to postransfusion hepatitis that produces persistent viremia in the absence of clinical manifestations.PEG-IFN plus ribavirin have been useful in the treatment of chronic hepatitis C infection.This study investigated the responses of TT virus (TTV) and hepatitis C virus (HCV) to PEG-IFN plus ribavirin therapy. METHODS:Fifteen patients infected with HCV were treated with PEG-IFN(0.5 μg/body weight/week) and ribavirin (1000 mg-1 200 mg/daily) for 48 weeks,Blood samples were drawn at the beginning and the end of the therapy.Serum TTV DNA and HCV RNA were quantified by real time PCR. RESULTS:At the beginning of treatment,TTV infection was detected in 10/15 (66.6%) of HCV-infected patients.Loss of serum TTV DNA at the end of therapy occurred in 6/10 (60%) patients.Out of these 6 patients,4 (67%) became positive for TTV DNA after 6 months of therapy.Regarding HCV viremia,11/15 (73%) patients were negative for serum HCV RNA after 48 weeks of therapy,7/11 (64%) of these cases also became negative for TTV DNA following the combined treatment.In the 3/4 (75%) patients who were positive for HCV RNA at the end of therapy,TTV DNA was detected as well.Sustained HCV response at 6 months after treatment was 53% (8/15). CONCLUSION:No TTV sustained response can be achieved in any patient after PEG-IFN plus ribavirin administration.

几种新传染病的发现

1975年10月,美国Connecticut州卫生当局接到Lyme地区居民反映该地区儿童发生有原因不明的青少年类风湿关节炎报告后立即派员前往调查。他们首先在该地区建立了一个专门的监测系统,以收集和记录类似关节炎病例及其有关情况。起初,通过对监测到的51例病人临床及流行病学特点的分析,认为此种关节炎是一种以前未被认识的独立疾病,这种关节炎与普通的青少年类风湿关节炎不同。