Shang D, Lin Y H, Rigopoulou I, Chen B, Alexander G J, Allain J P
Department of Haematology, Division of Transfusion Medicine, East Anglia Blood Centre, Cambridge, United Kingdom.
J Med Virol. 2000 Aug;61(4):455-61. doi: 10.1002/1096-9071(200008)61:4<455::aid-jmv7>3.0.co;2-p.
TT virus (TTV) is transfusion-transmissible but its involvement in post-transfusion hepatitis is uncertain. To investigate the potential association of TTV with liver diseases, the prevalence of TTV DNA was tested by semi-nested PCR in 113 carriers of hepatitis C virus (HCV), 10 patients with acute liver failure, 11 patients with cryptogenic cirrhosis and 200 control blood donors. Thirty-seven of these patients underwent liver transplantation and were tested pre- and post-transplantation. TTV DNA was semi-quantified in serial samples from seven patients with unexplained post-transplant hepatitis. TTV genotyping was performed on samples from 28 patients by sequence analysis. The prevalence of TTV DNA in blood donors was 1.5% and 17% in HCV infected haemophiliacs. In patients with acute or chronic liver disease or hepatitis, 6 to 27% prevalence was observed. After liver transplantation, the prevalence of TTV DNA increased from 16 to 46% (P < 0.01). In patients who developed unexplained hepatitis post-transplantation, TTV viraemia did not parallel ALT levels. TTV DNA either increased in titre or became detectable shortly after transplantation, suggesting that either TTV was transfusion-transmitted, or, more likely, that immunosuppression caused a recurrence of low level or undetectable TTV viraemia. TTV had considerable genomic diversity in the N22 region, corresponding to at least 4 genotypes. Genotype 2 was found in 14/28 patients.
TTV病毒（TTV）可通过输血传播，但其与输血后肝炎的关系尚不确定。为研究TTV与肝脏疾病的潜在关联，采用半巢式聚合酶链反应（PCR）检测了113例丙型肝炎病毒（HCV）携带者、10例急性肝衰竭患者、11例隐源性肝硬化患者和200名对照献血者的TTV DNA流行率。其中37例患者接受了肝移植，并在移植前后进行了检测。对7例不明原因的移植后肝炎患者的系列样本进行了TTV DNA半定量分析。通过序列分析对28例患者的样本进行了TTV基因分型。献血者中TTV DNA的流行率为1.5%，HCV感染的血友病患者中为17%。在急性或慢性肝病或肝炎患者中，流行率为6%至27%。肝移植后，TTV DNA的流行率从16%升至46%（P<0.01）。在移植后发生不明原因肝炎的患者中，TTV病毒血症与丙氨酸转氨酶（ALT）水平不平行。TTV DNA在移植后不久滴度升高或变得可检测到，这表明要么TTV是通过输血传播的，要么更有可能是免疫抑制导致了低水平或不可检测的TTV病毒血症复发。TTV在N22区域具有相当大的基因组多样性，至少对应4种基因型。在28例患者中有14例检测到2型基因型。
