TT病毒在肝病患者的感染状况及致病性

Prevalence and pathogenicity of TT virus infection in patients with liver diseases

目的:研究TTV在肝病人群中的感染率及致病性情况.方法:研究对象:(1)非甲-非戊型肝炎组83例,男58例,女25例;(2)慢性肝病组75例,男53例,女22例;(3)查体人群组105例,男55例,女50例.采用非翻译区(UTR)及ORF1区二套引物进行PCR检测TTV-DNA,用RFLP方法对ORF1引物PCR产物进行酶切分型,并对部分PCR产物测序.结果:TTV在非甲-非戊型肝炎组,慢性肝病组及查体人群组中阳性率分别为95.2%,93.3%及87.6%,三组间无显著性差异(P>0.05).经RFLP分型,三组中G1型TTV检出率分别为32.5%,38.7%及19.0%,前二组G1型TTV阳性率均显著高于查体人群组阳性率(P<0.05,P<0.01).乙型肝炎后肝硬化及肝癌患者中G1型TTV阳性率(25.0%)与慢性乙型肝炎,HBsAg携带者中阳性率(37.1%)无显著性差异(P>0.05);丙型肝炎后肝硬化及肝癌患者中G1型TTV阳性率(40%)与慢性丙型肝炎患者阳性率(100%)也无显著性差异(P>0.05).查体人群中TTV感染率与性别无相关性,21-30岁年龄段TTV感染率(72.2%)显著低于31-40岁年龄段感染率(96.2%,P<0.01)及41-50岁年龄段感染率(93.1%,P<0.05).结论:TTV在普通人群及肝病患者中有很高的感染率,30岁以下普通人群中感染率较低.G1型TTV与肝脏相关,但对慢性乙型肝炎,慢性丙型肝炎的病程及预后无影响,提示G1型TTV的致病性较弱.

AIM:To investigate the prevalence of TT virus in patientswith liver diseases and the association between liver dis-eases and TTV, especially genotype G1.METHODS:TTV DNA in serum were examined in 83 pa-tients with non A-non E hepatitis,75 patients with chronicliver diseases and 105 general people. TTV was detectedby PCR with two sets of primers, one of which was locatedin the 5' UTR and the other was in the ORF1. The genotypingassay was based on RFLP. Some PCR products weresequenced.RESULTS:The positive rates of TTV were 95.2%, 93.3%and 87.6% in patients with nonA-nonE hepatitis, patientswith liver diseases and general people respectively. Therewere no significant differences among the rates (P >0.05).The positive rates of genotype G1 were 32.5%, 38.7% and19.0% in three groups respectively. The positive rates ofG1 in patients with nonA-nonE hepatitis and in patients withliver diseases were significantly higher than that in the gen-eral people (P <0.05, P <0.01). But there were no signifi-cant differences in age, gender, level of ALT and frequencyof blood transfusion history between genotype G1 positiveand negative patients with nonA-nonE hepatitis. The posi-tive rate of genotype G1 was 25.0% in patients with livercirrhosis or carcinoma associated with HBV infection and37.1% in patients with chronic B hepatitis. There were nosignificant differences between them (P >0.05). The posi-tive rate of G1 was 40% in patients with liver cirrohosis orcarcinoma associated with HCV infection and 100% in pa-tients with chronic C hepatitis. There were no significantdifferences between them (P >0.05). There was no signifi- cant difference in age, gender, levels of ALT between G1positive and negative patients with chronic B hepatitis orHBsAg carrier (P >0.05). TTV-positive rate in the generalpeople aged 21-30 (72.2%) was significantly lower thanthat in the general people aged 31-40 (96.2%, P <0.01)and aged 41-50 (93.1%, P <0.05). The positive rate of G1infection in the general people was not related to age andgender.CONCLUSIONS:There is very high prevalence of TTV infec-tion in general population and patients with liver diseases.Genotype G1 is associated with liver disease,however, itspathogenicity may be very weak.