不同人群TTV DNA的检测及基因分型研究

目的检测健康人群及肝病患者TTV感染状况及基因分型。方法采用TTV（N22）区核苷酸序列设计引物,建立半巢式PCR（nPCR）方法,对314例7种不同人群血清检测TTV DNA,限制性内切酶Pstl、Ndel进行酶切分型。结果TTV在肝硬化患者、丙型肝炎、急性甲型肝炎、慢性乙型肝炎、急性乙型肝炎、健康人群和乙肝疫苗接种者中感染率分别为72.72%、60.71%、56.52%、48.00%、46.15%、44.21%和34.78%。肝硬化患者感染率明显高于正常人群和乙肝疫苗接种者（P〈0.01）,也显著高于急性乙型肝炎及慢性乙型肝炎（P〈0.05）。基因分型以G1型为主占（75.32%）,G2型占（9.09%）,（G1＋G2）混合型占（15.58%）。慢性乙型肝炎和丙型肝炎G1型阳性率最高,分别为83.33%和82.35%,但与其它组无差异（P〉0.05）。G1型男性感染率为73.33%,女性感染率为79.59%,不同年龄组G1型感染率最高为1-10岁年龄组（83.33%）最低是11-20岁年龄组（70.83%）。但年龄性别间无统计学意义（P〉0.05）。结论TTV在健康人群及肝病患者中有较高的感染率。基因型以G1型为主,提示G1型对肝脏的致病性较微弱,对乙型肝炎,丙型肝炎的病程及愈后无影响。

Detection and Genotyping of TT Virus DNA in Different Populations

Objective To detect the infection status and genotypes of TTV in healthy populations and patients with liver diseases. Methods Nest Polymerase Chain Reaction （nPCR） was established with the primers designed according to the N22 region of TTV. Altogether 314 individuals which came from 7 kinds of different human groups were detected for TTV DNA with nPCR. Results The infection rate of TTV in cirrhosis, hepatitis C, acute hepatitis A, chronic hepatitis B, acute hepatitis B, healthy population and individuals inoculated with vaccine against hepatitis B was 72.72%, 60.71%, 56.52%, 48.00 %, 46.15 %, 44.21%, and 34. ？8 % respectively. The infection rate of TTV in cirrhosis patients was significantly higher than that in healthy populations （ P〈 0.01 ）, the individuals inoculated with vaccine against hepatitis B （P〈 0.01 ）, and patients with acute hepatitis B or chronic hepatitis B （P〈 0.05）. The GI type was the main genotype detected （75.32 % ）, the G2 type accounted for 9.09% and （G1 ＋ G2） mixed type accounted for 15.58%. The positive rate of G1 type with chronic hepatitis B （83.33 % ） and hepatitis C （82.35 % ） hit the highest respectively, but there was no statistical significance as compared with the other groups （P 〉 0.05）. The G1 - infection rate was ？3.33 % in males and 79.59 % in females, with the highest infection rate in 1 - 10 year - old group （83.33 % ） and the lowest infection rate in 11 - 20 - year old group （70.83 % ）. However, no statistical significance was found between gender and age （P 〉 0.05）. Conclusions TTV infection rate is higher in healthy populations and patients with liver disease. The G1 type is the main genotype detected, which suggests that the pathogenicity of the GI type to the liver is weak, moreover, the GI type may not affect the course and the prognosis of hepatitis B and hepatitis C.