PCR扩增检测献血者中TT病毒DNA及部分TTV基因序列分析

目的：了解江苏地区献血者中新型肝炎相关病毒－－TT病毒的感染状况，探讨TTV感染与ALT异常的相关性，方法：设计通用引物，采用半套式聚合酶链反应（hemi-nested PCR)方法检测195份献血者血清标本，结果，在血清丙氨酸转氨酶（ALT）异常，HBsAg及抗HCV阴性的99份献血者血清标本中，检出TTV DNA阳性标本36份，TTV DNA的阳性检出率为36．3％，而在96份正常献血者血清标本中，检出TTV DNA阳性标本16份，TTV DNA阳性检出率为16．6％，明显低于ALT常献血者人群，对2株阳性株序列分析结果显示，一株与TX011（G1b日本代表株）的同源性为98．6％，属于G1b亚型，另一株虽可归属于G1，但与G1a ，Blb差异较大，可能为G1的新亚型，结论：江苏地区献血者人群中存在TTV感染，国内首次报告检出TTV G1b亚型及新的亚型，献血者ALT异常与TTV感染密切相关，输血可能成为传播TTV感染的途径之一。

Detection of TT Virus DNA and Sequence Analysis of Partial Gene of TTV in Sera from Blood Donors

A novel DNA Virus(TTV)was identified recently in Japanese patients with post transfusion hepatitis of unknown etiology.In order to investigate prevalence of TTV infection in blood donors in Jiangsu,a hemi nested polymerase chain reaction assay was employed ,sera from blood donors in Jiangsu were examined for the presence of TTV DNA sequences,and PCR amplified product was sequenced and the data were analyzed with the computer programs.The results showed that 16 of 96(16.6%) sera samples from blood donors with elevated transaminase level were positive for TT DNA,36 of 99 (36.3%)sera samples from blood donors with normal transaminase level were positive for the presence of TTV DNA.There were significant differences between them.Partial nucleotide sequences from two isolates were determined.By phylogenetic analysis,one TTV strains was classified into the genomic subgroup G1b described previously.The other was a new subgroup of G1.