献血员中TT病毒感染的检测及序列分析

目的： 研究ALT正常的献血员中TTV(transfusion transmitted virus) 的感染情况，探讨TTV感染的传播途径和致病性。方法： 设计TTV保守区域的特异性引物，聚合酶链反应(PCR)方法检测120例ALT正常的献血员，对1例TTV DNA阳性标本（TTVD026）进行PCR产物测序，并与已知TTV核苷酸序列比较同源性。结果： 120例ALT正常献血员中有20例为TTV DNA阳性，感染率为16.7％。同源性分析表明TTVD026与TA278,GH1,TTVCHN1和TTVCHN2的核苷酸同源性分别为99％，99％，99％和89％。结论： ALT正常的献血员中存在TTV的感染; TTVD026与TTV TA278,GH1,TTVCHN1和TTVCHN2可能属于同一个基因型;输血可能是TTV传播的主要途径。

Detection and sequence analysis of TT virus in blood donors

Objective: To investigate TTV infection among blood donors with normal ALT, the transmission of TTV, and the association between TTV and hepatitis. Methods: Plasma samples from donors with normal ALT were detected for TTV DNA using PCR method, the PCR products (TTVD026) were sequenced directly. Sequence homology analysis was conducted by Internet BLAST. Results: TTV DNA was detected in 20 of 120 donors with normal ALT, the positive rate was 16.7%. Compared with TA278, GH1, TTVCHN1 and TTVCHN2, the nucleotide identity of TTVD026 were 99%, 99%, 99% and 89%, respectively. Conclusion: TTV infection exists in blood donors with normal ALT. TTVD026 might belong to the same genotype as TA278, GH1, TTVCHN1 and TTVCHN2, which indicate that blood transfusion may play an important role in the transmission of TTV.