Comparison of systems performance for TT virus detection using PCR primer sets located in non-coding and coding regions of the viral genome

Background: the heterogeneity of the TT virus (TTV) DNA prevalence values r eported from comparable human cohorts suggests that diagnostic PCR protocol s still require to be optimized. Objectives: to design TTV PCR primer sets with low genotype restriction and to compare their performances with common ly used amplification systems. Study design: we compared full length TTV ge nomic sequences and identified conserved nucleotide patterns in the 5' and 3' non-coding regions of the viral genome. This permitted to design two new primer sets usable for the PCR amplification of the most divergent human i solates of TTV described to date. The performances of these amplification s ystems were compared with those of three other PCR systems earlier used for prevalence studies. Results: the primer systems P5Bx and P3Bx exhibited hi gher PCR scores than the other systems tested; 14 to 34% improvement values were obtained, and divergent positive results of earlier described PCR sys tems were confirmed systematically by our new detection assays. Conclusions : an optimized detection of TT virus DNA is a pre-requisite for the accurat e epidemiological survey of viral infection and for the realization of phyl ogenetic studies. Such PCR systems with low genotype restriction will be he lpful in the future for a better knowledge of natural history of TT virus i nfection. (C) 2001 Elsevier Science B.V. All rights reserved.