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Viral Metagenomics analysis of kidney donors and recipients: Torque teno virus genotyping and prevalence.

BACKGROUND
The viral load of the ubiquitous and non-pathogenic Torque Teno Virus (TTV) is associated with the grade of immunosuppression of its host. The development of Next Generation Sequencing (NGS) allowed to describe the human virome of the blood compartment in transplanted patients, and showed that TTV are the most important part of the virome.


OBJECTIVES
To describe the prevalence and diversity of TTVs in kidney donors and transplant recipients by NGS, and evaluate the potential transmission and the evolution of TTV in recipients.


STUDY DESIGN
Descriptive retrospective pilot study of sequencing plasma samples from 15 matched donors and recipients. After sample processing, nucleic acids were amplified by Rolling Circle Amplification and submitted to NGS by Ion Proton sequencing technology. Results were analyzed after mapping of reads on the 29 TTV reference genomes and de novo assembling of the reads with MIRA software.


RESULTS
The number of TTV species present in donors and recipients was, on average, 12 in donors and 33 in recipients. TTV species predominantly present in donors were: TTV-13 and TTV-18; and in recipients were: TTV-P15-2, TTV-27, TTV-HD14a and TTV-22. We highlighted a significant variability in abundance and composition in sequential samples from recipients. Temporal evolution of TTV populations was clearly observed in recipients, but no preferential transmission of a species from donor to recipient was evidenced.


CONCLUSION
Diversity and population expansion was observed in kidney recipients. Further study of TTV species could help assess the potential impact of each species of this virus. This article is protected by copyright. All rights reserved.