Effectiveness of BCV for the treatment of digestive diseases and disseminated adenovirus infections in recipients of pediatric hematopoietic stem cells

s / Journal of Clinical Virology 70 (2015) S1–S126 S15 and Sofosbuvir (NS5B inhibitor). 31 treatment-naive HIV-HCV co-infected patient samples were sequenced to measure the prevalence of naturally occurring resistance polymorphisms. Metagenomic sequencing was carried out without the need for primer-specific PCR, RNA was extracted using magnetic beads (Magjet), reverse transcribed (Maxima) and fragmented and indexed using transposon-based chemistry (Nextera XT). Sequencing libraries were run on an in house MiSeq Illumina next generation sequencing platform. Identification of resistance associated variants was performed using an inhouse bioinformatic pipeline. Results: The analysis covered 27 residues. Mutations detected at a frequency higher than 50% included NS3: (Q80), NS5A (M28, H58), but none in the NS5B region. Mutations detected at less than 50% of the total circulating population: NS3: (V36:22%, Q41:31%, F43:27%, T54:20%,V55:7%, Q80:57% V107:3%, R109:7%, I132:24%, R155:11%, A156:11%, V163:11%, D168:22%, NS5A: M28:27%, Q30:39%, L31:18%, P32:11%, H58:43%, E62:28%, Y93:20%, NS5B: L159:29%, S282:35%,L320:15%, V321:11%. Conclusion: The role of resistance mutations in patients with HCV therapy remains an area of active research. In addition to the presence of NS3 polymorphisms that may be associated with resistance, natural polymorphisms conferring resistance to NS5A inhibitorsmay also be associatedwith treatment failure. Resistance to the NS5B inhibitor (sofosbuvir) has been detected both in vitro and in vivo at the S282 locus (S282T) although this variant has not been reported as a majority variant natural polymorphism. As the mutation is associated with reduced replication fitness, it is highly likely to revert towildtype followingwithdrawal of the inhibitor; it may therefore be undetected in clinical trials if sampling is not carried out during or immediately after cessation of therapy. Further study into the role of minority variant polymorphisms associated with resistance will be important as new DAAs are rolled out. http://dx.doi.org/10.1016/j.jcv.2015.07.041