HIV-RNA decay in paired blood and semen samples of subjects receiving their first dolutegravir-based ART regimen

Background and objectives: We aimed to investigate to what extent a first-line DTG-based ART regimen reduces HIV-RNA in semen compared to plasma. Study design: In this prospective, observational study, ART-naïve, HIV-infected males starting their first ART regimen withDTGplus TDF/FTCorABC/3TCwere enrolled.Paired blood (BP) andseminal plasma(SP) samples werecollectedatbaseline(T0)andatweek-2/4/12/24afterARTinitiation.Sexuallytransmittedinfections(STI) were ruled out before enrolment. Results: Median baseline HIV-RNA levels were lower in SP compared to BP (657 versus 38.200 copies/ml, p < 0.001), three subjects had undetectable semen HIV-RNA. After 12 weeks of treatment, HIV-RNA was below the quantification limit in both BP and SP of 11 pts (61.1%). Discordant results were obtained in 6 subjects (33.3%), showing quantifiable HIV-RNA in blood only (2 cases) and in semen only (4 cases). Finally, one subject had a positive HIV-RNA in SP/BP. At W24, only in 2/16 subjects (12.5%) HIV-RNA was detectable in semen, while in the others it was negative on SP/BP. No concurrent STI was found in subjects with detectable VL in semen. Conclusions: DTG demonstrated effectiveness in reducing VL with different kinetics in blood and semen, despite seminal viral suppression after 6 months of ART was not obtained in the totality of subjects.