The latent HIV-1 reservoir in patients undergoing HAART: an archive of pre-HAART drug resistance.

Recent studies on patients with a history of pre-HAART drug resistance, but currently on a successful regimen, provided new insights into the dynamics of the latent cellular viral reservoir. Results indicated that the latent reservoir is an archive, composed of a mixture of wild-type and drug-resistant strains. The studies showed that, even after years of successful HAART, the wild-type viral strains that circulated before the initiation of the therapy as well as all the different drug-resistant viral strains that evolved over time during eventual periods of non-suppressive treatment, remain detectable in the proviral reservoir. These findings support the hypothesis that during active viral replication, new variants, including drug-resistant ones, continuously enter the latent viral reservoir. It can be concluded that, as a consequence of the lifelong conservation of this latent reservoir, the potency of drugs for which resistance once developed will remain reduced, even after years of withdrawal of the drug.