Can antiretroviral therapy ever be stopped? An update

Eradication of virus is not a reasonable goal of anti-HIV therapy because of the latent reservoir of HIV-1 in resting memory CD4+ T cells, which guarantees lifetime persistence of virus. Any drug-resistant viruses that arise and circulate for significant periods can be stored in the reservoir, limiting future treatment options, and mistakes in treatment can be "remembered" by the virus. Wild-type virus is also preserved in the reservoir and can reemerge if therapy is stopped. Since wild-type virus can be more virulent, suppression of this virus is one benefit of continuing therapy in patients who are experiencing treatment failure. If therapy is stopped, the reemergence of wild-type virus does not mean that drug-resistant virus is gone; it is still preserved in the latent reservoir. In patients who have viral suppression to below 50 copies/mL, there is still a low level of virus in the plasma, but it does not appear to be evolving. Thus, in principle, lifelong control of viral replication is possible if suppression of viremia to below 50 copies/mL is maintained.