Mark Mascolini, IAS News

HIV replication continues in children whose viral loads cannot be detected by standard sensitive assays, and the virus produced remains susceptible to antiretrovirals.

Because viral replication continues at low levels in adults taking highly suppressive antiretroviral therapy, Robert Siliciano and Johns Hopkins colleagues wanted to see if low-level replication could be spotted in children, especially those who begin antiretrovirals shortly after birth. They looked for low-level viraemia with an ultrasensitive assay and searched for mutations conferring resistance to protease inhibitors with an assay that allows genotyping at viral loads as low as 5 copies/mL. These findings emerged:

• Low-level viraemia continued in children taking potent regimens, even those who begin therapy in early infancy.
• Suppression of viraemia in these children was so strong that HIV-1-specific antibody responses were “absent or minimal.”
• Virus isolated at low levels lacked protease resistance mutations, even though many of the children took nelfinavir, which has a low barrier to resistance.
• The protease sequences detected resembled those of viruses in the latent reservoir of resting CD4 cells.

Source: International AIDS Society

http://www.ias.se/article/show.asp?article=2560

Ref: Persaud D, Siberry GK, Ahonkhai A et al. Continued production of drug-sensitive human immunodeficiency virus type 1 in children on combination antiretroviral therapy who have undetectable viral loads. Journal of Virology 2004;78:968-979.