How Do HIV Elite Controllers Do What They Do?

(See the article by Julg et al, on pages 233–238.) Soon after the initial discovery of human immunodeficiency virus (HIV) as the cause of AIDS, a small group of HIV-in-fected patients were identified who did not seem to progress immunologically toward AIDS. These “long-term nonprogressors” were initially defined on the basis of their ability to maintain high CD4 cell counts over many years in the absence of anti-retroviral therapy [1]. Over the past de-cade, many of the long-term nonprogres-sors exhibited slow progression to lower CD4 cell counts, a process that was pre-dicted in part by their level of viremia. This prompted further refinement of the “nonprogressor ” phenotype into one that was based primarily on viral load, with most studies now focusing on those who have undetectable viremia using conven-tional assays (HIV RNA!50 copies/mL, “elite controllers”) and those who have low but detectable viremia (HIV RNA!2000 copies/mL, “viremic controllers”) [2, 3]. It is widely hoped that knowledge gained regarding the mechanism of virus control could inform both the vaccine and the HIV eradication efforts [4]