“…Since the early 1990s, cohort studies have identified a small percentage ($5-10%) of HIV-1-infected people, called long-term non-progressors, who remain asymptomatic and maintain a relative high CD4 þ T-cell count (>500 cells/ml) for >8-10 years without antiviral therapy [Buchbinder and Vittinghoff, 1999]. Despite the absence of clinical symptoms for many years, most of those individuals display many hallmarks of HIV-1 infection including: low but persistent viral replication [Lefrere et al, 1997;Barker et al, 1998;Rodes et al, 2004], rapidly evolving viral quasispecies [Wolinsky et al, 1996;Delwart et al, 1997;Shioda et al, 1997], and evidence of chronic immune activation [Lifson et al, 1991;Sheppard et al, 1993;Ferbas et al, 1995;Lefrere et al, 1997;Barker et al, 1998;Zaunders et al, 1999]. After prolonged infection, many long-term non-progressors had evidence of immunologic damage and suffered a transition from the non-progressor to the progressor state, suggesting that most of them are actually slow progressors rather than true non-progressor patients [Lefrere et al, 1997;Learmont et al, 1999;Rodes et al, 2004].…”