Can HIV Be Eradicated from an Infected Individual?
Don’t apologize; the question was meant to be provocative. Why else would a tiny little meeting (participants included, among others, David Cameron (Holland), Doug Richman (US), Joep Lange (Denmark), Julio Montaner (Canada) and Luc Pelan (Switzerland) in June spring for a pricey PR firm and a 24-hour “Eradication Hotline?” The genesis of the meeting was apparently early results from a neonate study showing what the study’s investigators called “fading Western blot reactivity.” A similar observation was seen in an acute seroconversion study. (Now we know what David Ho et al. mean when they say “early.”) Still, UC-San Diego’s Douglas Richman (bless his heart), with characteristic candor, set us straight from the outset, “There is absolutely no evidence that, in fact, at this point it is possible.” When asked by Newsday’s Laurie Garrett “I don’t get it. What’s new here?” Richman explained that the news value (and perceived need to hire promotion professionals to handle the meeting) of the mini scientific summit was that they were allowing themselves to pose the question at all. If nothing else, this little performance has certainly whipped the media up into a frenzy: just what the Vancouver meeting doesn’t need.
The Seventy Percent Solution (a/k/a “Fools Rush In …”)
A team of HIV researchers (Saag et al., 1996 Nature Medicine), responding to a highly acclaimed study of the prognostic value of plasma HIV RNA which was published last month (Mellors JW et al., Science 272: 1167-70.) laid out their recommendations for initiating antiretroviral therapy based upon plasma viral load. Treatment can probably wait for individuals with viral loads less than 5,000 copies/ml, they say. For persons with viral load > 50,000 copies, antiretroviral therapy is called for across the board–regardless of T-cell count. Everything between 5,000 and 50,000 copies is gray. Changes in antiretroviral regimens should be considered, according to the authors, when there is evidence of clinical disease progression or viral escape (defined as > 0.3-0.5 log increase in HIV RNA, confirmed by at least two measurements). Now if Dr. Mellors and his would-be paradigm shifters could only explain why 30% of those with baseline RNA copy numbers < 10,000 progressed or died during the follow-up period–and why a similar percentage with copy numbers > 50,000 did not. Still more questions than answers, more art than science.
Nearly One Third Either Slow or Fast Progressors
Natural history data cited by AIDS research’s man of the hour, John Mellors, M.D., in his seminal plasma RNA paper report that the average time (for adults) between infection with HIV and the development of AIDS is 10-11 years, but around 20% progress more rapidly (within 5 years of infection) while still another 12% or so will remain free of AIDS for 20 years. (Muñoz A et al., J AIDS Hum Retrovir. 8: 496). No one knows why.