An ongoing dialogue on HIV/AIDS, infectious diseases,
June 1st, 2009
“Long-term Nonprogressors” and “HIV Controllers”: Rare Indeed
When giving an overview of HIV pathogenesis to a group of clinicians, Bruce Walker usually asks the assembled if they have any patients in their practice who have undetectable viral loads without antiretroviral therapy.
Generally about three-quarters of the audience has at least one such patient. They are then asked to refer them to his research cohort, which has a goal of trying to figure out why some patients can control HIV replication without needing antivirals.
But how common is this “controller” phenomenon really? And how about its immunologic correlate — people with long-term HIV infection but no significant decline in the CD4 cell count?
Nifty paper in AIDS this month trying to answer this question: Using the French Hospital Database, and starting with over 45,000 potentially eligible patients, the group found that only 69 were “elite controllers” — that is, had >10 years HIV infection, 90% of viral loads <500 cop/mL, and most recent viral load <50 cop/mL.
Stable CD4s were even less common. Only 25 patients were “elite long-term nonprogressors” — that is, had HIV for more than 8 years, CD4 cells > 600, and no CD4 cell decline. That’s an prevalence of 0.05%, or 5 for every 10,000 patients.
Medical students and residents sometimes ask me if a particular patient of mine, asymptomatic and not on antiretroviral therapy, is a “long-term nonprogressor.”
I always respond by asking them what specifically they mean by the term — because as this paper shows, when you look for a truly benign course of HIV infection, you need to look pretty darn hard.