Background:  HIV-1-infected patients who control viremia without treatment (elite suppressors) and patients on suppressive HAART-regimens both have viral loads below the clinical limit of detection, 50 RNA copies per mL of plasma (copies/mL). In patients on HAART, viremia reaches a stable plateau of ~3 RNA copies/mL. Low-level viremia in elite suppressors has been detected but not quantified. We hypothesize that viral loads in elite suppressors would be higher than in HAART-suppressed individuals.

Methods:  Through the use of an ultrasensitive real-time polymerase chain reaction (PCR) -based viral load assay with a limit of quantification of 8 copies/mL, viral loads from 8 individuals on suppressive HAART were measured and compared with viral loads from 11 HAART-naïve elite suppressors. For 6 of the elite suppressors, a repeated viral load measurement was to determine whether there were large fluctuations over time. In a longitudinal analysis, viral loads from 1 elite suppressor and 1 patient on HAART were measured over time to determine if their viral dynamics represented a steady-state.   

Results:  In the HAART-treated group, all 8 patients demonstrated viral loads below 8 copies/mL; 4 of those individuals had detectable plasma virus. Among the elite suppressors, 8 out of the 11 patients had viral loads below 8 copies/mL; 2 of those individuals had detectable virus. The remaining 3 elite suppressors with quantifiable viral loads had measurements of 48, 87, and 25 copies/mL. Of the 6 elite suppressors that had a second viral load measurement, 5 had viral loads below 8 copies/mL at both time-points and the remaining elite suppressor had an increase in viral load from 25 to 62 copies/mL (0.4 log₁₀ difference). In the longitudinal analysis, the HAART-suppressed individual remained below 8 copies/mL and had detectable virus. In contrast, the elite suppressor’s viral load fluctuated between 12 and 48 copies/mL (0.6 log₁₀ difference).

Conclusions:  We provide preliminary data on viral dynamics in elite suppressors. Compared with patients on suppressive HAART, elite suppressors demonstrated a greater range of viral loads. In 1 elite suppressor, the viral dynamics did not appear to follow a steady-state, but rather underwent significant changes (>0.3 log₁₀ copies/mL). Both phenomena may reflect the varying degrees of ongoing replication occurring in the absence of ART or the rate at which virus-producing cells are being cleared by the immune system.