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Plasma Viral Loads Approximate Pre-HAART Levels after Discontinuation of HAART H. HATANO*, S. VOGEL, J. METCALF, C. YODER, R. DEWAR, R. DAVEY, and M. POLIS.
NIAIDNIH, Bethesda, MD, and SAIS, Frederick, MD Introduction: It has been proposed that the use of potent antiretroviral therapy (HAART) with good viral load suppression may lead to a reduction in the reservoir of HIV-1 and eventually enable treated individuals to maintain adequate viral suppression after withdrawal of therapy. This study was designed to compare the HIV viral burden in individuals prior to receiving HAART with the viral burden after withdrawal of HAART.
Methods: Viral loads were measured from plasma or stored frozen serum on 12 patients off all antiretrovirals who subsequently had good viral suppression on HAART (< 500 HIV RNA copies/mL) and then went off antiretroviral therapy. Viral burden was measured by v3.0 bDNA assay (detection level 50 HIV RNA copies/ml, Chiron, Emeryville, CA). Viral loads were log transformed, and geometric means were calculated for multiple samples.
Results: Patients achieved viral control on HAART in a median 48 days (range, 15–527; mean, 143) and maintained viral control for a median 661 days (range, 53–929; mean, 576). HAART was temporarily discontinued because of patient preference (n=4), drug toxicity (3), or concomitant illness (1) or for protocol-driven reasons (4). Patients were off HAART for a median 55 days (range, 14–168; mean, 66). The median difference between the pre- and post-HAART viral loads was 0.45 logs (range, 0.06–2.14; mean, 0.65). Eight individuals had post-HAART values higher than pre-HAART values; 4 had lower values. The median duration between pre- and post-HAART viral load measurements was 2168 days, or 5.9 years (range, 117–3372; mean, 2032).
Conclusions: After discontinuing HAART, most individuals had rebounds in their viral burden approximating pre-HAART levels, even after a significant lapse of time approaching 6 years. Our data suggest that HAART with good viral suppression for almost 2 years may not alter intrinsic viral load set-points.
Key Words: antiretroviral therapy, viral load, viral set-point
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