Plasma HIV-1 RNA Detection Below 50 Copies/mL and Risk of Virologic Rebound in Patients Receiving Highly Active Antiretroviral Therapy
Clinical Infectious Diseases
Background. Plasma human immunodeficiency virus type 1 (HIV-1) RNA suppression ,50 copies/mL is regarded as the optimal outcome of highly active antiretroviral therapy (HAART). Current viral load (VL) assays show increased sensitivity, but the significance of RNA detection ,50 copies/mL is unclear. Methods. This study investigated the virologic outcomes of 1247 patients with VL ,50 copies/mL at an arbitrary time point during HAART (5 T0), according to whether the actual, unreported T0 VL was
... ported T0 VL was 40-49 copies/mL, RNA detected ,40 copies/mL (RNA 1 ), or RNA not detected (RNA 2 ), as measured by the Abbott Real Time assay. Predictors of rebound .50 and .400 copies/mL over 12 months following T0 were analyzed with Cox proportional hazards models incorporating the T0 VL and demographic and clinical data. Results. Rebound rates .50 copies/mL were 34.2% for T0 VL 40-49 copies/mL, 11.3% for RNA 1 , and 4.0% for RNA 2 ; rebound rates .400 copies/mL were 13.0%, 3.8%, and 1.2%, respectively. The adjusted hazard ratios for rebound .50 copies/mL were 4.67 (95% confidence interval, 2.91-7.47; P , .0001) and 1.97 (1.25-3.11; P , .0001) with T0 VL 40-49 copies/mL and RNA 1 , respectively, relative to RNA 2 , and 6.91 (2.90-16.47; P , .0001) and 2.88 (1.24-6.69; P , .0001), respectively, for rebound .400 copies/mL. The association was independent of adherence levels. Conclusions. In treated patients monitored by RealTime, a VL of 40-49 copies/mL and, to a lesser extent, RNA detection ,40 copies/mL predict rebound .50 and .400 copies/mL independently of other recognized determinants. The goal of HAART may need to be revised to a lower cutoff than 50 copies/mL.