title: Modification of the Abbott RealTime assay for detection of HIV-1 plasma RNA viral loads less than one copy per milliliter.
abstract: Although commercial tests are approved for detection of HIV-1 plasma viral loads ≥ 20 copies per milliliter (ml), only one specialized research assay has been reported to detect plasma viral loads as low as 1 copy/ml. This manuscript describes a method of concentrating HIV-1 virions from up to 30 ml of plasma, which can be combined with a commercial viral load test to create a widely available, reproducible assay for quantifying plasma HIV RNA levels less than 1 copy/ml. Using this pre-analytically modified assay, samples with a known level of 0.5 copy/ml were detected in 8 of 12 replicates (mean 0.47 copy/ml; 95% confidence interval (CI) 0.14-0.81 copy/ml) and samples with a known level of 1.0 copy/ml were detected in 13 of 13 replicates (mean 1.96 copy/ml; 95% CI 1.42-2.50 copy/ml). By concentrating virus from 30 ml of plasma, HIV RNA could be measured in 16 of 19 samples (84%) from 12 of 12 subjects (mean 2.77 copy/ml; 95% CI 0.86-4.68 copy/ml). The measured viral load correlated inversely (r = -0.78; p = 0.028) with the total duration of viral suppression (viral load<40 copies/ml).
authors.affiliation: San Francisco VA Medical Center, San Francisco, CA 94121, USA. steven.yukl@ucsf.edu
authors.forename: Steven A
authors.initials: SA
authors.lastname: Yukl
authors.forename: Peilin
authors.initials: P
authors.lastname: Li
authors.forename: Katsuya
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Harry
authors.initials: H
authors.lastname: Lampiris
authors.forename: Chuanyi M
authors.initials: CM
authors.lastname: Lu
authors.forename: C Bradley
authors.initials: CB
authors.lastname: Hare
authors.forename: Steven G
authors.initials: SG
authors.lastname: Deeks
authors.forename: Teri
authors.initials: T
authors.lastname: Liegler
authors.forename: Mark
authors.initials: M
authors.lastname: Pandori
authors.forename: Diane V
authors.initials: DV
authors.lastname: Havlir
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Wong
mesh_terms: D000328:Adult; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D010949:Plasma / Q000821:virology*; D012367:RNA, Viral / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D019562:Viral Load / Q000379:methods*
chemical_list: D012367:RNA, Viral