Clinical Evaluation of Branched DNA Signal Amplification for Quantifying HIV Type 1 in Human Plasma

Abstract

Quantification of HIV-1 RNA in human plasma has provided unique insight into AIDS pathogenesis and promises to hasten progress in antiretroviral therapy and vaccine research. However, no generally available HIV-1 RNA assay has yet been subjected to rigorous clinical testing or to comparative evaluation with research-based RNA assays using large numbers of well-characterized clinical specimens. In this study, the Chiron Quantiplex branched DNA (bDNA) signal amplification assay was used to measure viral RNA in the plasma of 152 HIV-1-positive individuals at all stages of infection and in 12 patients before and after initiating zidovudine therapy. Eighty-six percent of patients had bDNA assay results above the 10,000-RNA Eq/ml sensitivity cutoff. Branched DNA values were significantly correlated with plasma viral RNA levels determined by quantitative competitive polymerase chain reaction (QC-PCR) assay (Spearman rank correlation, r = 0.89), infectious plasma virus titers (r = 0.72), p24 antigen levels (r = 0.51), immune complex dissociated p24 antigen levels (r = 0.56), and CD4+ lymphocyte counts (r = -0.72; p < 0.0001 for all comparisons). Plasma viral RNA determinations by bDNA and QC-PCR assays were quantitatively similar in the range of 10(4) to 10(7) RNA molecules/ml [log bDNA = 0.93 + 0.80 (log QC-PCR); R2 = 0.81, p < 0.0001] and declined identically following the institution of zidovudine therapy (68-73% decrease from baseline). The close quantitative correlation between bDNA and QC-PCR results, and their significant association with other viral markers and CD4+ counts, support the use of plasma viral RNA measurement in HIV-1 clinical trials.

The Intracytoplasmic Domain of the Env Transmembrane Protein Is a Locus for Attenuation of Simian Immunodeficiency Virus SIVmac in Rhesus Macaques

“…Viral p27 gag antigen in longitudinal plasma samples was measured with an SIVmac p27 gag ELISA kit (Coulter Immunology). Viral RNA in plasma samples was determined by the branched-DNA (bDNA) assay (J. Booth and P. Dailey, Bayer Diagnostics, Emeryville, Calif.) (6).…”

Co-Infection with HIV and Mycobacterium tuberculosis: immunologic interactions, disease progression, and survival

“…The accumulated data are provided by (i) longitudinal studies showing that overall viral load increases over months and years, (ii) progressive loss of CD4 lymphocytes being associated with increasing viral burden, (iii) much more virions and HIV-infected cells being evident than previously thought, and (iv) circulating virus detected in peripheral blood are viruses that have escaped from lymphoid organs, the site of HIV replication and destruction of the virus (Rasz et al 1986, Simmonds et al 1990, Panteleo et al 1993, Embreton et al 1993, Piatiak et al 1993, Patterson et al 1993, , Wain-Hobson et al 1993, Connors et al 1993, Cao et al 1995. The most direct data were recently provided by two research groups (Wei et al 1995, Ho et al 1995a) These investigators demonstrated that the clearance of peripheral blood virions (between 10 8 to 10 9 viruses) is paralleled by turn-over of CD4 T cells (0.1 to 7 x 10 9 ).…”

Quantitative, Competitive PCR Assay for HIV-1 Using a Microplate-Based Detection System

“…The remaining two plasma samples had viral loads that were below the limit of quantification by bDNA (<10 000 copies/mL), which corresponded to the QC-PCR determination of 700 and 3000 copies/mL. These results indicate that this QC-PCR technique is capable of quantifying HIV-1 virus from plasma at values comparable to those obtained from an HIV-1 viral load assay that has been shown to be reproducibly accurate (29) and that correlates well with the QC-PCR assay (2).…”