McClernon DR, Madison S, Stocum M, St. Clair M; Interscience Conference on Antimicrobial Agents and Chemotherapy.

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 1999 Sep 26-29; 39: 231 (abstract no. 1584).

Glaxo Wellcome, Research Triangle Park, NC

BACKGROUND: Highly active antiretroviral therapy (HAART) regimens have increased the number of patients with undetectable HIV-1 RNA by standard viral load (VL) assays. As new studies support the benefit of a low nadir and prolonged suppression, assays are needed to reliably monitor low VL. Modifications to standard assays (<400 copies/ml) have allowed detection of VL at concentrations as low as 50 copies/ml. However, imprecision of these ultrasensitive assays is reported as higher than standard assays and results in copy numbers with wide confidence intervals.METHODS: A simple freeze-drying step (SuperSens[TM]), added to the NucliSens[TM] HIV-1 QT assay before amplification, concentrates the nucleic acid in 45 minutes (5 minutes additional labor). Internal controls allow for low VL quantification with accuracy and precision comparable to standard assay. The procedure, utilizing Boom silica technology, was automated on the NucliSen[TM] Extractor.RESULTS: Two ACTG VQA panels with HIV-1 RNA (vRNA) concentrations from 50 to 500 copies/ml were assayed (1.0 ml input, 100% detection rate). All negative plasma controls were negative. Precision ranged from 0.07 to 0.24 log[10] SD. [table: see text] Analysis of twenty clinical samples "undetectable" by standard assays, 45% were detected by SuperSens[TM]; median 61 copies/ml (range, 12 to 160). Further analysis will determine lower detection limit (LDL) and detection rate between 0-50 copies using known RNA copy panels and clinical samples.CONCLUSION: The SuperSens[TM] protocol is a fast, easy, and robust method for sensitive quantification of vRNA without ultracentrifugation. The procedure increased detection rates, improved precision and enhanced the LDL, which will aid monitoring viral load in trials using HAART.

Publication Types:

• Meeting Abstracts

Keywords:

• Acquired Immunodeficiency Syndrome
• Antiretroviral Therapy, Highly Active
• HIV Infections
• HIV-1
• Humans
• Nucleic Acids
• RNA, Viral
• Self-Sustained Sequence Replication
• Viral Load
• methods
• reverse transcriptase, Human immunodeficiency virus 1
• virology

Other ID:

• GWAIDS0007728

UI: 102245225

From Meeting Abstracts