11th International AIDS Conference Vancouver, British Columbia — July 7-12, 1996

Int Conf AIDS 1996 Jul 7-12; 11:22 (abstract no. LB.A.6005)
Dunne AL, Crowe SM; Macfarlane Burnet Centre for Medical Research, Fairfield, Australia. Fax: 61 3 9482 6152. E-mail: tolli@burnet.mbcmr.unimelb.edu.au.

OBJECTIVE: To examine the ability of two commercially available assays to quantify HIV-1 RNA of different genomic subtypes in plasma. Design: The branched chain DNA assay (bDNA; Quintiplex HIV-1, Chiron Corporation, Emeryville, CA, USA) and the reverse transcriptase polymerase chain reaction assay (RT-PCR; Amplicor Monitor by Roche Diagnostics Systems, Inc., Branchburg, NJ, USA) were used as these assays have different underlying methodology principles.

METHODS: A panel of HIV-1 isolates was prepared by expansion of each isolate in culture, untracentrifugation and then reconstitution in HIV-1 seronegative plasma, to emulate specimens as they would be received in a clinical setting. The panel contained 11 HIV-1 isolates comprising subtypes A-F, and was standardized so that each sample contained a similar amount of HIV-1 p24 antigen. The subtype classification of each panel member was unknown to the operator. HIV-1 RNA in each sample was quantified by the bDNA and RT-PCR assays, which were performed according to manufacturers instructions.

RESULTS: The bDNA assay was able to detect and quantify HIV-1 RNA of all subtypes tested (A-F). The RT-PCR assay detected subtypes B-F, but was unable to detect or quantify isolates of subtype A. The level of HIV-1 RNA in samples representing subtypes E and F was significantly lower when measured by RT-PCR than by the bDNA assay. There was good concordance between RT-PCR and bDNA for samples representing subtypes B, C and D.

CONCLUSIONS: The design of the RT-PCR assay prevents detection and quantification of HIV-1 of certain subtypes, although this assay successfully quantified HIV-1 RNA of subtypes B, C and D. The bDNA assay uses multiple probes for detection of HIV-1 and was able to detect and quantify HIV-1 of subtypes A-F.

960707
LBA6005

Copyright © 1996 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.