Levasseur PJ, Eustace DW, McCarty JM, Burg JL; International Conference on AIDS.

Int Conf AIDS. 2002 Jul 7-12; 14: abstract no. WeOrB1338.

bioMerieux, Inc., Rockland, United States

BACKGROUND: The VIDAS PROBE qHIV test is currently under development for determining HIV-1 viral loads. As this test has been anchored to the VQA subtype B standard, the purpose of this study was to determine the sensitivity, reproducibility and quantitative accuracy of HIV-1 non-B subtypes. METHODS: Nineteen HIV-1 culture isolates, representing Group M subtypes A, B, C, D, E, F, G and H and Group O (Boston Biomedica, Inc.), were serially diluted to nominal values of 10000, 1000, 100, and 50 RNA copies/mL based on electron microscopy (EM). HIV-1 RNA was isolated by specific target capture onto paramagnetic particles, amplified by automated TMA (transcription-mediated amplification) on the AMPstation instrument, and detected by an automated protocol on the VIDAS instrument. A replicate size of 5 was tested for each subtype at each level (2 operators, 3 days). RESULTS: Combining the results for all subtypes, the VIDAS PROBE qHIV test showed 98.8% detection at 50 RNA copies/mL and 100% detection at >= 100 RNA copies/mL. The only nondetectable result occurred with one Group O sample where the other four replicates gave values of 18, 20, 16 and 19 RNA copies/mL. The average precision, determined by the standard deviation of log10 transformed data, was 0.16, 0.20, 0.13 and 0.13 for inputs of 50, 100, 1000 and 10000, respectively. In general, quantitative accuracy was within 0.5 log10 of the expected EM values although one C and two F subtypes showed systematic quantitative bias. However, compared to expected values averaged from EM plus two molecular methods, only the one C subtype had an average log10 difference > +/- 0.5 log10 (-0.59 log10). CONCLUSIONS: These preliminary results indicate that the VIDAS PROBE qHIV test under development has excellent sensitivity, precision, linearity, and accuracy for all major HIV-1 subtypes. In particular, the four Group O samples showed similar results as the various Group M subtypes.

Publication Types:

• Meeting Abstracts

Keywords:

• Boston
• HIV-1
• Reagent Kits, Diagnostic
• Research Design
• Sensitivity and Specificity
• instrumentation
• methods

Other ID:

• GWAIDS0015408

UI: 102252906

From Meeting Abstracts