       Document 1882
 DOCN  M94A1882
 TI    Quantitation of plasma HIV-1 RNA by branched DNA (bDNA) signal
       amplification.
 DT    9412
 AU    Wilber J; Urdea M; Detmer J; Kolberg J; Zanki S; Todd J; Chiron
       Corporation, Emeryville, CA.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):43 (abstract no. 145B). Unique
       Identifier : AIDSLINE ICA10/94370693
 AB    OBJECTIVE: To measure HIV-1 RNA in a large number of plasma specimens
       precisely, accurately, and rapidly in order to monitor HIV therapy and
       to determine whether quantitation is affected by differences in HIV-1
       subtype. METHODS: HIV-1 RNA levels in plasma were measured using a solid
       phase nucleic acid hybridization assay (Quantiplex HIV-RNA) based on
       bDNA signal amplification technology. In vitro RNA transcripts of the
       pol region of HIV-1 subtypes A-E, purified and quantified by OD 260,
       phosphate analysis, and hyperchromicity, 148 specimens from patients who
       had > 400 CD4/microliters, and longitudinal samples from patients on
       therapy were quantified using the bDNA assay. A lower clinical cutoff
       was evaluated. RESULTS: All 5 distinct genetic subtypes quantified
       within a factor of 1.5. One operator could complete testing of 42
       specimens in duplicate in less than 24 hr. The new clinical cutoff
       increased the number of specimens detectable by this assay in patients >
       400 CD4 by > 20% (levels shown in Fig). DISCUSSION AND CONCLUSIONS: The
       bDNA assay is a simple, reproducible, and accurate method for measuring
       HIV-1 RNA regardless of subtype that may be useful in monitoring changes
       in RNA level during the course of disease and during antiviral therapy.
       HIV-1 RNA levels vary widely in patients with high CD4 levels,
       suggesting that stratification of treatment could be based on viral load
       rather than CD4 level. TABULAR DATA, SEE ABSTRACT VOLUME.
 DE    Antiviral Agents/THERAPEUTIC USE  DNA, Viral/GENETICS  Gene
       Amplification  Genes, pol  Human  HIV Infections/BLOOD/DRUG
       THERAPY/MICROBIOLOGY  HIV-1/CLASSIFICATION/GENETICS/*ISOLATION & PURIF
       Leukocyte Count  Nucleic Acid Hybridization  Reproducibility of Results
       RNA, Viral/*BLOOD/GENETICS  T4 Lymphocytes  Viremia/BLOOD/DRUG
       THERAPY/MICROBIOLOGY  Virology/*METHODS/STATISTICS & NUMER DATA  MEETING
       ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

