Document 1883
 DOCN  M94A1883
 TI    Precision and power of discrimination of a novel quantitative HIV RNA
       PCR assay.
 DT    9412
 AU    Kwok S; Christopherson C; McKinney N; Mulder J; Meyers L; Sninsky J;
       Roche Molecular Systems, Alameda, CA 94501.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):43 (abstract no. 146B). Unique
       Identifier : AIDSLINE ICA10/94370692
 AB    OBJECTIVE: Determine the precision and power of discrimination of a
       simple and colorimetric HIV-1 quantitative RNA PCR assay. METHODS: A
       quantitative PCR assay for HIV-1 RNA has recently been published (J.
       Clin Micro., Feb 1994). To assess the variability of the assay, each
       step of the assay (detection, amplification, and sample preparation) was
       dissected and studied. The reproducibility of the assay was determined
       by statistical analysis of duplicate standard deviations of log copies.
       This data was used to calculate error rates associated with the decision
       of whether two samples have different copy numbers. RESULTS: To
       determine the reproducibility of the microwell detection plates,
       amplified products were analyzed on duplicate wells on two plates. The
       coefficient of variation (CV) of O.D.s was 2-4% within plates and no
       more than 6.5% between plates. The analysis of multiple amplifications
       from the same prepared samples demonstrated O.D. CVs of less than 12%,
       which includes variability contributed by the detection system. To
       address variability in sample preparation, quadruplicate extraction were
       performed on 4 specimens. CVs of 8-30% were observed; the higher CVs
       were associated with lower copy numbers (300 copies/ml). The standard
       deviation of log copies (S) for the assay was determined to be 0.2
       (which approximately correlates to a CV of 20%). This allows one to
       recognize with 95% confidence that two samples are different if the
       ratio of the copy number estimates are not between 0.57 and 1.75.
       DISCUSSION AND CONCLUSION: The quantitative RNA assay described shows
       good precision and can discern relatively minor changes in viremia. With
       a sensitivity of 100 copies/ml, we have demonstrated that this procedure
       can be used to monitor viremia in individuals a) with undetectable p24
       antigen, b) with high CD4 counts, C) undergoing antiretroviral therapy,
       d) post-seroconversion, and e) diagnose neonates born to infected
       mothers.
 DE    Analysis of Variance  Antiviral Agents/THERAPEUTIC USE
       Colorimetry/METHODS/STATISTICS & NUMER DATA  Female  Human  HIV Core
       Protein p24/BLOOD  HIV Infections/BLOOD/DRUG THERAPY/MICROBIOLOGY  HIV
       Seropositivity/BLOOD/DIAGNOSIS/MICROBIOLOGY  HIV-1/*GENETICS/ISOLATION &
       PURIF  Infant, Newborn  Leukocyte Count  Maternal-Fetal Exchange
       Polymerase Chain Reaction/*METHODS/STATISTICS & NUMER DATA  Pregnancy
       Pregnancy Complications, Infectious/MICROBIOLOGY  RNA,
       Viral/*BLOOD/*GENETICS  Sensitivity and Specificity  T4 Lymphocytes
       Viremia/BLOOD/DRUG THERAPY/MICROBIOLOGY  MEETING ABSTRACT

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