Publications (3)8.31 Total impact
Article: Blinded, multicenter comparison of methods to detect a drug-resistant mutant of human immunodeficiency virus type 1 at low frequency.[show abstract] [hide abstract]
ABSTRACT: We determined the abilities of 10 technologies to detect and quantify a common drug-resistant mutant of human immunodeficiency virus type 1 (lysine to asparagine at codon 103 of the reverse transcriptase) using a blinded test panel containing mutant-wild-type mixtures ranging from 0.01% to 100% mutant. Two technologies, allele-specific reverse transcriptase PCR and a Ty1HRT yeast system, could quantify the mutant down to 0.1 to 0.4%. These technologies should help define the impact of low-frequency drug-resistant mutants on response to antiretroviral therapy.Journal of Clinical Microbiology 08/2006; 44(7):2612-4. · 4.15 Impact Factor
Article: Multicenter evaluation of use of dried blood and plasma spot specimens in quantitative assays for human immunodeficiency virus RNA: measurement, precision, and RNA stability.[show abstract] [hide abstract]
ABSTRACT: Eleven laboratories evaluated the use of dried blood and plasma spots for quantitation of human immunodeficiency virus (HIV) RNA by two commercially available RNA assays, the Roche Amplicor HIV-1 Monitor and the bioMerieux NucliSens HIV-1 QT assays. The recovery of HIV RNA was linear over a dynamic range extending from 4,000 to 500,000 HIV type 1 RNA copies/ml. The Monitor assay appeared to have a broader dynamic range and seemed more sensitive at lower concentrations. However, the NucliSens assay gave more consistent results and could be performed without modification of the kit. HIV RNA was stable in dried whole blood or plasma stored at room temperature or at -70 degrees C for up to 1 year. Dried blood and dried plasma spots can be used as an easy and inexpensive means for the collection and storage of specimens under field conditions for the diagnosis of HIV infection and the monitoring of antiretroviral therapy.Journal of Clinical Microbiology 06/2003; 41(5):1888-93. · 4.15 Impact Factor
Article: Multicenter Evaluation of Methods To Quantitate Human Immunodeficiency Virus Type 1 RNA in Seminal Plasma[show abstract] [hide abstract]
ABSTRACT: We have evaluated two commercially available kits (AMPLICOR MONITOR [Roche] and NASBA HIV-1 QT or NucliSens HIV-1 QT [Organon Teknika]) and two noncommercial methods for the accurate quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in seminal plasma. The same panels of coded specimens were tested on four separate occasions. Laboratories using the commercial assays employed silica beads to isolate HIV-1 RNA, which removed inhibitory factors sometimes found in seminal plasma. Sensitivities and specificities, respectively, for each assay were as follows: AMPLICOR MONITOR, 100 and 73%; NASBA HIV-1 QT, 84 and 100%; NucliSens HIV-1 QT, 99 and 98%; and noncommercial assays, 91 and 73%. When results from the laboratory that was inexperienced with the silica bead extraction method were excluded from the analysis, specificity for the Roche assay increased to 100%. The commercial assays demonstrated highly reproducible results, with intra-assay standard deviations (measured in log10 RNA copies/milliliter of seminal plasma) ranging from 0.11 to 0.32; those of the noncommercial assays ranged from 0.12 to 0.75. Differences in mean estimated HIV-1 RNA concentrations were ≤0.67 log10 and were greater at low viral loads. Suspension matrices that used blood plasma or seminal plasma did not make a difference in recovery of HIV-1 RNA, which suggested that blood plasma specimens can be used as external controls for seminal plasma assays. More variation in the HIV-1 RNA viral loads was observed in the seminal plasma values than in the blood plasma values when paired specimens from HIV-1-infected men were tested. Quantitation of HIV-1 RNA in seminal plasma can be reliably accomplished using two commercially available assays, and may be incorporated into the evaluations of HIV-1 seropositive men enrolled in clinical studies.