title: Clinical characterization of a competitive PCR assay for quantitative testing of hepatitis C virus.
abstract: Rational clinical application of quantitative assessments of hepatitis C virus (HCV) RNA depends on an understanding of factors affecting the assay and its intrinsic variability. The effects of three types of blood collection tubes, two storage temperatures, five processing times, and two laboratories on a commercially available quantitative reverse transcriptase PCR assay (AMPLICOR HCV MONITOR) were evaluated. HCV RNA concentrations were assessed in 356 specimens representing 178 aliquots from nine patients. In a multivariate generalized linear model, HCV RNA concentrations decreased when centrifugation was delayed more than 6 h (P = 0.005) and were marginally different between laboratories (P = 0.06), but precentrifugation storage temperature (P = 1.00) and anticoagulation (P = 0.22) had no effect. After adjusting for other factors, the HCV concentration of 95% of a subject's samples were within 0.44 log. Specimens procured for reverse transcriptase PCR-based quantitative HCV testing should be centrifuged within 6 h of collection. Serial assessments should ideally be performed in the same laboratory, and changes in HCV RNA concentration of less than 0.44 log may not be biologically important.
authors.affiliation: Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: E P
authors.initials: EP
authors.lastname: Miskovsky
authors.forename: A V
authors.initials: AV
authors.lastname: Carrella
authors.forename: K
authors.initials: K
authors.lastname: Gutekunst
authors.forename: C A
authors.initials: CA
authors.lastname: Sun
authors.forename: T C
authors.initials: TC
authors.lastname: Quinn
authors.forename: D L
authors.initials: DL
authors.lastname: Thomas
mesh_terms: D000328:Adult; D001667:Binding, Competitive; D005260:Female; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D016133:Polymerase Chain Reaction / Q000379:methods*; D012367:RNA, Viral / Q000097:blood; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors
chemical_list: D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic