ABSTRACT
BACKGROUND: Sensitive and accurate hepatitis C virus (HCV) RNA detection and quantification is essential for the management of chronic hepatitis C therapy. Currently available platforms and assays are usually batched and require at least 5hours of work to complete the analyses. OBJECTIVES AND STUDY DESIGN: The aim of this study was to evaluate the ability of the newly developed Aptima HCV Quant Dx assay that eliminates the need for batch processing and automates all aspects of nucleic acid testing in a single step, to accurately detect and quantify HCV RNA in a large series of patients infected with different HCV genotypes. RESULTS: The limit of detection was estimated to be 2.3 IU/mL. The specificity of the assay was 98.6% (95% confidence interval: 96.1%-99.5%). Intra-assay and inter-assay coefficients of variation ranged from 0.09% to 5.61%, and 1.05% to 3.65%, respectively. The study of serum specimens from patients infected with HCV genotypes 1 to 6 showed a satisfactory relationship between HCV RNA levels measured by the Aptima HCV Quant Dx assay, and both real-time PCR comparators (Abbott RealTime HCV and Cobas AmpliPrep/Cobas TaqMan HCV Test, version 2.0, assays). CONCLUSIONS: the new Aptima HCV Quant Dx assay is rapid, sensitive, reasonably specific and reproducible and accurately quantifies HCV RNA in serum samples from patients with chronic HCV infection, including patients on antiviral treatment. The Aptima HCV Quant Dx assay can thus be confidently used to detect and quantify HCV RNA in both clinical trials with new anti-HCV drugs and clinical practice in Europe and the US.
Subject(s)
Hepacivirus/genetics , Hepacivirus/isolation & purification , Hepatitis C, Chronic/virology , RNA, Viral/isolation & purification , Real-Time Polymerase Chain Reaction/methods , Viral Load , Data Accuracy , Genotype , Hepacivirus/classification , Hepatitis C, Chronic/diagnosis , Humans , Limit of Detection , RNA, Viral/genetics , Reagent Kits, Diagnostic , Real-Time Polymerase Chain Reaction/instrumentation , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Sensitive and accurate hepatitis B virus (HBV) DNA detection and quantification are essential to diagnose HBV infection, establish the prognosis of HBV-related liver disease, and guide the decision to treat and monitor the virological response to antiviral treatment and the emergence of resistance. Currently available HBV DNA platforms and assays are generally designed for batching multiple specimens within an individual run and require at least one full day of work to complete the analyses. The aim of this study was to evaluate the ability of the newly developed, fully automated, one-step Aptima HBV Quant assay to accurately detect and quantify HBV DNA in a large series of patients infected with different HBV genotypes. The limit of detection of the assay was estimated to be 4.5 IU/ml. The specificity of the assay was 100%. Intra-assay and interassay coefficients of variation ranged from 0.29% to 5.07% and 4.90% to 6.85%, respectively. HBV DNA levels from patients infected with HBV genotypes A to F measured with the Aptima HBV Quant assay strongly correlated with those measured by two commercial real-time PCR comparators (Cobas AmpliPrep/Cobas TaqMan HBV test, version 2.0, and Abbott RealTime HBV test). In conclusion, the Aptima HBV Quant assay is sensitive, specific, and reproducible and accurately quantifies HBV DNA in plasma samples from patients with chronic HBV infections of all genotypes, including patients on antiviral treatment with nucleoside or nucleotide analogues. The Aptima HBV Quant assay can thus confidently be used to detect and quantify HBV DNA in both clinical trials with new anti-HBV drugs and clinical practice.
Subject(s)
DNA/analysis , Genotype , Hepatitis B virus/isolation & purification , Nucleic Acid Amplification Techniques/methods , Viral Load/methods , Automation, Laboratory/methods , Hepatitis B/virology , Hepatitis B virus/genetics , Humans , Plasma/virology , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
BACKGROUND: Cornea graft recipients are exposed to viral transmission from the donor. Cadaveric donor serum is often of poor quality and frequently yields falsely positive results in serological assays that may result in the graft being needlessly discarded. OBJECTIVE: We examined the influence of the time of blood collection after death, and the macroscopic aspect of serum, on serological test results in cadaveric cornea donors. METHODS: Five hundred sixty-five consecutive cadaveric cornea donors were systematically tested for serological markers of human immunodeficiency virus type 1 and 2, human T-cell leukemia virus type 1, hepatitis B and hepatitis C viruses (HCV). We studied the influence of the macroscopic aspect of the donor's serum and the time of blood collection after death on the results of serological testing and on the subsequent decision to use or discard the graft. RESULTS: Twenty-one and a half percent of corneas were rejected on the basis of virological test results. We found significant relationships between the macroscopic aspect of serum at the time of testing and: (i) a positive, equivocal or discrepant result of immunoassays, for all markers except anti-HCV antibodies, (ii) non acceptance of cornea grafts, and (iii) the time of blood sampling after death. CONCLUSIONS: The macroscopic aspect of postmortem blood samples is the best predictor of the specificity of serological testing in cornea donors. Serological results should be interpreted with care when serum is macroscopically abnormal, and cadaveric donors should not be sampled more than 12 hr after death.
