Evaluation of Real-Time PCR Laboratory-Developed Tests Using Analyte-Specific Reagents for Cytomegalovirus Quantification

• Published in: Journal of Clinical Microbiology 2007-06, Vol.45 (6), p.1723-1727
• Main Authors: Caliendo, Angela M, Ingersoll, Jessica, Fox-Canale, Andrea M, Pargman, Sabine, Bythwood, Tameka, Hayden, Mary K, Bremer, James W, Lurain, Nell S
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cytomegalovirus; Cytomegalovirus - genetics; Cytomegalovirus - isolation & purification; Cytomegalovirus Infections - diagnosis; Cytomegalovirus Infections - virology; DNA, Viral - blood; DNA, Viral - isolation & purification; Fundamental and applied biological sciences. Psychology; Humans; Indicators and Reagents - standards; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - standards; Reagent Kits, Diagnostic - standards; Reproducibility of Results; Viral Load - standards; Virology
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.02558-06

Viral load testing for cytomegalovirus (CMV) has become the standard for the diagnosis of infection and monitoring of therapy at many transplant centers. However, no viral load test has been approved by the FDA. Therefore, many laboratories rely on laboratory-developed assays. This study evaluated the performance characteristics of two real-time PCR tests developed using the artus CMV analyte-specific reagents (ASRs). One version is distributed by Abbott Molecular and the other by QIAGEN. For plasma specimens, the Abbott test had a limit of detection of 2.3 log₁₀ copies/ml and a linear range up to at least 6.0 log₁₀ copies/ml. Comparison of plasma viral loads using the Abbott test and the Roche Amplicor Monitor test showed a mean difference of -0.012 log₁₀ copies/ml. In addition, the Abbott test viral loads correlated with the Digene Hybrid Capture assay ratios. Viral loads obtained from plasma specimens tested by the Abbott and QIAGEN tests were in very close agreement (mean difference, 0.144 log₁₀ copies/ml). When the QIAGEN test was evaluated with the QIAGEN, MagNA Pure, and easyMAG extraction methods, the viral loads for all three methods were within 0.370 log₁₀ copies/ml. Thus, there is good agreement between viral loads obtained by the different tests using the same extraction method or by the same test using different extraction methods. The availability of real-time PCR ASRs provides additional reagents that can be used for CMV viral load testing.