Cytomegalovirus quantification in plasma by an automated real-time PCR assay

• Published in: Journal of clinical virology Vol. 38; no. 4; pp. 298 - 303
• Main Authors: Yerly, Sabine, Perrin, Luc, Van Delden, Christian, Schaffer, Sven, Thamm, Sven, Wunderli, Werner, Kaiser, Laurent
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2007; Elsevier Science
• Subjects: Adult; Allergy and Immunology; Analysis of Variance; Biological and medical sciences; Cytomegalovirus; Cytomegalovirus - genetics; DNA, Viral - blood; Female; Fundamental and applied biological sciences. Psychology; Human viral diseases; Humans; Infectious Disease; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Plasma - virology; Plasma CMV DNA; Polymerase Chain Reaction - methods; Real-time PCR; Reproducibility of Results; Sensitivity and Specificity; Viral diseases; Viral Load - methods; Virology; Real-time PCR; Cytomegalovirus; Plasma CMV DNA; Microbiology; Herpesviridae; Real time; Betaherpesvirinae; Virology; Infection; Virus; Polymerase chain reaction; Viral disease; Quantitative analysis
• ISSN: 1386-6532; 1873-5967
• DOI: 10.1016/j.jcv.2007.01.003

Abstract Background Sensitive quantitation of cytomegalovirus (CMV) DNA in blood is helpful for the diagnosis of CMV infection or reactivation and the monitoring of transplanted patients. Objectives We compared a new PCR assay coupled with an automated extraction system (CMV real-time PCR, Abbott Molecular, Des Plaines, IL, USA) to a previously validated method (ultrasensitive Cobas Amplicor CMV DNA Monitor, Roche Molecular, Indianapolis, IN, USA). Results Using limiting dilutions of CMV DNA positive plasma, the two assays had a similar detection threshold ranging between 20 and 45 copies/ml. Coefficients of variation of CMV real-time PCR assay varied from 1 to 12% for CMV DNA levels between 10,000 and 20 copies/ml. Viral loads assessed by the two methods on 179 clinical samples showed an overall concordance of 89% and an excellent correlation ( R = 0.94). Discrepancies were only observed for samples with low CMV DNA levels (<300 copies/ml); 18 samples were positive by CMV real-time PCR only, and 2 samples by ultrasensitive Cobas CMV only. Values obtained by CMV real-time PCR were on average 0.4 log higher than those of ultrasensitive Cobas CMV. Successive samples of transplanted patients with evidence of CMV infection/reactivation revealed that CMV real-time PCR assay was positive earlier and for a longer period of time after treatment initiation. Conclusions Although both assays had similar analytical performances, the CMV real-time PCR assay has the advantages of automated extraction and higher dynamic range, and shows a trend for an improved sensitivity that might impact on clinical decisions.