This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Le, Q.-T. Articles by Zehnder, J. L. Search for Related Content PubMed PubMed Citation Articles by Le, Q.-T. Articles by Zehnder, J. L.

A Comparison Study of Different PCR Assays in Measuring Circulating Plasma Epstein-Barr Virus DNA Levels in Patients with Nasopharyngeal Carcinoma

Authors' Affiliations: Departments of ¹ Radiation Oncology and ² Pathology, Stanford University, Stanford, California and ³ Pamela Youde Nethersole Eastern Hospital, Hong Kong

Requests for reprints: Quynh-Thu Le, Department of Radiation Oncology, 875 Blake Wilbur Drive, CCG-228, Stanford, CA 94305-5407. Phone: 650-498-5032; Fax: 650-725-8231; E-mail: qle{at}stanford.edu.

Purpose: To compare the performance of three PCR assays in measuring circulating Epstein-Barr virus (EBV). DNA levels in nasopharyngeal carcinoma patients and to confirm its prognostic significance.

Experimental Design: Plasma from 58 newly diagnosed nasopharyngeal carcinoma patients were collected before, during, and every 3 to 6 months after radiotherapy. EBV DNA levels were determined by real-time quantitative PCR using primer/probe sets for polymerase-1 (Pol-1), latent membrane protein 2 (Lmp2), and BamHI-W. Pretreatment levels from the three assays were correlated with each other and serial measurements from the Pol-1 assay were correlated with clinical variables.

Results: Pol-1 was more accurate than BamHI-W in predicting EBV DNA concentrations in cell lines. Of the three assays, BamHI-W yielded the highest concentrations followed by Pol-1 in plasmas (n = 23). The correlation coefficient was 0.99 (P < 0.0001) for Pol-1 and Lmp2, 0.66 (P < 0.0001) for Pol-1 and BamHI-W, and 0.55 (P < 0.0001) for BamHI-W and Lmp2. Elevated pretreatment DNA levels as detected by Pol-1 were correlated with advanced nodal stage (P = 0.04) and overall stage (P = 0.028). There was no correlation between pretreatment EBV DNA levels and freedom-from-relapse or overall survival; however, there was a significant correlation between posttreatment levels and these variables. The 2-year freedom-from-relapse and overall survival rates were 92% and 94% for patients with undetectable, and 37% and 55% for those with detectable, posttreatment levels (P < 0.0001 and P < 0.002).

Conclusions: The three PCR assays yielded similar results in detecting EBV DNA in plasmas. The Pol-1-detected posttreatment EBV DNA level was the strongest predictor for treatment outcomes.

This article has been cited by other articles:

				M. L. Gulley, H. Fan, and S. H. Elmore Validation of Roche LightCycler Epstein-Barr Virus Quantification Reagents in a Clinical Laboratory Setting J. Mol. Diagn., November 1, 2006; 8(5): 589 - 597. [Abstract] [Full Text] [PDF]