Utility of Real-Time PCR in the Diagnosis of Primary Epstein-Barr Virus Infection

Abstract

Background: Despite the availability of several serological markers, Epstein-Barr virus (EBV) status of some patients is not easily resolved. Objectives: The aim of the present study was to investigate the quantification and the diagnostic utility of EBV DNA detection as an adjunct to serological diagnosis of primary EBV infection. Study Design: Sera from 118 patients referred for suspected primary EBV infection, were tested for heterophile antibodies (HA), IgM antibodies against viral capsid antigen (VCA IgM) and IgG against nuclear antigen (EBNA IgG). A quantitative real time EBV PCR assay (Light Cycler EBV Quant kit) was simultaneously performed in plasma of these patients. Results: EBV DNA was detected in 43 of 46 patients (93.5%) with serologically confirmed primary infection. By performing real time RCR in the remaining 72 samples, 24 additional cases were diagnosed: in 20 of them, VCA IgM was positive but not HA; in 4 cases, HA were positive, but not VCA IgM. EBV DNA load was detectable in all samples drawn until day 12 after onset of symptoms; 20 days after onset all samples were negative. Higher viral load levels were detected in younger patients and in male patients. Conclusions: The use of EBV PCR assay resulted in an increase in definitive diagnosis of primary EBV infection, enhancing overall diagnostic efficacy by 20.3%. Real time PCR is a reliable tool for diagnosis of primary EBV infection early in the course of disease and may especially serve as a useful diagnostic supplement in serologically unclear cases of EBV infection.