A prospective evaluation of the diagnostic potential of EBV-DNA in plasma and whole blood.

• A large patient cohort was tested with qPCR for EBV-DNA in plasma and whole blood. • Primary infection, T-cell and Hodgkin lymphomas were predominant EBV diseases. • WHO qPCR for EBV-DNA had a low positive predictive value for proven EBV disease. • The analysis had an excellent negative predictive value for proven EBV disease. • The risk of diagnostic latency was high for patients with EBV-positive lymphoma. Quantitative polymerase chain reaction (qPCR) for Epstein–Barr virus (EBV)-DNA is an important diagnostic tool for EBV-associated disease, but interpretation of its clinical significance is challenging. We assessed the diagnostic and clinical performance of WHO-standardised qPCR for EBV-DNA (WHO EBV-qPCR) in plasma and whole blood (WB) for proven EBV disease in a prospectively accrued patient cohort. Central Denmark Region patients, tested with WHO EBV-qPCR from November 2017 to March 2019, were screened for EBV disease. Incidence (IR) was estimated by Poisson regression. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated for EBV-qPCR in plasma and WB. Risk of diagnostic latency was compared between patients with EBV-positive and EBV-negative lymphomas. EBV disease was diagnosed in 95 of 1484 participants (IR: 16.3 per 1000 patientyears 95%CI; 13.3–19.9). Sensitivity and specificity of WHO EBV-qPCR in plasma was 82.4% (95% CI; 74.2–90.7%) and 87.8% (95% CI; 85.6–90%), yielding a PPV of 32.2% (95% CI; 24.9–39.5%) and NPV of 98.6% (95% CI; 97.7–99.5%) for proven EBV disease. Sensitivity and NPV were comparable in WB, while specificity and PPV decreased to 66.9% (95% CI; 60.6–73.1%) and 18.1% (95% CI; 7.5–28.7%). Risk of diagnostic latency was 2.3-fold (95% CI 1.4–4.1) higher for patients with EBV-positive compared with EBV-negative lymphomas. WHO EBV-qPCR in plasma and WB have a low PPV but a high NPV for proven EBV disease. Implementation of WHO EBV-qPCR could improve interpretation and facilitate EBV-positive lymphoma diagnosis. [ABSTRACT FROM AUTHOR]