Quantitative EBV detection from whole blood on the COBAS 6800 system in response to Song J, Kim S, Kwak E, Park Y. Applicability of the cobas 6800 System for Epstein-Barr viral load quantitation using whole-blood specimens

<h2>TO THE EDITOR</h2><p dir="ltr">Song <i>et al</i> recently reported an evaluation of the feasibility of Epstein-Barr virus (EBV) testing on the cobas 6800 (Roche Diagnostics) using whole blood, comparing it against the EBV RG PCR kit (Qiagen). We also recently evaluated the cobas EBV assay using whole blood on the Roche 6800 instrument against our existing, not fully automated, Roche LightMix EBV kit (TIB MolBiol). The existing assay runs on Roche’s LightCycler 480 instrument and was already validated for whole blood samples.</p><p dir="ltr">The cobas EBV assay is approved by the US Food and Drug Administration and is Conformite Europeenne (CE) in vitro diagnostics (IVD) marked only for EDTA plasma but not whole blood samples.2</p><p dir="ltr">Most commercially available systems use plasma as the preferred sample type. However, analyzing whole blood and peripheral blood mononuclear cells enables a more sensitive diagnosis due to the detection of clonal expansion of B cells for EBV-associated infections, such as posttransplant lymphoproliferative disorder.3-5 Additionally, the effects of cell lysis on plasma viral load measurements are mitigated, providing a more stable measurement over time.3</p>