Epstein-Barr virus (EBV)-encoded RNA: automated in-situ hybridization (ISH) compared with manual ISH and immunohistochemistry for detection of EBV in pediatric lymphoproliferative disorders

Abstract

Detection of Epstein-Barr virus (EBV) may be achieved by various methods, including EBV-encoded RNA (EBER) in-situ hybridization (ISH) and immunohistochemistry (IHC) for latent membrane protein (LMP-1). We compared novel automated ISH and IHC techniques in pediatric lymphoproliferative disorders with results obtained by manual ISH. Thirty-seven pediatric cases previously studied by manual EBER ISH (including 18 EBER-positive, 15 EBER-negative, and 4 EBER-equivocal cases) were used for the study. Automated EBER ISH and automated LMP-1 IHC were performed using the BondMax autostainer and prediluted EBER probe and EBV cell surface 1 to 4 at 1:50 dilution, respectively. Results of each of the automated techniques for EBV detection were compared with results by manual EBER ISH. Compared with manual EBER ISH as the gold standard, automated ISH had a sensitivity and specificity of 94% and 69%, respectively, accuracy of 83%, positive predictive value (PPV) of 79%, and negative predictive value (NPV) of 90%. Automated IHC had a sensitivity of 44%, specificity of 93%, accuracy of 67%, PPV of 88%, and NPV of 59%. Automated ISH and IHC correlated significantly (P < 0.045). Automated ISH is useful for diagnosis of EBV-related pediatric neoplasms, being easy to perform and interpret and requiring only the technologist's time to set up and having a high sensitivity and NPV The automated IHC protocol is of too low sensitivity for routine use, although results show high specificity and PPV.