Abstract
To analyse the phenotype of Epstein-Barr virus (EBV)-infected lymphocytes in EBV-associated infections, cells from eight haematopoietic stem cell/liver transplantation recipients with elevated EBV viral loads were examined by a novel quantitative assay designed to identify EBV-infected cells by using a flow cytometric detection of fluorescent in situ hybridization (FISH) assay. By this assay, 0.05-0.78% of peripheral blood lymphocytes tested positive for EBV, and the EBV-infected cells were CD20+ B-cells in all eight patients. Of the CD20+ EBV-infected lymphocytes, 48-83% of cells tested IgD positive and 49-100% of cells tested CD27 positive. Additionally, the number of EBV-infected cells assayed by using FISH was significantly correlated with the EBV-DNA load, as determined by real-time PCR (r2 = 0.88, P < 0.0001). The FISH assay enabled us to characterize EBV-infected cells and perform a quantitative analysis in patients with EBV infection after stem cell/liver transplantation.