Comparison of immortalization assay and polymerase chain reaction detection of Epstein-Barr virus in pediatric transplant recipients and control samples

The polymerase chain reaction technique (PCR) has become a standard for the detection of Epstein-Barr virus (EBV). Several studies have shown that solid organ transplant recipients fated to develop post-transplant lymphoproliferative disease (PTLD) have higher mean levels of EB viremia as measured by PCR. We directly compared PCR and immortalization assay (IA) for EBV detection from control cell lines as well as from peripheral blood mononuclear cells (PBMC) and saliva samples from 9 pediatric solid organ transplant recipients. Results were expressed as the lowest amount of DNA and/or number of cells detected. All samples negative for EBV by PCR had amplifiable DNA detected using beta-actin primers. When control cell lines were assayed and positive in both assays, PCR was at least 200 times more sensitive than IA, as expected. When PBMC and saliva were compared, 1 patient, with a mononucleosis-like syndrome, was positive for EBV by IA only. When both IA and PCR were positive however, PCR was able to detect 5-500 times less EBV than IA, as expected. The associations of a positive test with each assay and the diagnosis of PTLD were similar.