Background: Epstein–Barr virus (EBV) encodes 2 small nonpolyadenylated noncoding RNAs termed EBERs. EBERs are the most common viral transcripts found in EBV-infected cells. In the present study we aimed to examine various aspects of EBER positivity in PTLD patients. Material/Methods: We conducted a comprehensive search for the available data by Pubmed and Google Scholar search engines for reports indicating results of EBERs in PTLD patients. Data from 27 previously published studies were included into analysis. Finally, 243 recipients of allograft were included into analysis. Results: One and 5 years survival rates for PTLD patients with EBER-positive results were 61% and 50%, respectively, compared to 55% and 49%, respectively, for EBER-negative PTLD patients. When death specifically due to PTLD was used as the final outcome, EBER-positive PTLD patients had relatively superior outcome; although p-value did not reach the significance level (p=0.09). EBER-positive patients were significantly more likely to develop PTLD lesions of B cell types (vs. T cell type; p=0.018); and early onset PTLD (p<0.001). EBER-positive PTLD patients were significantly more likely to be polymorphic versus monomorphic (p=0.05). EBER-negative PTLD patients were more likely to develop non-Hodgkin PTLD lesions (p<0.001). Conclusions: We found that PTLD patients with positive results for EBER represent relatively better histopathological features than those in EBER-negative PTLD patients, and the survival rate of EBER-positive PTLD patients is not inferior to that of the EBER-negative subjects. Moreover, they were more likely to represent early onset PTLD of B cell type with polymorphic and Hodgkin-like lesions; and biopsy specimens from different organs were significantly different regarding EBER test results. Future studies with large PTLD populations are needed to confirm our findings.

Keywords: post transplant lymphoproliferative disorders, EBV-Encoded RNA, EBER, in situ hybridization, PTLD