Epstein-Barr virus as a possible etiologic agent in primary central nervous system lymphoma in immunocompetent individuals

Background: Primary central nervous system lymphoma (PCNSL) occurs in both immunocompetent and immunosuppressed individuals. The role of Epstein-Barr virus (EBV) has been implicated in immunosuppressed individuals but its role is not established in immunocompetent individuals. Aims: To study the possible role of EBV in PCNSL in immunocompetent individuals. Setting and Design: Retrospective study. Materials and Methods: Thirty patients with PCNSL were studied immunohistochemically with antibodies to CD45, CD20, CD3 and EBV latent membrane protein-1 (EBV LMP-1). In situ hybridization was done in 19 patients where enough tissue was available using a specific oligonucleotide probe for EBV-Early RNA (EBER). Results: All the patients were immunocompetent and mean age was 41.6 years. Histologically they were diffuse large cell lymphoma: 25 (83.3%) were B cell, 1(3.3%) was T cell and 4 (13.3%) were unclassified. EBV LMP-1 showed variable membrane and cytoplasmic positivity in 24 (80%) patients. In situ hybridization for EBER was negative in all the 19 patients studied. Conclusion: In this region of the world probably EBV has no etiologic role in PCNSL in immunocompetent individuals.