Detection of Eber-1 RNA in primary brain lymphomas in immunocompetent and immunocompromised patients

Tissue from primary central nervous system lymphoma (PCNSL) which developed in five patients with acquired immuno deficiency syndrome (AIDS), nine patients without immunodeficiency, and two Epstein-Barr virus (EBV)-positive control cell lines (B95-8 and Raji) were examined for the presence of EBER-1 RNA. The tissues were hybridized with digoxigenin-labeled sense or anti-sense EBER-1 riboprobes. In all five AIDS-related PCNSLs, strong hybridization signals were found with the EBER-1 anti-sense probe. Signals could be eliminated by preincubation of the tissues with RNase-A. Hybridization with the EBER-1 sense probe showed no signal. All PCNSLs from immunocompetent patients (five paraffin-embedded, four frozen) showed no hybridization signals with EBER-1 sense or antisense probe but good hybridization signals with probes to immunoglobulin kappa or lambda light chain indicating RNA preservation. The paraffin-embedded B95-8-positive control cell-line showed positive hybridization in most cells with the anti-sense EBER-1 probe, and up to one percent of the cells had a weak signal with the sense probe. Most Raji cells showed a uniform signal with the anti-sense EBER-1 probe only. We conclude that, PCNSLs that arise in AIDS patients are associated with latent EBV infections, whereas PCNSLs from immunocompetent patients are not indicating a probable role for EBV in pathogenesis of these tumors.