Expression of Epstein-Barr virus encoded latent genes in nasal T cell lymphomas.

AIMS To determine the expression of Epstein-Barr (EB) virus encoded latent genes in nasal T-cell lymphomas in The Netherlands. METHODS Seven europid (Dutch) cases of nasal T cell lymphoma were investigated for the presence of EB virus by RNA in situ hybridisation (EBER). The expression of the EB virus encoded genes BARF0, EBNA1, EBNA2, LMP1, LMP2A, LMP2B, and ZEBRA was studied at the mRNA level using reverse transcriptase polymerase chain reaction. At the protein level the expression was investigated of EBNA2 and LMP1 by immunohistochemistry. RESULTS In all seven nasal T cell lymphomas EBER was detected in the nuclei of virtually all tumour cells. BARF0 mRNA was detected in all samples. EBNA1 mRNA was found in six cases, LMP1 mRNA in five, LMP2A mRNA in three, LMP2B mRNA in one, and ZEBRA mRNA in one. EBNA2 mRNA was not found in any case. At the protein level occasional LMP1 positive tumour cells were seen in only one case. The EBNA2 protein was not detected. CONCLUSIONS Nasal T cell lymphomas in The Netherlands are strongly associated with EB virus. The virus shows a type II latency pattern (EBNA1+, LMP1+, EBNA2-) that seems to be similar to the EB virus associated nasal T cell lymphomas in oriental countries.