EXPRESSION OF EPSTEIN-BARR-VIRUS ENCODED LATENT GENES IN NASAL T-CELLLYMPHOMAS

Aims-To determine the expression of Epstein-Barr (EB) virus encoded la tent genes in nasal T-cell. lymphomas in The Netherlands. Methods-Seve n europid (Dutch) cases of nasal T-cell lymphoma were investigated for the presence of EB virus by RNA in situ hybridisation (EBER). The exp ression of the EB virus encoded genes BARF0, EBNA1, EBNA2, LMP1, LMP2A , LMP2B, and ZEBRA was studied at the mRNA level using reverse transcr iptase 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 v irtually all tumour cells. BARF0 mRNA was detected in all samples. EBN A1 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 i n any case. At the protein level occasional LMP1 positive tumour cells were seen in only one case. The EBNA2 protein was not detected. Concl usions-Nasal T-cell lymphomas in The Netherlands are strongly associat ed with EB virus. The virus shows a type II latency pattern (EBNA1+, L MP1+, EBNA2-) that seems to be similar to the EB virus associated nasa l T-cell lymphomas in oriental countries.