LOW INCIDENCE OF EPSTEIN-BARR-VIRUS PRESENCE IN PRIMARY CUTANEOUS T-CELL LYMPHOPROLIFERATIONS

Multiple biopsies taken from 76 European human immunodeficiency virus (HIV)-negative patients with primary cutaneous T-cell lymphoproliferat ions, including mycosis fungoides (MF), pleomorphic T-cell lymphoma (P MTCL), anaplastic large cell lymphoma (ALCL) and lymphomatoid papulosi s (LyP) were investigated for the presence of Epstein-Barr virus (EBV) through a combined approach. Polymerase chain reaction (PCR) was empl oyed for EBV-DNA detection, in situ hybridization (ISH) for cellular l ocalization of EBV-encoded nuclear RNAs (EBER1 and EBER2) and immediat e early Bam H-fragment; lower frame (BHLF) RNA, and immunohistology (I H) for the identification of EBV-encoded latent membrane protein 1 (LM P1) and of nuclear antigen (EBNA) 2 expression. EBV-DNA was detectable by PCR in 1.5 of 76 cases (19.7%). EBER-ISH combined with IH identifi ed a variable, usually very low, number of infected neoplastic cells i n only seven of the 15 EBV-DNA-harbouring cases. This discrepancy betw een the results obtained with PCR and ISH is apparently caused by the low number of the infected cells per tissue section. The PMTCL entity produced the greatest number of positive cases, whilst ALCL and LyP ca ses were almost constantly devoid of the virus. BHLF transcripts were not detectable in any case, nor did any of the EBER-positive cells sho w an LMP1 or EBNA2 expression. These data show that primary cutaneous T-cell lymphoproliferations display an infrequent association with a l atent EBV infection and that the pathogenic role of the virus in the p ositive cases remains obscure as the virus frequently infects only a m inority of the atypical cells.