PRESENCE OF EPSTEIN-BARR-VIRUS IN CUTANEOUS LESIONS OF MYCOSIS-FUNGOIDES AND SEZARY-SYNDROME

It has been suggested that prolonged antigenic stimulation contributes to the development of epidermotropic cutaneous T cell lymphoma (CTCL) , mycosis fungoides and Sezary syndrome, characterized by a cutaneous infiltration of proliferating helper T cells. Since Epstein-Barr virus (EBV) antibodies were increased in CTCL sera, we investigated a possi ble etiologic role for EBV in epidermotropic CTCL by looking for the E BV genome in 25 cutaneous biopsies of mycosis fungoides or Sezary synd rome and 12 reactional inflammatory skin lesions. The use of a non-iso topic in situ hybridization procedure based on the detection of Epstei n-Barr encoded RNAs with biotinylated oligonucleotide probes (EBER) re vealed 32% of the lesions with CTCL to be positive for EBV (3 in dermi s, 3 in epidermis, 2 both in dermis and epidermis), as compared to no detection of the EBV genome in the reactional inflammatory skin lesion s. Moreover, a combined hybridization (EBER probe) and immunochemistry technique (anti-CD3 or anti-Kil monoclonal antibody) permitted the id entification of EBV in T cells of dermis and in keratinocytes, respect ively. The identification of EBV in epidermotropic CTCL suggests that this virus could play a role in the development of these CTCLs, either as an etiological agent or more probably as a chronic activating agen t. Indeed, the infection of keratinocytes by EBV could activate them a nd so induce the production of in situ cytokines (IL1a, IL6, TNFa) pla ying a role in the development of tumoral infiltrate.