The oncogenic 30 and 69 bp deletion variants of the EBV LMP-1 gene are common in HIV-negative lymphoproliferations, both malignant and benign

Background: In vitro studies have shown that the 30 and 69 base pair (bp) d eletion variants of the latent membrane protein (LMP)-1 gene of the Epstein -Barr virus (EBV) have a higher transforming capacity than the wild-type va riant. In recent years these studies have triggered an in vivo search for s uch potentially oncogenic variants in lymphoid tissues. Patients and methods: We used polymerase chain reaction (PCR) to investigat e the prevalence of LMP-1 gene variants in EBV-positive lymph nodes from 60 HIV-negative Italian patients with benign and malignant lymphoid disorders . Results: The 30 bp variant was detected in 10 of 39 (25.6%) malignant lymph omas but also in 4 of 13 (30%) reactive lymphadenitis with follicular hyper plasia. Of note is the fact that the 69 bp variant was detected in three ca ses of malignant lymphoproliferation but also in two cases of localized Cas tleman's disease of hyalin vascular type. Conclusions: The molecular detection of the oncogenic variants of the LMP-1 gene in a lymph node biopsy as an indicator of the aggressiveness of the E BV-associated lymphoproliferative disease must be considered with caution. The relatively high frequency of the 69 bp variant in our series compared w ith that reported in the literature probably reflects a different incidence of LMP-1 variants in healthy populations from different geographical areas .