High frequency of a 30‐bp deletion of Epstein–Barr virus latent membrane protein 1 gene in primary HIV non‐Hodgkin's brain lymphomas

A characteristic 30-base pair (bp) deletion (del) in the 3′ end of the Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) gene, coding for the C-terminal NF-kappaB activation domain, has been identified in various lymphoproliferative disorders and nasopharyngeal carcinomas. In the single report to date of human immunodeficiency virus primary brain lymphomas (HIV-PBLs), del-LMP1 was noted in seven cases out of nine. The present study was designed to identify this deletion in a series of 31 diffuse large B-cell HIV-PBLs, with the aim of determining its possible oncogenic action. The presence of EBV was confirmed by EBER mRNA in situ hybridization. After genomic extraction from frozen tissue, two 20-base oligonucleotide primers flanking the site of the 30-bp deletion were used. DNA sequencing of the polymerase chain reaction (PCR) products confirmed an identical segment spanning 30-bp and 69-bp, frequently associated with mutational hotspots in 19 cases (61%). A role for del-LMP1 in the oncogenic potential of EBV in systemic proliferations is a matter of debate. Its high incidence suggests that the oncogenic mechanism of LMP1 in the brain might differ significantly from that in systemic lymphoid proliferations, and might be enhanced by HIV infection.