BCL-2 PROTOONCOGENE AND EPSTEIN-BARR-VIRUS LATENT MEMBRANE PROTEIN-1 EXPRESSION IN AIDS-RELATED LYMPHOMA

The expression of bcl-2 protein and Epstein-Barr virus (EBV) latent me mbrane protein 1 (LMP-1) was investigated in 18 cases of lymphoma occu rring in the acquired immunodeficiency syndrome (AIDS). EBV small RNAs were detectable in tumour cells in all cases by in situ hybridization with EBER oligonucleotides. LMP-1 expression was detected in 61% of t he cases, and 55% were positive for bcl-2. Dual expression of LMP-1 an d bcl-2 was found in 8/18 (44%) cases, while five cases (28%) expresse d either LMP-1 or bcl-2 and five expressed neither. Thus, there was an inconsistent relationship between the presence of EBV and the express ion of bcl-2. One LMP-1 negative case was found to express bcl-2 in re active lymphocytes but not in lymphoma cells. No clinical features wer e found to correlate statistically with LMP-1 or bcl-2 expression in t he tumour cells. However, CD4 counts at diagnosis were significantly l ower in bcl-2 positive cases (P < 0.05). The respective roles of EBV L MP-1 and the expression of bcl-2 in lymphogenesis in AIDS patients rem ains complex and is not yet fully understood.