GENOTYPING OF EPSTEIN-BARR-VIRUS IN BRAZILIAN BURKITTS-LYMPHOMA AND REACTIVE LYMPHOID-TISSUE - TYPE-A WITH A HIGH PREVALENCE OF DELETIONS WITHIN THE LATENT MEMBRANE-PROTEIN GENE

Both Epstein-Barr virus (EBV) types A and B are found in endemic Burki tt's lymphoma (BL) occurring in equatorial Africa. We studied 17 cases of Brazilian BL previously demonstrated to be EBV-positive to determi ne the EBV type as well as the presence of a characteristic 30 bp dele tion within the 3' end of the latent membrane protein-1 (LMP-1) gene t hat may be important to the pathogenesis of several EBV-associated neo plasms. All case in which the age was known were children. We found ty pe A EBV in 13 of 14 (93%) evaluable cases, and type B in one case. Th e LMP-1 deletion was found in 12 of 15 (80%) evaluable cases, includin g the one case of type B EBV, and a similar high prevalence (59%) of t he deletion was detected in EBV-positive normal and reactive lymphoid tissues from individuals from the same geographic region. The high pro portion of cases associated with type A EBV suggests that immunodefici ency is not an important factor in the pathogenesis of Brazilian BL, i n contrast to endemic African BL. The presence of the LMP-1 deletion i n a high prevalence in the normal population in this region is unexpla ined.