Human herpes virus-8 is not associated with primary central nervous systemlymphoma in HIV-negative patients

Primary central nervous system lymphomas (PCNSL) are derived from germinal center B cells. Recent molecular studies indicate that the tumor cells or t heir precursors have experienced antigenic stimulation. Attractive candidat es for such antigens are pathogens with the capacity to reside in the brain . The aim of the present study was to evaluate whether human herpes virus ( HHV)-8 is involved in the pathogenesis of PCNSL. A series of 46 PCNSL, 31 f rom HIV-negative and 15 from HIV-positive patients, were analyzed using var ious molecular biological and immunological approaches. Nested PCR with two different protocols unequivocally demonstrated that PCNSL from HIV-negativ e patients did not harbor HHV-8 DNA. Among AIDS-associated PCNSL, HHV-8 DNA was found in only I tumor. In situ hybridization studies revealed that the lymphoma cells were HHV-8 negative in all cases. Single small mononuclear cells, most likely corresponding to bystander lymphocytes, were identified as the cellular source of HHV-8 in the HIV-positive patient with an HHV-8 P CR signal. These studies largely rule out a role for HHV-8 in the pathogene sis of PCNSL in both HIV-negative as well as HIV-positive patients.