Immunohistochemical assessment of human herpesvirus 8 infection in primarycentral nervous system large B cell lymphomas

Background/Aims-Primary central nervous system large B cell lymphomas (PCNS Ls) are frequently associated with Epstein-Barr virus (EBV) in patients wit h AIDS and less frequently in those without AIDS. Human herpesvirus 8 (HHV- 8) has been detected in these tumours by the polymerase chain reaction (PCR ) at low copy number, suggesting its presence in a cell compartment other t han the malignant one. The aim of this study was to use immunohistochemistr y to assess HHV-8 infection in a series of PCNSLs from patients with and wi thout AIDS. Methods-The antibody LN53, which reacts with the latent nuclear antigen I ( LNA1) of HHV-8, was used on tissue sections from 35 patients (17 with and 1 8 without AIDS) with PCNSL. In addition, DNA was available for PCR (open re ading frame 26 (ORF 26), ORF 72, ORF 75) in three patients (two without AID S, one with AIDS). Results-None of the 35 cases contained either DNA sequences or LNA1 positiv e cells. Conclusions-These results confirm the lack of HHV-8 infection in tumour cel ls of PCNSL. In addition, HHV-8 infected bystander cells do not express LNA 1 latent protein in this setting.