THE KAPOSIS-SARCOMA-ASSOCIATED HERPESVIRUS (HUMAN HERPESVIRUS-8) IN KAPOSIS-SARCOMA, MALIGNANT-LYMPHOMA, AND OTHER DISEASES

Background: Two novel nonhuman DNA fragments were discovered in an AID S-related Kaposi's sarcoma (KS) lesion using representational differen ce analysis. Design: These sequences belong to a previously unidentifi ed gamma-2-herpesvirus exhibiting homology with Herpesvirus saimiri an d Epstein-Barr virus. This virus was named Kaposi's sarcoma-associated herpesvirus (KSHV) and provisionally designated human herpesvirus-8 ( HHV-8). Results. KSHV is detectable in more than 90% of classical-Medi terranean, iatrogenic, endemic-African, and AIDS-epidemic KS lesions. In situ PCR studies have demonstrated KSHV in the spindle cells and en dothelial cells of KS lesions. KSHV appears to be a transmissible B-ly mphotropic herpesvirus. It is detectable in circulating B cells in som e HIV-infected patients, and this finding appears to predict the futur e development of KS among these individuals. KSHV has been identified in a rare and distinct subset of malignant lymphoma referred to as bod y cavity-based lymphoma but not in other lymphoid neoplasms. KSHV is a bsent from most other HIV- and non-HIV-associated lymphadenopathies. C onclusions: Further studies should lead to a better understanding of t he role of KSHV in the pathogenesis of these disorders and may eventua lly show that KSHV represents the long sought-after etiologic agent of Kaposi's sarcoma.