HHV-8, an always intriguing, sometimes relevant herpesvirus

The virus associated with Kaposi's sarcoma (KSHV) is also known as the human herpesvirus type 8 (HHV-8), due to its biological and genetic homology to other human herpesviruses. Since its identification in 1994, a growing body of evidence supports its role in the pathogenesis of Kaposi's sarcoma. Moreover, other lymphoproliferative disorders, such as Multicentric Castleman's disease and primary effusion lymphomas, have been also linked to HHV-8 infection. However, many questions still remain unanswered. HHV-8 seems a necessary but not sufficient factor in the oncogenic process. The exact pathways leading to tumoural development are not well understood. This review summarises the epidemiological, clinical and biological studies on which current understanding of HHV-8 and its pathogenic role are based. The relationship between HHV-8 and HIV infection is also discussed.