Human herpesvirus-8 and Kaposi sarcoma after kidney transplantation: mechanisms of tumor genesis.

Human herpesviruses (HHVs) are able to escape from complete clearance by the immune system. Their ability to become latent is due to their delicate interferences with the immune system. This characteristic makes some of them known as important tumor viruses. Based on the prevalence of the seropositivity for the HHV-8, the world can be divided into 4 regions, one of which is the Middle East with a seroprevalence of 5% to 20%. The incidence of iatrogenic Kaposi sarcoma, a cancer linked with HHV-8 following organ transplantation, is 500 times higher than that in general population. In the Middle East, Kaposi sarcoma is the most common malignancy reported in kidney transplant recipients. In an immunocompromised host, the primary infection with HHV-8 presents with fever, hepatosplenomegaly, lymphoid hyperplasia, pancytopenia, and liver dysfunction. Occasionally, rapid-onset Kaposi sarcoma develops in association with apparent primary HHV-8 infection. In this article, the tumor genesis mechanism of HHV-8 in kidney transplant recipients was reviewed.