Role of human herpesvirus 8 in Kaposi sarcoma unclear.

The statement by Lebbe et al 1 that the detection of human herpesvirus (HHV) 8 sequences in peripheral blood mononuclear cells (PBMCs) of patients with Kaposi sarcoma (KS) is related to the tumor burden seems hazardous. This conclusion is contrary to all we know of HHV biological behavior. For none of the HHVs has the amount or even the existence of latently infected cells been correlated with a clinical disease or viral diffusion in other tissues. Indeed, some, if not all, of the known HHVs are carried by PBMCs in healthy individuals. For example, in Italy, using polymerase chain reaction (PCR), we recently detected HHV-7 DNA sequences in PBMCs in 11 (44%) of 25 healthy individuals.2 As for HHV-8, its sequence has been detected in the blood of healthy individuals. This virus is so widespread that in the American population approximately 25% of adults and 2% to 8% of children