Direct correlation between human herpesvirus-8 seroprevalence and classic Kaposi's sarcoma incidence in northern Sardinia

The human herpesvirus-8 (HHV-8) has been associated with the development of Kaposi's sarcoma. A high incidence of classic Kaposi's sarcoma has been de scribed in Sardinia, an island West of Italy's mainland. Different seroepid emiological analyses have reported that prevalence of HHV-8 infection varie s worldwide: a high HHV-8 seroprevalence has been shown in Italy. The prese nt survey was carried out to evaluate the correlation between HHV-8 infecti on and classic Kaposi's sarcoma incidence in northern Sardinia. Blood sampl es were collected from 226 healthy donors born and resident in five differe nt areas of North Sardinia. Seroprevalence to HHV-8 was determined searchin g antibodies to viral lytic proteins by immunofluorescence in sera diluted at 1:10. Classic Kaposi's sarcoma incidence data spanning a period of 23 ye ars were examined in the areas studied. The present screening revealed that seroprevalence was 35%, within a range of 15.346.3% in the five areas, alt hough it should be considered that the seroprevalence to HHV-8 can be estab lished more accurately by the combined use of different assays. Age emerged as an important risk factor. Indeed, subjects aged > 50 years showed a hig her seroprevalence to HHV-8 as compared with younger individuals. A strong direct correlation between HHV-8 prevalence and classic Kaposi's sarcoma in cidence has been also observed. The wide diffusion of HHV-8 in Sardinia app ears to represent an important factor in the high incidence of classic Kapo si's sarcoma reported in the island. However, additional co-factors, such a s age, sex, genetic traits, or viral strain pathogenicity, are likely to pl ay a role in the development of the disease. (C) 2001 Wiley-Liss, Inc.