Kaposi's sarcoma associated with previous human herpesvirus 8 infection inkidney transplant recipients

This study investigates the prevalence of human herpesvirus 8 (HHV-8) infec tion in kidney transplant patients, evaluating the risk of HHV-8 transmissi on via transplantation and the association between pre- and posttransplanta tion HHV-8 infection and the subsequent development of Kaposi's sarcoma (KS ). Immunofluorescence and an enzyme immunoassay mere used to determine HHV- 8 seroprevalence in 175 patients awaiting kidney transplantation and 215 co ntrols who were attending our clinic for other reasons. All patients in the study came from central or southern Italy. Seroprevalence was similar in b oth groups (14.8 versus 14.9%), with no significant difference between the rates for male and female patients. Of the 175 patients, 100 were tested fo r anti-HHV-8 antibodies at various times during follow-up, During follow up , seroprevalence increased from 12% on the date of transplantation to 26%. This increase was paralleled by an age-related increase in seroprevalence i n the control group. During follow-up from 3 months to 10 years after trans plantation, KS was diagnosed in seven patients (4.0%). Six of these patient s were positive for HHV-8 prior to transplantation. Overall, 23.0% of patie nts who were HHV-8 positive before transplantation developed KS, whereas on ly 0.7% of seronegative patients developed the disease (relative risk, 34.4 ; 95% confidence interval, 4.31 to 274.0), This finding suggests that the k ey risk factor for KS is infection prior to transplantation and that antibo dy detection in patients awaiting transplantation could be useful in identi fying patients at high risk for KS. In patients from geographic areas with a high prevalence of HHV-8, serological tests on donors may be less importa nt.