Human herpesvirus 8 (HHV-8) infection in Italian allogeneic bone marrow transplant (BMT) recipients

Background: HHV-8 may be transmitted by transplanted organs and tissues, and this represents a model to study both viral reactivation and primary infection. We determined seroprevalence of HHV-8 infection in bone marrow transplant (BMT) recipients and donors and evaluated the rate of HHV-8 seroconversion after BMT. Methods: We conducted a retrospective study testing sera from 187 related BMT donor/recipient pairs coming from Central and South Italy, who underwent allogeneic BMT between January 1991 and January 2000 at a single institution in Rome, Italy. Donors were sampled once, recipients were sampled before, 30 and 180 days post-BMT or earlier in case of death. The sera were examined for HHV-8 latent and lytic antibodies by immunofluorescence. Results: 24 of 187 (13%) donors, 20 of 187 (11%) recipients before BMT and 28 of 187 (15%) recipients after BMT were HHV-8 seropositive. Among the 167 HHV-8 seronegative recipients before BMT, seroconversion occurred in 19 cases (11%): 14 of the recipients from HHV-8 seronegative donor and 5 from HHV-8 seropositive donor. 10 BMT recipients seroconverted within 30 days following BMT and the remaining 9 patients within 180 days. 11 HHV-8 seropositive recipients before BMT became seronegative post BMT. Conclusions: The HHV-8 seroprevalence observed among BMT donors (13%) and patients before BMT (11%) is comparable to that found in the general population in the same geographic areas (Central and South Italy). HHV-8 seroconversion following BMT is probably due to factors other than BMT.