Infectious human herpesvirus 8 in a healthy North American blood donor.
BACKGROUND
Molecular studies have provided strong evidence for the association of human herpesvirus 8 (HHV-8) with Kaposi's sarcoma. These data have been supported by serological studies, which have also suggested that HHV-8 can be found in the healthy population. We report the presence of infectious HHV-8 in a healthy donor to a North American blood bank.


METHODS
We examined the peripheral blood mononuclear cells or CD19 cells of blood donors by PCR for evidence of HHV-8 infection. The CD19 cells were separated from peripheral blood mononuclear cells by immunomagnetic-bead selection. To enhance detection of HHV-8, the CD19 cells from eleven unsystematically selected blood donors were activated with phorbol ester and recombinant interleukin-6; the culture fluid was filtered and inoculated onto HHV-8-negative target CD19 cells that had been prepared from phytohaemagglutinin-stimulated peripheral blood mononuclear cells. These inoculated target cells were cultured for 3 days and then analysed for HHV-8 sequences by PCR. Serum samples were tested for antibodies to HHV-8 by an indirect immunofluorescence assay.


RESULTS
One blood donor was consistently found to be infected with HHV-8 by PCR after the cell-culture activation procedure. He was seropositive for the virus. The HHV-8 recovered was infectious, as shown by a reverse-transcription-PCR technique that detected HHV-8 RNA in the inoculated target cells.


CONCLUSIONS
These data provide the first indication that HHV-8 can be recovered from the blood of a healthy individual, a blood donor, and that the virus is infectious. This observation suggests that HHV-8 could be transmitted by blood transfusion, a possibility that merits further study.
Blackbourn
D J
DJ
Department of Medicine, University of California, San Francisco 94143-1270, USA.
Ambroziak
J
J
Lennette
E
E
Adams
M
M
Ramachandran
B
B
Levy
J A
JA
D000328:Adult; D001483:Base Sequence; D001771:Blood Banks; D001782:Blood Donors; D002478:Cells, Cultured; D016384:Consensus Sequence; D019288:Herpesvirus 8, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D009656:North America; D017354:Point Mutation; D016133:Polymerase Chain Reaction