Background: Human herpesvirus 8 (HHV-8) infection has been linked to the development of Kaposi's sarcoma and to rare lymphoproliferative disorders.
Methods: We used molecular methods, serologic methods, in situ hybridization, and immunohistochemical analyses to study HHV-8 infection in association with nonmalignant illnesses in three patients after transplantation.
Results: Primary HHV-8 infections developed in two patients four months after each received a kidney from the same HHV-8-seropositive cadaveric donor. Seroconversion and viremia occurred coincidentally with disseminated Kaposi's sarcoma in one patient and with an acute syndrome of fever, splenomegaly, cytopenia, and marrow failure with plasmacytosis in the other patient. HHV-8 latent nuclear antigen was present in immature progenitor cells from the aplastic marrow of the latter patient. Identification of the highly variable K1 gene sequence of the HHV-8 genome in both the donor's peripheral-blood cells and the recipients' serum confirmed that transmission had occurred. HHV-8 viremia also occurred after autologous peripheral-blood stem-cell transplantation in an HHV-8-seropositive patient with non-Hodgkin's lymphoma. Reactivation of the infection was associated with the development of fever and marrow aplasia with plasmacytosis; there was no evidence of other infections. HHV-8 transcripts and latent nuclear antigen were expressed in the aplastic marrow but not in two normal marrow samples obtained before transplantation.
Conclusions: Primary HHV-8 infection and reactivation of infection may be associated with nonneoplastic complications in immunosuppressed patients.