[Human herpesvirus 6(HHV-6) and HHV-8 in malignant lymphoma]

Over the past 14 years three new human herpesviruses(HHV-6, -7 and -8) have been recognized and implicated as etiological agents of several human diseases. HHV-6 has been cited as a possible cause or as a modulating element of certain human lymphoproliferative disorders, particularly malignant lymphomas including Hodgkin's disease and Burkitt's lymphoma. Despite the genomic homology and serological cross-reactivity between HHV-6 and HHV-7, evidence for the association of HHV-7 with lymphoproliferative diseases has been scarce. HHV-8 was originally found in patients with Kaposi's sarcoma, and subsequently shown to be implicated in primary effusion lymphoma(PEL), a novel lymphoma entity. We found that HHV-6 genome is integrated into host DNA of lymphoma cells. Further studies are warranted to determine whether chromosomally integrated HHV-6 has any role in the pathogenesis of viral genome-positive lymphoproliferative diseases.