HHV‐8 infection and multiple myeloma

Human herpes virus 8 (HHV‐8) also known as Kaposi's sarcoma‐associated herpes virus has been strongly implicated in the pathogenesis of Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease. Recently, this gamma‐herpes virus was also found in the nonmalignant bone marrow dendritic cells of the majority of myeloma patients. In addition, HHV‐8 is also detectable in the peripheral blood of most myeloma patients. In contrast, this virus is rarely detected in close contacts of myeloma patients or healthy subjects. Furthermore, only about one‐third of patients with monoclonal gammopathy of undetermined significance (MGUS) are infected with HHV‐8. Sequencing of HHV‐8 DNA isolated from myeloma patients shows both interpatient differences and conserved differences unique to myeloma compared to HHV‐8 in other malignancies. Consistent expression of both the viral homologs of interferon regulatory factor and interleukin‐8 receptor in myeloma suggests a possible role for these transforming viral genes in the pathogenesis of this disease. J. Leukoc. Biol. 66: 357–360; 1999.