HHV-8 and multiple myeloma in the UK

Abstract

Rettig and colleagues reported an association between HHV-8 and multiple myeloma. HHV-8 genomic sequences were detected by PCR in cultured bone-marrow stromal cells from 15 of 15 patients with multiple myeloma and from two of eight patients with monoclonal gammopathy of uncertain significance, but not from 26 controls. The association is biologically plausible since HHV-8 encodes an interleukin-6 (IL-6) homologue and IL-6 is known to be an important growth factor for myeloma cells; furthermore Rettig and colleagues showed expression of viral IL-6 in three of three myeloma bone-marrow stromal cells. The investigators therefore proposed that HHV-8 has a causative, albeit indirect, role in the pathogenesis of multiple myeloma. Unlike other human herpesviruses, with the exception of herpes simplex virus type 2, infection with HHV-8 is not widespread in the population. Serological assays seem to give the best indication of prevalence. On the basis of antibody reactivity to a latency associated nuclear antigen (LANA) and a recombinant capsid-related protein, encoded by open reading frame (orf) 65·2, HHV-8 seroprevalence in the UK is estimated at about 5%; in the USA it appears to be a little higher. In some Mediterranean countries HHV-8 seroprevalence is around 10–20%, and in Uganda around 50%. By an immunofluorescence assay for lytic HHV-8 antigens, an upper estimate for the HHV-8 prevalence in the USA is around 25%. All three assays suggest a marked geographical variation in prevalence. HHV-8 and multiple myeloma in France