Human herpesvirus 8 open reading frame 26 and open reading frame 65 sequences from multiple myeloma patients: A shared pattern not found in Kaposi's sarcoma or primary effusion lymphoma

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herp esvirus, has been implicated in the pathogenesis of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), multicentric Castleman's disease, and rece ntly multiple myeloma (MM), DNA sequence analyses of HHV-8 suggest that mul tiple HHV-8 strains exist. We extracted DNA from 24 patients with MM and 3 patients with monoclonal gammopathy of undetermined significance and compar ed HHV-8 open reading frames (ORFs) 26 and 65 sequences with those derived from patients with KS, PEL, and two HHV-8-positive PEL cell lines KS-1 and BC-1, ORF26 sequence data suggest that MR I patients are consistently carri ers of HHV-8 strain subtype C3, All MM patients also consistently revealed either a single bp deletion or substitution at position 112197 in ORF65, Th is unique alteration is not present in patients with KS or PEL or in PEL ce ll lines. It occurs in the portion of ORF65 that is known to be responsible for a serological response to HHV-8.