CD68(+)/CD83(+)/CD1a(-) dendritic cell subsets from patients with multiplemyeloma are not infected with human herpesvirus 8

Recently, a subset of dendritic cells with the phenotype CD68(+)/CD83(+)/CD 1a(-), present in patients with multiple myeloma (MM), was reported to be i nfected with human herpesvirus 8 (HHV-8). Therefore we wished to clarify wh ether HHV-8 infection might be related to the pathogenesis of MM. In an att empt to identify HHV-8 infected cells in patients with MM, longterm bone ma rrow cultures from 8 MM patients and dendritic cell cultures from 11 MM pat ients were established. In addition, fresh bone marrow aspirates from 10 MM and 10 patients with monoclonal gammopathy of undetermined significance (M GUS) were included in the study. All samples were analysed by a sensitive s emi-nested PCR assay and were found to be consistently PCR negative. Phenot yping of day 7 dendritic cell cultures demonstrated the presence of a suffi cient number of CD68(+)/CD1a(-) and CD83(+)/CD1a(-) cells, However, to excl ude the presence of infrequent HHV-8 infected cells, the CD68(+)/CD1a(-) su bset from 3 dendritic cell cultures was sorted in numbers of 10(5) for each PCR test, and again a negative PCR result was observed. This study documen ts that the CD68(+)/CD83(+)/CD1a(-) dendritic cells in patients with MM are not generally infected with HHV-8 and, as a consequence, it is unlikely th at HHV-8 plays a role in the pathogenesis of MM.