Demonstration of a unique Epstein-Barr virus-positive cellular clone in metachronous multiple localizations of Hodgkin's disease.

The recent detection of clonal episomes of Epstein-Barr virus (EBV) in a significant proportion of Hodgkin's disease (HD) cases has suggested a re-evaluation of the possible pathogenetic role of EBV in the development of the disease. Here we report that in two EBV-positive HD, arisen in human immunodeficiency virus-1-infected drug users, a unique episomal EBV genome was detected in multiple metachronous HD lesions of each patient. These findings demonstrated that the same EBV-positive cellular clone was present in multiple localizations of HD as well as in specimens taken at different times. Combined in situ hybridization and immunohistological analyses evidenced EBV genome and EBV-encoded latent membrane protein-1 on Reed-Sternberg cells. Therefore, the data strongly support the possibility of a causal role for EBV in the pathogenesis of HD.