Comparative genomic analyses of primary effusion lymphoma

Background.-A rare subset of human immunodeficiency virus (HIV) lymphomas, known as primary effusion lymphomas (PELs), are high-grade tumors carrying human herpes virus 8. Mechanisms postulated to contribute to lymphomagenesi s include impaired immune surveillance, alterations in hemopoietic regulato ry pathways due to expressed viral genes, and acquisition of genomic altera tions in regions of the genome that contain regulatory genes. In PEL, limit ed information exists about the nature of genome-wide aberrations in these rare lymphomas. Methods.-We used comparative genomic hybridization to detect regions of seq uence gain and loss throughout the genome of 8 PEL cases. Regions of DNA se quence loss or gain were confirmed using forward and reverse hybridization and t-statistic analyses. Results.-Genomic aberrations were identified in 6 of 8 cases, including rec urrent gain of sequence in chromosomes 12 [ish enh (12q22;12q23, 12q12;12q2 3)] in 3 of 8 cases and X [ish enh (X, Xp)] in 2 of 8 cases. Conclusions.-DNA copy number changes occurred in a majority of PEL cases an d are consistent with changes observed in other HIV lymphomas. These observ ations suggest that common genetic events may occur in HIV-associated lymph oid malignancies, but they probably do not contribute to the unique markers and morphology of PEL. Although individual genetic loci have been evaluate d previously in a few PEL cases, to our knowledge this study represents the first reported genome-wide scan of copy number changes in these rare HIV-a ssociated tumors.