DNA aneuploidy in Hodgkin's disease. A multiparameter flow-cytometric analysis with cytologic correlation

In 15 cases of Hodgkin's disease, the authors studied the DNA content of isolated nuclei from deparaffinized tissue by using multiparameter flow cytometry. An antinucleolar antibody preparation was employed as well as a secondary antibody that had been conjugated with fluorescein isothiocyanate. By simultaneously quantitating nucleolar fluorescence and DNA content, rare but distinct aneuploid populations were detected among the nuclei with brightly stained nucleoli. DNA aneuploidy was found in each case when this multiparameter analysis was used, but was detected in only 1 case when DNA content was analyzed alone. With the multiparameter analysis, two to four aneuploid populations were found in each case. These populations exhibited incremental duplications of DNA content that suggested endopolyploidy, ie, replication of DNA without accompanying nuclear division. The aneuploid stem line was hypodiploid or hypotetraploid in 6 cases, hyperdiploid in 7 cases, and near-triploid in 2 cases. These various abnormalities in ploidy showed only some correlation with histologic subtypes. Cell sorting showed that some nuclei with more than four or nearly eight times normal DNA content resembled nuclei of typical Reed-Sternberg cells. Many nuclei with an intermediate aneuploid DNA content resembled nuclei of mononuclear Reed-Sternberg cells. The near-diploid and near-triploid nuclei corresponded to nuclei of cells which were not readily recognizable as neoplastic in histologic sections. It is concluded that multiparameter analysis of DNA content can provide further insights into the neoplastic cells in Hodgkin's disease and may offer an objective basis for studying heterogeneity in this disorder.