Mitotic activity and nuclear DNA damage of large cells in Hodgkin's disease: comparison with the expression of p53 and bcl-2 proteins and the presence of Epstein-Barr virus.

The roles of the bcl-2 and p53 proteins in Hodgkin's disease (HD) are poorly understood. We therefore compared their detected presence in Hodgkin and Reed-Sternberg/large atypical (H-RS/LA) cells immunohistochemically with the percentages of these cells double-labeled for CD30 and DNA strand breaks (DNA fragmentation index, DFI); mitotic indices (MI); and the EBV infection status. We found a highly significant inverse correlation between the fractions per case of H-RS/LA cells expressing bcl-2/p53 proteins and the DFI of CD30+ elements. No marked effect of these two oncoproteins on MI was noticed, although these parameters and DFI of CD30+ cells were linearly related. EBV infection of H-RS/LA cells exerted only a limited effect on the parameters tested. The results of this study suggest that overexpressed bcl-2 and, to some extent, p53 proteins in H-RS/LA cells of HD primarily counteract deletion of these cells.