CORRELATION BETWEEN THE NUMBER OF APOPTOTIC CELLS AND EXPRESSION OF THE APOPTOSIS-RELATED ANTIGENS FAS, LE(Y) AND BCL-2 PROTEIN IN NON-HODGKINS-LYMPHOMAS

The relationship between the number of apoptotic cells and the express ion of apoptosis-related antigens was examined in 56 cases of non-Hodg kin's lymphomas and in 10 cases of reactive hyperplastic lymph nodes ( RHL). Apoptosis was visually quantified by the in situ end-labeling (I SEL) method, and the expression of Fas, Le(y) antigens and bcl-2 prote in was examined by immunohistochemistry. The expression of Ley antigen was observed in germinal centers of RHL and 45% of non-Hodgkin's lymp homas, The apoptotic cell count (AC) in follicular lymphomas was signi ficantly less than that in diffuse lymphomas. The distribution pattern of apoptotic cells in follicular lymphomas was inverse to that in RHL . In follicular lymphomas, AC was lower in follicles than in interfoll icular areas. In contrast, AC was higher in follicles than in interfol licular areas in RHL. Le(y) antigen-positive lymphomas showed a signif icantly higher AC than the negative cases. The Fas antigen-positive ly mphomas showed a higher AC than the negative cases. However, AC in bcl -2 protein-positive and negative cases was not significantly different . These results suggest that Le(y) and Pas antigens appear to be invol ved in the apoptotic tendency of tumor cells in non-Hodgkin's lymphoma s, whereas bcl-2 does not necessarily.