APOPTOSIS IN HODGKINS-DISEASE

Previous studies have concentrated on the proliferative behaviour of the neoplastic cell compartment in Hodgkin's disease (HD). The aim of the current investigation was to analyse: the frequency of programmed cell deaths in Hodgkin and Reed-Sternberg (HRS) cells in the different subtypes of HD and to correlate this phenomenon with the expression of the bcl-2 oncogene. For this purpose, we investigated paraffin-embedded material from 63 cases of HD. Oncogene expression was determined by immunohistochemistry with the monoclonal antibody bcl-2-124. The detection of apoptotic cells was facilitated by application of the in situ end-labelling (ISEL) technique. Our results confirmed that bcl-2 expression is low in the lymphocyte-predominant subtype of HD. Apoptotic cells were found in all subtypes to a variable extent and were not significantly associated with any particular subtype. Interestingly, there was no correlation of bcl-2 expression and the presence or absence of apoptotic HRS cells. Hence, other factors must be operative in the regulation of programmed cell death in HD. Such mechanisms have been described for lymphocytes under various conditions, such as negative selection in germinal centres and within the thymus, DNA damage due to irradiation, and cellular cytotoxicity.