(18) One possible explanation for this phenomenon is that the low lymphocyte count might reflect a histologic change in HL toward a pattern with more proliferation of H-RS cells, rather than a pattern of reactive inflammatory cell stimulation.
(52) Interestingly, several studies have suggested a key role of IL-13 as an autocrine growth factor in HL, (13,24,40,41) and IL-13 mRNA is frequently expressed in the tumors, almost exclusively by H-RS cells.
The expression of bcl-2, bak, p53 and Ki-67 was analyzed by examining all the fields at a magnifying power of 40X and counting the number of H-RS cellspositive or negative for each immunostain in all fields.
Apoptotic index: Apoptotic H-RS cells were detected by TdT-mediated dUTP-Nick-End Labelling (TUNEL) technique using a fluorometric TUNEL system (Promega, USA) as per supplier's instructions.
The differences in means of percentage of H-RS cells expressing bcl-2, p53, and AI were compared using student's t-test.
Apoptosis-related proteins, apoptotic index and proliferation index: Bcl-2 and bak cytoplasmic expression was seen in 110(83.3%) out of 132 and 135(94%) out of 133 cases, with a range of positive expression of 10-65.8 per cent and 10-85.2 per cent of H-RS cells respectively.
Thus the ratio of bcl-2/bak expression in H-RS cells was categorized in various possible ways, but none showed any survival difference between the categories when OS and FFS were assessed (data not shown).
Response to chemotherapy was poorer in cases with p53 expression in more than 50 per cent of H-RS cells [CR in 70.0 vs.
The level of bak expression in H-RS cells was unrelated to disease stage, treatment response or survival of children with HL.