ABSTRACT
We have planned this work to evaluate the significance and prognostic values of both membrane and soluble APO-1 as markers of apoptosis in patients with acme leukaemia before and alter chemotherapy. For that, 30 patients suffering from acute leukaemia [15 patients with ALL and 15 patients with AMD and 10 apparently healthy individuals serving as control group, were selected and subjected to the following: thorough history and clinical examination, routine investigations including: complete blood picture, bone marrow examination, cytochemistry, immunopheno typing of the blast cells and specific investigations including: detection of mAPO1 [CD95] on surface of blast cells by flow cytometry, detection of DNA fragmentation by agarose gel electrophoresis and measurement of soluble APO-1 by ELISA technique before and after chemotherapy. Surface membrane CD9S was found to be expressed on the majority of ALL blast cells [86.6%] and in only 60% of AML blast cells. The degree of surface membrane expression was variable ranging from 23-86% in ALL and from 43-89%; in AML. In both ALL and AML patients, a significant relationship was detected between surface CD95 expression and response to initial induction chemotherapy. Ninety-one percent of ALL patients and 84% of AML patients who had surface CD95 expression>20% on their blast cells showed complete hematological remission after initial induction chemotherapy. This was confirmed by finding that DNA extracted from patients under chemotherapy, whose blast cells CD95 expression was>20%, showed DNA fragmentation [DNA laddering] by agarose gel electrophoresis [characteristic of apoptosis]. As regards soluble CD9S [SCD95] before starting chemotherapy, no statistically significant difference was observed between the level of soluble CD9S in both ALL and AML patients and the control group [P>0.05]. But, in AML patients, the level of soluble CD95 tended to be etevated [not significantly] in comparison with normal control. After initial induction chemotherapy, the level of soluble CD95 was found to be significantly decreased in both ALL and AML patients in comparison to its level before therapy [P<0.001 and<0.01, respectively]. By following up patients who were resistant to chemotherapy, it was observed that patients who did not achieve complete remission after induction chemotherapy had relatively higher levels of sAPO-1. From these results we can conclude that, since there is a significant relationship between surface CD95 expression in both ALL and AML patients and response to chemotherapy, the expression of surface CD95 could serve as a new prognostic marker as it is helpful in predicting the outcome of therapy. In addition, because soluble APO-1 was found to be relatively high in patients resistant to anti-leukaemic therapy, so measurement of s-APO-1 in sera of acute leukaemia patients could serve as a putative marker for an active persisting leukaemia