Expression of cd95 in b-cell acute lymphoblastic leukemia

Abstract EN

Background; The l'ailuie oi' anti leukemic tlierapy lias been largely attributed to résistance of apoptosis.

In principle, résistance to apoptosis may be caused by lack or reduced function of pro-apoptotic molecLiles or alternatively, by the dominance of anti-apoptotic programs.

Members of the tumor necrosis factor receptor (TNFR) siiperfamily and tlieir ligands are crucial regulators of cellular activation and death.

CD95 is one membcr of the TNFR superfamily which is involved mainly in apoptotic processes as it is a pro apoptotic receptor.

Objective: to evaluate the level of the expression of CD95 in B-cell acute lymphoblastic leukemia (B-ALL) cases at présentation and 6 month following therapy and to evaluate its rehition to risk status (low/standard risk or high risk) in the newly diagnosed B- ALL cases, or response to therapy in the follow up B- ALL cases.

Materials and Methods: a total of 84 subjects were included in this study.

They were classified into 3 groups; one group included 36 ncwly diagnosed B-ALI.

cases, another groiip included 28 follow up B-ALL cases (received chemotherapy for 6 month) and a third group included 20 âge and sex matched healthy subjects as Controls .

Flowcytometry analysis was carried oui to evaluate the expression of CD95 using fluorochrome labeled monoclonal antibodics against CD95.

Results: In this study CD95 expression percentage (%) and CD95 mean tluoresccncc intensity (MFl) are significantly increased in the follow up B-ALL cases whcn compared to the normal healthy Controls.

CD95 expression % and CD95 MFl are insignificantly increased in the ncwly diagnosed B-ALL cases when compared to the normal healthy Controls.

There is significant increasc in CD95 expression % and CD95 MFl in low/standard risk newly diagnosed B-ALL.

patients (16/36) compared to high risk newly diagnosed B-ALL patients (20/36).

There is significant increase in CD95 expression % and CD95 MF! in the follow up B-ALL patients in rémission (20/28) compared to the follow up B-ALL patients not in remission / rclapsed patients (8/28).

CD95 expression % and CD95 MFl are insignificantly increased in the newly diagnosed Adulthood B-ALL cases (16/36) when compared to the newly diagnosed Childhood B-ALL cases (20/36).

There is significant négative corrélation between CD95 expression % and the BM malignant cell % in the follow up cases of B-ALL (28 cases, 20 of them were in remission).

Conclusions; In this study, it is evidenced that CD95 expression is highcr in the leukemic cells of low/standard risk B- ALL patients than in the leukemic cells ol' high risk B- ALL patients and in responsive cases of B- ALL than in résistant cases indicating that évaluation of CD95 expression can be used as a prognostic indicator of response to therapy and clinical outcome of B- ALL and that deregulation of the expression of CD95 may occur in leukemic cells in a trial to cvade cytotoxic killing.