ANALYSIS OF THE EXPRESSION OF APOPTOSIS MARKERS ON PERIPHERAL BLOODLYMPHOCYTES AND BLAST CELLS IN ACUTE LEUKEMIA IN CHILDREN

Relevance: A topical issue of oncohematology is the search for effective approaches to therapy and methods of predicting the course of acute leukemia. A promising direction in this field is the study of changes in the expression of molecular markers on the cell surface in the dynamics of chemotherapy. The study aimed to determine the expression level of proteins annexin V, Bcl-2, CD95, and p53 on peripheral blood lymphocytes and leukemic bone marrow cells in children diagnosed with acute leukemia. Methods: the study design was cross-sectional. Research method: immunophenotyping. Peripheral blood and bone marrow of 106 patients with acute leukemia diagnosed for the first time at 1 month to 16 years (study group) and peripheral blood of 23 conditionally healthy children aged 2 to 17 years (control group) served as the study materials. The obtained data were subjected to statistical processing. Results: The study of Bcl-2 expression in B-ALL did not reveal reliable differences; in T-ALL, Bcl-2 expression was significantly higher on peripheral blood lymphocytes than on blasts. In OML, Bcl-2 expression was significantly higher in the blast cell population than in lymphocytes. When CD95 expression was analyzed in ALL, expression was significantly higher on peripheral blood lymphocytes than on the membrane of leukemic cells. The results of the analysis of the expression of annexin V showed that lymphocytes expressed a marker of early ОРИГИНАЛЬНЫЕ ИССЛЕДОВАНИЯ 32 Онкология и Радиология Казахстана, №4 (74) 2024 apoptosis significantly more than bone marrow blasts. This phenomenon is a dangerous sign indicating a decrease in antitumor immunity. Comparative analysis of p53 protein expression on the surface of lymphocytes and blast cells showed no significant differences in leukemia variants. Conclusion: The study indicated the prognostic significance of Bcl-2 and CD95 in acute leukemia. Annexin V and p53 did not show reliable sensitivity and specificity, which allows not to include these markers in the leukemia immunophenotyping panel.