GLUCOCORTICOID-INDUCED APOPTOSIS AND TREATMENT SENSITIVITY IN ACUTE LYMPHOBLASTIC-LEUKEMIA OF CHILDREN

Sensitivity of leukemic blasts to steroid therapy is one of the progno stic factors in acute lymphoblastic leukemia (ALL) in children. We exa mined the number of steroid receptors and the increase in the apoptoti c index in peripheral blast cells after administration of prednisolone monotherapy in 21 children with ALL. A new diagnostic method was esta blished based on determination of the apoptotic index in peripheral bl ood lymphoblasts to evaluate the steroid sensitivity of leukemic cells during the first day of therapy. The increase in apoptotic ratio, ana lyzed by morphologic and/or flow cytometric studies, was most expresse d in the first 6 hours of treatment. The apoptotic ratio showed a good correlation with the clinical response. The number of steroid recepto rs (gcRs) on the blast cells was also examined, but it proved to be le ss informative than the in vivo steroid response itself.