EVOLUTION OF TUMOR-CELL IMMUNOPHENOTYPE I N RECURRENCES OF ACUTE LYMPHOBLASTIC-LEUKEMIA IN CHILDREN

Monoclonal immunophenotyping of leukemia cells of bone marrow was made in 9 children with acute lymphoblastic leukemia (ALL) while diagnosti c puncture in early isolated bone marrow recurrence. The reaction was studied on the films of the sternal puncture biopsies using RAP and 15 -20 monoclonal antibodies (DAKO, BECTON DICKINSON, ICO, BCA-B). B-ALL (DR, CD 10, 19, 22 and DR, CD 10, 19) was in 7 children; DR, CD34, 13, 33 immunotype was in 1 child and 1 patient had T-ALL CD2,3,5. Remissi on in all the children was achieved on the treatment day 33. After pol ychemotherapy according to protocols 1,M,2 of BFM-90 ALL program the c hildren received maintenance treatment. In recurrence patients were gi ven chemotherapy ALL rezidiv BFM-90, 13 protocol and recurrence progra ms for acute myeloblastic leukemia. Unrelated myeloid antigens CD 13 a nd 33 were initially expressed in one case and in 6 recurrences. The m ain B-specific antigens did not change in 4 of 8 cases of B-ALL. In T- ALL in recurrence antigens CD7 and CD38 emerged on leukemia cells. All the cases of alterations of immunophenotype of leukemia cell dominati ng population can be presented as the result of artificial selection o f the most resistent cells of the continuum of bone marrow leukemia ce lls in the course of treatment.