Detection of BCR/ABL transcripts by reverse transcriptase polimerase chain reaction in pediatric acute Lymphoblastic Leukemia: ıncidence and clinical eatures

BCR/ABL expression, which is the molecular equivalent of the Philadelphia chromosome, is an independent poor risk factor in acute lymphoblastic leukemia (ALL). We used a two-step (nested) reverse transcriptase polimerase chain reaction (RT-PCR) assay to examine BCR/ABL expression in the diagnostic bone marrow specimen of children with ALL, prospectively. Among 75 de novo ALL patients, 4 (%5.3) were found to be BCR/ABL- ositive, whereas 4 of 17 relapsed patients (23.5%) were positive. This preliminary study in Turkish children showed an incidence similar to reports from Europe and the U.S.A. More intensive chemotherapies and allogeneic bone marrow transplantations (BMT) uring the first remission were planned if a donor was available. Out of 8 BCR/ABL-positive patients, complete remission (CR) was achieved in 7 patients and partial remission (PR) was achieved in 1 patient. Three patients underwent allogeneic BMT during the first CR and 1 under went autologous BMT during the first PR. The Kaplan-Meier estimate of vent-free survival (EFS) of BCR/ABL negative de novo ALL patients was 78.36% at 3 years, whereas the EFS of positive patients was 31.25% at 26 ± 6.4 months. Molecular screening for the Philadelphia chromosome should become a part of the routine diagnostic panel in ALL patients in order to predict which patients have a poor prognosis and need tailored therapy.