Text Box: PROGNOSTIC VALUE OF BLASTOCYTEMIA IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) Khalifa, A. S., Ibrahim, W. , Abd El Halim, A., Abdel Aziz, A. Pediatrics and Clinical Pathology Departments Faculty of Medicine, Ain Shams University, Cairo, Egypt Objective: To determine the prognostic impact of circulating blasts day 8 and persistent bone marrow blasts day 15 after induction chemotherapy. Methods: 35 newly diagnosed ALL patients, 20 males and 15 females, mean age 4.7 ± 3.8 years, were subjected to full clinical history, thorough examination, C.B.C., Bone marrow aspiration and immunophenotyping. Results: Blastocytemia day 8 was detected in 14.4%, significantly correlated with lack of CD10 +ve. Remission induction rate was lower. Adverse features (male sex, organomegaly, C.N.S. leukemia at presentation, high total leucocytic count, L2-L3 morphology, T-cell phenotype, high Hb level, low platelets count) were commoner. Persistent bone marrow blasts day 15 were found in 20% with a significant +ve correlation with circulating blasts day 8. Conclusion: Persistent circulating blasts day 8 is a simple non invasive, universally applicable prognostic indicator. Patients, thus identified, might benefit from early modification using more intensive therapy to achieve better outcome. 1851