RESUMEN
OBJECTIVE: To determine the prognostic value of preB immunophenotype and its variants on early treatment response among of acute pediatric lymphoblast leukemia. PATIENTS AND METHODS: A case-control study nested in a cohort was carried out with male and female patients 15 years and younger with recently diagnosed pre-B lymphoblast leukemia. A panel of B, T, monoclonal antibodies of the myelo-monocytic and megakaryocytic cell type was used. Response was assessed by bone marrow aspiration 14 days post treatment. RESULTS: 54 patients were included. The median age was 7 years (2 months - 14 years) median leukocyte count was 13,450/mm3 (1200-986,000/mm3). We identified 29 cases with late pre-B immune phenotype, 19 cases with common pre B and 6 cases with early preB immunophenotype. Eleven, patients also displayed myeloid antigens. A significant association (p=0.034) was found between early treatment response and the presence of myeloid antigens. No association was found between the pre-B immunophenotype, age and leukocyte count with early treatment response (p=0.264). CONCLUSIONS: We need to pay special emphasis on early treatment response in children with lymphoblast leukemia as our study did not corroborate the common finding that clinical factors and immune phenotype can be predictive factors.