Alterações citogenéticas em crianças portadoras de leucemia linfoide aguda B no Amazonas

Abstract

Acute lymphoblastic leukemia (ALL) is a neoplasia characterized by lymphoblasts accumulated in bone marrow, suppressing the development of normal cells. The LLA is the most common cancer in pediatrics and 85% of cases include lymphocyte lineage B (LLA-B). Genetic alterations are related to the pathogenesis of the disease and its identification is useful for a more refined diagnosis and allows the treatment optimization through patient´s stratification into the risk groups. The aim of this study is to estimate the frequency of the genetic alterations of prognostic importance in pediatric patients with ALL-B de novo at the FHHEMOAM. Cytogenetic evaluations of the cells obtained from bone marrow and / or peripheral blood were performed, using techniques such as G banding and in situ hybridization by fluorescence (FISH). Thirty-five pediatric patients diagnosed with ALL-B recruited were included in the period of one year. Among samples analyzed 40% were female and 60% male, 20% caucasians and 80% brown. Their ages ranged from 1 to 17 years, with a median of 3. Most patients (57.1%) were from the Capital, and the remaining 42.9%, were from other cities. It was observed that the most of the patient´s mothers had elementary school, and receive between 1 and 3 minimum salaries. Cytogenetic analysis identified 6 hyperdiploidy cases, 3 chromosome deletion cases (11q23) and 2 translocation cases t (9; 22). No statistical difference was found between cytogenetics in relation to gender, median age, race and origin. Evaluation of the FISH technique, showed changes in only one sample with (9;22) resulting in a fusion BCR / ABL. The frequency of cytogenetic changes were similar to those already described in the literature and karyotype analysis remains the best method for assessment of numerical changes and to assess the general karyotype. The FISH technique should be part of the diagnostic testing as molecular methodology for cryptic rearrangements of identification that escape conventional cytogenetic analysis.