Détection du chromosome Philadelphie chez les patients atteints de leucémie myéloïde chronique: Places respectives de la cytogénétique de l'hybridation in situ en fluorescence et de l'analyse moléculaire par RT-PCR

Abstract

Chronic myelogenous leukemia (CML) is characterized by a translocation t(9;22)(q34;q11) that can be cytogenetically observed in hematopoietic cells of 95 % of leukemic patients. The fusion of the abl oncogene with the bcr gene which results from this translocation can also be detected by molecular analysis. Fluorescence in situ hybridization (FISH) is a specific and sensitive method for detection of the bcr/abl fusion gene in samples from CML patients. A good correlation is observed between cytogenetic and FISH results in patients at diagnosis or under treatment. However dyscrepancies between the results of these two techniques must be considered. FISH is usefull for detecting cryptic or variant translocations, or for assessing the remission rate when cytogenetics is unsuccesfull. Reverse transcriptase polymerase chain reaction (RT-PCR) is more sensitive than cytogenetics. The need of quantitative methods is evident, but technical problems in standardization limits its application for residual disease evaluation.