Study on the application of fluorescence in situ hybridization method in acute promyelocytic leukemia

Objective To investigate the value of fluorescence in situ hybridization (FISH) in the detection MRD and diagnosis of APL(acute promyelocytic leukemia).Methods Eight cases at initial diagnosis,6 cases at complete remission and 1 case normal control were detected by PML/RARα translocation probe.The results were compared with that detected by conventional cytogenetic methods.Results Being studied by chromosomal G-banding,8 cases at initial diagnosis were all showed positive t(15,17),3 of 6 cases with APL during complete remission showed positive t(15;17) and the other 3 showed normal karyotypes.Being studied by FISH,8 cases at initial diagnosis and 5 cases during complete remission all showed PML/RARα fusion gene red/green signal.Only one case of CR and normal control were showed normal chromosomal 15 red signal and chromosomal 17 green signal.The percentage of cells with PML/RARα fusion gene in 2 cases of M3V were found more than 80%.The positive percentage in M3 was about 60%.However the percentage in CR patients were found less than 20%.Conclusion FISH technique is a new sensitive,distinguished cytogenetics,it has important value in the diagnosis of APL and the detection of MRD.