[Detection of t(15;17) using cytogenetic, fluorescent in situ hybridization, and molecular techniques. Comparative study of 11 patients with acute promyelocytic leukemia].

Objectives: Analysis and comparison of the sensitivity for the detection of t(15; 17) with conventional cytogenetic (CC), Southern blotting (SB), metaphase fluorescence in situ hybridization (M-FISH), interphase fluorescence in situ hybridization (I-FISH) and polymerase chain reaction (PCR) techniques.
Patients and Methods: 11 acute promyelocytic leukaemia (APL) patients (9 M3 and 2 M3v) were studied at diagnosis and partial remission and analyzed with CC (11 cases), SB (7 cases), I-FISH (2 cases) and PCR (3 cases) techniques.
Results: The percentages of detection of t(15;17) were: 90.9% (CC), 71.4% (SB), 85.7% (M-FISH) and 100% (I-FISH and PCR). Additional chromosomal abnormalities were detected in 2 cases with CC techniques.
Conclusions: 1.- There is a very good correlation in the detection of t(15; 17) between the techniques analyzed. 2.- At diagnosis, partial remission and relapse, M-FISH and PCR provide a reliable diagnosis of t(15; 17). Nevertheless, it is important to perform a CC analysis because it enables the recognition of additional chromosome abnormalities with putative prognostic importance. 3.- At complete remission, I-FISH and PCR provide a rapid and safe screening of putative residual cells. 4.- The great sensibility of the techniques available for the detection of t(15; 17) translocation allows the use in each laboratory of the most appropriate techniques according to their substructure and the patients' clinical stage.