[Detection of the Philadelphia chromosome in adult B-lineage acute lymphoblastic leukemia using dual-color dual-fusion interphase fluorescence in situ hybridization].

OBJECTIVE

To investigate the incidence of Philadelphia chromosome (Ph) in adult B-lineage acute lymphoblastic leukemia (B-ALL).

METHODS

One hundred and twelve adult patients with previously untreated B-ALL were prospectively investigated by interphase dual-color dual-fusion fluorescence in situ hybridization (DD-FISH) with two-color break apart probe BCR-ABL and the results were compared with that of conventional cytogenetics (CC).

RESULTS

The incidence of Ph chromosome was 17.98% (16/89) and 31.25% (35/112) by CC and DD-FISH, respectively. The mean positive rate of Ph+cells by FISH was 66.23% (ranging 18.5%-99%). Of the 35 Ph+ALL patients by FISH, 25 were successfully karyotyped by CC which included 5 normal karyotypes, 20 abnormal karyotypes including 16 Ph chromosome and 13 complex abnormalities.

CONCLUSION

The incidence of Ph chromosome was 31.25% in adult with B-ALL. DD-FISH with BCR-ABL probe provides a powerful technique for the diagnosis of Ph+B-ALL. It is an important supplement to the CC analysis. DD-FISH technique should be used as a routine method for the diagnosis for adult acute B-ALL.