Effect of interferon-alpha in patients with chronic myelogenous leukemia in the accelerated phase: cytogenetic and...

Human interferon-alpha (IFN-alpha) has been shown to be effective in the treatment of Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) in the benign stable phase. The present study indicates that IFN-alpha may have a suppressive effect on Ph1-positive clones not only in the early stable phase but also in the accelerated phase with additional chromosomal abnormalities in some patients. In this study, in addition to 5 benign-phase patients, 3 patients with CML in the accelerated phase who had additional chromosomal abnormalities were treated with IFN-alpha. The presence of the Ph1-positive clone was estimated by chromosomal analysis and by Southern analysis at the DNA level using a 3' breakpoint cluster region (bcr) probe. Hematological remission and the suppression of proliferation of Ph1-positive clone to various extents were achieved by IFN-alpha treatment in 2 benign-phase patients and 3 patients with additional chromosomal abnormalities. Interestingly, in one of the latter three patients, Ph1-positive clones with or without additional chromosomal abnormalities were completely suppressed judging from chromosomal analysis and from the disappearance of bcr gene rearrangements.