Molecular monitoring in 3 representative patients in CR on IFN therapy.

In patient A, a transient complete cytogenetic response was followed by a hematologic, cytogenetic, and molecular relapse. In patient B, relapse occurred after withdrawal of IFN because of adverse effects. Patient C is in stable complete cytogenetic remission with very low ratios BCR-ABL/ABL 10.4 years after initiation of IFN therapy. The upper dotted line indicates the levels of 2% BCR-ABL/ABL at which cytogenetic relapse is expected,9 and the lower dotted line (0.1% BCR-ABL/ABL) the median ratio of all samples of patients investigated in CR.