[Emergence and decrement of Ph-negative clone with trisomy 8 in CML during imatinib therapy].

An increase in the presence of the Ph-negative, trisomy 8 clone has been reported in chronic myelogenous leukemia (CML) under imatinib therapy, but any impact of the clone on patient prognosis remains uncertain. We report here on a 42-year-old male with CML who received imatinib after failure of interferon-alpha therapy. A chromosomal analysis revealed 18/20 trisomy 8 in bone marrow at 10 months of imatinib administration. Continuing imatinib at 300 mg daily resulted in a decrease in the number of trisomy 8 clones as well as the disappearance of Ph clone. Furthermore, the patient's pancytopenia was gradually improved. Imatinib therapy could be continued even with the emergence of trisomy 8.