Philadelphia chromosome-negative cells with trisomy 8 after busulfan and interferon treatment of Ph1-positive chronic myelogenous leukemia.

A 48-year-old Japanese man with Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) was treated with busulfan followed by interferon-alpha (IFN-alpha). Ten months after IFN-alpha treatment, Ph1(-) cells with trisomy 8 were detected by the conventional banding technique and fluorescence in situ hybridization (FISH) analysis. Add(Y)(q12) was also found in Ph1(-) cells with trisomy 8. Although Ph1(+) cells disappeared after the treatment with IFN-alpha, Ph1(-) cells with trisomy 8 did not. We summarize four previous case reports of Ph1(+) CML developing Ph1(-) cells with trisomy 8. All four patients had received busulfan and IFN-alpha. These drugs may be related to the ontogenesis of Ph1(-) cells with trisomy 8, but the significance of Ph1(-) cells with trisomy 8 is not known, and further observation is needed.