[Reversion to chronic phase of chronic myelogenous leukemia in blast crisis with small-dose daunorubicin and oral prednisolone].

In December 1993, a 76-year-old Japanese male presented with general fatigue. Peripheral blood (PB) examination indicated marked leukocytosis (WBC count, 19.8 x 10(4)/microliter; leukemic blast differential, 89.5%). Leukemic blasts were positive for CD33, and negative for lymphoid antigens, with 2% of the blasts being positive for myeloperoxidase staining. On admission, chromosome analysis of leukemic cells in PB showed 45, X,-Y, t (9;22) [12/15]/46, XY, t (9;22) [3/15]. Southern blot analysis of the DNA from PB showed a rearrangement at the M-BCR region and germline configurations of both TCR beta and IgH chain genes. The patient was diagnosed as Philadelphia-positive chronic myelogenous leukemia (CML) in blast crisis. We commenced treatment with daunorubicin (DNR; 20 mg/day x 1 IV) and daily prednisolone (PSL; 60 mg/day PO). Leukemic blasts disappeared rapidly from PB, while the promyelocytes showed a transient increase, peaked 7 days after the start of therapy, and then disappeared. Myelocytes and metamyelocytes also showed transient increases. Without a period of severe myelosuppression, the patient reverted to the chronic phase of CML and karyotypic analysis of bone marrow cells showed 45, X,-Y, t (9;22) [33/35]/46, XY, [2/35]. Consolidation chemotherapy with DNR and BHAC was started, but the patient's condition deteriorated due to bacterial infection and he died of hepatic failure on March 1994. In this case, reversion to the chronic phase of CML in blast crisis may be accomplished by the cytodifferentiating effects of small-dose DNR and oral PSL to the leukemic blasts.