[Treatment of CML with blastic crisis by the combination therapy of VP and low-dose Ara-C].

Forty-three-year-old man with schizophrenia, who had been diagnosed as chronic myelogenous leukemia (CML) and had been treated with hydroxyurea for 3 months, developed blastic crisis. The cytochemical study of the blastic cells showed POX (+), SBB (+) and TdT (+). The surface marker analysis revealed that the blastic cells expressed both myeloid (CD13, 33) and lymphoid (CD10, 19) markers. In the chromosomal analysis, additional chromosomal abnormality (11q+) was detected in all cells analysed (20/20) in addition to the standard type Ph1 chromosome. He was diagnosed as bi-phenotypic blastic crisis, and vincristine-prednisolone therapy was started. Initially, he responded to VP therapy well, but gradually became refractory to the therapy after 5 courses of VP. As many myeloblasts containing azurophilic granules were seen in the bone marrow after VP therapy, low dose Ara-C therapy was combined to VP. After 21 days of low dose Ara-C and VP, the percentage of the blast in the BM was significantly decreased and normal myeloid differentiation was observed after transient BM suppression. The chromosomal analysis showed the partial reappearance of standard Ph1 chromosome in 55% of the cells analyzed (11/20). Taken together, our data suggested that the combination of VP and low-dose Ara-C therapy might have some therapeutic benefit for the treatment of the CML with blastic crisis.