Basophils exhibit rearrangement of the bcr gene in Philadelphia chromosome-positive chronic myeloid leukemia

Basophils were isolated from the peripheral blood of two patients with Philadelphia positive-chronic myeloid leukemia using monoclonal antibody Bsp-1 and fluorescence activated cell sorting. DNA blot analyses demonstrated rearrangement of the breakpoint cluster region gene in the isolated basophils, which suggests their leukemic origin. Isolated T cells from these patients that were cultured for 14 days in the presence of interleukin-2 lacked rearrangement of the breakpoint cluster region gene and are therefore unlikely to be derived from the chronic myeloid leukemia clone.