T cells and probably B cells arise from the malignant clone in chronic myelogenous leukemia.

Bone marrow cells from a patient with Ph' positive chronic myelogenous leukemia in chronic phase were cultured for multilineage hematopoietic colonies (CFU-GEMMT), erythroid bursts, and granulocytic colonies. With CFU-GEMMT colonies, T lymphocytes were identified by reaction with monoclonal antibodies Leu-5 and OKT-3; B cells were identified by reaction with B1. All CFU-GEMMT colonies examined contained the Ph' chromosome. Recloned secondary colonies of T cells reacted with Leu-5 and OKT-3 and were Ph' positive. This demonstrates that Ph' positive T lymphocytes were generated from the pluripotential stem cell of this patient. The presence of B cells in the mixed colonies indicates that these may also be derived from the neoplastic clone.