SIMULTANEOUS DEMONSTRATION OF THE PHILADELPHIA-CHROMOSOME IN T-CELLS,B-CELLS, AND MYELOID CELLS

A patient presented with lymphoblastic lymphoma in lymph-nodes and chr onic myelogenous leukemia (CML) in marrow and peripheral blood. All ma rrow and unstimulated peripheral blood cells contained the Philadelphi a chromosome{t(9:22)}. Lymphoma cells were analyzed by flow cytometry and were identified as T cells (CD2+CD5+CD7+CD34+). All fresh lymphoma cells contained the t(9:22) translocation. Cultures of purified perip heral blood T and B cells and specifically stimulated NK cells reveale d that 59% of the B cells, 10% of the NK cells, and none of the normal T cells contained the translocation. The lack of translocation in nor mal peripheral T cells is attributed to their long lifespan. No rearra ngement of immunoglobulin or T cell receptor beta or gamma genes was f ound in either the leukemia or lymphoma cells. Analysis of the DNA fro m cryopreserved lymphoma biopsy showed clonal rearrangement within the common breakpoint cluster region of the bcr gene identical to the bcr rearrangement in DNA from leukemia blood cells. The data support the concept that T and B cells originate in the patient's totipotent stem cell from which the CML is also derived. (C) 1993 Wiley-Liss, Inc.