Expression of Lymphocyte Antigens on Blast Cells from Patients with Chronic Granulocytic Leukemia

Abstract

Chronic granulocytic leukemia (CGL) is a myeloproliferative disorder and is associated, in more than 90% of cases, with a karyotypic marker, the Philadelphia chromosome (Ph¹) (1,2). Although during the chronic phase of the disease the blood picture is dominated by leukemic granulocytes of various maturation stages, the disease is not confined to the granulocyte lineage. Isoenzyme (G6PD) studies have revealed that in most patients non-lymphoid cells in the peripheral blood are in majority derived from the malignant clone (3,4). Such studies have also shown involvement of B lymphoid cells in CGL (5), and together with additional evidence this has led to the notion that the target cell for malignant transformation in CGL is a common progenitor for myeloid cells and B lymphocytes (6). Based on cell membrane marker studies during CGL blast crisis, the involvement of T cell progenitors in CGL is controversial (6–8,12). Clonal evolution of CGL cells in the blast crisis of the disease (2) and/or the inability of CGL cells to mature to well-defined T cells (6,12) may be at the basis of this controversy.