Heterogeneity of B-CLL Cells Defined by Monoclonal Antibodies

Leukemic cells from patients with B chronic lymphocytic leukemia (B-CLL) are thought to represent immature B lymphocytes, at a differentiation stage intermediate between pre-B cell and mature B lymphocyte, a stage not normally found in the peripheral blood (1–2). The characterization of B-CLL cells by their expression of cytoplasmic (clg) or monoclonal surface immunoglobulin (SIg) (3) and by monoclonal antibodies directed against antigens restricted or associated to B cell lineage (2) suggests a large degree of heterogeneity. Whether this phenotypic diversity is related to significant heterogeneity of organ localization, degree of bone marrow involvement, disease course, or response to therapy, is not clear. In an attempt to achieve a better B-CLL cell characterization we analyzed 25 CLLs with a panel of monoclonal antibodies defining both B- restricted and B-associated antigens. In addition we tried to relate phenotypic characteristics to the extent of dissemination as measured by biological and clinical criteria, according to Binet’s classification (4).