Phenotype of chronic lymphocytic leukemia (CLL) B-cells. B-CLL cells express the Leu-8 antigen

In the present report we studied the phenotype of peripheral blood mononuclear cells (PBMC) from 25 patients with B-cell chronic lymphocytic leukemia (CLL). Cells from all the cases expressed monoclonal surface immunoglobulins (SmIg), formed rosettes with mouse erythrocytes (MRFC) and were positive with OKB 2 and OKIa monoclonal antibodies. In addition, CCB 1 monoclonal antibody was positive in 17 out of 20, Leu-1 in 18 out of 21 and Leu-8 in 23 out of 25 cases. Double labelling experiments confirmed that the Leu-8 antigen was co-expressed on Leu-1+, CCB2+, HLA-DR+ B-CLL cells. Thus, B-CLL cells generally express the SmIg+, MRFC+, Leu-1+, OKB2+, Leu-8+ phenotype. Since it is known that normal peripheral blood B cells may be divided into two subpopulations according to Leu-8 expression, our data indicate that B-CLL cells originate from the more immature Leu-8+ B-cell subset which will respond to anti-IgM, whereas it reacts poorly to pokeweed mitogen.

The analysis of expanded cells from patients with lymphoproliferative disorders of granular lymphocytes may help to clarify the NK cell differentiation

Surface phenotype and functional in vitro activities were studied in 2 cases of lymphoproliferative disorders of granular lymphocytes. Cells from both patients presented the same, previously unreported, surface phenotype (i.e. T3+, T8+, T4-, HNK-1-, NK-15+, M1-), were unable to display either Natural Killer (NK) activity or suppressor function in a poke-weed-driven system, and showed a defective response to phytohemagglutinin (PHA). On the basis of available schemes for NK cells ontogenesis, we will discuss the phenotype and functional activities of patients' cells suggesting that the cell population expressing the T3+, T8+, HNK-1-, NK-15+, M1- phenotype might represent a discrete stage along the NK-cell differentiation pathway.