Increased Proportion of Complement-Receptor Lymphocytes in the Peripheral Blood of Patients With Chronic Lymphocytic Leukemia

In the present study we present evidence that the proportion of complement-receptor lymphocytes (CRL) is greatly increased in the circulation in most cases of chronic lymphocytic leukemia (CLL). Lymphocytes (> 99% pure, 70% recovery) were obtained from the peripheral blood of normal individuals by separation of the mononuclear cells from the leukocyte-enriched plasma by differential flotation in Hypaque-Ficoll and incubation of the mononuclear cells with iron-containing particles followed by removal of the phagocytes with a magnet. Complement - receptor lymphocytes were detected by incubating lymphocytes with sheep erythrocytes coated with antibody and mouse complement (EAC) and counting the EAC—CRL rosettes under the microscope. 7.1 ± 3.8% of normal peripheral blood lymphocytes, 31.0 ± 6.9% of lymph node, and 59.6 ± 13.2% of tonsil lymphocytes bind EAC. The binding was C3-dependent since it could be inhibited specifically by papain fragments of rabbit antibodies to mouse C3. Among lymphocytes from the peripheral blood of patients with CLL, 50.7 ± 25.0% bear the complement receptor. These results suggest that CLL preferentially affects B cells.