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 (> 990/0 pure, 700/0 recovery) were obtained from the peripheral blood of normal Individuals by separation of the mononuclear cells from the leukocyte-enrlched 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 weredetected 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#{176}/oof normal peripheral blood lymphocytes, 31.0 ± 6.9#{176}/oof lymph node, and 59.6 ± 13.2#{176}/o 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#{176}/obear the complement receptor. These results suggest that CLL preferentially affects B cells.