Quantitation of complement C3b and C3d surface receptors on neoplastic IgM positive B lymphocytes.

C3b and C3d complement receptors on the surface of mononuclear cells from blood, lymph nodes, and spleens were investigated in twenty-nine CLL patients and in eight patients with non-Hodgkin malignant lymphoma. Compared with a normal material, especially the lymphoid tissues but also the blood of the patients contained a high number of C3d receptor positive lymphocytes with a strong expression of C3d receptors per cell. The majority of the cells with high C3d receptor expression also had SmIgM. The number of C3b receptor positive cells was decreased in the patients but the C3b receptor expression per cell was normal.