Membrane receptor sites for the identification of lymphoreticular cells in benign and malignant conditions

The cells of the lymphoreticular system are heterogeneous both morphologically and functionally. The bone marrow derived (B) lymphocyte can be identified by the presence of easily detectable surface immunoglobulin and a receptor for antigen-antibody-complement (EAC) complexes. Monocytes and histiocytes also bear a receptor for EAC and in addition possess a receptor for cytophilic antibody detected with red cell--IgG complexes (IgGEA). In man, thymus derived (T) lymphocytes form non-immune rosettes with sheep red blood cells (E). We have examined a number of malignant lymphoreticular populations for the presence of the EAC, EA, and E receptors on suspensions of cells and have adapted the technique to demonstrate the EAC and EA receptors on frozen tissue sections. Rosetted malignant cells can also be cytologically examined on Millipore filters. The malignant cells both in section and suspension from the spleens and lymph nodes of 6 patients with nodular lymphoma bound EAC but not IgGEA or E; by these criteria these malignant cells are of B lymphocytic origin. The malignant cells from the spleens of 2 patients with leukaemic reticuloendotheliosis and 1 patient with malignant histiocytosis could be classified as being of histiocytic origin by the selective binding of IgGEA. In 3 cases of diffuse lymphocytic lymphoma the malignant cells bound only E and are therefore of T lymphocytic origin. The application of these techniques to the classification of malignant lymphoma may lead to important theoretical and therapeutic advances.