Changes in the Con-A-induced redistribution pattern of lymphocytes: a possible aid in the differential diagnosis between malignant lymphoma and other diseases.

Lymphocytes isolated from the peripheral blood of healthy individuals and of patients with nonmalignant and malignant disorders were studied for redistribution of concanavalin A (Con-A) receptors after ligand contact. Upon ligand contact. Con-A receptors are redistributed in the plane of the membrane and can form a cap at one part of the cell surface. Redistribution of Con-A surface receptors was determined by the cap-forming ability after binding of fluorescent Con-A. The present studies were performed on lymphocytes from 328 patients with malignant lymphomas, 1 03 patients with chronic Iymphocytic leukemia (CLL). 92 healthy individuals, 1 63 patients with nonmalignant disorders. and 32 patients with carcinomas. The results show a marked reduction in the cap-forming ability of lymphocytes from patients with malignant lymphoma and CLI (mean value 9.9%) as compared with lymphocytes from healthy individuals and from patients with nonmalignant disorders or carcinoma (mean value 22.8%). Lymphocytes isolated from lymphoma patients during remission stages of the disease exhibited an intermediate level of cap-forming ability (16%-20%). The present results that concur with previous observations show that normal lymphocytes and lymphocytes from patients with nonmalignant disorders are characterized by a high degree of mobility of Con-A receptors. whereas lymphocytes from patients with malignant Iymphoma and CLI are characterized by a low mobility of Con-A receptors. We suggest the Con-A cap-forming ability test may be useful as an aid in the differential diagnosis between malignant lymphomas and nonmalignant disorders.