Possible Sites of Macroglobulin Synthesis: A Study Made With Fluorescent Antibody

Summary This paper describes experiments on the localization of macroglobulins by the fluorescent antibody technique in the tissues of two patients, one showing Mikulicz's syndrome and the other suffering from myeloma. The first patient had the macroglobulin in large quantities in mature and immature plasma cells in the bone marrow. It was considered that the macroglobulin was a product of a plasmacytosis reactive to the pathological process in the patient's parotid gland. The second patient had both a macroglobulin and a myeloma globulin in his serum. The fluorescent antibody studies suggested that these two abnormal proteins originated in different plasma cells in the bone marrow, which were, however, morphologically identical with orthodox staining. Neither protein could be demonstrated in frozen sections of other tissues obtained at autopsy.