Characterization of anti-thyroglobulin factors in human serum.

Investigations in patients with thyroid disease led to the discovery of serum factors which react like antibodies with thyroglobulin-containing extracts of human thyroid gland (1, 2). These serum factors have been shown to be among the av-globulins (3). Pressman and colleagues (4) reported that the serum anti-thyroglobulin activity in one patient was associated with the y-macroglobulins. Korngold, Van Leeuwen and Brener (5), utilizing gel-diffusion immunochemical techniques, recently reported an additional instance of anti-thyroglobulin activity associated with a y-macroglobulin but found the activity in three other patients to be associated with the smaller 6.6S y-globulins. Roitt, Campbell and Doniach (3), using gel-diffusion techniques to characterize the thyroid antigens, obtained data that can be interpreted as showing that the antibodies in the sera tested were the smaller, probably 6.6S, y-globulins. Recent studies have emphasized that y-globulins should be regarded as an electrophoretic grouping of related but not identical proteins. They may be subdivided on the basis of size, hexose content and immunochemical properties into two major groups, the 6.6S and 18S y-globulins, with molecular weights of about 160,000 and 1,000,000, respectively (6-8). Many physiologic and pathologic antibody activities belong in one or the other or, in some instances, in both of these y-globulin fractions (9-11 ). In the present studies anion-exchange cellulose chromatography (12), which has proved to be particularly useful in y-globulin subfractionation, was combined with electrophoretic and ultracentrifugal procedures to characterize the anti-thyroglobulin factors found in seven sera. In five patients the anti-thyroglobulin reactivity was found associated with 6.6S y-globulins and in two cases, with both 18S and 6.6S y-globulins. METHODS