Abstract
Interactions between antiserum (rabbit anti-human normal thyroglobulin-serum) and human thyroglobulin preparations (obtained from the tissues of the normal thyroid gland, thyroid adenoma, and carcinoma) were compared by inhibition effect with the binding between 131I-labeled standard thyroglobulin and antiserum, set up by a double antibody RIA.
Thyroglobulins isolated from normal glands (designated as Nor-Tg) have a high affinity to the antiserum. In contrast, thyroglobulins in follicular adenoma or adenomatous goiter (designated as Ad-Tg) decrease the potency of the affinity to the antiserum. Furthermore, thyroglobulins in papillary or follicular carcinoma (designated as Ca-Tg) markedly decrease such a potency. With the t-test, the inhibition curves of Nor-Tgs are almost parallel to each other. Most of the inhibition curves of Ad-Tgs and Ca-Tgs are not parallel to the curve of Nor-Tg (1) (P-value for non-parallelism?0.05).
Therefore, it seems that Tg preparations obtained from tumor tissue are heterogeneous in terms of specificity and/or affinity to antiserum, judging from the results of the nonparallel inhibition curves. The present results also show that the contribution of iodine content in Tg has little or no effect on the nature of Tg-immunogenecity.
