EFFECT OF RADIOIODINE ON STIMULATORY ACTIVITY OF GRAVES’IMMUNOGLOBULINS

Abstract

The effects of 131I therapy on the activity of thyroid stimulating antibody (TSAb) and TSH binding inhibiting Ig (TBII) in 19 patients with Graves'' disease were studied. Prior to 131I administration TSAb was detected in 84%, and TBII in 68% of patients. Following 131I administration TSAb and TBII were detectable in 100% of patients. The elevation 3 mo. after treatment of the means of both the TSAb and TBII indices for the group of 19 patients was highly significant compared with pretreatment values. All the patients went into remission during the course of the study and the TSAb index declined in all patients, becoming undetectable in 11; TBII also declined in most patients but remained detectable in 13. The study furthermore afforded the opportunity for a direct comparison of binding with stimulatory activity. After 131I therapy for Graves'' hyperthyroidism there is a transient increase in TSAb as well as TBII, followed by a decline. The measurement of binding and stimulatory activities are in good general agreement.