Thyroid Autoantibodies as a Useful Guideline in Hyperthyroidism Patients Treated with Radioactive Iodine

Abstract

Zena A. Khalaf, Hameed M. Jasim, Satar M. Kadam, Ali A. Mahdi

Background: Several investigations are commonly used in the clinical practice to investigate a patient with hyperthyroidism, including measurement of thyroid autoantibodies (TPO-Ab, TG-Ab, ANA, and dsDNA antibodies).
Methods: Fifty-two hyperthyroidism patients (Graves' disease and Toxic multinodular goiter) and 21 normal healthy volunteers were included in this study. Thyroid antibodies were measured before and after one and four months of radioactive iodine (RAI-131). Treatment success and recovery of patients administer either 10mCi or 20mCi of RAI-131 was analyzed according to clinical data.
Results: A significantly increase in serum levels of TPO-Ab, TG-Ab, ANA antibodies were detected in hyperthyroidism patients before treatment with RAI-131, while a normal levels of dsDSA antibodies was noticed in those patients compared with normal health controls. Serum levels of TPO-Ab, TG-Ab, and ANA antibodies were increased after one month of treatment with RAI-131 (either dose 10 or 20mCi). After four months of radiotherapy, levels of TPO-Ab and TG-Ab antibodies were still increased except a decrease in their levels in GD patient administered the dose 20mCi, while the levels of ANA antibodies were decreased significantly in hyperthyroidism patients treated with RAI-131 except an increase in TMNG patients administered dose 20mCi. On the other hand, serum levels of double-stranded DNA (dsDSA) antibodies were increased significantly in GD patients administered either dose 10 or 20mCi of radioiodine, and TMNG patients administered dose 20mCi.
Conclusion: Successful RAI-131 therapy for hyperthyroidism with 10-20mCi dose can be achieved with decline in thyroid antibodies, ANA and dsDSA.