Acute-phase response after radioiodine treatment in hyperthyroidism

Purpose: Acute-phase response is an innate body defense seen during acute illnesses and involving the increased production of certain blood proteins termed acute-phase proteins. There are limited data about acute-phase response after radioiodine therapy. This study is designed to determine whether acute-phase response changes after radioiodine therapy. Materials and Methods: Twenty-six hyperthyroid patients were included in this study, aged between 25 and 69 years (mean, 47.7 +/- 10.5, 18 females and 8 males). All patients were given radioiodine therapy (8-15 mCi). Leukocyte, hemoglobin, platelet, erythrocyte sedimentation rate, and C-reactive protein (CRP) were measured before radioiodine therapy and after 24 hours, 72 hours, 1 week, 1 month, and 3 months. Free T3, free T4, TSH, thyroglobulin (Tg), antithyroid antibody, and antimicrosomal antibody (AMA) were measured before radioiodine therapy and after 1 and 3 months. Results: Mean CRP levels were 3.74, 3.90, 4.29, 5.71, 3.85, and 5.41 mg/L, respectively. There was a significant difference between the initial and the first-week results. Mean Tg levels were 68.15, 143.90, and 77.00 ng/mL, respectively, with a significant difference between the initial and the first-month and third-month results. Mean AMA levels were 158.80, 178.85, and 636.25 IU/mL, respectively, demonstrating a significant difference between the initial and the third-month and first- and third-month results. Conclusion: We have shown that radioiodine therapy causes an increase in CRP, Tg, and AMA levels. We conclude that radioiodine treatment is a cause of the increase in the CRP, Tg, and AMA levels in hyperthyroid patients.