Serum levels of the cytokines IL-1β, IL-6 and ICAM-1 after 131I-treatment of Graves' disease and nodular goiter

Cytokines might be involved in the immunological flare up, seen in some patients after I-131-treatment. Therefore, we measured serum levels of interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta), interleukin-6 soluble receptor (IL-6sR) and Intercellular-adhesion-molecule-1 (ICAM-1) as well as tumor necrosis factor (TNF-alpha) after I-131-treatment of Graves' disease and nodular goiter. Seven patients with Craves' disease, eight with toxic nodular goiter and seven with non-toxic nodular goiter, were followed after I-131-treatment. The patients were treated in the euthyroid state. Blood samples were drawn at day 0, 4, 7, 21 and after 3 months. Significant increases were seen in free T-4 index (FT4II), free T-3 index (FT3I) and thyroglobulin (Tg) within the first weeks, and TSH simultaneously decreased. None of the cytokines demonstrated any change during follow-up, neither in the entire group nor in subgroups. FT4I and FT3I correlated significantly to ICAM-1. In conclusion, our data suggest that there does not seem to be prolonged cytokine activation after I-131-treatment for thyroid disorders.