IMMUNE ACTIVITY AND SERUM INTERLEUKIN-2 R ECEPTOR CONCENTRATION IN AUTOIMMUNE THYROID-DISEASES

Serum interleukin-2 receptor (IL-2R) concentrations were compared in 5 5 patients with thyrotoxicosis (14 men, 41 women, mean age 43.5 +/- 17 years), 18 patients with Hashimoto's thyroiditis (5 men, 13 women, me an age 47 +/- 15 years) and 28 healthy subjects (12 men, 16 women, mea n age 30 +/- 10 years). The patients with thyrotoxicosis were divided into three groups depending on the activity or stage of the disease: 1 7 patients with florid untreated hyperthyroidism, 23 euthyroid patient s receiving treatment with antithyroid drugs and 15 patients with thyr otoxicosis in remission after completing one year's antithyroid treatm ent. The patients with untreated thyrotoxicosis had significantly high er IL-2R values than the euthyroid patients receiving treatment or tho se in remission (207 +/- 112 vs 139 +/- 66 and 91 +/- 26 U/ml, P < 0.0 5 and P < 0.01). The IL-2R values of patients with thyrotoxicosis in r emission were, however, significantly lower than those of the 28 healt hy subjects (126 +/- 34 U/l; P < 0.01) or the euthyroid patients recei ving treatment (P < 0.05). The 18 patients with Hashimoto's thyroiditi s had significantly lower serum IL-2R values (70 +/- 39 U/ml) than the healthy controls. These data show that the serum IL-2R level depends on the state of thyroid metabolism and on the activity phase of the th yrotoxicosis. The low serum levels of IL-2R in patients with Hashimoto 's thyroiditis could signify a genetically determined decrease in IL-2 R production or might be linked with the destruction of thyroid tissue by the chronic autoimmune process.