Serum-soluble interleukin-2 receptor levels before and after surgical treatment for Graves' disease

Serum-soluble interleukin-2 receptor (ssIL-2R) is released from its specific affinity membrane receptor on activated T lymphocytes and is detected as a form of the alpha-chain of IL-2R in the peripheral blood. We measured the ssIL-2R levels by enzyme-linked immunosorbent assay in 29 healthy subjects and 39 patients with Graves' disease who were given antithyroid drugs to prepare them for surgical treatment. The preoperative ssIL-2R levels in Graves' patients were significantly higher than those in the healthy controls (681 +/- 387 vs 369 +/- 149 U/ml); in particular, the preoperative levels in hyperthyroid patients were significantly higher than those in euthyroid patients. On the 5th day after thyroid resection, their ssIL-2R levels (560 +/- 296 U/ml) were significantly lower than the preoperative levels. There were no correlations between the preoperative ssIL-2R levels and the immunological parameters such as thyroglobulin antibody, microsomal antibody, and thyroid-stimulating hormone receptor antibody. Thus, we conclude that ssIL-2R levels can be decreased by surgical resection of goiter in Graves' patients whose hyperthyroid status does not respond to the administration of antithyroid drugs, and this may be a useful indicator of immunological status after surgical treatment of Graves' disease.