Soluble interleukin-2 receptor is a thyroid hormone-dependent early-response marker in the treatment of thyrotoxicosis.
Thyrotoxic patients exhibit increased levels of immune activation molecules (soluble interleukin-2 receptor [sIL-2R], intercellular adhesion molecule-1 [ICAM-1], and endothelial-leukocyte adhesion molecule-1 [ELAM-1]) in serum, although the clinical significance of these measurements remains unclear. In a randomized 4-week study, we have recently shown that in the treatment of hyperthyroidism, the combination of cholestyramine and methimazole (MMI) resulted in faster lowering of serum thyroid-hormone levels than did MMI alone. Stored serial serum samples from patients participating in this randomized treatment trial were analyzed for sIL-2R, soluble ICAM-1 (sICAM-1), and soluble ELAM-1 (sELAM-1). The levels of all three molecules were elevated in patients with hyperthyroidism. Although the levels of sICAM-1 and sELAM-1 remained elevated through the 4-week follow-up period in both groups of patients, the sIL-2R levels (normal levels, 1.0 to 4.2 ng/ml) decreased significantly in the 10 patients who received cholestyramine in addition to MMI (week 0, 14.2 +/- 1.5 ng/ml; week 2, 10.8 +/- 1.2 ng/ml; week 4, 8.9 +/- 1.5 ng/ml). In eight patients who received MMI alone, sIL-2R decreased less rapidly (week 0, 12.3 +/- 1.4 ng/ml; week 2, 12.3 +/- 1.3 ng/ml; week 4, 10.9 +/- 1.3 ng/ml). sICAM-1 and sELAM-1 were elevated at baseline but did not decrease during therapy. In the former group, free thyroxine and free triiodothyronine decreased faster. These data show that levels of sIL-2R in serum, but not those of sICAM-1 and sELAM-1, may be of clinical use in the early follow-up evaluation of medically treated patients.
Smallridge
R C
RC
Endocrinology Division, Mayo Clinic Jacksonville, Florida 32224, USA.
Tsokos
G C
GC
Burman
K D
KD
Porter
L
L
Cranston
T
T
Sfikakis
P P
PP
Solomon
B L
BL
D013956:Antithyroid Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D002792:Cholestyramine Resin / Q000627:therapeutic use; D019040:E-Selectin / Q000097:blood; D005260:Female; D006111:Graves Disease / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D015999:Multivariate Analysis; D016032:Randomized Controlled Trials as Topic; D015375:Receptors, Interleukin-2 / Q000097:blood*; D013963:Thyroid Hormones / Q000097:blood; D013971:Thyrotoxicosis / Q000097:blood* / Q000188:drug therapy
D013956:Antithyroid Agents; D015415:Biomarkers; D019040:E-Selectin; D015375:Receptors, Interleukin-2; D013963:Thyroid Hormones; D002792:Cholestyramine Resin; D018799:Intercellular Adhesion Molecule-1; D008713:Methimazole