interleukin-8 and Goiter--Nodular

It has been shown that human thyrocytes can synthesize cytokines which activate T and B lymphocytes. These immune cells play important roles in the initiation and continuation of thyroid autoimmunity. The aim of this study was to estimate serum concentrations of soluble interleukin-6 receptor (sIL-6R), interleukin-6 (IL-6) and interleukin-8 (IL-8) in patients with Graves' disease (GD) (n=44, mean age 14.8 years), in patients with nontoxic nodular goiter (NTNG) (n=36, mean age 15.6 years) and in a group of healthy controls (n=20, mean age 14.5 years). ELISA was used to determine the concentration of cytokines, antithyroglobulin and antithyroid peroxidase antibodies in patients with thyroid disease. Radio receptor assay (RRA) was performed to detect anti-TSH receptor autoantibodies (TRAb). Serum levels of IL-6, sIL-6R and IL-8 were markedly elevated in patients with GD before treatment with methimazole (p<0.0001 for IL-6, p<0.006 for sIL-6R, p<0.004 for IL-8) and after 8 weeks of therapy (p<0.011 for IL-6, p<0.04 for IL-8). However, following 24 months of treatment, normal serum concentrations of these cytokines were restored. Furthermore, patients with NTNG showed a slightly elevated concentration of cytokines (IL-6, IL-8). Serum levels of tri-iodothyronine in patients with GD positively correlated with serum concentrations of IL-6 (r = 0.35, p<0.025) and sIL-6R (r = 0.31, p<0.047), while no correlation was found between thyroxine and cytokines. Moreover, we observed a positive correlation between serum levels of TPO-Abs, TRAb and IL-6 (r = 0.43, p<0.008; r = 0.5, p<0.003) and between TPO-Abs and IL-8 (r = 0.67, p<0.0001). However, in patients with NTNG no correlation was observed between serum levels of antithyroid antibodies or thyroid hormones and serum levels of cytokines. We conclude that the cytokines (IL-6, sIL-6R, IL-8) could play an important role in the development of Graves' disease and that their levels are modulated by thyreostatic treatment.

Topics: Adolescent; Antithyroid Agents; Autoantibodies; Child; Female; Goiter, Nodular; Graves Disease; Humans; Interleukin-6; Interleukin-8; Male; Methimazole; Receptors, Interleukin-6; Thyroid Gland; Thyroid Hormones; Thyroxine

Overproduction of thyroid hormones promotes bone resorption in vivo and in vitro, and we have evaluated whether mediators of such effects could include the osteotropic cytokines. Previous studies have demonstrated raised serum interleukin (IL)-6 in thyrotoxic patients, but differentiating the contribution of the elevated thyroid hormones from that of the autoimmune inflammation present in Graves' disease (GD) has been difficult. We undertook a longitudinal study of 34 patients (19-45 yr old) with GD, toxic nodular goiter (TNG), or a history of thyroid carcinoma but no evidence of disease recurrence, receiving sufficient T4 to suppress TSH. Controls were 12 euthyroid females. The following measurements were made basally and for 6 months after carbimazole treatment: serum free T4, T3, bone-specific alkaline phosphatase (b-ALP), IL-6, IL-8, IL-1beta, tumor necrosis factor-alpha, IL-11, and urinary deoxypyridinoline (Udpd). Compared with controls (IL-6, 1.1 +/- 0.3 ng/L; IL-8, 3.2 +/- 0.8 ng/L), untreated patients with GD and TNG had elevated IL-6 (GD, 7.11 +/- 0.88 ng/L; TNG, 7.30 +/- 0.77 ng/L; P < 0.001) and IL-8 (GD, 10.3 +/- 1.23 ng/L; TNG, 9.81 +/- 1.27 ng/L; P < 0.001). These levels fell after treatment and were then indistinguishable from those in control subjects. Thyroid carcinoma patients on TSH suppressive therapy also had significantly raised levels of IL-6 (2.5 +/- 0.42 ng/L) and IL-8 (4.4 +/- 0.63 ng/L). When data from all the patients were pooled, the levels of IL-6 and IL-8 correlated with serum T3 and free T4 but not with Udpd or b-ALP. IL-1beta, IL-11, and tumor necrosis factor-alpha were not raised in any patient. The elevations in serum IL-6 and -8 that occur in hyperthyroidism seem to result from the chronic effects of thyroid hormone excess rather than the accompanying autoimmune inflammatory condition produced by Graves' thyroid or eye disease. The site of the presumed increased production of IL-6 and -8 is most likely from bone osteoblasts, despite the inability of bone markers (such as Udpd and b-ALP) to correlate with acute changes in thyroid hormone status produced by antithyroid therapy.

Topics: Adult; Antithyroid Agents; Carbimazole; Cytokines; Female; Goiter, Nodular; Graves Disease; Humans; Hyperthyroidism; Interleukin-6; Interleukin-8; Longitudinal Studies; Male; Thyroid Neoplasms; Thyrotropin; Thyroxine; Triiodothyronine