Increase of circulating CXCL9 and CXCL11 associated with euthyroid or subclinically hypothyroid autoimmune...

Recently, CXCL9 and CXCL11 have been shown to be involved in autoimmune thyroid disorders; however, no data are present about CXCL9 and CXCL11 circulating levels in thyroid autoimmunity.

Our objective was to evaluate circulating CXCL9 and CXCL11 in autoimmune thyroiditis (AIT). DESIGN AND PATIENTS OR OTHER PARTICIPANTS: Serum CXCL9 and CXCL11 have been measured in 141 consecutive patients with newly diagnosed AIT (AIT-p), 70 euthyroid controls, and 35 patients with nontoxic multinodular thyroid. The three groups were similar in gender distribution and age; among the AIT-p, 26% had subclinical hypothyroidism.

Serum CXCL9 and CXCL11 levels were significantly (P < 0.0001 for both) higher in AIT-p (143 ± 164 and 121 ± 63 pg/ml, respectively) than in controls (68 ± 37 and 65 ± 19 pg/ml, respectively) or patients with multinodular thyroid (87 ± 43 and 71 ± 20 pg/ml, respectively). Among AIT-p, CXCL9 and CXCL11 levels were significantly higher in patients older than 50 yr or those with a hypoechoic ultrasonographic pattern or with hypothyroidism. In a multiple linear regression model including age, thyroid volume, hypoechogenicity, hypervascularity, TSH, anti-thyroglobulin, and anti-thyroid peroxidase, only age and TSH were significantly (P < 0.05) related to serum CXCL9 or CXCL11 levels. In a multiple linear regression model of CXCL9 vs. age, TSH, and CXCL11, TSH (P = 0.032) and CXCL11 (P = 0.001) were significantly and independently related to CXCL9.

We first show that circulating CXCL9 and CXCL11 are increased in patients with thyroiditis and hypothyroidism and are related to each other. These results underline the importance of a Th1 immune attack in the initiation of AIT.