Influence of methimazole and radioactive iodine treatment in the serum levels of the chemokine CXCL10 in hyperthyroid patients with Graves' disease.

The chemokine CXCL10 plays an important role in Graves' disease (GD); however, data regarding the effectiveness of therapy are contradictory. Serum CXCL10 levels in 31 hyperthyroid patients were measured before and after establishing euthyroidism: 16 newly diagnosed GD patients received methimazole (MMI), 15 relapsed GD patients were treated with radioactive iodine (RAI), and 18 healthy subjects served as a control group. Baseline serum CXCL10 levels were higher than in controls (MMI group 144.0 ± 48.24, RAI group 156.3 ± 71.81 and control 71.32 ± 26.03 pg/ml; p < 0.01). In the MMI group, serum CXCL10 levels decreased following euthyroidism at 6 months (76.51 ± 22.06 pg/ml; p < 0.01) and 12 (76.42 ± 34.07 pg/ml; p < 0.01). In the RAI group, serum CXCL10 levels decreased after 3, 6, 9, and 12 months of RAI administration (82.37 ± 55.01, 66.35 ± 48.62, 68.76 ± 28.87, and 74.94 ± 49.74 pg/ml, respectively; p < 0.05). Elevated serum TRAb levels in the MMI group (33.15 ± 30.84) decreased at 6 months (14.64 ± 16.57 IU/l; p = 0.0070), whereas in the RAI group (44.61 ± 60.66 IU/l) they increased to a peak level at 6 months (66.40 ± 104.2 IU/l; p = 0.003), which was significantly higher than those of the MMI group, but were decreased at 12 months (28.91 ± 35.13 IU/l). Serum CXCL10 levels correlated with FT3 (r = 0.48, p < 0.0001), FT4 (r = 0.47, p < 0.0001) and TRAb (r = 0.37, p = 0.0014). In conclusion, these data show a relationship between serum CXCL10 and GD activity and suggest that a more complex mechanism is involved in the generation of the thyroid auto-antibodies TPOAb and TRAb.