Th1 and Th2 Serum Cytokine Profiles Characterize Patients with Hashimoto's Thyroiditis (Th1) and Graves' Disease (Th2)

Objectives: The aim of this study was to document the pattern of immune response, assessed by the measurement of both Th1 and Th2 serum cytokines, in patients suffering from autoimmune thyroid disease and toxic nodular goiter.

Methods: Both Th1 and Th2 serum cytokine levels were assayed in patients suffering from Graves' disease (GD, n = 25), Hashimoto's thyroiditis (HT, n = 21), and toxic nodular goiter (TNG, n = 7) and compared with corresponding levels of 25 healthy controls. Serum concentrations of IL-2, IL-1 beta, INF-gamma, TNF-alpha, IL-12, IL-15, IL-10, IL-18, IL-4 and IL-5 were assayed in fasting serum samples.

Results: It was found that patients with HT had higher IL-2 serum levels (12.16 +/- 0.66 pg/ml) compared to patients with TNG (9.25 +/- 0.84 pg/ml), GD (7.86 +/- 0.30 pg/ml) and controls (7.36 +/- 0.45 pg/ml; p = 0.0001), higher INF-gamma levels (7.60 +/- 0.33 pg/ml) compared to patients with TNG (5.77 +/- 0.55 pg/ml), GD (5.74 +/- 0.24 pg/ml) and controls (5.09 +/- 0.27 pg/ml; p = 0.0009), higher IL-12 levels (3.57 +/- 0.19 pg/ml) compared to patients with TNG (2.57 +/- 0.21 pg/ml), GD (2.48 +/- 0.13 pg/ml) and controls (2.59 +/- 0.23 pg/ml; p = 0.004), and higher IL-18 levels (27.52 +/- 1.75 pg/ml) compared to patients with TNG (18.71 +/- 2.24 pg/ml), GD (15.44 +/- 1.39 pg/ml) and controls (15.16 +/- 1.62 pg/ml; p = 0.0002). In contrast, patients with GD had higher serum levels of IL-4 (4.11 +/- 0.33 pg/ml) compared to patients with HT (3.0 +/- 0.16; p = 0.02) and higher IL-5 levels (4.22 +/- 0.30 pg/ml) compared to patients with TNG (3.21 +/- 0.58 pg/ml), HT (2.75 +/- 0.16 pg/ml) and controls (2.0 +/- 0.19 pg/ml; p = 0.0001). Patients had lower IL-1 beta serum levels (TNG 2.45 +/- 0.20, HT 2.52 +/- 0.14, GD 2.68 +/- 0.12 pg/ml) compared to controls (3.6 +/- 0.20 pg/ml; p = 0.008).

Conclusions: The above findings suggest that a Th1 pattern of immune response characteristic of cellular immunity is dominant in HT, whereas the predominance of Th2 cytokines in GD indicates a humoral pattern of immune reaction.