Both Th1-and Th2-derived cytokines in serum are elevated in Graves' ophthalmopathy

Increased serum cytokine levels have been reported in patients with autoimm une thyroid disease, but less is known about their levels in patients with Graves' ophthalmopathy (GO). It is not known whether GO is a cell-mediated or humoral autoimmune disease. We investigated whether serum cytokines are elevated in GO patients and whether the cytokines were Th1- or Th2-derived. In addition, elevated cytokines might reflect the activity of GO, and thus we investigated whether cytokine levels could predict the clinical respons e to orbital radiotherapy. We studied 62 consecutive patients with moderate ly severe untreated GO and 62 healthy controls, matched for sex, age and sm oking habits. Serum concentrations of IL-1RA, sIL-2R, IL-6, sIL-6R, tumour necrosis factor-alpha (TNF-alpha) RI and II and sCD30 were measured using h ighly sensitive ELISAs, in the patients before and 3 and 6 months after rad iotherapy. All patients were euthyroid, with anti-thyroid drugs, before and during the entire study period. All baseline cytokine and cytokine recepto r levels were significantly elevated in GO patients compared with healthy c ontrols, except for IL-1RA. The levels did not correlate with parameters of the thyroid disease, nor with the duration, activity or severity of GO. Ho wever, backward logistic regression analysis showed that IL-6, sCD30 and TN F alpha RI were able to predict a beneficial response to orbital radiothera py. We therefore conclude that both Th1- and Th2-derived cytokines are elev ated in GO patients compared with its controls. IL-6, sCD30 and TNF alpha R I had some value for predicting therapeutic outcome to orbital irradiation, and may thus reflect active eye disease.