The efficacy of immunosuppressive treatment of Graves’ orbitopathy is not affected by previous anti-thyroid drugs or by radioiodine therapy of Graves’ disease

Abstract

Introduction: We studied the efficacy of immunosuppressive treatment of GO in a group of patients who had been treated with antithyroid drugs (the ATD group) and in another group that had undergone radioiodine therapy (the 131-I group).

Material and methods: A total of 214 patients with exacerbation of GO were studied; the ATD group consisting of 168 patients, and the 131-I group consisting of 46 patients. All patients were treated with methylprednisolone IV pulses (total dose 8.0 g) followed by orbital irradiation (20 Gy in 10 fractions). CAS and IO indices, TSH, fT4, and TRAb levels were evaluated prior to, and 1, 6, and 12 months after treatment.

Results: One month after treatment the CAS index decreased significantly in both groups, against values before treatment, p < 0.05. In the ATD group the median level of TRAb-0 before treatment was 5.6 IU/L (min = 0.1; max = 114.0), and 12 months later (TRAb-12) it was 1.4 IU/L (min = 0.1; max = 75.3) (p < 0.05). In the 131-I group the median level of TRAb-0 was 14.3 IU/L (min = 0.6; max = 90.0) vs. TRAb-12 of 3.65 IU/L (min = 0.1; max = 41.0) (p < 0.05). In the ATD group the median value of IO-0 before treatment was 5.0 (min = 1.0; max = 12.0) vs. IO-12 of 2.0 (min = 0.0; max = 8.0) (p < 0.05). In the 131-I group the median value of IO-0 was 5.0 (min = 2.0; max = 9.0) vs. IO-12 of 2.0 (min = 0.0; max = 6.0) (p < 0.05).

Conclusions: The severity of GO in the ATD and 131-I groups did not differ significantly over the course of observation despite differences noted in their TRAb levels. The efficacy of GO treatment did not differ between these groups. (Endokrynol Pol 2016; 67 (6): 554–561)