Endocrine Abstracts

Background: Thyroid eye disease (TED) is an autoimmune inflammatory disease that can be both disfiguring and potentially sight threatening. Suppression of inflammation in active disease can reduce the risk of visual loss and limit long-term sequelae of the disease. Current disease management involves suppression of inflammation using glucocorticoids. The aim of our study was to evaluate the efficacy of early disease intervention with targeted immunomodulatory therapy to alter the disease course. This paper reports the efficacy of low dose rituximab in reducing clinical activity in TED in a small population.

Methods: A retrospective audit of consecutive patients with active TED at the Oxford Joint Thyroid Clinic (Ox-TED) managed primarily with rituximab. Patients with a VISA clinical activity score of three or more were considered to have active disease and were included in the study. Exclusion criteria included age less than 18 years, pregnancy or breastfeeding, a previous adverse reaction to rituximab, active infection, immunocompromised state or positive HIV or hepatitis serology. All patients were treated with a 100 mg rituximab infusion and 500 mg IV methylprednisolone. Further glucocorticoid or steroid sparing agents were given if clinically indicated. VISA clinical activity score, VISA overall severity score and Oxford Quality of Life score were recorded at baseline and subsequent follow-up visits. TSH receptor antibody (TRAb) levels and B cell subsets were recorded at baseline and following treatment. Any adverse reactions were documented.

Results: Twelve patients were followed up for an average of 6.3 months (1–12 months). VISA clinical activity scores significantly decreased from baseline to most recent follow up (4.69–1.58, P<0.001). VISA overall severity scores significantly reduced by 50% from 12 to 6, P<0.001. The average cumulative dose of IV methylprednisolone was 2.25 g, half the cumulative dose recommended by EUGOGO for patients with moderate to severe active TED. Rituximab induced a significant depletion in B-cells (CD19⁺), n=11, P<0.001. In those patients with markedly elevated serum TRAb levels >2.5 IU/L (n=7) two reduced to moderate levels (0.5–2.5 IU/l) and five remained markedly elevated. A transient infusion related rash was the only adverse effect noted in four patients. QOL scores did not differ markedly before and after treatment.

Conclusion: Low dose rituximab is an efficacious, well-tolerated and safe treatment for active TED; reducing disease activity and allowing reduced administration of systemic steroid.