Emerging pharmacotherapy for treatment of Graves' disease

Intraorbital Steroid Injection for Active Thyroid Ophthalmopathy

Purpose

To evaluate the effect of orbital steroid injections in patients with active thyroid ophthalmopathy resistant to or dependent on systemic steroids, or with complications related to systemic steroid use.

Methods

This prospective non-comparative case series includes 31 eyes of 17 patients with active thyroid ophthalmopathy and clinical activity score (CAS) of 3 or more, without compressive optic neuropathy or overt exposure keratopathy. All subjects had a history of previous systemic steroid use (with steroid resistance or dependence) or had developed complications related to steroids. A combination of steroids including triamcinolone acetonide 20 mg and dexamethasone 4 mg was injected in the upper and lower retroseptal orbital spaces three or four times at one-month intervals. The patients were examined periodically after each injection and at least three months after the last injection.

Results

Mean pre-injection CAS was 5.2 ± 1.3 which was improved to 1.6 ± 1 after the fourth injection (P< 0.001). Upper and lower lid retraction improved in 100% and 68.2% of the affected eyes, respectively. Strabismus completely resolved in one of five affected patients and the most significant improvement was observed in supraduction. Mean improvement in exophthalmos was 1.2 ± 1.1 mm. Visual acuity did not significantly change after the injections. Eyelid ecchymosis and/or subconjunctival hemorrhage was observed in 7.1% and intraocular pressure rise occurred in 8.8% of eyes.

Conclusion

Orbital steroid injections can be used for the treatment of active thyroid ophthalmopathy when the patient is resistant to or dependent on systemic steroids or has developed complications of systemic steroids.

Synthetic gene network restoring endogenous pituitary-thyroid feedback control in experimental Graves' disease

Graves' disease is an autoimmune disorder that causes hyperthyroidism because of autoantibodies that bind to the thyroid-stimulating hormone receptor (TSHR) on the thyroid gland, triggering thyroid hormone release. The physiological control of thyroid hormone homeostasis by the feedback loops involving the hypothalamus-pituitary-thyroid axis is disrupted by these stimulating autoantibodies. To reset the endogenous thyrotrophic feedback control, we designed a synthetic mammalian gene circuit that maintains thyroid hormone homeostasis by monitoring thyroid hormone levels and coordinating the expression of a thyroid-stimulating hormone receptor antagonist (TSHAntag), which competitively inhibits the binding of thyroid-stimulating hormone or the human autoantibody to TSHR. This synthetic control device consists of a synthetic thyroid-sensing receptor (TSR), a yeast Gal4 protein/human thyroid receptor-α fusion, which reversibly triggers expression of the TSHAntag gene from TSR-dependent promoters. In hyperthyroid mice, this synthetic circuit sensed pathological thyroid hormone levels and restored the thyrotrophic feedback control of the hypothalamus-pituitary-thyroid axis to euthyroid hormone levels. Therapeutic plug and play gene circuits that restore physiological feedback control in metabolic disorders foster advanced gene- and cell-based therapies.

Graves' Ophthalmopathy: VISA versus EUGOGO Classification, Assessment, and Management

Graves' ophthalmopathy (GO) is an autoimmune inflammatory disorder associated with thyroid disease which affects ocular and orbital tissues. GO follows a biphasic course in which an initial active phase of progression is followed by a subsequent partial regression and a static inactive phase. Although the majority of GO patients have a mild, self-limiting, and nonprogressive ocular involvement, about 3–7% of GO patients exhibit a severe sight-threatening form of the disease due to corneal exposure or compressive optic neuropathy. An appropriate assessment of both severity and activity of the disease warrants an adequate treatment. The VISA (vision, inflammation, strabismus, and appearance), and the European Group of Graves' Orbitopathy (EUGOGO) classifications are the two widely used grading systems conceived to assess the activity and severity of GO and guide the therapeutic decision making. A critical analysis of classification, assessment, and management systems is reported. A simplified “GO activity assessment checklist” for routine clinical practice is proposed. Current treatments are reviewed and management guidelines according to the severity and activity of the disease are provided. New treatment modalities such as specific monoclonal antibodies, TSH-R antagonists, and other immunomodulatory agents show a promising outcome for GO patients.

Rituximab in the Treatment of Thyroid Eye Disease: A Review

Graves disease is an autoimmune thyroid disease classically characterised by a clinical triad consisting of hyperthyroidism, diffuse goitre, and thyroid eye disease. Thyroid eye disease is an immunologically mediated condition in which humoral immunity is thought to play a central role. Thyroid eye disease is traditionally treated with high-dose glucocorticosteroids and surgical orbital decompression. However, responses are inadequate and alternative treatment options are needed. Rituximab, an anti-CD20 monoclonal antibody, shows promise as a novel therapeutic option for thyroid eye disease. There are 43 cases of thyroid eye disease treated with rituximab in the medical literature, and larger studies are warranted to determine the long-term effectiveness of rituximab. Rituximab may represent an attractive new treatment option for thyroid eye disease, especially in the case of disease that is refractory to current treatment strategies.

Diagnosis and management of Graves disease: a global overview

Graves disease is an autoimmune disorder characterized by goitre, hyperthyroidism and, in 25% of patients, Graves ophthalmopathy. The hyperthyroidism is caused by thyroid hypertrophy and stimulation of function, resulting from interaction of anti-TSH-receptor antibodies (TRAb) with the TSH receptor on thyroid follicular cells. Measurements of serum levels of TRAb and thyroid ultrasonography represent the most important diagnostic tests for Graves disease. Management of the condition currently relies on antithyroid drugs, which mainly inhibit thyroid hormone synthesis, or ablative treatments ((131)I-radiotherapy or thyroidectomy) that remove or decrease thyroid tissue. None of these treatments targets the disease process, and patients with treated Graves disease consequently experience either a high rate of recurrence, if receiving antithyroid drugs, or lifelong hypothyroidism, after ablative therapy. Geographical differences in the use of these therapies exist, partially owing to the availability of skilled thyroid surgeons and suitable nuclear medicine units. Novel agents that might act on the disease process are currently under evaluation in preclinical or clinical studies, but evidence of their efficacy and safety is lacking.

Graves' orbitopathy: imperfect treatments for a rare disease

Graves' orbitopathy (GO) is the most frequent and invalidating extrathyroidal expression of Graves' disease. Its incidence and prevalence are, however, low. About three quarters of Graves' patients have no GO at diagnosis, and moderate-to-severe and severe forms represent no more that 5-6% of cases. Progression to severe forms occurs rarely, but it may be caused by risk factors, the most important being smoking and poor control of thyroid dysfunction. Lot of progress has been recently achieved in the understanding of GO pathogenesis, while the disease remains a therapeutic challenge and dilemma. Common treatments for moderate-to-severe and active forms of GO (glucocorticoids and orbital radiotherapy) frequently provide incomplete responses and may be followed by relapse or progression of GO. After the disease has been inactivated by medical treatment, many patients need rehabilitative surgery for residual manifestations (orbital decompression for exophthalmos, squint surgery for extraocular muscle dysfunction, eyelid surgery for eyelid malposition). Novel pharmacological treatments are on the horizon and might target pathogenetic mechanisms of the disease better than glucocorticoids. Clinical evidence concerning their efficacy and safety is presently lacking.