A Study on the Combined Use of Tocilizumab and Flupentixol-Melitracen in the Treatment of Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a serious, progressive, vision-threatening autoimmune disease with an incidence rate of about 19-42 per 100,000. Currently, it ranks first among orbital diseases and is one of the primary causes of blindness. The extensive involvement of intraorbital tissues and the significant variability in the course of moderate to severe active TAO make its treatment outcomes uncertain, classifying it as refractory thyroid-associated ophthalmopathy. The pathogenesis of TAO has not been fully elucidated; however, activation of the thyrotropin receptor (TSHR) and insulin-like growth factor receptor-1 (IGF-1R) complex is considered a critical step in TAO, leading to abnormal immune proliferation responses within the orbit, causing hypertrophy of extraocular muscles and increased orbital fat tissue. These changes result in various clinical manifestations such as exophthalmos, diplopia, pain, and compressive optic neuropathy. Intravenous glucocorticoid therapy is recommended as the first-line treatment by guidelines, yet this treatment often leads to numerous side effects (including Cushing's facies, elevated blood pressure, glucose, and lipid levels, osteoporosis, urinary tract infections, peptic ulcers, etc.), and many patients with moderate to severe active TAO do not show significant improvement in ocular symptoms (such as impairment of eye movement, blurred vision, diplopia, etc.). Therefore, scholars at home and abroad have been committed to finding new effective treatments for refractory TAO. Biological agents represent emerging therapies for TAO, with domestic and international multicenter randomized controlled trials confirming that tocilizumab is effective in treating TAO and can be considered as a second-line treatment option for moderate to severe active TAO. Tocilizumab is a monoclonal antibody against the IL-6 receptor. Interleukin-6 (IL-6) can activate T cells and B cells and produce TSHR-stimulating immunoglobulins, and it can also directly act on preadipocytes in the orbit to promote adipose hyperplasia. Tocilizumab reduces memory B cell and immunoglobulin levels, thereby improving eye movements and clinical activity scores (CAS), and enhancing quality of life scores.

Most TAO patients exhibit proptosis, and severe cases may develop incomplete eyelid closure, resulting in exposure keratitis, corneal ulcers, and significant eye pain, photophobia, and lacrimation. Changes in appearance due to TAO and even potential blindness can cause patients to experience significant psychological stress, leading to feelings of inferiority, anxiety, depression, and other negative emotions. Additionally, patients with coexisting hyperthyroidism may exhibit irritability, insomnia, anger, and other emotional reactions. Studies have shown that serum and tear fluid IL-6 levels are elevated in TAO patients, which are hormone factors related to behavioral and emotional changes and can influence emotional regulation, including anxiety modulation, by acting on the brain. Moreover, neurogenic inflammation is considered part of the psychosomatic pathogenic mechanism of TAO. Under conditions of prolonged anxiety and psychological stress, TAO patients release norepinephrine from primary neurons, generating neurogenic inflammation, and enhance the pro-inflammatory effects of platelets and leukocytes. Anxiety and depression levels in TAO patients are higher than those in other chronic diseases, increasing the risk of unnatural deaths, including suicide, thus impacting public health. Several studies indicate that TAO significantly affects patients' quality of life, including reduced participation in daily activities and poorer emotional health, and adverse emotions like anxiety and depression might exacerbate the condition and affect prognosis.

Therefore, while treating the symptoms of thyroid-associated eye disease, attention should also be paid to the varying degrees of negative psychology experienced by these patients, necessitating enhanced psychological interventions for them. We hypothesize that in refractory TAO patients with anxiety, combined treatment with Flupentixol Melitracen might help alleviate anxiety and depressive moods, improve quality of life, facilitate treatment, and improve ocular prognosis. This clinical study aims to evaluate the efficacy of tocilizumab (Actemra) in combination with Flupentixol Melitracen (Lepan) in the treatment of refractory thyroid-associated ophthalmopathy.