Alemtuzumab-Induced Thyroid Eye Disease: A Comprehensive Case Series and Review of the Literature

Understanding the clinical and molecular basis of thyroid orbitopathy: a review of recent evidence

Thyroid eye disease (TED) is an autoimmune orbital inflammatory disease which ranges from mild to severe. Tissue remodeling, fibrosis and fat proliferation cause changes in the orbital tissues which can affect esthetics and visual function. In its severe form, it is sight threatening, debilitating, and disfiguring and may lead to social stigma, the embarrassment about which has an impact on the quality of life of those affected and the family members. The pathogenesis of TED, which is influenced by genetic, immunological, and environmental factors, is complex and not fully elucidated. However, it remains unknown what factors determine the severity of the disease. Recent research has revealed a number of diagnostic and prognostic biomarkers of this disease. In this overview of TED, we focus on new insights and perspectives regarding biological agents that may provide a basis for new treatment modalities.

Prevalence, Risk Factors, and Clinical and Biochemical Characteristics of Alemtuzumab-Induced Graves Disease

OBJECTIVE

Atypical Graves disease (GD) is a common complication in multiple sclerosis (MS) patients treated with alemtuzumab. We present epidemiological, clinical, and biochemical characteristics of alemtuzumab-induced GD.

METHODS

Retrospective follow-up study of MS patients treated with alemtuzumab from 2014 to 2020, including clinical course of GD, pregnancy outcome, and thyroid eye disease (TED).

RESULTS

We enrolled 183 of 203 patients (90%, 68% women) treated with alemtuzumab at 4 hospitals in Norway. Seventy-five (41%) developed thyroid dysfunction, of whom 58 (77%) had GD. Median time from the first dose of alemtuzumab to GD diagnosis was 25 months (range, 0-64). Twenty-four of 58 GD patients (41%) had alternating phases of hyper- and hypothyroidism. Thyrotropin receptor antibodies became undetectable in 23 of 58 (40%) and they could discontinue antithyroid drug treatment after a median of 22 (range, 2-58) months. Conversely, 26 (44%) had active disease during a median follow-up of 39 months (range, 11-72). Two patients (3%) received definitive treatment with radioiodine, 6 (10%) with thyroidectomy. Nine developed TED (16%), 7 had mild and 2 moderate to severe disease. Four patients completed pregnancy, all without maternal or fetal complications. Patients who developed GD had a lower frequency of new MS relapses and MRI lesions than those without.

CONCLUSION

GD is a very common complication of alemtuzumab treatment and is characterized by alternating hyper- and hypothyroidism. Both remission rates and the prevalence of TED were lower than those reported for conventional GD. Pregnancies were uncomplicated and GD was associated with a lower risk of subsequent MS activity.

Alemtuzumab induces severe orbitopathy in relapsing-remitting multiple sclerosis

CONTEXT

Treatment with Alemtuzumab (ALZ) in patients with Relapsing-Remitting Multiple Sclerosis (RRMS) is associated with the development of ALZ-induced Graves' disease (GD-ALZ). Some cases may develop associated Graves´ Orbitopathy (GO-ALZ), with possible visual compromise.

AIM

The aim of this study was to describe the main clinical and biochemical characteristics of GD-ALZ, as well as the clinical course of a case series of GO-ALZ METHODS: This study is a retrospective observational study, carried out in a reference hospital for the care of patients with RRMS in Spain. Cases treated with ALZ in the period 2014-2022 were included. GO-ALZ cases were identified among those with clinical symptoms compatible with thyroid eye disease after initiating ALZ treatment.

RESULTS

A total of 135 cases, with a mean follow-up of 69.6 months after the first ALZ cycle, were included. The incidence of GD-ALZ was 32.6% (44/135), with a predominance of women (77.3%) and mean age of 41.9 years. The presence of first-degree relatives with hypothyroidism was identified as risk factor for the development of GD-ALZ (adjusted P-value: 0.02). GO-ALZ was diagnosed in 6 cases (incidence: 13.6%), of which 3 had severe clinical forms of GO, requiring anti-IL-6 treatment. A favorable response was reported in all of them, with a significant decrease in disease activity and improvement in proptosis.

CONCLUSIONS

We report one of the largest cohorts of GD-ALZ and GO-ALZ cases. The diagnosis of these entities should be taken into account in patients treated with Alemtuzumab, given the risk of developing severe clinical forms. In moderate-severe forms of GO-ALZ, drugs with anti-IL-6 activity are a safe and effective option.

Fibrocyte Participation in Thyroid-Associated Ophthalmopathy Suggests New Approaches to Therapy

PURPOSE

Review the historical context of research and changing therapeutic landscape of thyroid-associated ophthalmopathy (TAO) by focusing on the relationship between TAO, CD34+ fibrocytes, thyrotropin receptor (TSHR), and insulin-like growth factor-I receptor (IGF-IR).

METHODS

A literature review using search terms, including fibrocytes, IGF-IR, TSHR, TAO, and thyroid eye disease.

RESULTS

The mechanisms involved in TAO have been partially identified. Substantial progress has been made over several decades, including 1) recognizing the interplay between the professional immune system and orbital tissues; 2) TSHR and IGF-IR act interdependently in mediating the pathogenesis of TAO; 3) Multiple cytokines and specific immune cells are involved in activating and remodeling orbital tissue; 4) Recognition of these mechanisms is allowing the development of target therapies such as teprotumumab, a monoclonal antibody IGF-IR inhibitor approved by the US Food and drug administration for treatment of TAO; and 5) It appears that teprotumumab acts on the systemic immune system peripheral to the orbit.

CONCLUSION

Additional molecules targeting IGF-IR and other plausible disease mechanisms are currently under development. This activity in the TAO therapeutic space portends even greater improvements in patient care.