Prevalence and impact of autoimmune thyroid disease on myasthenia gravis course

Abstract

ObjectivesAutoimmune thyroid diseases (ATDs) frequently accompany myasthenia gravis (MG) and may influence its course. We aimed to determine the association and impact of ATD with early‐ (<50 years), late‐onset MG, or thymoma‐MG.Materials and MethodsPrevalence of ATD was measured in a cross‐sectional study of 343 consecutive patients with MG (236 F, 107 M) aged 4–89 years; 83.8% were seropositive, in 2.9%, anti‐MuSK antibodies were detected. Concentrations of antithyroid peroxidase antibodies, antithyroglobulin antibodies, antithyrotropin receptor antibodies, and TSH level were measured in all patients. MG clinical course, treatment received, and treatment results were evaluated.ResultsAutoimmune thyroid diseases were diagnosed in 92 (26.8%) of MG patients including 4.4% with Graves (GD), 9% with Hashimoto thyroiditis (HT), and 13.4% with antithyroid antibodies only. GD patients had ocular symptoms more often than patients with antithyroid antibodies or HT (p = .008). ATD prevalence was comparable in MG with early and late onset, while non‐ATDs were more frequent in thymoma‐MG (p = .049). Immunosuppressive therapy was less frequently needed in the patients with MG and ATD, indirectly indicating milder MG course (p = .005). Risk of myasthenic crisis and the results of treatment did not differ between patients with and without ATD.ConclusionsAutoimmune thyroid diseases are frequently accompanied by early‐and late‐onset MG, while thymoma‐MG is related to higher risk of non‐ATD. Myasthenia coexisting with ATD follows milder course than MG alone.

Gender and quality of life in myasthenia gravis patients from the myasthenia gravis foundation of America registry

“…Thymectomy is associated with improved QOL in women, effectively eliminating the gender gap with men, regardless of whether the men had or had not undergone thymectomy. Autoimmune and treatment related comorbidities were commonly reported in this population, consistent with previous reports …”

“…For example, systemic lupus erythematosus was reported in 1.8% of our study population, while the prevalence in general population is less than 0.1% . A greater prevalence of other autoimmune diseases among MG has been well described . Autoimmune thyroid disease, systemic lupus erythematosus, and inflammatory bowel disease were more common in women, whereas type 1 diabetes mellitus and psoriasis were not, which is also consistent with the literature …”

Treatment outcome in juvenile‐onset myasthenia gravis

“…In our cohort, thyroid diseases were most common as previously reported. In our earlier study, MG accompanied by autoimmune thyroid disease had a milder course than MG alone . Ocular symptoms could not be attributed to thyroid disease in any of our patients.…”

“…The presence of concomitant diseases and MG is common, both in children and adults . It is of interest that such association does not worsen the prognosis.…”

Clinical Profile of Patients with Myasthenia Gravis in a Tertiary Center of Nepal

“…17 Although the association between MG and autoimmune thyroid disorders is still unclear, likelihood of genetic mechanism and sharing of similar epitopes have been postulated. 3,16 Some studies have postulated regarding the thyroid hormonal imbalance is likely in MG. 11,12 Muscle weakness and fatigability are the features of MG. Ocular involvement is usually seen in about 70-90% MG patients. 13,20 In our study, about 95% patients had drooping of eyelids or diplopia and 87% had restricted eye movements.…”