title: Prevalence and impact of autoimmune thyroid disease on myasthenia gravis course.
abstract: OBJECTIVE
  Autoimmune 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.
  
  
  METHODS
  Prevalence 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.
  
  
  RESULTS
  Autoimmune 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.
  
  
  CONCLUSIONS
  Autoimmune 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.
authors: Department of Neurology Medical University of Warsaw Warsaw Poland.
authors: Justyna
authors: J
authors: Kubiszewska
authors: Department of Neurology Medical University of Warsaw Warsaw Poland.
authors: Beata
authors: B
authors: Szyluk
authors: Department of Neurology Medical University of Warsaw Warsaw Poland.
authors: Piotr
authors: P
authors: Szczudlik
authors: Department of Internal Medicine and Endocrinology Medical University of Warsaw Warsaw Poland.
authors: Zbigniew
authors: Z
authors: Bartoszewicz
authors: Department of Immunology, Biochemistry and Nutrition Medical University of Warsaw Warsaw Poland.
authors: Małgorzata
authors: M
authors: Dutkiewicz
authors: Department of Psychology SWPS University of Social Sciences and Humanities Warsaw Poland.
authors: Maksymilian
authors: M
authors: Bielecki
authors: Department of Internal Medicine and Endocrinology Medical University of Warsaw Warsaw Poland.
authors: Tomasz
authors: T
authors: Bednarczuk
authors: Department of Neurology Medical University of Warsaw Warsaw Poland.
authors: Anna
authors: A
authors: Kostera-Pruszczyk
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology / Q000628:therapy; D015995:Prevalence; D012720:Severity of Illness Index; D013959:Thyroid Diseases / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology / Q000628:therapy; D055815:Young Adult
chemical_list: D001323:Autoantibodies
keywords: Graves’ disease; Hashimoto's thyroiditis; autoimmune thyroid diseases; myasthenia gravis