title: Acetylcholine receptor antibodies in myasthenia gravis are associated with greater risk of diabetes and thyroid disease.
abstract: OBJECTIVE
  Myasthenia gravis (MG) may be associated with the presence of acetylcholine receptor antibodies (AChRAb) [seropositive MG (SPMG)] or their absence [seronegative MG (SNMG)]. Along with features of MG, the presence of the AChRAb may relate to the existence of other immune-mediated diseases. We sought to determine the association of SPMG with other potential autoimmune diseases.
  
  
  METHODS
  A retrospective evaluation of prospectively identified MG patients at a tertiary care center was performed, with patients separated into SPMG and SNMG. Prevalence of other immune-mediated disorders, as well as the epidemiology, sensitivity of diagnostic testing, and thymic pathology, was contrasted between both patient groups.
  
  
  RESULTS
  Of the 109 MG patients identified, 66% were SPMG. SPMG was associated with a greater likelihood of significant repetitive stimulation decrement, the presence of either thymoma or thymic hyperplasia, and the presence of thyroid disease. In addition, all patients with a diagnosis of diabetes, concurrent with MG, were found to be SPMG.
  
  
  CONCLUSIONS
  AChRAb and SPMG impart not only a distinctive clinical and electrophysiological phenotype of MG, but are also associated with the heightened presence of endocrinological disease.
authors.affiliation: Department of Clinical Neurosciences, University of Calgary and the Calgary Health Region, Calgary, Alberta, Canada. corytoth@shaw.ca
authors.forename: C
authors.initials: C
authors.lastname: Toth
authors.forename: D
authors.initials: D
authors.lastname: McDonald
authors.forename: J
authors.initials: J
authors.lastname: Oger
authors.forename: K
authors.initials: K
authors.lastname: Brownell
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D001323:Autoantibodies / Q000097:blood*; D015984:Causality; D002648:Child; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D015995:Prevalence; D011446:Prospective Studies; D011950:Receptors, Cholinergic / Q000276:immunology*; D012189:Retrospective Studies; D012306:Risk; D017678:Sex Distribution; D013945:Thymoma / Q000276:immunology / Q000503:physiopathology; D013953:Thymus Neoplasms / Q000276:immunology / Q000503:physiopathology; D013959:Thyroid Diseases / Q000453:epidemiology / Q000276:immunology* / Q000503:physiopathology
chemical_list: D001323:Autoantibodies; D011950:Receptors, Cholinergic