title: Autoimmunoreactive IgGs from patients with postural orthostatic tachycardia syndrome.
abstract: OBJECTIVE
  Autoantibodies are implicated in the pathogenesis of cardiovascular diseases and cardiac arrhythmias. In this pilot study, we tested the hypothesis that autoantibodies are present in patients with postural orthostatic tachycardia syndrome (POTS).
  
  
  METHODS
  Seven control subjects (6 F:1 M, average age 36.1 years) and ten patients with the diagnosis of POTS (7 F: 3 M, average age 35.1 years) provided informed consent and 30 mL of venous blood. Human heart membrane proteins were resolved by 2DE and immunoblotted against purified IgGs from controls and patients.
  
  
  RESULTS
  Eighteen protein spots immunoreactive specifically against patient IgGs were detected and they were excised from gels, trypsin-digested, and analyzed by nanoLC-electrospray MS/MS. Forty unique proteins were identified and these include proteins that are associated with cardiac hypertrophy (mimecan, myozenin), cardiac remodeling (periostin), cardiomyopathy (desmin, desmoplakin), cell survival (laminin), structural integrity (filamin), chaperone proteins (crystalline, HSP70), mitochondrial enzymes, and channel proteins. Ingenuity Pathway Analysis showed multiple pathways were involved including those that regulate energy metabolism, redox, fibrosis, cardiac hypertrophy, and degeneration.
  
  
  CONCLUSIONS
  Autoantibodies are present in patients with POTS. These autoantibodies cross-react with a wide range of cardiac proteins and may induce alterations in cardiac function. Autoimmune pathogenetic mechanisms should be further explored in these patients.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA. wang.xiaoli@mayo.edu
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chai
authors.forename: M Cristine
authors.initials: MC
authors.lastname: Charlesworth
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Figueroa
authors.forename: Phillip
authors.initials: P
authors.lastname: Low
authors.forename: Win-Kuang
authors.initials: WK
authors.lastname: Shen
authors.forename: Hon-Chi
authors.initials: HC
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D054972:Postural Orthostatic Tachycardia Syndrome / Q000276:immunology*; D060066:Protein Interaction Maps / Q000276:immunology; D020543:Proteome / Q000737:chemistry / Q000378:metabolism; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D020543:Proteome