title: In arterial occlusive disease autoantibodies against ETAR and AT(1)R correlate with each other but are not associated with classical cardiovascular risk factors.
abstract: BACKGROUND
  Autoantibodies (Abs) against angiotensin-II type 1 (AT(1)R) and endothelin-1 type A receptors (ETAR) are investigated in the present study as B-cell originated humoral factors that may activate the respective receptors on endothelial cells. The prevalence of the Abs was determined in patients with peripheral arterial occlusive disease (PAD).
  
  
  METHODS
  In a prospective observational study 200 patients undergoing angiography and proven advanced PAD were enrolled. Serum samples, clinical data and laboratory values for classical cardiovascular risk factors were collected. Autoantibody titers for AT(1)R and ETAR were determined by solid-phase ELISA and correlative analyses with laboratory parameters and clinical data for common cardiovascular risk factors were performed.
  
  
  RESULTS
  Anti-ETAR antibody titers were detected in 57 % of the patients, elevated anti-AT(1)R titers in 61.5 %. About 50 % were positive for both Abs. A strong intercorrelation between ETAR and AT(1)R titers was present (r2 0.79). In patients with positive titers for both Abs females presented significantly higher titers for ETAR (p = 0.045) and AT(1)R (p = 0.02). Autoantibody titers directed against surface receptors ETA and AT(1) are highly correlated in PAD. Titers were independent from classical risk factors in any patient subgroup.
  
  
  CONCLUSIONS
  This study opens a new perspective on the involvement of the immune system, hereby represented by functional autoantibodies, in the atherosclerotic pathophysiology, leaving behind the common background of classical risk factors.
authors.affiliation: Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Albert
authors.affiliation: Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Germany.
authors.forename: Marie
authors.initials: M
authors.lastname: von Schultzendorff
authors.affiliation: Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Germany, and University of Medicine and Pharmacy Gr.T.Popa Iasi, Romania.
authors.forename: Delia
authors.initials: D
authors.lastname: Şalaru
authors.affiliation: Department of Vascular Surgery, Otto-von-Guericke University Magdeburg, Germany.
authors.forename: Zuhir
authors.initials: Z
authors.lastname: Halloul
authors.affiliation: Department of Nephrology and Intensive Care Medicine, Charité University, Berlin, Germany.
authors.forename: Duska
authors.initials: D
authors.lastname: Dragun
authors.affiliation: CellTrend GmbH, Luckenwalde, Berlin, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Heidecke
authors.affiliation: Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke University Magdeburg, Germany.
authors.forename: Peter Rene
authors.initials: PR
authors.lastname: Mertens
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D056724:Immunity, Humoral; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000276:immunology*; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D044140:Receptor, Angiotensin, Type 1 / Q000276:immunology*; D044022:Receptor, Endothelin A / Q000276:immunology*; D012307:Risk Factors
chemical_list: C544065:AGTR1 protein, human; D001323:Autoantibodies; D015415:Biomarkers; D044140:Receptor, Angiotensin, Type 1; D044022:Receptor, Endothelin A
keywords: 1 type A receptor; Angiotensin II type 1 receptor; autoantibodies; cardiovascular risk profiles; endothelin; peripheral arterial disease