title: Autoantibodies Toward the Angiotensin 2 Type 1 Receptor: A Novel Autoantibody in Alzheimer's Disease.
abstract: BACKGROUND
  Autoantibodies with agonist function are described in cardiovascular disorders. Since vascular risk factors are associated with an increased risk for Alzheimer's disease (AD), we investigated a potential association between antibodies to the angiotensin 2 type 1 receptor (anti-AT1R) and AD.
  
  
  OBJECTIVE
  The primary objective of this study was to investigate the association between anti-AT1R and AD. The secondary objective was to investigate the association between clinical or biomarker features of AD and anti-AT1R.
  
  
  METHODS
  Samples from patients with mild AD participating in a longitudinal study in Western Norway (n = 92, 65 [71%] females, mean age 74.8 [range 50-89]) and age- and gender-matched healthy controls (n = 102) were included. Cerebrospinal fluid (CSF) AD biomarkers were assessed in a subgroup of patients. Patients were examined annually, including Mini-Mental State Examination. ELISA was used to measure anti-AT1R in serum. Non-parametric tests were used for statistical calculations and a p <  0.05 was considered significant.
  
  
  RESULTS
  AD patients had significantly higher levels of anti-AT1R compared with healthy controls (10.2 U/mL versus 8.1 U/mL, p = 0.04). This difference was found only in patients without hypertension and diabetes. Anti-AT1R levels correlated with CSF total tau (p = 0.03) and phosphorylated tau (p = 0.03) levels, and inversely with blood pressure in AD (Spearman R -0.277, p = 0.008).
  
  
  CONCLUSIONS
  AD is associated with increased levels of anti-AT1R, and the antibodies correlated with CSF total, and phosphorylated tau levels. Further research is needed to understand the blood pressure response in AD without hypertension and a potential link between tau and anti-AT1R in AD.
authors.affiliation: Department of Internal Medicine, Haraldsplass Deaconess Hospital, Bergen, Norway.
authors.forename: Lasse M
authors.initials: LM
authors.lastname: Giil
authors.affiliation: Institute of Clinical Science, University of Bergen, Bergen, Norway.|Department of Immunology and Transfusion Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Einar K
authors.initials: EK
authors.lastname: Kristoffersen
authors.affiliation: Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Christian A
authors.initials: CA
authors.lastname: Vedeler
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Stockholm, Sweden.|Centre for Age-Related Diseases (SESAM), Stavanger University Hospital, Stavanger, Norway.
authors.forename: Dag
authors.initials: D
authors.lastname: Aarsland
authors.affiliation: Institute of Clinical Science, University of Bergen, Bergen, Norway.|Department of Cardiology, Stavanger University Hospital, Stavanger, Norway.
authors.forename: Jan Erik
authors.initials: JE
authors.lastname: Nordrehaug
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Winblad
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Angel
authors.initials: A
authors.lastname: Cedazo-Minguez
authors.affiliation: Institute of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Lund
authors.affiliation: Department of Immunology and Transfusion Medicine, Haukeland University Hospital, Bergen, Norway.|Centre for Age-Related Diseases (SESAM), Stavanger University Hospital, Stavanger, Norway.
authors.forename: Tove Ragna
authors.initials: TR
authors.lastname: Reksten
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000134:cerebrospinal fluid / Q000453:epidemiology / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D044139:Receptor, Angiotensin, Type 2 / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D044139:Receptor, Angiotensin, Type 2
keywords: AT1R; autoimmunity; dementia; neurodegeneration