title: Combined analysis of cross-reacting antibodies anti-β1AR and anti-B13 in advanced stages of Chagas heart disease.
abstract: Autoantibodies cross-reacting with the β1 adrenergic receptor (anti-β1AR and anti-p2β) and cardiac myosin antigens (anti-B13) have been related to the pathogenesis of chronic Chagas heart disease (CCHD). Studies exploring their levels in different stages are scarce. We aimed to evaluate the relationship of these autoantibodies with the clinical profile of chronic patients, especially regarding their classificatory accuracy in severe presentation with heart failure.
  
  
  
  We conducted a cross-sectional study of 155 T. cruzi-seropositive patients and 26 age- and gender-matched healthy controls. They were categorised in three stages of CCHD. Serum antibodies were measured by specific immunoassays. Symptomatic individuals showed increased levels of anti-β1AR and anti-B13, while anti-p2β antibodies were similar between groups. A composite logistic regression model including anti-B13, anti-β1AR antibody levels and age was able to predict systolic heart failure yielding an area under the curve of 83% (sensitivity of 67% and specificity of 89%).
  
  
  
  In our study, anti-β1AR and anti-B13 antibodies were higher in individuals with chronic Chagas heart disease stage III, mainly in those with dilated cardiomyopathy associated with systolic heart failure. Logistic regression analysis showed that both antibodies were good predictors of severe CCHD. As well as being involved in disease progression, anti-β1AR and anti-B13 antibodies may be used as a serum marker of poor prognosis in terms of heart compromise.
authors.affiliation: Laboratory of Immunological Techniques, National University of Littoral, Santa Fe, Argentina.|Internal Medicine Department, National University of Littoral, Santa Fe, Argentina.
authors.forename: Luz M
authors.initials: LM
authors.lastname: Rodeles
authors.affiliation: Laboratory of Immunological Techniques, National University of Littoral, Santa Fe, Argentina.|Internal Medicine Department, National University of Littoral, Santa Fe, Argentina.
authors.forename: Miguel H
authors.initials: MH
authors.lastname: Vicco
authors.affiliation: Laboratory of Immunological Techniques, National University of Littoral, Santa Fe, Argentina.
authors.forename: Iván A
authors.initials: IA
authors.lastname: Bontempi
authors.affiliation: Organic Chemistry Department, National University of Littoral, Santa Fe, Argentina.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Siano
authors.affiliation: Organic Chemistry Department, National University of Littoral, Santa Fe, Argentina.
authors.forename: Georgina
authors.initials: G
authors.lastname: Tonarelli
authors.affiliation: Institute of Clinical and Experimental Immunology, UNR-CONICET, Rosario, Argentina.
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Bottasso
authors.affiliation: Human Physiology Department, National University of Rosario, Rosario, Argentina.
authors.forename: Pablo
authors.initials: P
authors.lastname: Arias
authors.affiliation: Laboratory of Immunological Techniques, National University of Littoral, Santa Fe, Argentina.
authors.forename: Iván S
authors.initials: IS
authors.lastname: Marcipar
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001323:Autoantibodies / Q000097:blood*; D024722:Cardiac Myosins / Q000276:immunology*; D002598:Chagas Cardiomyopathy / Q000097:blood / Q000276:immunology* / Q000469:parasitology; D014355:Chagas Disease; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006333:Heart Failure / Q000209:etiology* / Q000276:immunology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018342:Receptors, Adrenergic, beta-1 / Q000276:immunology*; D012720:Severity of Illness Index; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D018342:Receptors, Adrenergic, beta-1; D024722:Cardiac Myosins
keywords: Chagas disease; anti-B13 antibodies; anticorps anti-B13; anticuerpos anti-B13; beta-1 adrenergic receptors; enfermedad de Chagas; fallo cardiaco; heart failure; insuffisance cardiaque; maladie de Chagas; receptores beta-1 Adrenérgicos; récepteurs adrénergiques bêta-1