title: Tissue transglutaminase antibodies in patients with end-stage heart failure.
abstract: OBJECTIVE
  For celiac disease (CD), screening a trend has recently emerged to measure tissue transglutaminase antibodies (tTGA) by immunoassays instead of the more laborious endomysial antibodies (EmA), as they recognize the same target, tissue transglutaminase (tTG). However, a high rate of false-positive results has been reported in some patient series with diseases known to be associated with CD. Moreover, tTG is a ubiquitous, multifunctional enzyme, overexpressed in experimental models of heart failure. Therefore, we assessed the specificity of tTGA assays in a large series of EmA-negative patients with end-stage heart failure.
  
  
  METHODS
  We studied 288 patients with end-stage heart failure and 60 blood donors. No subject had clinical evidence of CD or IgA deficiency, and all were EmA negative. Serum IgA and IgG tTGA were measured by means of commercial kits using as substrate, either guinea pig or recombinant human tTG. Blocking studies and Western blots were also performed using recombinant human tTG.
  
  
  RESULTS
  All blood donor sera were IgA tTGA negative. IgA tTGA positivity was observed in 47.6% and 49.1% of patients with heart failure using, respectively, guinea pig tTG and recombinant human tTG as substrates. Preincubation of positive sera with recombinant human tTG resulted in 81% blocking of IgA tTGA in immunoassay. Western blot analysis confirmed the presence of antibodies against recombinant human tTG. IgA tTGA-positive sera were also IgG tTGA positive.
  
  
  CONCLUSIONS
  IgA and IgG tTGA occur in a large number of EmA-negative patients with end-stage heart failure, and their presence is unlikely to be caused by concomitant CD.
authors.affiliation: IRCCS-Ospedale Maggiore, University of Milan, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Peracchi
authors.forename: Cristina
authors.initials: C
authors.lastname: Trovato
authors.forename: Massimo
authors.initials: M
authors.lastname: Longhi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasparin
authors.forename: Dario
authors.initials: D
authors.lastname: Conte
authors.forename: Cristina
authors.initials: C
authors.lastname: Tarantino
authors.forename: Daniele
authors.initials: D
authors.lastname: Prati
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Bardella
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D002446:Celiac Disease / Q000201:enzymology / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006333:Heart Failure / Q000201:enzymology* / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D011503:Transglutaminases / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011503:Transglutaminases