title: Improvement in diagnosis of rheumatoid arthritis using dual indirect immunofluorescence and immunoblotting assays for antifilaggrin autoantibodies: a retrospective 3 year study.
abstract: OBJECTIVE
  To determine the clinical usefulness of measuring antistratum corneum (ASC) and antifilaggrin autoantibodies (AFA) to discriminate between rheumatoid arthritis (RA) and other rheumatic or autoimmune diseases, using an indirect immunofluorescence (IIF) assay, along with a complementary immunoblotting technique (IB) when IIF detection of ASC was negative.
  
  
  METHODS
  Sera from 346 patients were studied: 189 sera from patients with RA seen in the same clinic, 92 from patients with non-RA rheumatic diseases, 24 from nonrheumatic autoimmune diseases, and 41 from healthy blood donors. ASC and AFA were detected using IIF and IB, respectively.
  
  
  RESULTS
  ASC detection using IIF showed a specificity of 97.5% for RA with 44.4% sensitivity. When both IIF and IB techniques were used, sensitivity for RA increased significantly (up to 53.4%; p < 0.01) with no decrease in specificity (p < 0.01).
  
  
  CONCLUSIONS
  These data confirm the usefulness of 2 different techniques performed simultaneously for detecting ASC/AFA, and the usefulness of these biological markers for discriminating between RA and other rheumatic diseases in clinical practice.
authors.affiliation: UF Autoimmuné, Laboratoire d'Immunologie, Centre Hospitalier Lyon-Sud, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Ferraro-Peyret
authors.forename: Jacques
authors.initials: J
authors.lastname: Tebib
authors.forename: Agnes
authors.initials: A
authors.lastname: Desbos
authors.forename: Rene
authors.initials: R
authors.lastname: Bihannic
authors.forename: Christelle
authors.initials: C
authors.lastname: Genestier
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Letroublon
authors.forename: Sophie
authors.initials: S
authors.lastname: Veber
authors.forename: Etienne
authors.initials: E
authors.lastname: Benoit
authors.forename: Cecile
authors.initials: C
authors.lastname: Veysseyre-Balter
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Monier
authors.forename: Nicole
authors.initials: N
authors.lastname: Fabien
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D000091344:Filaggrin Proteins; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D015151:Immunoblotting; D007381:Intermediate Filament Proteins / Q000276:immunology*; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins