title: Diagnostic accuracy of blood B-cell subset profiling and autoimmunity markers in Sjögren's syndrome.
abstract: BACKGROUND
  The aims of this study were to evaluate the diagnostic accuracy of blood B-cell subset profiling and immune-system activation marker assays in primary Sjögren's syndrome (pSS) and to assess whether adding these tools to the current laboratory item would improve the American-European Consensus Group (AECG) criteria.
  
  
  METHODS
  In a single-center cohort of patients with suspected pSS, we tested the diagnostic performance of anti-SSA, antinuclear antibody (ANA), rheumatoid factor (RF), gammaglobulins, IgG titers, and B-cell ratio defined as (Bm2 + Bm2')/(eBm5 + Bm5), determined using flow cytometry. The reference standard was a clinical diagnosis of pSS established by a panel of experts.
  
  
  RESULTS
  Of 181 patients included in the study, 77 had pSS. By logistic regression analysis, only ANA ≥1:640 (sensitivity, 70.4%; specificity 83.2%) and B-cell ratio ≥5 (sensitivity, 52.1%; specificity, 83.2%) showed independent associations with pSS of similar strength. In anti-SSA-negative patients, presence of either of these two criteria had 71.0% sensitivity but only 67.3% specificity for pSS; whereas combining both criteria had 96.2% specificity but only 12.9% sensitivity. Adding either of these two criteria to the AECG criteria set increased sensitivity from 83.1% to 90.9% but decreased specificity from 97.1% to 85.6%, whereas adding both criteria in combination did not substantially modify the diagnostic performance of the criteria set. The adjunction of RF + ANA ≥1:320, as proposed in the new American College of Rheumatology (ACR) criteria, did not improve the diagnostic value of anti-SSA.
  
  
  CONCLUSIONS
  Blood B-cell subset profiling is a simple test that has good diagnostic properties for pSS. However, adding this test, with or without ANA positivity, does not improve current classification criteria.
authors.forename: Divi
authors.initials: D
authors.lastname: Cornec
authors.forename: Alain
authors.initials: A
authors.lastname: Saraux
authors.forename: Jacques-Olivier
authors.initials: JO
authors.lastname: Pers
authors.forename: Sandrine
authors.initials: S
authors.lastname: Jousse-Joulin
authors.forename: Thierry
authors.initials: T
authors.lastname: Marhadour
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Roguedas-Contios
authors.forename: Steeve
authors.initials: S
authors.lastname: Genestet
authors.forename: Yves
authors.initials: Y
authors.lastname: Renaudineau
authors.forename: Valérie
authors.initials: V
authors.lastname: Devauchelle-Pensec
mesh_terms: D019540:Area Under Curve; D001323:Autoantibodies / Q000097:blood*; D015551:Autoimmunity / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D015415:Biomarkers / Q000097:blood*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012859:Sjogren's Syndrome / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers