title: Clinical performance of the Roche cobas e411 automated assay system for thyrotropin-receptor antibodies for the diagnosis of Graves' disease.
abstract: BACKGROUND
  The clinical performance of the Roche cobas e411 automated assay for the measurement of thyrotropin (TSH)-receptor antibodies (TRAbs) for the diagnosis of Graves' disease was evaluated in the setting of new referrals to a specialized thyroid clinic.
  
  
  METHODS
  The final diagnosis of 102 new patients attending their first outpatient appointment at a thyroid clinic was correlated with the TRAbs result. In all cases, the diagnosis was made independently of the TRAbs result by the same consultant (ADT) based on clinical examination, thyroid function tests (TSH, free thyroxine, total triiodothyronine measured on Architect; Abbot Diagnostics), and a technetium-99m uptake and scan. TRAbs were measured using the cobas e411 (Roche Diagnostics). The clinical sensitivity and specificity of the assay were determined and compared with other published performance characteristics of the assay.
  
  
  RESULTS
  Optimal sensitivity (95%) and specificity (98%) were obtained using a cut-off of 1.6 IU/L. The positive and negative predictive values at this cut-off were calculated as 98% and 94%, respectively.
  
  
  CONCLUSIONS
  Using a cut-off of 1.6 IU/L, considered independently of thyroid function tests, the Roche cobas e411 automated immunoassay for TRAbs is a convenient, sensitive and specific tool for the differential diagnosis of hyperthyroidism.
authors.affiliation: Clinical Biochemistry, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK. neil.syme@luht.scot.nhs.uk
authors.forename: Neil R
authors.initials: NR
authors.lastname: Syme
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Toft
authors.forename: Mary
authors.initials: M
authors.lastname: Stoddart
authors.forename: Geoff J
authors.initials: GJ
authors.lastname: Beckett
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D057205:Automation, Laboratory; D019937:Diagnostic Techniques and Procedures / Q000295:instrumentation; D006111:Graves Disease / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D011989:Receptors, Thyrotropin / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D011989:Receptors, Thyrotropin