title: Impact of the clinical context on the 14-3-3 test for the diagnosis of sporadic CJD.
abstract: BACKGROUND
  The 14-3-3 test appears to be a valuable aid for the clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) in selected populations. However, its usefulness in routine practice has been challenged. In this study, the influence of the clinical context on the performance of the 14-3-3 test for the diagnosis of sCJD is investigated through the analysis of a large prospective clinical series.
  
  
  METHODS
  Six hundred seventy-two Spanish patients with clinically suspected sCJD were analyzed. Clinical classification at sample reception according to the World Health Organization's (WHO) criteria (excluding the 14-3-3 test result) was used to explore the influence of the clinical context on the pre-test probabilities, and positive (PPV) and negative (NPV) predictive values of the 14-3-3 test.
  
  
  RESULTS
  Predictive values of the test varied greatly according to the initial clinical classification: PPV of 98.8%, 96.5% and 45.0%, and NPV of 26.1%, 66.6% and 100% for probable sCJDi (n = 115), possible sCJDi (n = 73) and non-sCJDi (n = 484) cases, respectively. According to multivariate and Bayesian analyses, these values represent an improvement of diagnostic certainty compared to clinical data alone.
  
  
  CONCLUSIONS
  In three different contexts of sCJD suspicion, the 14-3-3 assay provides useful information complementary to clinical and electroencephalographic (EEG) data. The test is most useful supporting a clinical impression, whilst it may show deceptive when it is not in agreement with clinical data.
authors.affiliation: Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain. ncuadrado@isciii.es
authors.forename: Natividad
authors.initials: N
authors.lastname: Cuadrado-Corrales
authors.forename: Adolfo
authors.initials: A
authors.lastname: Jiménez-Huete
authors.forename: Carmen
authors.initials: C
authors.lastname: Albo
authors.forename: Rafael
authors.initials: R
authors.lastname: Hortigüela
authors.forename: Luz
authors.initials: L
authors.lastname: Vega
authors.forename: Laura
authors.initials: L
authors.lastname: Cerrato
authors.forename: Maríajosé
authors.initials: M
authors.lastname: Sierra-Moros
authors.forename: Alberto
authors.initials: A
authors.lastname: Rábano
authors.forename: Jesús
authors.initials: J
authors.lastname: de Pedro-Cuesta
authors.forename: Miguel
authors.initials: M
authors.lastname: Calero
mesh_terms: D048948:14-3-3 Proteins / Q000134:cerebrospinal fluid*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019411:Clinical Laboratory Techniques / Q000379:methods; D007562:Creutzfeldt-Jakob Syndrome / Q000134:cerebrospinal fluid* / Q000145:classification / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D048948:14-3-3 Proteins