Impact of the clinical context on the 14-3-3 test for the diagnosis of sporadic CJD.
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.
Cuadrado-Corrales
Natividad
N
Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain. ncuadrado@isciii.es
Jiménez-Huete
Adolfo
A
Albo
Carmen
C
Hortigüela
Rafael
R
Vega
Luz
L
Cerrato
Laura
L
Sierra-Moros
Maríajosé
M
Rábano
Alberto
A
de Pedro-Cuesta
Jesús
J
Calero
Miguel
M
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
D048948:14-3-3 Proteins