Validation of 14-3-3 Protein as a Marker in Sporadic Creutzfeldt-Jakob Disease Diagnostic

• Published in: Molecular neurobiology Vol. 53; no. 4; pp. 2189 - 2199
• Main Authors: Schmitz, Matthias, Ebert, Elisabeth, Stoeck, Katharina, Karch, André, Collins, Steven, Calero, Miguel, Sklaviadis, Theodor, Laplanche, Jean-Louis, Golanska, Ewa, Baldeiras, Ines, Satoh, Katsuya, Sanchez-Valle, Raquel, Ladogana, Anna, Skinningsrud, Anders, Hammarin, Anna-Lena, Mitrova, Eva, Llorens, Franc, Kim, Yong Sun, Green, Alison, Zerr, Inga
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2016; Springer Nature B.V
• Subjects: 14-3-3 Proteins - cerebrospinal fluid; 14-3-3 Proteins - metabolism; Alzheimer's disease; Biomarkers; Biomarkers - metabolism; Biomedical and Life Sciences; Biomedicine; Blotting, Western; Cell Biology; Cerebrospinal fluid; Creutzfeldt-Jakob disease; Creutzfeldt-Jakob Syndrome - cerebrospinal fluid; Creutzfeldt-Jakob Syndrome - diagnosis; Creutzfeldt-Jakob Syndrome - metabolism; Enzyme-Linked Immunosorbent Assay; Hospitals; Humans; Laboratories; Neurobiology; Neurology; Neurosciences; Preservation, Biological; Protein Isoforms - metabolism; Proteins; Reference Standards; Reproducibility; Reproducibility of Results; S100 Proteins - metabolism; Sensitivity and Specificity; Signal transduction; Standardization; tau Proteins - metabolism; Sweden; Germany; Biomarker; 14-3-3 protein; Cerebrospinal fluid; Pre-mortem test; Creutzfeldt-Jakob disease; Standardization
• ISSN: 0893-7648; 1559-1182
• DOI: 10.1007/s12035-015-9167-5

At present, the testing of 14-3-3 protein in cerebrospinal fluid (CSF) is a standard biomarker test in suspected sporadic Creutzfeldt-Jakob disease (sCJD) diagnosis. Increasing 14-3-3 test referrals in CJD reference laboratories in the last years have led to an urgent need to improve established 14-3-3 test methods. The main result of our study was the validation of a commercially available 14-3-3 ELISA next to the commonly used Western blot method as a high-throughput screening test. Hereby, 14-3-3 protein expression was quantitatively analyzed in CSF of 231 sCJD and 2035 control patients. We obtained excellent sensitivity/specificity values of 88 and 96 % that are comparable to the established Western blot method. Since standard protocols and preanalytical sample handling have become more important in routine diagnostic, we investigated in a further step the reproducibility and stability of 14-3-3 as a biomarker for human prion diseases. Ring trial data from 2009 to 2013 revealed an increase of
Fleiss’ kappa
from 0.51 to 0.68 indicating an improving reliability of 14-3-3 protein detection. The stability of 14-3-3 protein under short-term and long-term storage conditions at various temperatures and after repeated freezing/thawing cycles was confirmed. Contamination of CSF samples with blood appears likely to be an important factor at a concentration of more than 2500 erythrocytes/μL. Hemolysis of erythrocytes with significant release of 14-3-3 protein started after 2 days at room temperature. We first define clear standards for the sample handling, short- and long-term storage of CSF samples as well as the handling of blood- contaminated samples which may result in artificially elevated CSF levels of 14-3-3.