Journal Article

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

Stoeck, Katharina, Baldeiras, Ines, Schmitz, Matthias, Skinningsrud, Anders, Zerr, Inga, Kim, Yong Sun, Collins, Steven, Laplanche, Jean-Louis, Sklaviadis, Theodor, Llorens, Franc, Ebert, Elisabeth, Calero, Miguel, Sanchez-Valle, Raquel, Satoh, Katsuya, Karch, André, Ladogana, Anna, Golanska, Ewa, Mitrova, Eva, Green, Alison, Hammarin, Anna-Lena

2016

Overview

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.

• Publisher: Springer US,Springer Nature B.V
• Subject: 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