Real-Time Quaking-Induced Conversion Analysis for the Diagnosis of Sporadic Creutzfeldt-Jakob Disease in Korea

• Published in: Journal of clinical neurology (Seoul, Korea) Vol. 12; no. 1; pp. 101 - 106
• Main Authors: Park, Jeong-Ho, Choi, Yeong-Gon, Lee, Yun-Jung, Park, Seok-Joo, Choi, Hong-Seok, Choi, Kyung-Chan, Choi, Eun-Kyoung, Kim, Yong-Sun
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Neurological Association 01.01.2016; 대한신경과학회
• Subjects: Original; 신경과학; 14-3-3; total tau protein; Creutzfeldt-Jakob disease; cerebrospinal fluid; RT-QuIC
• ISSN: 1738-6586; 2005-5013
• DOI: 10.3988/jcn.2016.12.1.101

The level of 14-3-3 protein in the cerebrospinal fluid (CSF) is increased in Creutzfeldt-Jakob disease (CJD) patients, which has led to it being used as a clinical biomarker for the ante-mortem diagnosis of human prion diseases. However, the specificity of the 14-3-3 protein is less reliable for CJD diagnosis. Newly developed assays including real-time quaking-induced conversion (RT-QuIC) have made it possible to detect the PrPSc-like abnormal prion isoform with a high sensitivity in animal and human specimens that might contain a minute amount of PrP(Sc) due to in vitro prion replication. This study applied a highly sensitive RT-QuIC assay using recombinant human PrP to detect PrP(Sc) in the CSF of 81 patients with sporadic CJD (sCJD) in Korea. RT-QuIC analysis of the CSF samples based on the expression levels of 14-3-3 and total tau proteins revealed positivity in 62 of 81 sCJD patients (sensitivity of 76.5%) but no positive results in the 100 non-CJD patients. The sensitivity of the RT-QuIC in this study was similar to that in some previous reports, and the specificity of RT-QuIC was higher than that of 14-3-3 in CSF, suggesting that RT-QuIC analysis can complement the weakness of the specificity of 14-3-3 for the diagnosis of sCJD. These results indicate that RT-QuIC might be very useful for the rapid and specific diagnosis of sCJD and provide a practical novel method for the ante-mortem diagnosis of human prion diseases.