High sensitivity of an ELISA kit for detection of the gamma-isoform of 14-3-3 proteins: usefulness in laboratory diagnosis of human prion disease
- Equal contributors
1 Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan
2 Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Science, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
3 Cyclex Co.LTD, 1063-103 Ohara, Terasawaoka, Ina, Nagano 396-0002, Japan
4 Center for Community and Campus Health, Nagasaki University, 1-14 Bunkyo, Nagasaki 852-8521, Japan
5 Nagasaki Kita Hospital, 800 Tokitsu, Nagasaki 851-2103, Japan
BMC Neurology 2011, 11:120 doi:10.1186/1471-2377-11-120Published: 4 October 2011
The gamma-isoform of the 14-3-3 protein (14-3-3 gamma) is expressed in neurons, and could be a specific marker for neuronal damage. This protein has been reported as a detectable biomarker, especially in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) patients by Western blotting (WB) or enzyme-linked immunosorbent assays (ELISAs). Western blotting for 14-3-3 gamma is not sensitive, and the reported data are conflicting among publications. An ELISA specific for 14-3-3 gamma is not available.
CJD patients (n = 114 sporadic CJD patients, 7 genetic CJD, and 3 iatrogenic CJD) and 99 patients with other neurodegenerative diseases were examined in this study. The CSF samples obtained were analyzed by Western blotting for 14-3-3 gamma, and by ELISA for total tau protein. We evaluated the sensitivity and specificity of the newly developed sandwich ELISA for 14-3-3 gamma.
The cut-off value of the 14-3-3 gamma ELISA was > 1, 683 AU/ml; and sensitivity was 95.2%, with 72.7% specificity. This specificity was the same for the total tau protein ELISA. Seven CJD cases were negative by WB but positive using the 14-3-3 gamma ELISA, indicating that the ELISA is more sensitive. All 21 cases of early stage CJD could be diagnosed using a combination of the 14-3-3γ ELISA and diffusion weighted MR imaging (DWI-MRI).
The 14-3-3 gamma ELISA was more sensitive than conventional WB, and was useful for laboratory diagnosis of CJD, similar to the ELISA for the tau protein. Using DWI-MRI and these ELISA tests on CSF, diagnosis of CJD will be possible even at early stages of the disease.