Detection of CSF 14-3-3 Protein in Sporadic Creutzfeldt-Jakob Disease Patients Using a New Automated Capillary Western Assay

Sporadic Creutzfeldt-Jakob disease (sCJD) is a fatal rapidly progressive dementia. The detection of 14-3-3 protein in cerebrospinal fluid (CSF) is included in the WHO diagnostic criteria for the pre-mortem diagnosis of CJD. The aim of this study is to assess CSF 14-3-3 protein analytical and diagnostic performances using a new automated capillary Western technology (Simple Western technology-SW). For the validation of this assay, samples from a cohort of 268 patients suspected from sCJD were analyzed: 77 sCJD (including 40 definite sCJD) and 191 non-CJD samples were tested using both SW and the current Western Blot (WB) assays. Automated capillary Western determination provided better analytical performances than WB with a lower intra- and inter-assay variability. Analytical interferences such as hemolysis and high total protein concentration known to lead to false positive WB results were also assessed using SW assay: unfortunately, these interferences still remain confounders of CSF 14-3-3 protein determination. Finally, automated capillary Western assay's sensitivity and specificity were superior to those of WB assay (93.5 and 95.3%, respectively, compared to 92.2 and 84.8% for WB). In conclusion, with a shorter time of analysis than WB assays' (4 h versus 1.5 day), automated capillary Western assay is an excellent routine alternative method to the currently performed WB assay for CSF 14-3-3 protein detection in patients suspected of sporadic Creutzfeldt-Jakob disease.