DETECTION OF 14-3-3 PROTEIN IN THE CEREBROSPINAL-FLUID SUPPORTS THE DIAGNOSIS OF CREUTZFELDT-JAKOB-DISEASE

The analysis of 14-3-3 protein in cerebrospinal fluid (CSF) was shown to be highly sensitive and specific for the diagnosis of Creutzfeldt-J akob disease (CJD). However, the predictive value of this test in the clinical diagnosis of, and its relation to, sporadic, genetic, and iat rogenic CJD cases have yet to be established. CSF samples of suspect C JD cases seen in the prospective German surveillance study were tested for the presence of 14-3-3 protein by using a modified western blot ( WB) technique. WE detected 14-3-3 protein in 95.4% of definite and 92. 8% of probable cases. In two patients classified initially as not havi ng CJD the test was positive, and both were later proved to have defin ite CJD. The positive predictive value is 94.7% and the negative predi ctive value is 92.4%. False-positive results in a single CSF analysis were seen in patients with herpes simplex encephalitis, hypoxic brain damage, atypical encephalitis, intracerebral metastases of a bronchial carcinoma, metabolic encephalopathy, and progressive dementia of unkn own cause. WE analysis for 14-3-3 protein was positive in only 5 of 10 cases of familial forms of spongiform encephalopathies. CSF analysis for 14-3-3 protein should thus be performed in any case suspect for CJ D.