Background and objectives: A definitive diagnosis of Creutzfeldt-Jakob disease (CJD) requires histopathological examination of a brain biopsy or autopsy specimen. The detection of a normal brain protein, protein 14-3-3, in cerebrospinal fluid (CSF) appear to be sensitive and specific for the diagnosis of CJD. Our objective has been to evaluate its diagnostic value.
Patients and methods: The presence of 14-3-3 protein in the CSF from 97 patients with neurological diseases was analyzed by immunoblot. In the analyzed results we only included patients with pathologically or genetic confirmed CJD, and those with criteria for clinically definite CJD (Brown et al).
Results: The 14-3-3 protein was detected in 29 of 32 cases of CJD (90.6%). The 3 false negative results were from 3 patients with familial CJD associated with the 178 codon mutation. In the 18 patients with final diagnosis of CJD tested when the degree of certainty was probable, the 14-3-3 protein was positive. The false positive results were seen in 9 patients with other neurological diseases, but only in three of them (hypoxic encephalopathy, encephalopathy associated to Hashimoto thyroiditis and cerebral amyloid angiopathy) the disease could be included in the differential diagnosis of CJD.
Conclusions: The test for detection of 14-3-3 protein is highly sensitive in patients with sporadic CJD. The 14-3-3 protein can be detected early when clinical manifestations do not allow the diagnosis of clinically definite CJD.