DIAGNOSIS OF CREUTZFELDT-JAKOB-DISEASE AND RELATED HUMAN SPONGIFORM ENCEPHALOPATHIES

Spongiform encephalopathies are transmissible diseases (TSE) of animal s and humans. With the appearance of bovine spongiform encephalopathy (BSE) in 1986 and in 1996 with the identification of an apparantly new variant of the human spongiform encephalopathy CreutzfeLdt-Jakob dise ase (CJD), great concerns of a potential transmission of BSE to humans have been voiced. The agent known to transmit CJD and other human and animal spongiform encephalopathies is designated as prion, ie, protei naceous infectious agent, due to the absence of evidence for the invol vement of a nucleic acid in disease transmission. In humans the clinic al diagnosis of typical CJD cases can now be supported by paraclinical parameters. Electroencephalographic changes, so called periodic sharp wave complexes, are pathognomonic for CJD but by no means specific. T he detection of neuronal enzymes in the cerebrospinal fluid (CSF) such as neuron specific enolase (NSE) or glial proteins such as S-100 aids greatly in the diagnosis of a human spongiform encephalopathy. By far the most specific marker in CSF are a group of proteins designated 14 -3-3. Current evidence suggests that by including elevated levels of N SE (greater than or equal to 35 ng/mL), S-100 (greater than or equal t o 8 ng/mL) and tau protein in the CSF and the presence of 14-3-3, a la boratory supported diagnosis of CJD can be achieved which in the appro priate clinical setting has a better diagnostic accuracy than the curr ently used clinical and paraclinical diagnostic criteria alone.