[Biological markers for Alzheimer disease].

The development of diagnostic markers for earlier and more reliable diagnosis of Alzheimer disease (AD) is essential, particularly because therapeutic medication is available for AD. Cerebrospinal fluid (CSF) is a useful source of diagnostic information. Previously we found the increase of total tau protein in CSF in normal pressure hydrocephalus patients, and others reported the increase also in corticobasal degeneration and frontotemporal dementia. To differentiate the AD from other diseases, further approach was employed and oxidized protein in CSF was investigated. Heat stable fractions of CSF were analyzed on the content of carbonyl residues, which are derivatives of protein oxidization. The result suggests that protein oxidation is highly involved in AD and that this method might be useful to differentiate AD from other neurological disease.