Objective: The aim of this study was to confirm the diagnostic yield of these tests for differential diagnosis and prognosis of neurodegenerative disorders. Methods: Total tau protein, phospho-tau and beta amyloid were determined in CSF samples taken in a group of patients (N=40) with various neurological diagnoses. They were classified into 3 groups: Suspected neurodegenerative disease (N=24), other neurological diagnosis (OND; N=8) and a control group (N=8) without dementia and positive inflammatory findings in CSF. Immunosorbent assay (ELISA) developed by Innogenetics was used for the quantitative analysis of these specific brain proteins. Results: In a group of suspected neurodegenerative disease abnormal values of all three proteins were found in 2 patients with clinical diagnosis of Alzheimer disease (AD). High concentration of total tau protein but normal phospho-tau correlates well with one case of autopsy proved Pick’s disease. In 2 patients with mild cognitive impairment (MCI) increased levels of both total tau and phospho-tau indicate higher risk of further development of AD. There was normal total tau protein in OND and control group, phospho-tau was slightly increased in 1 patient while beta amyloid was positive in 4 patients of OND group and in 2 patients of a control group. Conclusion: Results of this study suggest that this methodology is profitable in prediction (especially in patients with MCI) and differential diagnosis of patients with dementias. Pros and cons in relation to costs of AD therapy are discussed.

        Key words: Alzheimer’s disease, total tau protein, phospho-tau protein, beta amyloid, cerebrospinal fluid.