CSF A beta 42, Tau and phosphorylated Tau, APOE epsilon 4 allele and MCI type in progressive MCI

Background: The patients with mild cognitive impairment (MCI) have an elevated risk for Alzheimer's disease (AD). Especially the amnestic MCI is seen as prodrome of AD. Apolipoprotein E (APOE) epsilon 4 allele, abnormal CSF A beta 42, Tau and phosphorylated Tau (phospho-Tau) levels are associated with elevated risk for AD. Methods: APOE genotyping was done by PCR based method and baseline CSF A beta 42, Tau and phospho-Tau were measured by ELISA from 60 controls and 79 MCI patients. Results: Thirty-three MCI patients developed dementia during an average of 3.5 years follow-up. CSF A beta 42 was decreased and Tau and phospho-Tau were increased in the progressive MCI patients. The APOE epsilon 4 allele was more frequent in the progressive MCI patients. The APOE epsilon 4 allele showed a dose dependent association to the A beta 42 levels in the progressive MCI patients and to all of the markers in controls. Conclusions: Decreased CSF A beta 42 and elevated Tau or phospho-Tau together with APOE epsilon 4 allele are highly predictive for the dementia in MCI patients with amnestic or executive symptoms. (c) 2006 Elsevier Inc. All rights reserved.