CSF Abeta42, Tau and phosphorylated Tau, APOE epsilon4 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) epsilon4 allele, abnormal CSF Abeta42, 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 Abeta42, 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 Abeta42 was decreased and Tau and phospho-Tau were increased in the progressive MCI patients. The APOE epsilon4 allele was more frequent in the progressive MCI patients. The APOE epsilon4 allele showed a dose dependent association o the Abeta42 levels in the progressive MCI patients and to all of the markers in controls.

Conclusions: Decreased CSF Abeta42 and elevated Tau or phospho-Tau together with APOE epsilon4 allele are highly predictive for the dementia in MCI patients with amnestic or executive symptoms.