The presence of
apolipoprotein E (
ApoE) ε4 allele is a risk factor for
Alzheimer's disease (AD) and associated with a more pronounced reduction of
amyloid-β 1-42 (Aβ1-42) in the cerebrospinal fluid (CSF). Because a decrease of Aβ1-42 and increase of
tau protein levels, both important
biomarkers for AD, are also reported in
Creutzfeldt-Jakob disease (CJD), we analyzed if a similar relationship can be observed in this rapid progressive
dementia. Our study included 309 patients with
sporadic CJD (147 neuropathologically confirmed and 162 probable cases). We analyzed the role of
ApoE ε4 in
sporadic CJD (sCJD), in particular the influence on the CSF-markers
14-3-3 protein,
tau protein,
neuron-specific enolase,
S100 protein, Aβ1-42, and Aβ1-40. No differences in the
ApoE ε4 allele frequency and
ApoE genotype distribution between sCJD and published healthy controls were observed. The
ApoE ε4 allele had no effect on disease duration or age at onset. We detected a dose-dependent
ApoE ε4 effect on the decrease of Aβ1-42 in sCJD.
ApoE ε4 carriers with one
ApoE ε4 allele showed significantly reduced Aβ1-42 values (p < 0.0001) in comparison with non-carriers.
ApoE ε4 allele is not a risk factor for sCJD but modifies the Aβ1-42 levels in CSF in a similar manner as in AD. Based on our results in sCJD patients, we hypothesize that the
ApoE ε4 effect on Aβ1-42 values might not be disease-specific.