Is ApoE ε 4 a good biomarker for amyloid pathology in late onset Alzheimer's disease?

Amyloid plaques are pathological hallmarks of Alzheimer's Disease (AD) and biomarkers such as cerebrospinal fluid (CSF) beta-amyloid 1-42 (A beta 1-42) and amyloid positron emission tomographic (PET) imaging are important in diagnosing amyloid pathology in vivo. epsilon 4 allele of the Apolipoprotein E gene (ApoE epsilon 4), which is a major genetic risk factor for late onset AD, is an important genetic biomarker for AD pathophysiology. It has been shown that ApoE epsilon 4 is involved in A beta deposition and formation of amyloid plaques. Studies have suggested the utility of peripheral blood ApoE epsilon 4 in AD diagnosis and risk assessment. However it is still a matter of debate whether ApoE epsilon 4 status would improve prediction of amyloid pathology and represent a cost-effective alternative to amyloid PET or CSF A beta in resource-limited settings in late onset AD. Recent research suggest that the mean prevalence of PET amyloid-positivity is 95% in ApoE epsilon 4-positive AD patients. This short review aims to provide an updated information on the relationship between ApoE epsilon 4 and amyloid biomarkers.