Apolipoprotein E Genotype Affects Size of ApoE Complexes in Cerebrospinal Fluid.

Apolipoprotein E (apoE) is associated with lipoproteins in the cerebrospinal fluid (CSF). APOE4 increases and APOE2 decreases the risk for Alzheimer disease (AD) compared to the risk associated with APOE3 Because apoE4 is less efficient at cholesterol efflux than apoE2 or apoE3 in vitro, we hypothesized that APOE genotype may affect apoE particle size in vivo and that these size differences may be related to AD risk. We used nondenaturing gel electrophoresis to test for differences in the size of apoE complexes in human CSF samples of various APOE genotypes and created profiles of each sample to compare the patterns of apoE distribution.