Sandwich ELISA for the measurement of Apo-E4 levels in serum and the estimation of the allelic status of Apo-E4 isoforms.
Apolipoprotein-E (Apo-E) isoforms, especially theApo-E4 isoform, are considered to be genetic risk factors for familial as well as sporadic Alzheimer's disease (AD). Using monoclonal antibodies specific for Apo-E4 (MAb412-1-7) and Apo-E (LZ18), we established a sandwich ELISA for the measurement of Apo-E4 levels in serum. Total Apo-E also was determined by sandwich ELISA with a second pair of monoclonal antibodies, LZ12 and LZ18. Estimation of a patient's homozygous or heterozygous status for the Apo-E4 isoform was subsequently calculated as the ratio of Apo-E4/total Apo-E, respectively. Although the antibody for Apo-E used here does not have equivalent reactivity toward Apo-E2, -E3, or -E4, we were able to attain a fairly reliable assay system to estimate the status of the Apo-E4 isoform through a simple formula for the calculation of total Apo-E versus Apo-E4 isoform.
Uchida
Y
Y
Diagnostic Research Laboratories, Fujirebio, Inc., Hachioji, Tokyo, Japan.
Ito
S
S
Nukina
N
N
D000483:Alleles; D000544:Alzheimer Disease / Q000235:genetics; D000911:Antibodies, Monoclonal; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000097:blood* / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D020022:Genetic Predisposition to Disease; D006720:Homozygote; D006801:Humans; D012307:Risk Factors; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D053327:Apolipoprotein E4; D001057:Apolipoproteins E