Quantification of lipoprotein(a) particles containing various apolipoprotein(a) isoforms by a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apolipoprotein B detection antibody sandwich enzyme immunoassay.
A quantitative sandwich ELISA for lipoprotein(a) [Lp(a)], utilizing a monoclonal capture antibody that recognizes human and rhesus monkey apolipoprotein(a) [apo(a)] isoforms in combination with a polyclonal anti-apolipoprotein B-peroxidase conjugate was developed. This assay generates a linear calibration curve from 31.2 to 1000 mg/L, is highly reproducible (intra- and interassay CV of < 5% and < or = 12%, respectively), and shows no interference from plasminogen (1 g/L), low-density lipoprotein (6.00 g/L), triglycerides (27.00 g/L from chylomicrons and 10.00 g/L from very-low-density lipoprotein), hemoglobin (5 g/L), or bilirubin (30 mg/L). This assay format quantifies the concentration of Lp(a) on an equal molar basis regardless of apo(a) isoform. In contrast, a commercially available ELISA [Macra Lp(a)] method with a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apo(a) conjugate was found to underestimate the Lp(a) concentrations of individuals with lower-M(r) apo(a) isoforms--whether quantifying the Lp(a) in plasma or the purified lipoprotein. This demonstrates the importance of assay format selection in quantifying Lp(a).
Taddei-Peters
W C
WC
Organon Teknika/Biotechnology Research Institute, Rockville, MD 20850.
Butman
B T
BT
Jones
G R
GR
Venetta
T M
TM
Macomber
P F
PF
Ransom
J H
JH
D000818:Animals; D000906:Antibodies; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D001054:Apolipoproteins A / Q000032:analysis* / Q000276:immunology; D001055:Apolipoproteins B / Q000276:immunology; D001663:Bilirubin / Q000097:blood; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D000939:Epitopes / Q000276:immunology; D006454:Hemoglobins; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008253:Macaca mulatta / Q000097:blood; D010958:Plasminogen; D011786:Quality Control
D000906:Antibodies; D000911:Antibodies, Monoclonal; D001054:Apolipoproteins A; D001055:Apolipoproteins B; D000939:Epitopes; D006454:Hemoglobins; D017270:Lipoprotein(a); D010958:Plasminogen; D001663:Bilirubin