Lipoprotein(a) quantified by an enzyme-linked immunosorbent assay with monoclonal antibodies.

Abstract

This new, sensitive, specific "sandwich"-type enzyme-linked immunosorbent assay (ELISA) for quantifying lipoprotein(a) [Lp(a)] in human serum and in ultracentrifugal lipoprotein fractions is based on use of a monoclonal antibody raised against apolipoprotein(a) as coating protein and a polyclonal antibody, raised against either apo B or against Lp(a) and conjugated with peroxidase, for detection of bound Lp(a). Mean intra- and interassay CVs for assay of 16 samples were 3.0% and 5.6%, respectively. Sample pretreatment with urea did not enhance Lp(a) immunoreactivity, and treatment with nonionic detergents decreased binding to the monoclonal antibody. Results correlated well (r = 0.99, n = 38) with those by radial immunodiffusion (RID). The ELISA assay, however, detects amounts corresponding to Lp(a) contents of 10 to 1000 mg/L in plasma samples diluted 1000-fold, compared with 100-500 mg/L for RID. For 92 normolipidemic subjects, the mean Lp(a) concentration was 120 (SD 130) mg/L. In patients undergoing coronary angiography, Lp(a) concentrations increased with the severity of the disease but were not correlated with either HDL cholesterol, triglycerides, apo A-I, or apo B, and only weakly with plasma cholesterol and apo A-II. These two correlations were even weaker in normal subjects, and only the correlation with total cholesterol was valid. Lp(a), measured at birth and at seven days and six months, steadily increased with age. This assay is well suited for measuring Lp(a) in plasma and in lipoprotein fractions and also for screening programs evaluating this significant genetic risk factor for the development of atherosclerosis.

Lipoprotein A profiles in Arab newborns

“…Lipoprotein A in cord blood is characterized by low concentrations, approximately 2.6‐fold lower than the concentration of LpA found in our previous study in children. The gradual increase of LpA concentration throughout the first year of life, observed in other studies 18 , 21 , 22 accounts for the interpretation that very low LpA values found at birth in the present study are a real phenomenon.…”

Lipoprotein(a) the Insurgent: A New Insight into the Structure, Function, Metabolism, Pathogenicity, and Medications Affecting Lipoprotein(a) Molecule

“…Plasma Lp(a) levels increase soon between a er birth until the 7th postnatal day [188] and reach a constant concentration within a few months of life [189]. In adults, Lp(a) levels range widely, from <2 up to 2500 mg/L [190].…”

Lipoprotein(a): what's in a measure?

“…A variety of methodological approaches have been used. Early methods included radial immunodiffusion, 11 radioimmunoassay 12 and electroimmunoassay, 13 but these were superseded by more sensitive, less labour-intensive enzymelinked immunosorbent assays (ELISAs) and immunoradiometric assays (IRMAs). 14,15 More recently, immunoturbidimetric and nephelometric methods have become more popular due to their rapid throughput, ease of automation and now improved precision.…”