A monoclonal-antibody-based enzyme-linked immunosorbent assay of lipoprotein(a)

1990 ◽  
Vol 36 (2) ◽  
pp. 192-197 ◽  
Author(s):  
W L Wong ◽  
D L Eaton ◽  
A Berloui ◽  
B Fendly ◽  
P E Hass
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Clinical Laboratory ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Apo B ◽  
Lipoprotein A ◽  
Premature Coronary Heart Disease ◽  
Large Populations

Abstract Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL)-like lipoprotein particle recently described as a risk factor for premature coronary heart disease, stroke, and atherosclerosis. Structurally, Lp(a) is similar to LDL in that it has comparable lipid composition and contains apolipoprotein B-100 (apo B-100). In addition, Lp(a) contains the glycoprotein apolipoprotein(a) [apo(a)], which is disulfide-linked to apo B-100. The recent awareness of a striking correlation between atherosclerosis and concentrations of Lp(a) in plasma prompted our development of an accurate quantitative assay for plasma Lp(a), a monoclonal-antibody-based enzyme-linked immunosorbent assay for Lp(a) that is shown to be sensitive, precise, and highly specific. The response to several isoforms of Lp(a) is linear, and as many as 80 samples can be quantified on one plate. This easily performed assay is suitable for use in the clinical laboratory and for screening large populations.

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

1989 ◽  
Vol 35 (7) ◽  
pp. 1380-1384 ◽  
Author(s):  
C Labeur ◽  
G Michiels ◽  
J Bury ◽  
D C Usher ◽  
M Rosseneu
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Plasma Cholesterol ◽  
Sample Pretreatment ◽  
Hdl Cholesterol ◽  
Normal Subjects ◽  
Enzyme Linked Immunosorbent Assay ◽  
Apo B ◽  
Lipoprotein A ◽  
Screening Programs

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.

Monoclonal antibodies can precipitate low-density lipoprotein. I. Characterization and use in determining apolipoprotein B.

1985 ◽  
Vol 31 (10) ◽  
pp. 1654-1658 ◽  
Author(s):  
S Marcovina ◽  
D France ◽  
R A Phillips ◽  
S J Mao
Keyword(s):  
Monoclonal Antibodies ◽  
Apolipoprotein B ◽  
Polyclonal Antibodies ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Radial Immunodiffusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Density ◽  
Apo B ◽  
Blotting Technique

Abstract We produced 20 mouse monoclonal antibodies against human plasma low-density lipoprotein (LDL). Individually they failed to precipitate LDL in agarose gel by the double-immunodiffusion technique; collectively they did, or as few as two combined monoclonal antibodies could do so. To mimic polyclonal antibodies in determination of apolipoprotein B (apo B) by radial immunodiffusion, a combination of four particular monoclonal antibodies (clones A, B, C, and D) was necessary. We characterized these four clones with respect to temperature dependency, affinity, total binding to 125I-labeled LDL, and specificity to the different species of apolipoprotein B. Two monoclonal antibodies (B and C) bound 100% of 125I-labeled LDL; clones A and D bound 80% and 87%, respectively. All four clones bound maximally to LDL at 4 degrees C. The affinity constants for clones A, B, C, and D were 0.6, 2.1, 3.8, and 2.3 X 10(9) L/mol, respectively. By the Western blotting technique, the four monoclonal antibodies all reacted with the species B-100 and B-74 of apolipoprotein B, and to various degrees with B-48 and B-26. Radial immunodiffusion (chi) and direct enzyme-linked immunosorbent assay (y) with a mixture of the four monoclonal antibodies gave almost identical results for 70 patients: y = 0.921 chi-2.58; r = 0.933.

Biological variability of cholesterol, triglyceride, low- and high-density lipoprotein cholesterol, lipoprotein(a), and apolipoproteins A-I and B

1994 ◽  
Vol 40 (4) ◽  
pp. 574-578 ◽  
Author(s):  
S M Marcovina ◽  
V P Gaur ◽  
J J Albers
Keyword(s):  
High Density Lipoprotein ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
High Density ◽  
Biological Variability ◽  
Apo B ◽  
Lipoprotein A ◽  
The Individual

Abstract Biological variability is a major contributor to the inaccuracy of cardiovascular risk assessments based on measurement of lipids, lipoproteins, or apolipoproteins. We obtained estimates of biological variation (CVb) for 20 healthy adults and calculated the percentiles of CVb as an expression of the variability of CVb among individuals for cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] by four biweekly measurements of these analytes. The CVb for the group was approximately 6-7% for cholesterol, HDL cholesterol, apo A-I, and apo B; approximately 9% for LDL cholesterol; and 28% for triglyceride. However, for each analyte, there was a considerable variation of CVb among individuals. For all analytes except Lp(a), there was no relation between the individual's CVb and the analyte concentration. Lp(a) was inversely related to CVb, and there was a very wide variation in the CVb for Lp(a) among the participants, ranging from 1% to 51%. The number of independent analyses to perform to accurately assess an individual's risk for coronary artery disease should be determined on the basis of the individual CVb for a given analyte rather than the average CVb.

Relation of lipoprotein(a) in 11- to 19-year-old adolescents to parental cardiovascular heart disease

1993 ◽  
Vol 39 (3) ◽  
pp. 477-480 ◽  
Author(s):  
J C Vella ◽  
E Jover
Keyword(s):  
Heart Disease ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Young Population ◽  
Serum Samples ◽  
Apo B ◽  
Lipoprotein A ◽  
Cardiovascular Heart Disease

Abstract We studied several risk factors in relation to parental cardiovascular heart disease: total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] were determined in 322 serum samples (43 from subjects with and 279 without parental cardiovascular heart disease). The distribution of Lp(a) concentrations in our young population was similar to that of other white populations, i.e., markedly skewed, with higher frequencies at low values. As compared with children whose parents did not report cardiovascular heart disease, those with affected parents had a higher mean Lp(a) (0.23 vs 0.18 g/L; P < 0.05). Moreover, 42% of the children with parental cardiovascular heart disease, but only 19% of those with no parental cardiovascular heart disease, exhibited Lp(a) values > 0.30 g/L. These results suggest not only that Lp(a) is an important risk factor for cardiovascular heart disease, but also that Lp(a) is more strongly related to the risk of cardiovascular heart disease than are HDL- and LDL-cholesterol and apo A-I and B.

Changes in serum lipoprotein(a) and lipids during treatment of hyperthyroidism

1995 ◽  
Vol 41 (2) ◽  
pp. 226-231 ◽  
Author(s):  
A W Kung ◽  
R W Pang ◽  
I Lauder ◽  
K S Lam ◽  
E D Janus
Keyword(s):  
Thyroid Hormones ◽  
Geometric Mean ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serum Lipoprotein ◽  
Transitional Period ◽  
Lipoprotein Cholesterol ◽  
Apo B ◽  
Lipoprotein A ◽  
Free Thyroxine Index

Abstract Because of suggestions that thyroid hormones modulate serum lipoprotein(a) [Lp(a)] concentration, we evaluated prospectively the serial changes of serum Lp(a), measured as apolipoprotein(a) [apo(a)], and other lipoproteins in 40 subjects with hyperthyroidism treated with radioactive iodine (RAI) therapy. Hyperthyroid patients had lower (P < 0.001) concentrations of apo(a), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and apo B, but higher apo A-I concentrations compared with age-matched controls [geometric mean (range)]; apo(a) 81 (17-614) vs 187 (17-1808 IU/L): TC 4.07 +/- 0.8 vs 5.22 +/- 1.00 mmol/L (mean +/- SD); LDL-C 2.47 +/- 0.89 vs 3.40 +/- 0.88 mmol/L; HDL-C 1.05 +/- 0.33 vs 1.24 +/- 0.34 mmol/L; apo B 0.66 +/- 0.23 vs 1.13 +/- 0.34 g/L, and apo A-I 2.07 +/- 0.42 vs 1.46 +/- 0.28 g/L, respectively. Euthyroidism was associated with normalization of serum TC, LDL-C, and apo B within 1 month of treatment. However, apo(a) required 4 months to normalize, and HDL-C and apo A-I were still abnormal 6 months after RAI. Serum apo(a), TC, LDL-C, and apo B were negatively correlated with serum thyroxine (T4), free thyroxine index, and triiodothyronine (T3) and positively correlated with thyrotropin during the transitional period from hyperthyroidism to euthyroidism. Parallel changes of these lipoproteins and thyroid hormones were also observed after treatment of hyperthyroidism. In conclusion, thyroid hormones do modulate lipoproteins, particularly Lp(a). The delay in normalization of apo(a) but not LDL suggests an effect on apo(a) production rather than on LDL removal.

Two new monoclonal antibody-based enzyme-linked assays of apolipoprotein B.

1986 ◽  
Vol 32 (8) ◽  
pp. 1484-1490 ◽  
Author(s):  
S G Young ◽  
R S Smith ◽  
D M Hogle ◽  
L K Curtiss ◽  
J L Witztum
Keyword(s):  
Monoclonal Antibody ◽  
Solid Phase ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Apo B ◽  
Competitive Assay ◽  
Microtiter Plates ◽  
Ldl Particles ◽  
Direct Assay

Abstract We describe two new monoclonal antibody-based, solid-phase immunoenzymometric assays for the quantification of apolipoprotein (apo) B in plasma: a competitive assay and a direct assay. For both, we utilize 96-well microtiter plates and native low-density lipoprotein (LDL) for preparing the standard curve. A single monoclonal antibody, MB24, is used in the competitive assay. The direct assay involves use of two monoclonal antibodies, MB24 and MB47. These two antibodies bind to distinct, unrelated apo B epitopes expressed by all LDL particles, and both antibodies detect apo B in very low-density and intermediate-density lipoproteins as well as LDL. With the two-step competitive assay, which involves use of LDL-coated microtiter plates, the intra- and interassay reproducibility in plasma apo B measurements averaged 6% and 12%, respectively. In the one-step direct assay, which takes less than 2 h for completion, plasma samples and peroxidase-labeled MB24 are incubated simultaneously on MB47-coated microtiter wells. The amount of labeled MB24 bound to lipoproteins trapped by MB47 is proportional to apo B concentration. With the direct assay, intra- and interassay CVs averaged 7% and 12%, respectively. These assays are simple, reproducible, involve convenient incubation intervals, and do not require radioisotopes; thus they can be widely applied in clinical laboratories.

Quantitation of plasma oxidatively modified low density lipoprotein by sandwich enzyme linked immunosorbent assay

1993 ◽  
Vol 218 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Hualiang Wang ◽  
Sicong Chen ◽  
Xiantao Kong ◽  
Xiaoli Wang ◽  
Guoyuan Chang ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Low Density ◽  
Oxidatively Modified

Decreases in Apolipoprotein(a) after Renal Transplantation: Implications for Lipoprotein(a) Metabolism

1992 ◽  
Vol 38 (3) ◽  
pp. 353-357 ◽  
Author(s):  
I W Black ◽  
D E Wilcken
Keyword(s):  
Renal Transplantation ◽  
Creatinine Clearance ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Apo B ◽  
Lipoprotein A ◽  
Patients Âgés ◽  
Apolipoprotein A ◽  
End Stage

Abstract Serum concentrations of apolipoprotein(a) [apo(a)], the unique glycoprotein of lipoprotein(a), are increased in patients with end-stage renal failure. We prospectively studied serum apo(a) and other lipoproteins in 20 consecutive patients, ages 46 +/- 11 years, before and for six months after successful renal transplantation. All patients received cyclosporine, and no patient was treated for hyperlipidemia. The mean creatinine clearance increased from 7.5 mL/min before transplant surgery to 40.9 mL/min six months afterwards (P less than 0.001). Apo(a) decreased from a median of 403 units/L before transplantation to 184 units/L at one week (P less than 0.001) and was 170 units/L (P less than 0.001) at six months. For the assay used, 1 unit of apo(a) is equivalent to 1 mg of lipoprotein(a). In contrast, from baseline to six months, increases were found for low-density lipoprotein (LDL) cholesterol (P = 0.03), high-density lipoprotein cholesterol (P = 0.06), apo B (P = 0.07), and apo A-I (P = 0.01). The decrease in apo(a) in individual patients was significantly correlated with the increase in creatinine clearance (r = -0.48, P less than 0.001). The single patient who developed nephrotic syndrome after renal transplantation had marked increases in apo(a) (693-1595 units/L), apo B, and LDL cholesterol, which paralleled the degree of proteinuria. These findings suggest that abnormal renal function affects the regulation of lipoprotein(a) metabolism.

Monoclonal antibodies can precipitate low-density lipoprotein. II. Radioimmunoassays with single and combined monoclonal antibodies for determining apolipoprotein B in serum of patients with coronary artery disease.

1985 ◽  
Vol 31 (10) ◽  
pp. 1659-1663 ◽  
Author(s):  
S Marcovina ◽  
B A Kottke ◽  
S J Mao
Keyword(s):  
Coronary Artery Disease ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Coronary Artery ◽  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Apo B ◽  
Artery Disease

Abstract We have established four lines of monoclonal antibodies against human low-density lipoproteins (LDL) that, mixed in equal proportions, can precipitate LDL in gel and so can be used for apolipoprotein (apo) B determination in plasma. One monoclonal antibody (clone A), with a relatively low binding affinity to LDL (ka = 0.6 X 10(9) L/mol) and recognizing only two species of apo B, significantly underestimated the concentration of apo B in 74 patients with and 27 without coronary artery disease (CAD). High-affinity monoclonal antibody C (Ka = 3.8 X 10(9) L/mol), which recognized all four apo B species, gave the same value for apo B as determined with the mixture of monoclonal antibodies. The latter results (by radioimmunoassay, y) correlated well with those by radial immunodiffusion (chi): y = 0.994 chi + 0.003 (r = 0.987). The CAD patients showed an increased concentration of apo B as compared to the angiographically documented CAD-negative patients. Except for the values determined by clone B (p = 0.07), the increase was statistically significant (p = 0.002-0.018) for values determined by use of the other clones or their mixture.

Sign in / Sign up

Export Citation Format

Share Document