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.
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.
D000911:Antibodies, Monoclonal; D001055:Apolipoproteins B / Q000097:blood* / Q000276:immunology; D003327:Coronary Disease / Q000097:blood*; D003331:Coronary Vessels; D005612:Freeze Drying; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D005779:Immunodiffusion; D008077:Lipoproteins, LDL / Q000032:analysis / Q000276:immunology*; D008297:Male; D008722:Methods; D011859:Radiography; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D001055:Apolipoproteins B; D008077:Lipoproteins, LDL