TABLE 3.

Comparison of the main features of published assays and commercially available kits for the assay of modified LDL antibodiesa

Author(s)Type of assayAntigen coatingModification controlCalibrators; unitsQuality controls
Virella and others (21, 25, 60)Competitive EIA for oxLDL total antibodyCopper-oxidized LDL, 7.5 μg/ml in 1-mol/liter bicarbonate buffer, pH 9.6Continuous monitoring of fluorescence emission (25)Human serum with known antibody concentration (21); values calculated as mg/literAdded to each plate
Palinski et al. (39) Hulthe et al. (15)Direct binding EIA for IgG and IgM antibodies; postcoating of plates to control nonspecific absorptionCopper-oxidized LDL and MDA-LDL, 5 μg/ml in PBS (pH 7.4) containing antioxidantsElectrophoretic mobility in agarose gelsOne internal standard; values calculated as ratio unknown (serum minus postcoat)/internal standard (serum minus postcoat)None mentioned
Erkkilä et al. (8); Maggi et al. (28, 55); Monaco et al. (32)Direct binding EIA for oxLDL total antibody; native LDL-coated plates to control nonspecific absorptionCopper-oxidized LDL, 2 μg/ml (8), 5 μg/ml (28), MDA-LDL, 5 μg/ml (28, 55), in PBS containing antioxidants, LDL oxidized with peroxidase + hydrogen peroxide (32)Not mentionedValues calculated as the ratio between binding to oxLDL and that to native LDL (8; ref. 146 of ref. 28) or as the difference in OD between binding to oxLDL and that to native LDL (55)Added to each plate (8)
Wu and Lefvert (71)Direct binding EIA for oxLDL antibodies of different isotypesCopper-oxidized LDL, 2 μg/ml in 5 mM bicarbonate buffer, pH 9.7TBARS assayValues expressed as ODNone mentioned
Wu et al. (72)Chemiluminescence assay for IgG and IgM antibodies to oxLDL and MDA-LDLCopper-oxidized LDL and MDA-LDL, 5 μg/ml in TBS containing antioxidantsNot mentionedValues expressed as relative luminescence unitsNone mentioned
Salonen et al. (44)RIA for antibodies to oxLDL and MDA-LDLCopper-oxidized LDL and MDA-LDL, 5 μg/ml in PBS containing antioxidantsMeasurement of MDA-modified lysnes in MDA-LDLValues expressed as the ratio between binding to oxLDL and that to native LDLNone mentioned
Boullier et al. (4); Craig (6)Direct binding EIA for antibodies to MDA-LDLMDA-LDL, 5 μg/ml (4), 25 μg/ml (6)Electrophoretic mobility; TBARS assayValues expressed both as the ratio and as the difference in OD between binding to oxLDL and that to native LDLNone mentioned
Craig (6)EIA for antibodies to MDA-LDLMDA-LDL, 25 μg/mlTBARS assay
Alpco Diagnostics; Kamiya Biomedical Co.EIA for oxLDL antibodiesCopper-oxidized LDLNot mentionedValues expressed as mU/ml, based on calibration with a reference serumHigh and medium quality control samples
  • a Abbreviations: RIA, radioimmunoassay; PBS, phosphate-buffered saline; TBS, Tris-buffered saline; ref., reference.