Antibody against oxidized low-density lipoprotein predicting myocardial infarction.
BACKGROUND
Oxidation of low-density lipoprotein is believed to be an important step in the pathogenesis of atherosclerosis. The purpose of the present study was to determine whether antibody against oxidized low-density lipoprotein, reported to be associated with the progression of carotid atherosclerosis, is predictive of cardiac death and nonfatal myocardial infarction.


METHODS
Serum samples from 135 cases and their controls, drawn at entry from middle-aged dyslipidemic men participating in the Helsinki Heart Study, a 5-year coronary primary prevention trial with gemfibrozil, were tested for immunoglobulin G class antibodies against oxidized low-density lipoprotein by enzyme-linked immunosorbent assay.


RESULTS
The mean antibody level, expressed in optical density units, was significantly higher in cases than in controls (0.412 vs 0.356, P = .002). After adjustment for age, smoking, blood pressure, and high-density lipoprotein cholesterol level, there was a 2.5-fold increased risk (95% confidence interval, 1.3 to 4.9) of a cardiac end point in the highest tertile of antibody level vs the lowest tertile (P = .005 for trend).


CONCLUSIONS
Elevated levels of antibodies against oxidized low-density lipoprotein were predictive of myocardial infarction. The effect was independent of low-density lipoprotein cholesterol levels, and the joint effect was additive. Elevated antibody levels modified the effects of classic coronary risk factors.
Puurunen
M
M
National Public Health Institute, Helsinki, Finland.
Mänttäri
M
M
Manninen
V
V
Tenkanen
L
L
Alfthan
G
G
Ehnholm
C
C
Vaarala
O
O
Aho
K
K
Palosuo
T
T
D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000276:immunology*; D006801:Humans; D006949:Hyperlipidemias / Q000276:immunology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D010084:Oxidation-Reduction
D001323:Autoantibodies; D008078:Cholesterol, LDL; D002784:Cholesterol