Autoantibodies to oxidized low-density lipoprotein in patients with type 2 diabetes mellitus.
BACKGROUND
Oxidation of low-density lipoprotein (LDL) is a crucial step in atherogenesis. There is an urgent need for direct measures of in vivo oxidative stress. Autoantibodies against oxidized low-density lipoprotein (Ab against Ox-LDL) are a direct measure of oxidative stress and predict cardiovascular disease. Our aim was to evaluate an ELISA for Ab against Ox-LDL in Type 2 diabetes, a condition with increased oxidative stress.


METHODS
Ab against Ox-LDL were measured by ELISA and expressed as a ratio of Ox-LDL to native LDL (N-LDL). Samples were obtained from 45 Type 2 diabetic patients and 25 matched controls before and after supplementation with alpha tocopherol (AT, 1200 IU/day).


RESULTS
The assay had good precision. While there was no interference with bilirubin and hemolysis, triglycerides 500 mg/dl increased antibody titer, which was abrogated by airfuging. Compared to controls, significantly increased titers of Ab against Ox-LDL were found in diabetics (diabetes mellitus Type 2) with macrovascular disease (DM2-MV), but not without macrovascular disease (DM2) (DM2: 1.32+/-0.33; DM2-MV: 1.48+/-0.44 vs. controls, 1.21+/-0.28; p<0.05). AT supplementation significantly decreased titers of Ab against Ox-LDL in both diabetic groups (p<0.01).


CONCLUSIONS
This assay may serve as a future test for the assessment of cardiovascular risk especially in patients with increased oxidative stress.
Hsu
Rebecca M
RM
Department of Pathology, Division of Clinical Biochemistry and Human Metabolism, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390-9073, USA.
Devaraj
Sridevi
S
Jialal
Ishwarlal
I
D001323:Autoantibodies / Q000032:analysis* / Q000187:drug effects; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D024505:Tocopherols / Q000627:therapeutic use
D001323:Autoantibodies; D008077:Lipoproteins, LDL; D024505:Tocopherols