A new protective factor in coronary artery disease. Very low density lipoprotein toxicity-preventing activity.

A newly discovered activity in human serum protects porcine aortic endothelial cells in culture from injury by very low density lipoproteins (VLDL). This factor, toxicity-preventing activity (TxPA), was measured in 29 relatively young men (43 +/- 8 years) who had undergone coronary angiography. The level of TxPA was found to be significantly reduced (P less than 0.001) in men who demonstrated more than 15% narrowing of their coronary arteries. Men (n = 18) who had 15% or less narrowing were found to have 104 +/- 48 units of TxPA while men (n = 11) with coronary artery disease had 48 +/- 24 units of TxPA. A value derived from the product of TxPA and the high density lipoprotein cholesterol (HDL-C) level divided by the non-HDL-C (total cholesterol-HDL-C) accurately separated 97% of the men into 2 groups. TxPA thus appears to be a new protective factor in coronary artery disease, which, when combined with total cholesterol and high density lipoprotein cholesterol values, provides an accurate classification of established coronary artery disease in these subjects.