Identification and quantitation of alpha 2-HS-glycoprotein in the mineralized matrix of calcified plaques of atherosclerotic human aorta.

alpha 2-HS-glycoprotein (HSGP) is a minor constituent of plasma with negative acute-phase reactant properties. HSGP has been shown previously to accumulate in the mineralized matrix of bone and dentin to concentrations substantially higher than those present in plasma. In addition, HSGP has also been found in experimentally induced dermal calcifications in animals. Here we show that HSGP is occluded in the organic matrix of pathological calcifications of atherosclerotic human aortic tissue in a concentration approximately 7-fold greater than that found in plasma.