[Metabolism of collagen in coronary patients]

The alterations observed in connective tissue of the arterial wall and dermis in atherosclerosis incited us to investigate collagen metabolism in patients with coronary disease. We first studied collagen metabolism in fibroblast cultures, then measured serum levels of type III procollagen aminoterminal peptide. Fibroblast collagen metabolism was investigated in 12 consecutive patients of less than 45 years of age presenting with coronary disease and coronary atherosclerosis was found to be preserved in patients with atherosclerosis, but less type III type I procollagen was synthesized (14.6 +/- 6.6% versus 22.3 +/- 4.3%). This abnormality, found in 83% of our coronary patients, seemed to be unrelated to risk factors or to the severity of atherosclerosis. Serum type III procollagen aminoterminal peptide was assayed comparatively in 36 patients with coronary atherosclerosis confirmed at coronary-ventriculography and in 35 patients free from coronary disease as defined by the W.H.O. criteria. Serum levels of this peptide were significantly higher in patients with coronary atherosclerosis (26.76 +/- 16 ng/ml) than in controls (10.43 +/- 3.18 ng/ml). 61% of coronary patients had a peptide level higher than the normal value (17 ng/ml). No correlation was found between this rise in type III procollagen aminoterminal peptide and the severity of coronary lesions or the importance of risk factors. Thus, collagen metabolism is altered in coronary patients, and this alteration can be detected by a peripheral marker. However, the use of this marker to diagnose the presence or evaluate the course of atherosclerosis requires clarification.