Blood elastolytic activity in patients with aortic aneurysm.

The question of why obstruction of the aorta (Leriche's syndrome) develops in some patients with severe atherosclerosis of the abdominal aorta while an abdominal aortic aneurysm occurs in others was examined. Significant differences in age, height, weight, mortality, and subsequent operative treatment were found between 335 patients with Leriche's syndrome and 103 patients with abdominal aortic aneurysm. Almost all in both groups smoked and demonstrated leukocytosis. In smokers with aneurysm, circulating serum elastolytic activity and leukocytic granular elastolytic activity were significantly increased, whereas serum antiproteolytic capacity was reduced. These results indicate that the development of abdominal aortic aneurysm in patients who smoke correlates with an abnormal homeostasis between proteolytic and antiproteolytic activity.