Sera and leukocyte elastase-type protease and antiprotease activity in healthy and atherosclerotic subjects of various ages.

Serum and granulocyte elastase-type protease activities were determined simultaneously with their main plasma proteinase inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin in healthy control and atherosclerotic (ATS) subjects. The age-related associations of these parameters were also investigated. Serum elastase-type protease activity increased, but not statistically significantly, with aging in both control and ATS subjects. The enhancement of elastase-type protease activity in sera of ATS patients was significantly (p less than .02) greater than control subjects only in the case of the elderly. The granulocytes' elastase activity was significantly greater in granulocytes derived from both middle-aged and elderly ATS patients (p less than .03 and p less than .06) compared to age-matched control subjects. Alpha-1-antitrypsin was not significantly lower, whereas alpha-2-macroglobulin was significantly lower in sera of ATS subjects compared to age-matched control subjects (p less than .01). The conclusion is that increased elastase-type activity and decreased antiproteinase activity should be considered as potential factors in atherosclerotic arterial wall damage. The similarity of the results in the elderly and the ATS subjects suggest that atherosclerosis is an early aging process.