Increased elastase and cathepsin G activity in activated lymphocytes from aged patients: Role of denutrition and dementia

Elastase and cathepsin G activities in cell-lysates and in culture supernates of activated human lymphocytes (incubated for 96 h in the presence of 5 μg/ml of phytohemagglutinin with/without 2 μg/ml of elastin peptides) of 25 old, hospitalized patients (average age: 88.48±6.81 years), suffering from vascular-type dementia or denutrition were examined, in comparison with samples of 11 young, healthy donors. Elastase activity was found to be significantly elevated, the excreted fraction of elastase activity strongly decreased in lymphocytes of these patients as compared to young donors. The highest values of enzymatic activities in the culture supernates and also in the cell-lysates were obtained for samples of undernourished patients. Lymphocytes from young, healthy donors showed a significant increase both of excreted and intracellular elastase activity when cultured in presence of elastin peptides. The activation of elastolytic activity by elastin peptides decreased with the age of donors. The results for cathepsin G are essentially similar but the differences between age-categories are less pronounced than for elastase activity.