Figure 4.

Aging is associated with increased PMN neutrophil elastase activity. PMNs from young or elderly donors were incubated for 45 min with complement-opsonized S. pneumoniae TIGR4. The level (A,C) and activity (B,D) of cathepsin G or neutrophil elastase in PMN lysates were determined (see Materials and Methods). Data from 5 young and 8 elderly donors are shown. Significant differences were determined by a Mann-Whitney test and denoted by “^*.”