Neutrophil proteases, chronic wounds

Neutrophils also contain several cationic serine proteases (5). The enzyme, elastase, is particularly abundant The amount of elastase contained in the granules of a single neutrophil is in excess of one picogram (4) Several groups have used specific inhibitors as well as antisera to demonstrate that elastase or an elastase-like protease is abundant in chronic wound fluids (13,22-24). Mean levels of elastase activity is approximately 12-fold higher in fluids of chronic dermal ulcers compared to surgical... 

Additional serine proteases have been found in chronic wounds and neutrophils probably are also the primary source of these enzymes. These include cathepsin G, another cationic serine protease with broad substrate specificity, urokinase-type plasminogen activator (itfA), and protease 3 (3,32-35). In all probability, when looked for, elevated levels of additional neutrophil proteases will be found in chronic dermal ulcers. 

Another abundant plasma protease inhibitor, ai-antiprotease (apantitrypsin), irreversibly inhibits neutrophil elastase by forming an enzyme-inhibitor complex (38). Levels of complexed forms of ai-antiprotease are significantly increased in chronic wound fluids and at least some of these complexes contain elastase (13,22). 

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