Degradation of antiproteinases, complement and fibronectin in chronic leg ulcers

It has been proposed that excessive and uncontrolled proteolytic activity is an important pathogenetic factor for chronic wounds. Identification of molecules that either control or reflect proteolysis in wounds may prove to be useful in determining wound healing activity. In this study wound fluid was sampled under a polyurethane dressing or on hydrophilic glass filters. Multiple chronic wound fluid components were identified; viz. the previously described alpha2-macroglobulin, alpha1-antitrypsin and fibronectin, as well as "novel" wound fluid molecules such as complement factor C3, inter-alpha-inhibitor, kininogen, IgG, IgA, C-reactive protein, tetranectin, orosomucoid and ceruloplasmin. There appeared to be a highly variable degradation of alpha1-antitrypsin in the wounds; furthermore, the activation of C3 appeared to correlate with the appearance of fibronectin breakdown products. In wound fluid, inter-alpha-inhibitor was degraded. The influence of the sampling procedures was studied. It was shown that contact phase activation must be taken into account in the study of molecules (such as kininogens) activated by hydrophilic charged surfaces.