The use of proteases as prognostic markers for the healing of venous leg ulcers.

Abnormally high levels of some proteases are associated with pathological changes in the wound bed of venous leg ulcers. This study involved two experiments which measured proteases in wound fluid harvested from leg ulcers in order to predict healing. In the first experiment, neutrophil elastase, a protease, was harvested from wound fluid extracted from the bandages of seven patients with leg ulcers. This was undertaken once a week over a period of up to six weeks. The amount of elastase recovered from the bandages showed wide variation between patients and there was no consistent correlation between the activity of elastase and healing of the ulcers, as determined nine months after sampling for the enzyme. The second experiment determined the stability of neutrophil elastase that was added to bandages for one week. The stability was found to vary from approximately 50% to 100%, depending on the type of bandage used. In addition to the possibility of using protease measurements to predict healing, the procedure was found to be simple, non-invasive and relatively inexpensive, and could be performed routinely in the clinic.