Chronic venous ulcers represent the last stage of chronic venous insufficiency. As reported, about 50-80% of chronic venous ulcers heal in 24 weeks. Chronic inflammation appears to be the most important reason for prolonged healing. Matrix metalloproteinases (MMPs) are involved in the pathophysiology of chronic venous ulcer healing. Cyclooxygenase-2 (COX-2) is an important enzyme in prostanoid synthesis, which is induced during inflammation.
29 venous ulcers in 22 patients were included in the study and observed for 24 weeks. All ulcers were measured at enrolment and after 4 weeks, using laser triangulation, and biopsy of the ulcer tissue and healthy skin was performed. Horizontal and vertical initial healing rates were calculated using laser measurements. Expression of MMP-1, MMP-2 and COX-2 was assessed in biopsy samples using immunohistochemistry.
The first aim of our study was to compare the expression of MMP-1, MMP-2 and COX-2 in wound tissue to that in normal skin. The second aim was to observe the expression of the above factors at the beginning and 4 weeks later, in relation to healing rates and final healing outcome after 24 weeks. The enrolled population was divided into two groups, namely healed and non-healed wounds after 24 weeks.
Horizontal initial healing rates (p=0.027) and vertical initial healing rates (p=0.031) in the first 4 weeks, as well as previous ulcer duration (p=0.034), proved to be an important predictive factor of healing in 24 weeks. In the healed group, MMP-1 decrease in the first 4 weeks was statistically significant (p=0.03). Decreases in MMP-1 and MMP-2 after 4 weeks of observation were distinct, positive predictors for ulcer healing. The healing odds were 3.7 times higher for a decrease in MMP-1 and 2.1 times higher for a decrease in MMP-2, compared to the healing odds for a non-decrease in MMP-1 and MMP-2.
In conclusion, a decrease in active form of MMP-1 and MMP-2, but not COX-2, in wound biopsy samples after 4 weeks of observation can predict better healing of chronic venous ulcers.
|