Prognostic value of markers of collagen remodeling in venous ulcers

A 25 patient study was conducted into the relationship between markers of collagen metabolism in venous ulcer exudates and healing status, and their prognostic value in predicting healing performance. Wounds were sampled on at least 5 occasions over 12 months, the frequencies of which were determined by the need for clinic attendance. Specimens were taken from several sites on each ulcer using sterile preweighed filters. Wound margins were traced and sites recorded for each collection. Sample sites were evaluated for severity as improving, static, or deteriorating according to subsequent wound progression. Specimens were analyzed for levels of proenzyme and active forms of matrix metalloproteinases 2 and 9, neutrophil elastase, and type I collagen C propeptide. There was an overall trend of greater expression of all markers with increasing severity of wound site, this being highly significant for pro-matrix metalloproteinase-9 (p = 0.006). For samples collected simultaneously from improving and deteriorating regions of the same wound, paired data analysis showed statistically significant differences for pro-matrix metalloproteinase-9 (p < 0.001), neutrophil elastase (p < 0.005) and activated matrix metalloproteinase-9 (p < 0.05). Taken overall, these data show the potential of markers of collagen biochemistry as predictors of repair in venous ulcers; in particular pro-matrix metalloproteinase-9 and neutrophil elastase were found to be accurate prognostic indicators of subsequent healing.