Iron and 8-isoprostane levels in acute and chronic wounds

The purpose of this study was to determine differences in iron and iron protein (ferritin and transferrin) levels in chronic venous ulcers and acute wounds. The deleterious effect of iron in free-radical-induced tissue damage was indirectly examined by assessing 8-isoprostane levels and antioxidant status in wound fluid samples. Wound fluid samples from chronic leg ulcers in nonhealing and healing phases and wound fluid from mastectomy wounds were assayed for ferritin, transferrin, total iron, 8-isoprostane, and total antioxidant status. Immunohistochemistry and Perls' staining were performed on paired biopsies from chronic leg ulcers and on normal skin biopsies. Chronic wound fluid had significantly greater levels of ferritin (p<0.05) and lower levels of transferrin (p<0.001) than acute wound fluid and there was a significant reduction in the level of ferritin in healing compared to nonhealing chronic leg ulcers (p < 0.05). No significant differences were observed in the levels of total iron present in the wound fluids. Histologic staining showed consistently more ferritin and ferric iron in chronic wound tissue than in normal skin. Elevated levels of 8-isoprostane and antioxidants were observed for chronic wound fluid compared to acute wound fluid (p<0.001). These results suggest the existence of an environment of oxidative stress in chronic wounds and the likely contribution of iron to exacerbating tissue damage and delaying healing in these wounds.