Matrix metalloproteinases and their tissue inhibitors in severely burned children

Severe burns cause not only skin injury but several marked systemic derangements. During wound healing, matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases play an important role in tissue regeneration and remodeling processes. Therefore, in the present study, we determined the serum levels of MMPs and tissue inhibitor of metalloproteinase-1 in burn patients over time. Serum samples from 12 severely burned children (mean age 7.9 +/- 2.5 years) with >40% total body surface area burns were obtained within 0.5 hours, 3, 7, and 21 days after injury. Pro-MMP-1, MMP-3, MMP-9, and tissue inhibitor of metalloproteinase-1 serum levels were assayed by enzyme-linked immunoassay and compared to normal healthy volunteers. Two-way analysis of variance and Bonferroni's test were used for statistical analysis. Pro-MMP-1 levels in the serum were significantly elevated by the seventh day after burn. MMP-3 and MMP-9 levels showed significant increases by day 3 and 21 compared to normals, respectively. Tissue inhibitor of metalloproteinase-1 levels did not change with time after burn but were significantly higher by 3 days after burn compared to normal serum. In conclusion, changes in MMPs and tissue inhibitor of metalloproteinase-1 occur in burn patients and those changes may be a mechanism beneficial to wound healing.