Clinical significance of serum matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 in the first phase of burn trauma evolution

No prospective study has specifically examined the serum levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the early shock phase of burn-injured patients. Thus, we aimed to detect early changes, activity dynamics, and the predictive value of MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio to better understand the early repair mechanisms for the development of future therapies for patients with thermal burns. Twenty-five patients with a total body surface area (TBSA) affected by burn <25%, and 30 healthy subjects were enrolled in the study. Serum levels of MMP-9 and TIMP-1 were determined by the ELISA method. Our results showed that MMP-9 concentrations increased immediately after injury and remained on a plateau. In contrast, TIMP-1 showed an upward trend throughout the 7-day study period, and the time course of the MMP-9/TIMP-1 ratio followed the inverse dynamics of TIMP-1. Analysis of the areas under the receiver operating characteristic (ROC) curves (AUC) showed that patients with burn wounds tended to have a MMP-9 value higher than 421.5 ng/ml (AUC=0.979), TIMP-1 value higher than 231.6 ng/ml (AUC=0.908), and MMP-9/TIMP-1 ratio higher than 2.31 (AUC=0.959) (P<0.001). Our findings suggest that although the variations in the two biomarkers were different regarding the time of the initial insult, their ratio is a specific and sensitive indicator of burn evolutivity in patients with a TBSA affected by a burn <25%.