Immunohistochemical detection of chemokines in human skin wounds and its application to wound age determination

Immunohistochemical studies on the time-dependent expression of the chemokines such as interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha were performed on 50 human skin wounds with different wound ages (group 1 0-12 h, group IT 1-4 days, group III 7-14 days and group IV 17-21 days). In the wound specimens with wound ages between 4 and 12 h, neutrophils mainly showed positive reactions for IL-8, MCP-1 and MIP-1alpha. With increasing wound ages, macrophages and fibroblasts were positively stained with anti-IL-8, MIP-1alpha and MCP-1 antibodies. Morphometrically, there was a similar distribution in the positive ratios of the inflammatory cells among IL-8, MCP-1 and MIP-1alpha. The positive ratios of each chemokine were very low in group I and a considerable increase of the positive ratios in each chemokine was observed in group 11 (mean standard error IL-8: 59.8 +/- 2.1%, MCP-1: 42.4 +/- 3.1% and MIP-1alpha: 50.4 +/- 3.7%). Although the positive ratios for each chemokine gradually decreased according to the wound age, the mean positive ratios in groups III and IV were significantly higher than those in group I. From the forensic aspect, these chemokines are considered useful markers for wound age determination. Thus, ratios of > 50% for IL-8, > 30% for MCP-1 or > 40% for MIP-1alpha indicate a wound age of at least 1 day. Moreover, the combined investigation of these three chemokines can make wound age determination more objective and accurate.