Immunohistochemical and morphometrical study on the temporal expression of interleukin-1alpha (IL-1alpha) in human skin wounds for forensic wound age determination.

An immunohistochemical and morphometrical study on the temporal expression of interleukin-1alpha (IL-1alpha) was performed on 40 human skin wounds with different wound ages. Immunohistochemically, polymorphonuclear neutrophils mainly showed positive reactions for IL-1alpha in wounds aged between 4 h and 1 day, but with increasing wound age, neutrophils were no longer present, and macrophages and fibroblasts were positively stained. Morphometrically, the ratio of the number of IL-1alpha-positive infiltrating cells to the total number of infiltrating cells was evaluated. A considerable increase in the IL-1alpha-positive cell ratio was observed in wound specimens aged 4 h to 1 day, and the maximum ratio was 46.5% in a 7 hold wound. The mean value of the IL-1alpha-positive ratio in 10 wound specimens with different wound ages between 4 h and 1 day was 32.8 +/- 9.7%. In most cases the ratio of IL-1alpha-positive cells gradually decreased in wounds aged between 1.5 and 21 days to less than 30%, and the mean value was 17.5 +/- 7.2% (n = 27). These results suggest that ratios of IL-1alpha-positive cells considerably exceeding 30%, indicate a postinfliction interval of 1 day or less.