Immunohistochemistry as a tool to characterize human skin wounds of hanging marks

Abstract

Estimation of age and vitality of human skin wounds both in the living and dead is essential in forensic practice. The use of immunohistochemical parameters for the age estimation and vitality of human skin wounds remains difficult. Forensic literature describes different biomarkers and methods for the differential diagnosis of vital and post-mortem wounds, but to this day it is unclear its utility. The aim of this study was analysed wounds vital origin in a series of suicidal hangings were vitality had been demonstrated using fibronectin, cathepsin D and P-selectin, in order to discover the morphological changes that occur in a vital wound, and consequently, find useful vital injury diagnosis markers. A total of 15 human vital skin wounds from ligature marks from deaths by suicidal hanging and skin controls from same cadaver were analyzed in a postmortem interval between 19-36 hours. Fibronectine, cathepsin D and P-selectin were detected by immunohistochemistry. Our result shows a strongly fibronectin-positive reaction in basement membranes and interstitial connective tissue in all specimen of wounds of ligature mark. Granular staining pattern characteristic of cathepsin D was observed mainly in the basal layer of the epidermis in normal and wound skin. Cathepsin D analysis in ligature mark showed moderate positive and strong positive cells. A weak positive immunoreactivity P-selectin were found in vital wound compared with undamaged skin. In conclusion, our data show an increase of fibronectin and cathepsin D immunoreactivity expression and a decrease of P-selectin immunoreactivity in skin wounds from ligature marks from deaths by suicidal hanging of a postmortem interval between 19-36 hours.