Skin wounds vitality markers in forensic pathology: An updated review

Wound age evaluation is one of the most challenging issues in forensic pathology. In the first minutes or hours, standard histological examination may not determine whether the wound was inflicted in the pre- or post-mortem period. While red blood cell infiltration is classically considered as a sign of vital reaction, several studies have shown that extravasation of blood cells may also occur after death and cannot be used as a reliable marker in the diagnosis of wound vitality. Numerous studies about wound vitality are available in the literature. They have evaluated markers involved in coagulation or inflammation, using various methods such as enzymology, molecular biology or immunohistochemistry. In this update, we first introduce some methodological principles. Then, we review the main studies available in the literature. Immunohistochemistry seems to be the most valuable method, given its easy application and the possibility to analyse the localization of the molecules of interest. Some markers are promising, such as CD15, TNFα, IL-6, IL-1β, TGFα or TGFβ1. Prior to their application in daily practice, these early results need to be confirmed with other studies, conducted by independent teams and integrating multiple controls. Most notably, the antibodies have to be tested in numerous post-mortem wounds. Indeed, a critical risk of overexpression in post-mortem wounds is present. Some promising markers have been later invalidated because of post-mortem false positivity. Finally, optimal sensitivity and specificity values could probably be reached by combining several markers, validated by large groups of pre- and post-mortem wounds.