Tryptase, CD15 and IL-15 as reliable markers for the determination of soft and hard ligature marks vitality

Abstract

In forensic practice, it is required to distinguish between suicidal or accidental hanging and simulated hanging. Conventional macroscopic and histological findings may be unreliable; vital signs are often absent, and they can be produced postmortem. The application of immunohistochemical techniques opened up a new field of investigation in the issue of ligature marks. We investigated the immunohistochemical expression of a panel of cytokines and inflammatory cells in skin specimens in autopsy cases of death due to hanging, to discuss their significance in assessing whether hanging mark and signs occurred before or after the death of the victim. We selected 21 cases in which broad, soft and yielding materials were used and 28 cases in which materials used for hanging were hard. The control group included the following 21 cases: 14 cases of sudden cardiac death and 7 cases of postmortem hanging (suspension) of bodies (drug overdose or suffocation as cause of death in all the cases). An immunohistochemical investigation of skin samples was performed utilizing antibodies anti-tryptase, fibronectin, TNFα, IL-6, IL-8, IL-10, MCP-1, IL-15, IL-1ß, CD45, CD4, CD3, CD8, CD68, CD20, CD15. We conclude that tryptase, IL-15, and CD15 appear to be reliable parameters in the determination of ligature marks’ vitality with the accuracy needed for forensic purposes. This fact especially applies to soft marks which are particularly difficult to evaluate on the basis of gross examination and of conventional histological studies.