Vimentin and p53 Immunoreactivity in Cases of Traumatic Brain Injury

Abstract

Background: Traumatic brain injury (TBI) is one of the main causes of death in trauma pathology, especially among the youngest victims. After having evaluated the causality relationship between damage to the brain tissue and death, pathologists should try to estimate the duration between the TBI and death. Immunohistochemistry could be used in this field as a personalized medico-legal approach. This study aims to evaluate the possible role of vimentin and p53 as TBI markers to assess vitality and date the TBI. Methods: Twelve cases of TBI deaths were selected (two women and ten men, with a mean age of 46.83 years). In seven cases, death occurred immediately after the trauma, while in the others, death occurred after some days. An immunohistological study of brain samples using anti-p53 and anti-vimentin antibodies was performed. A semi-quantitative scale was adopted to grade the immunohistochemical reaction. Results: Our results showed a strong relationship between the p53 immunoreaction grade and TBI (X-squared value 10.971, p-value < 0.01), suggesting that p53 expression is enhanced in TBI cases. Vimentin is more expressed when the PTI is longer. Vimentin-immunoreaction was weaker than p53-immunoreaction (+0.75 vs. +1.83 mean values, respectively) in a group predominantly including short post-traumatic interval cases. Conclusions: The present research is limited by the small sample size; however, the molecules tested, vimentin and p53, have shown great potential to be used, in addition to others, as biological markers for the diagnosis and timing of TBI.

Keywords: forensic neuropathology; p53; traumatic brain injury; vimentin; vitality.

Figure 1

Positive controls. (A) Skin sample positive for vimentin; (B) breast cancer sample positive for p53.

Figure 2

Vimentin and p53 positivity in TBI. (A) Monocyte/macrophage-like cells (red asterisk) with cytoplasm positive for p53 in pericontusional zone of cerebral cortex (p53, original magnification × 600). (B) Leukocytes positive for p53 in intracerebral hemorrhage (p53, original magnification × 100). (C) Glial cells (red arrow) and neurons positive for p53 in pericontusional zone of cerebral cortex (p53, original magnification × 400). (D) Leukocytes positive for vimentin within cerebral vessel (vimentin, original magnification × 100). (E) Astrocytes (red asterisks) positive for vimentin in pericontusional zone of cerebral cortex (vimentin, original magnification × 600 and × 400 (F).

Figure 3

Graphs showing the different grade distribution among the two groups. The y-axis shows the number of cases, while the x-axis shows the immunoreaction grade.

Figure 4

Spearman rank correlation between the immunoreaction grade and the time between trauma and death. Vimentin is on the left and p53 is on the right.