Immunohistochemical detection of CD14 and combined assessment with CD32B and CD68 for wound age estimation

Estimation of wound age is a major topic of study for forensic pathologists, but few markers exist that can indicate a specific period 1-5 days postinfliction, and a method to estimate wound age with high accuracy has not yet been established. This study examined CD14 as such a marker in mouse skin wounds of different ages (0min and 1, 2, 3, 5, 7, and 9 days) and in human subjects (group 1, 0-1 day; group 2, 1-5 days; group 3, >7 days) using Western blot analysis and/or immunohistochemical staining. In addition, we evaluated a combination of immunohistochemical markers in human skin wounds using transmembrane proteins, CD14, CD32B, and CD68, expressed on inflammatory cells. The expression of CD14 was detected only during 1-5 days postinfliction and, thus, the evaluation of CD14-expressing cells could specify wound age during 1-5 days postinfliction in mouse skin wounds. The ratio of samples assessed to be CD14(+) was significantly high in human skin wounds in group 2. Combined assessment using the three markers increased the specificity of diagnosis and shortened the range of wound age, compared with the assessment using a single marker. Our results indicate that CD14 may be a useful marker of wound age, 1-5 days postinfliction, and that combined assessment with CD14, CD32B, and CD68 may be a good method for the accurate estimation of wound age.