Assessment of Inflammation-Related Biomarkers in Forensic Postmortem Samples

Postmortem identification of infection-related deaths remains a significant diagnostic challenge in forensic medicine. Although C-reactive protein (CRP) is widely used as an inflammatory marker, its limited specificity underscores the need for more accurate biomarkers. We evaluated the forensic utility of procalcitonin (PCT), interleukin-6 (IL-6), and CRP in postmortem samples. A total of 191 autopsy cases were analyzed, and serum levels of PCT, IL-6, and CRP were measured. The positivity rates were 11.5% for PCT, 98.9% for IL-6, and 32.9% for CRP. PCT demonstrated greater specificity for bacterial infections, with only two cases (1.0%) testing PCT-positive but CRP-negative, compared with 43 cases (22.5%) that were CRP-positive but PCT-negative. In contrast, IL-6 demonstrated high sensitivity but poor specificity. To evaluate field applicability, PCT levels were determined using both a point-of-care testing (POCT) device and a central laboratory analyzer. Although most measurements were concordant, the POCT method exhibited reduced sensitivity, failing to detect 64.7% of cases identified as positive by the central analyzer. These findings suggest that PCT is a specific and practical biomarker for identifying infection-related deaths, demonstrating superior specificity compared with CRP and IL-6, and should be interpreted alongside these markers for accurate postmortem evaluation. Incorporating PCT into routine postmortem investigations may enhance the accuracy and efficiency of forensic diagnosis in inflammation-related deaths.