Post-mortem sepsis diagnosis through vitreous humour biomarkers: A retrospective forensic cohort study

Sepsis remains a challenging post-mortem diagnosis due to the nonspecificity of autopsy findings. This study evaluates five sepsis biomarkers (urea, high-sensitivity C-reactive protein, procalcitonin, lactic acid, and glucose) detected in vitreous humour.

In this retrospective study, 127 vitreous humour samples were analysed. Septic deaths were defined by clinical, radiological, and autopsy evidence, serving as reference standard for case/control group identification. Concentrations of urea, hs-CRP, PCT, lactic acid, and glucose were measured using ELISA and compared between septic/non-septic groups. Marker stability was tested across five post-mortem interval groups. A systematic literature review following PRISMA guidelines was conducted to contextualise the findings within the existing forensic evidence on sepsis biomarkers.

Urea and hs-CRP levels were significantly higher in septic cases (p < 0.001). hs-CRP demonstrated superior discriminatory ability (AUC = 0.729) and specificity (88.4%) compared to urea (AUC = 0.686), which showed higher sensitivity (85.7%) in ROC analyses. Combined analysis yielded an AUC of 0.781. All biomarkers except glucose and lactic acid remained stable during post-mortem up to 187 h.

Vitreous humour represents a promising matrix for post-mortem sepsis diagnosis. Urea and hs-CRP in vitreous humour demonstrated both discriminatory ability and post-mortem stability, making them valuable forensic tools, particularly when conventional matrices are unavailable. However, as a proof-of-concept study conducted in a selected forensic cohort with documented post-mortem intervals, these findings require validation in broader forensic scenarios. The demonstrated stability of urea, hs-CRP and PCT up to 187 h suggests potential applicability when the exact post-mortem interval is unknown.