The role of nasal cytology and vitreous humor during forensics pathologist’s investigation to determine the postmortem interval

Filippo Milano¹, Stefania Urso², Carmelo Russo³, Silvestro Mauriello¹, Gian Luca Marella ⁴, Carlo Chiaramonte⁵, Luigi Tonino Marsella¹, Sergio Bernardini³, Saverio Potenza¹

¹Department of Biomedicine and Prevention, University of Tor Vergata, Rome, Italy - ²PhD School in Applied Medical Surgical Sciences, University of Tor Vergata, Rome, Italy - ³Department of Experimental Medicine and Surgery, University of Tor Vergata, Rome, Italy - ⁴Department of Surgical Sciences, University of Tor Vergata, Rome, Italy - ⁵Department of Statistics, University of Tor Vergata, Rome, Italy

Introduction: The Post-Mortem Interval (PMI) estimation is very important in medico-legal practice for the related possible legal repercussions. The most commonly used method to determine the time of death is the Henßge - Madea method, but it has several limitations. Other research criteria include the study of different body fluids, such as vitreous humor (HV), with particular reference to potassium (K⁺) levels; however this analyte alone was not sufficient for an adequate estimate of the PMI and therefore further new parameters were taken into consideration.  

Materials and methods: In this paper we propose, for the first time, the simultaneous analysis of biological matrices represented by the most studied components of the vitreous humor (K⁺, Na⁺) and by the nasal mucosa aimed at finding a connection between the intravitreal levels of K⁺ and Na⁺, the degradation of the nasal ciliated cells, the presence of bacterial and/or mycotic colonies for a more accurate estimate of the PMI. The statistical processing was carried out by the “multivariate linear regression” model for the determination of the forecast value of the PMI (expressed in hours) in relation to the values assumed by the empirical variables previously selected.

Results: The results obtained using the equation we proposed to calculate the PMI. show a confidence interval of 94% between the values obtained and the known values.

Conclusion: The results demonstrate that the chosen matrices could play a leading role in improving the accuracy of the PMI estimate in support of the work of the forensic pathologist in the dating of the time of death.