Histological quantification of decomposed human livers: a potential aid for estimation of the post-mortem interval?

Ann-Sofie Ceciliason,Håkan Sandler,Håkan Sandler,Sofia Nyberg,M Gunnar Andersson

doi:10.1007/s00414-020-02467-x

Ann-Sofie Ceciliason, Håkan Sandler + Show 3 more

Open Access

https://doi.org/10.1007/s00414-020-02467-x

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Abstract

The objective of this study was to determine if a novel scoring-based model for histological quantification of decomposed human livers could improve the precision of post-mortem interval (PMI) estimation for bodies from an indoor setting. The hepatic decomposition score (HDS) system created consists of five liver scores (HDS markers): cell nuclei and cell structure of hepatocytes, bile ducts, portal triad, and architecture. A total of 236 forensic autopsy cases were divided into a training dataset (n = 158) and a validation dataset (n = 78). All cases were also scored using the total body score (TBS) method. We specified a stochastic relationship between the log-transformed accumulated degree-days (log10ADD) and the taphonomic findings, using a multivariate regression model to compute the likelihood function. Three models were applied, based on (i) five HDS markers, (ii) three partial body scores (head, trunk, limbs), or (iii) a combination of the two. The predicted log10ADD was compared with the true log10ADD for each case. The fitted models performed equally well in the training dataset and the validation dataset. The model comprising both scoring methods had somewhat better precision than either method separately. Our results indicated that the HDS system was statistically robust. Combining the HDS markers with the partial body scores resulted in a better representation of the decomposition process and might improve PMI estimation of decomposed human remains.

Highlights

Estimation of the post-mortem interval (PMI) is one of the most complicated tasks in forensic practice
The overall objective of this study was to determine if a novel scoring-based model for histological quantification of decomposed human livers could improve the precision of PMI estimation
We will begin by presenting the decomposition changes observed in the human liver in an indoor setting, and the hepatic decomposition score (HDS) system constructed

Summary

Introduction

Estimation of the post-mortem interval (PMI) is one of the most complicated tasks in forensic practice. There is a constant desire to identify good predictors of the PMI that would yield a more accurate estimate or at least assign a narrower time interval. The most decisive factor affecting the rate of decomposition is the ambient temperature; a higher temperature speeds up the onset of post-mortem tissue changes and bacterial growth as well as enzymatic function [3, 4]. Other extrinsic factors of importance include ventilation and humidity; dry areas with a constant air flow cause rapid dehydration of a dead body, reducing bacterial growth and inducing mummification, as opposed to humid climates, which accelerate decomposition [3, 5]

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