Intra-individual alterations of serum markers routinely used in forensic pathology depending on increasing post-mortem interval

Lina Woydt,Benjamin Ondruschka,Ralph Burkhardt,Michael Bernhard,Holger Kirsten,Jan Dreßler,André Gries,Niels Hammer

doi:10.1038/s41598-018-31252-5

Abstract

Post-mortem biochemistry of serum markers has been the subject of numerous studies, but in-situ marker stability after death has not been sufficiently evaluated yet. Such laboratory analyses are especially necessary in the cases of functional deaths without morphological evidence of the death causes and also in cardiac death cases with only very short survival times. The aim of the study was to determine the post-mortem stability of commonly-used serum markers at predefined time points. In 20 cases, peripheral venous samples were taken starting immediately after circulatory arrest and ending 48 hours after death. Serum creatinine, urea, 3-β-hydroxybutyrate, tryptase, myoglobin, troponin T, creatin kinase and creatin kinase-MB have been included. For all markers, we observed increasing marker levels for longer post-mortem intervals. Significant marker level changes began two hours after death. Excessive increases were observed for cardiac and muscle markers. Marker levels showed high intra-assay precision. Furthermore, the markers were robust enough to withstand freeze-thaw cycles. Potential contamination of arteriovenous blood did not influence the post-mortem marker levels. Post-mortem blood should be sampled as soon as possible, as increased post-mortem intervals may heavily change marker levels in-situ in individual cases, whereas the markers are mostly unaffected by laboratory conditions.

Highlights

Since the 1960’s, numerous articles and intermittent reviews considering post-mortem biochemistry have been published[1,2,3], showing both an increasing number of authors occupying themselves with this sector of forensic science and the relevance of this topic in legal medicine
The application of biochemical markers in post-mortem investigations of both disciplines, forensic and clinical pathology, is still not well-established and is not used routinely, biochemistry is declared necessary to solve the ultimate causes of death in about 10% of natural deaths in forensic routine[3], e.g. in cases of acute kidney failure, metabolic ketoacidosis, anaphylaxis and in cardiac death cases with only very short survival times
The aim of the present study was to show if a selection of widely known and used biochemical markers of renal insufficiency, ketoacidosis, anaphylaxis or ischemic heart damage could be declared as stable intra-individually in the early post-mortem interval to conclude their reliability in forensic application

Summary

Introduction

Since the 1960’s, numerous articles and intermittent reviews considering post-mortem biochemistry have been published[1,2,3], showing both an increasing number of authors occupying themselves with this sector of forensic science and the relevance of this topic in legal medicine. There are, unrelated to the cause of death, hardly any published research attempts investigating the intra-individual stability of markers used in forensic medicine by serial peripheral venous blood measurements in the same body after the onset of death. Very few existing studies address the small number of biochemical markers of sepsis and anaphylaxis[8,9,10,11,12], and myoglobin[13] in post-mortem serum; there remain many organ systems whose characteristic markers have not been evaluated considering intra-individual changes after death. All were measured repeatedly in blood samples of the bodies post-mortem to determine their intra-individual in-situ stability after death in predefined time intervals and are outlined briefly in the following paragraph

Objectives

Methods

Results

Conclusion