Usability of Immunohistochemistry in Forensic Samples With Varying Decomposition

Area of Science:

• Forensic Pathology
• Immunohistochemistry
• Tissue Analysis

Background:

• Immunohistochemistry (IHC) is crucial in surgical pathology but underutilized in forensic pathology.
• Postmortem tissue degradation is a suspected limitation for IHC validity.
• The actual impact of decomposition on IHC staining requires further investigation.

Purpose of the Study:

• To assess the impact of postmortem interval on the validity of immunohistochemistry (IHC) staining in forensic autopsy samples.
• To determine the reliability of IHC for postmortem diagnosis in relation to tissue decomposition.
• To evaluate the utility of specific antibodies (KL1, S100, vimentin, CD45) in postmortem IHC.

Main Methods:

• Analysis of 120 forensic autopsy tissue samples (liver, lung, brain) with postmortem intervals from 1 to over 14 days.
• Utilized the tissue microarray technique for sample preparation.
• Employed light microscopy and a scoring system for IHC reaction extent and intensity using antibodies KL1, S100, vimentin, and CD45.

Main Results:

• A correlation was observed between the postmortem interval and IHC staining scores across all tested tissues.
• Positive staining was consistently achieved with all antibodies in samples with postmortem intervals of 1 to 3 days.
• Samples with longer postmortem intervals exhibited reduced staining rates, indicating decreased reliability.

Conclusions:

• Immunohistochemistry (IHC) is a viable diagnostic method for postmortem analysis, particularly in cases with limited tissue decomposition.
• The findings support the successful application of IHC in forensic pathology for diagnosing conditions in autopsy samples within the initial 3 days postmortem.
• Further research may refine IHC protocols for optimal use in cases with advanced decomposition.