Immunohistochemical study of fibronectin for postmortem diagnosis of early myocardial infarction

Area of Science:

• Forensic Pathology
• Cardiovascular Pathology
• Immunohistochemistry

Background:

• Diagnosing early myocardial infarction postmortem presents significant forensic challenges.
• Current methods may lack sensitivity or be affected by postmortem changes.
• A reliable biomarker for early detection is crucial in forensic practice.

Purpose of the Study:

• To evaluate fibronectin (FN) immunohistochemistry as a novel method for diagnosing early myocardial infarction in autopsy cases.
• To determine the reliability of FN staining in cardiomyocytes for postmortem identification of acute myocardial infarction.

Main Methods:

• An immunohistochemical study using the streptavidin/biotin/peroxidase technique was performed on 34 autopsy hearts.
• Fibronectin (FN) staining was assessed in cardiomyocytes of cases with confirmed myocardial infarction, suspected early infarction, and controls.
• Cases included those autopsied between 8 hours and 4 days postmortem, with some fixed in formalin for over 10 years.

Main Results:

• Positive FN staining in cardiomyocytes was observed in all 5 definite myocardial infarction cases.
• 15 out of 18 suspected early myocardial infarction cases showed positive FN staining.
• No positive FN staining was detected in 11 non-cardiac death control cases.
• Satisfactory FN staining results were obtained even in cases fixed for over 10 years, indicating resistance to autolysis and formalin fixation.

Conclusions:

• Positive fibronectin (FN) staining in cardiomyocytes is a reliable and sensitive marker for the postmortem diagnosis of acute myocardial infarction.
• FN immunohistochemistry offers a valuable new method for routine forensic practice, particularly for retrospective analysis.
• Fibronectin's stability against postmortem autolysis and formalin fixation makes it suitable for long-term archival cases.