Comparison of postmortem stability of six markers for the diagnosis of myocardial infarction / 中国法医学杂志

ABSTRACT

Objective Investigate the postmortem stability of the six immunohistochemical markers of fibronectin(Fn),fibrinogen(Fg),C5 complement(C5), myoglobin(Mb), actin(HHF35)and desmin(Dm)for the postmortem diagnosis of myocardial infarction.Method The areas of depletion ofMb、HHF35 and Dm,and the positive reaction areas of Fn、Fg and C5 in the ischemic myocardium were studied with immunohistochemistry,image analysis technique and statistical system.The postmortem stability of the six immunohistochemical markers was compared.Results The specimens of normal myocardium kept at 4℃ for 1 to 2 days showed homogenous brown reactions for Dm, HHF35 and Mb; depletion of Dm, HHF35 and Mb became evident when these specimens were kept at 4℃ for 3 days postmortem, and the depletion area increased with the lapse of postmortem interval; the depletion area of Dm, HHF35 and Mb in ischemic myocardial tissues also increased with the lapse of postmortem interval;the positive reaction areas of Fg, C5 and Fn in ischemic myocardial tissues decreased with the lapse of postmortem interval.Fg became negative when the ischemic myocardium were kept at 4℃ for 2 weeks postmortem,C5 became negative when kept at 4℃ for 3 weeks postmortem,but Fn remained positive when kept at 4℃ for 4 weeks postmortem.No positive reactions for Fg,C5 and Fn could be found in normal myocardium when kept at 4℃ for different time intervals. The image analysis result showed that the positive reaction areas decreased with the lapse of postmortem interval. Conclusion The Dm and HHF35, Mb showed least postmortem stability, easily influenced by autolysis, only suitable for detection in fresh corpses(1to 2dayspostmortem) ;Fgislittlebitbetter,suitableforcorpsesat4℃ 1weekpostmortem ;C5isbet ter,suitableforcorpsesat 4℃ 2weekspostmortem ;Fnisthebestmarker ,suitableforcorpsesat 4℃ 4 weekspostmortem .