Postmortem Biochemistry and Immunohistochemistry in Anaphylactic Death Due to Hymenoptera Sting: A Forensic Case Report

Abstract

Background: Postmortem assessment of anaphylactic death is a challenge for forensic pathologists. One of the most frequent elicitors of anaphylaxis is insect venom. Here, a case of anaphylactic death due to Hymenoptera stings is reported to highlight the contribution of postmortem biochemistry and immunohistochemistry in assessing the cause of death. Case report: A 59-year-old Caucasian man working on his farm was presumably stung by a bee and died. He had a history of previous sensitization to insect venom. The autopsy revealed no signs of insect puncture, mild edema of the larynx, and foamy edema in the bronchial tree and lungs. Routine histology showed endo-alveolar edema and hemorrhage, bronchospasm, and scattered bronchial obstruction due to mucus hyperproduction. Biochemical analysis was performed, and serum tryptase was equal to 189 µg/L, total IgE was 200 kU/L, and specific IgE dosage was positive for bee and yellow jacket species. Immunohistochemistry for tryptase detection was carried out, revealing mast cells and degranulated tryptase expression in the larynx, lungs, spleen, and heart. These findings led to the diagnosis of anaphylactic death due to Hymenoptera stings. Conclusions: The case highlights that the role of biochemistry and immunohistochemistry in the postmortem assessment of anaphylactic reactions should be stressed by forensic practitioners.

An Insight into Kounis Syndrome: Bridging Clinical Knowledge with Forensic Perspectives

“…Thus, at postmortem evaluation, the main gross findings can be observed in the respiratory system, where the presence of laryngeal edema, tracheobronchial hypersecretion of mucus and mucosal edema with lumen obstruction, and pulmonary edema can support the occurrence of anaphylaxis [27]. Histological analysis provides the confirmation of these macroscopic data and, also, can show other signs such as bronchospasm, emphysema, and acute pulmonary edema [26]; then, an important finding, strongly related to anaphylaxis, is leukocyte infiltration, mostly mediated by basophils, eosinophils, and mast cells [23].…”

“…The postmortem assessment of anaphylactic death is considered a challenge because the evidence emerging from autopsy and histology is not pathognomonic. The diagnosis should be based on the integration of circumstantial and anamnestic data, autopsies, histological findings, and biochemical and immunohistochemical data [26,27]. This approach has a pivotal role also in those cases where the occurrence of KS is suspected after analyzing the anaphylaxis effectors in the biological fluids and in common target tissues, together with heart and coronary arteries [28].…”

“…Anaphylactic deaths are often related to a combination of factors, including upper airway obstruction from mucosal edema, asphyxia from bronchospasm, and shock due to massive fluid shifts [26]. Thus, at postmortem evaluation, the main gross findings can be observed in the respiratory system, where the presence of laryngeal edema, tracheobronchial hypersecretion of mucus and mucosal edema with lumen obstruction, and pulmonary edema can support the occurrence of anaphylaxis [27].…”

“…However, since these findings cannot be considered pathognomonic, other analyses, such as biochemistry and immunohistochemistry, can contribute to performing the postmortem diagnosis of anaphylaxis and KS [26].…”

Fatal Outcome Due to Kounis Syndrome Following Fluorescein Retinal Angiography: A Case Report

“…In general, the post mortem assessment of an anaphylactic death is considered a challenge because frequently no pathognomonic gross and microscopic findings are detected at autopsy. Thus, the diagnosis must be performed by the integration of several findings emerging from different types of investigations, among which biochemistry and immunohistochemistry are considered the most useful [ 7 ]. This post mortem approach is crucial also in cases with suspicion of KS, in which particular attention should also be given to the heart and coronary arteries [ 8 ].…”