Diagnosis of anaphylactic death in forensics: Review and future perspectives

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

Kounis Syndrome (KS) is a clinical entity triggered by allergic or hypersensitivity reactions capable of inducing acute coronary events. Several causes can induce KS, including drugs and insect stings. Here, a rare case of post mortem assessment of fatal KS related to fluorescein retinal angiography has been reported. An 80-year-old man in follow-up for a retinal vein thrombosis underwent a retinal fluoroangiography. Approximately 30 min later, the patient complained of sweating and dizziness, and suddenly lost consciousness due to a cardiac arrest. Despite the immediate cardiopulmonary resuscitation, he died. The autopsy revealed foamy yellowish edema in the respiratory tract and coronary atherosclerosis with eccentric plaques partially obstructing the lumen. The routine histology highlighted lung emphysema and myocyte break-up with foci of contraction band necrosis at the myocardial tissue. Biochemistry showed increased serum tryptase, troponin, and p-BNP. Activated and degranulated (tryptase) mast cells were detected, using immunohistochemistry, in the larynx, lungs, spleen, and heart. Acute myocardial ischemia due to allergic coronary vasospasm related to fluorescein hypersensitivity has been assessed as cause of death. KS-related deaths are considered rare events, and the post mortem assessment of KS quite difficult. The integration of several investigations (gross and microscopic examination, biochemistry, immunohistochemistry) can provide useful findings to support the diagnosis, helping to reduce the unrecognized cases as much as possible.

Anaphylactic deaths: A retrospective study of forensic autopsy cases from 2009 to 2019 in Shanghai, China

Anaphylaxis is a rare but well-known cause of sudden unexpected death, although data from forensic autopsies in anaphylactic deaths are limited. Herein, a retrospective study of a series of allergic deaths from 2009 through 2019 in Shanghai, China, was conducted to investigate the demographic, medical, and forensic pathological characteristics of fatal anaphylaxis to improve medicolegal understanding on anaphylactic death. Sixty-two autopsy cases of anaphylactic death were registered in this study. Males dominated the cases (74.2%) against females (25.8%), with an average age of 38.8 years. Medications (98.4%), particularly antibiotics (72.6%), were the most frequent cause of anaphylaxis, and 44 cases (71.0%) occurred in clinics administered illegally by unlicensed clinicians. The anaphylactic symptoms began within a few minutes to less than 1 h in 53 cases, with dyspnea (56.5%) and sudden shock (46.8%) being the most common clinical signs. Thirty cases (48.4%) of anaphylaxis resulted in death within 1 h. Laryngeal edema and multiple tissue eosinophil infiltration (85.5%) were the most prevalent autopsy findings, followed by pulmonary edema and congestion (24.2%), which were considered to be non-specific but suggestive. The comorbidities were mainly cardiovascular disease (33.9%), pneumonia (8.1%) and asthma (8.1%). Serum IgE were measured in 11 of 62 cases, ranging from 43.3 to 591 IU/ml, severed as a helpful marker. Therefore, we suggested a thorough analysis of allergen exposure, clinical history and autopsy findings is required for the diagnosis of anaphylactic death currently.

Medicolegal Implications of Deaths due to Agricultural Accidents

ABSTRACT

Agriculture encompasses a variety of activities that carry with them a variety of different risks. The unsafe use of vehicles, machinery, and tools as well as animal husbandry, working at heights, and exposure to chemical, biological, and weather events may result in the deaths of agricultural workers. Inexperienced operators and/or their inappropriate conduct may lead to avoidable fatalities. Forensic pathologists operating with the support of agricultural engineers or other professionals must evaluate the death scene, the case background and circumstances, the autopsy findings, and the toxicological data to establish the factors and dynamics responsible for such accidents and deaths.The aim of this review is to focus on the diagnostic approach required, by means of an interdisciplinary approach, to identify the cause of some typical agricultural fatalities, to confirm that death was accidental, and to help exclude the possibility of homicide or suicide.

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

Kounis syndrome (KS) is an acute coronary syndrome triggered by allergic or hypersensitivity reactions. Incidence rates vary, with studies reporting 19.4 per 100.000 among all admissions and 3.4% among allergy patients. This review explores the expanding understanding of KS, encompassing various manifestations, and focusing on both clinical data and forensic findings useful in performing a diagnosis. The pathophysiology of this syndrome involves a complex interplay between allergic reactions and the cardiovascular system. Mast cell activation, histamine release, leukotrienes, cytokines, and platelet activation can contribute to coronary events. Three types of classification systems (allergic angina, allergic myocardial infarction, allergic stent thrombosis) aid in categorizing presentations. The diagnosis of KS relies on clinical presentation, laboratory findings, and imaging. Postmortem assessment of KS is based on the integration of circumstantial data, autopsy, and histological findings. Biochemical and immunohistochemical analyses also contribute to postmortem diagnosis. In conclusion, a combined, multidisciplinary approach should be used to ease the diagnostic process, which is crucial for forensic practitioners in confirming KS occurrence.

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

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.

Attenuated total reflection-Fourier transform infrared spectroscopy: a universal analytical technique with promising applications in forensic analyses

Contemporary criminal investigations are based on the statements made by the victim and the eyewitnesses. They also rely on the physical evidences found in the crime scene. These evidences, and more particularly biological ones, have a great judicial value in the courtroom. They are usually used to revoke the suspect’s allegations and confirm or refute the statements made by the victim and the witnesses. Stains of body fluids are biological evidences highly sought by forensic investigators. In many criminal cases, the success of the investigation relies on the correct identification and classification of these stains. Therefore, the adoption of reliable and accurate forensic analytical methods seems to be of vital importance to attain this objective. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a modern and universal analytical technique capable of fingerprint recognition of the analyte using minimal amount of the test sample. The current systematic review aims to through light on the fundamentals of this technique and to illustrate its wide range of applications in forensic investigations. ATR-FTIR is a nondestructive technique which has demonstrated an exceptional efficiency in detecting, identifying and discriminating between stains of various types of body fluids usually encountered in crime scenes. The ATR-FTIR spectral data generated from bloodstains can be used to deduce a wealth of information related to the donor species, age, gender, and race. These data can also be exploited to discriminate between stains of different types of bloods including menstrual and peripheral bloods. In addition, ATR-FTIR has a great utility in the postmortem investigations. More particularly, in estimating the postmortem interval and diagnosing death caused by extreme weather conditions. It is also useful in diagnosing some ambiguous death causes such as fatal anaphylactic shock and diabetic ketoacidosis.

Postmortem investigation of fatalities following vaccination with COVID-19 vaccines

Thorough postmortem investigations of fatalities following vaccination with coronavirus disease 2019 (COVID-19) vaccines are of great social significance. From 11.03.2021 to 09.06.2021, postmortem investigations of 18 deceased persons who recently received a vaccination against COVID-19 were performed. Vaxzevria was vaccinated in nine, Comirnaty in five, Spikevax in three, and Janssen in one person. In all cases, full autopsies, histopathological examinations, and virological analyses for the severe acute respiratory syndrome coronavirus 2 were carried out. Depending on the case, additional laboratory tests (anaphylaxis diagnostics, VITT [vaccine-induced immune thrombotic thrombocytopenia] diagnostics, glucose metabolism diagnostics) and neuropathological examinations were conducted. In 13 deceased, the cause of death was attributed to preexisting diseases while postmortem investigations did not indicate a causal relationship to the vaccination. In one case after vaccination with Comirnaty, myocarditis was found to be the cause of death. A causal relationship to vaccination was considered possible, but could not be proven beyond doubt. VITT was found in three deceased persons following vaccination with Vaxzevria and one deceased following vaccination with Janssen. Of those four cases with VITT, only one was diagnosed before death. The synopsis of the anamnestic data, the autopsy results, laboratory diagnostic examinations, and histopathological and neuropathological examinations revealed that VITT was the very likely cause of death in only two of the four cases. In the other two cases, no neuropathological correlate of VITT explaining death was found, while possible causes of death emerged that were not necessarily attributable to VITT. The results of our study demonstrate the necessity of postmortem investigations on all fatalities following vaccination with COVID-19 vaccines. In order to identify a possible causal relationship between vaccination and death, in most cases an autopsy and histopathological examinations have to be combined with additional investigations, such as laboratory tests and neuropathological examinations.

Expression of FcεRIα and tryptase in human lung tissue during drug-induced anaphylactic death

The diagnosis of drug-induced anaphylactic death is an important component of forensic medicine. The purpose of this study was to explore the expression of FcεRIα and tryptase in human lung tissue during drug-induced anaphylactic death and its value for forensic medicine. The expression of FcεRIα and tryptase in lung tissues of the drug-induced anaphylactic death group (n = 30) and control group (who died due to sudden cardiac death, falling from a height, or traffic accidents, n = 30) was detected by immunohistochemistry and immunofluorescence staining. The difference in FcεRIα and tryptase expression in the lung tissue between the drug-induced anaphylactic death group and the control group was statistically significant (p < 0.05). The levels of FcεRIα and tryptase expression greatly increased in the lung tissue of the drug-induced anaphylactic death group, which may provide morphological evidence and a reference for the diagnosis of drug-induced anaphylactic death in forensic medicine.

Differences Between Central and Peripheral Postmortem Tryptase Levels

ABSTRACT

Postmortem tryptase is a commonly used biochemical test to aid in the diagnosis of fatal anaphylaxis, which is currently recommended to be sampled from peripheral (femoral) veins because of a research showing comparatively elevated levels from central blood sources. Previous studies have used nonstandardized or nondocumented sampling methods; however, more recent research demonstrates that tryptase levels may vary depending on the sampling method. This study used the recommended sampling method of aspirating the femoral vein after clamping and compared in a pairwise comparison with aspiration of central venous and arterial blood sources (inferior vena cava and aorta) in 2 groups of 25 nonanaphylactic deaths. We found no statistically significant differences in postmortem tryptase between central and femoral vein blood; however, sporadic outliers in central blood (particularly aortic blood reaching levels above documented cutoffs for fatal anaphylaxis) were observed. Our findings provide evidence for the existing recommendations that femoral vein blood remains the preferred sample for postmortem tryptase over central blood.

Postmortem diagnostics of assumed suicidal food anaphylaxis in prison: a unique case of anaphylactic death due to peach ingestion

Suicidal ingestion of food which the victim is aware they are allergic to is an exceptional occurrence in the forensic field. To the best of our knowledge, no cases of suicidal food anaphylaxis have been reported to date. Therefore we present the first case described in the literature. A 30-year-old prisoner was found dead inside his cell with the remains of a peach remains next to his body, and a handwritten farewell note in his pocket. The autopsy revealed only non-specific findings, while laboratory investigations (serological, toxicological, histological, and immunohistochemical) played a pivotal role in determing the cause and manner of death. In particular, a high titer of both total and specific IgE antibodies was detected, as well as an increase of the tryptase level in cadaveric blood. Moreover, a massive concentration of salicylates was measured in the gastric contents. Microscopically, cellular residues characterized by a vegetal structure were observed in the gastric contents and elements suggestive of mast cells were detected in the glottis, lungs, and myocardium. The immunohistochemical investigation with anti-CD117 and anti-tryptase antibodies showed positivity for mast cells, some of which appeared degranulated. Such findings were entirely consistent with an acute systemic anaphylactic reaction triggered by allergy. Therefore, the prisoner’s death was attributed to self-induced food anaphylaxis caused by the ingestion of peaches. This conclusion was achieved based only on circumstantial data, anamnestic information, autopsy findings, and multiple laboratory results. This integrated approach should be used to pursue a post-mortem diagnosis of anaphylaxis.

Fatal anaphylactic shock: A review of postmortem biomarkers and diagnostics

Diagnosing anaphylactic shock postmortem is challenging since differential diagnoses exist and the forensic pathologist often faces subtle findings and lacks relevant information which prevents reaching an opinion of certainty. This review provides an overview of the literature covering research and existing recommendations on the postmortem diagnosis of anaphylactic shock. In order to harmonize the approach and provide guidance for diagnosing deaths from anaphylactic shock in the six forensic centers in Sweden, a guidance protocol aligned with the notion of a holistic view in the approach was devised. Areas in need of further studies include both immunohistological and biochemical investigations to stratify quantitative approaches based on condition and anaphylactic trigger and to lay the ground for and possibly establish alternative matrices.

Anaphylactic Death: A New Forensic Workflow for Diagnosis

Anaphylaxis is a life-threatening or fatal clinical emergency characterized by rapid onset, and death may be sudden. The margin of certainty about the diagnosis of anaphylactic death is not well established. The application of immunohistochemical techniques combined with the evaluation of blood tryptase concentrations opened up a new field of investigation into anaphylactic death. The present study investigated eleven autopsy cases of anaphylactic death, carried out between 2005 and 2017, by the Departments of Forensic Pathology of the Universities of Foggia and Catania (Italy). An analysis of the medical records was carried out in all autopsies. Seven autopsies were carried out on males and four on females. Of the eleven cases, one showed a history of asthma, one of food ingestion, two of oral administration of medications, six did not refer any allergy history, and one subject was unknown. All cases (100%) showed pulmonary congestion and edema; 7/11 (64%) of the cases had pharyngeal/laryngeal edema and mucus plugging in the airway; only one case (9%) had a skin reaction that was found during external examination. Serum tryptase concentration was measured in ten cases, and the mean value was 133.5 µg/L ± 177.9. The immunohistochemical examination using an anti-tryptase antibody on samples from the lungs, pharynx/larynx, and skin site of medication injection showed that all cases (100%) were strongly immunopositive for anti-tryptase antibody staining on lung samples; three cases (30%) were strongly immunopositive for anti-tryptase antibody staining on pharyngeal/laryngeal samples; and eight cases (80%) were strongly immunopositive for anti-tryptase antibody staining on skin samples. We conclude that a typical clinical history, blood tryptase level >40 µg/L, and strongly positive anti-tryptase antibody staining in the immunohistochemical investigation may represent reliable parameters in the determination of anaphylactic death with the accuracy needed for forensic purposes.

Omics era in forensic medicine: towards a new age

Background/aim

Forensic medicine and sciences is a multidisciplinary branch of science, which frequently benefit from novel technologies. State of the art omics technologies have begun to be performed in forensic medicine and sciences, particularly in postmortem interval, intoxication, drugs of abuse, diagnosis of diseases and cause of death. This review aims to discuss the role and use of great omics (metabolomics, proteomics, genomics and transcriptomics) in forensic sciences, in detail.

Materials and methods

A detailed review of related literature was performed, and studies were subdivided as per the type of omics.

Results and conclusion

Omics seems as a revolutionary step in forensic science and sure carries it towards a new age. The number of forensic studies utilizing omics steadily increases in last years. Omics strategies should be used together in order to gather more accurate and certain data. Additional studies need to be performed to incorporate omics into routine forensic methodology.

Post mortem tryptase: A review of literature on its use, sampling and interpretation in the investigation of fatal anaphylaxis

Post mortem tryptase is a commonly-used ancillary test in the investigation of possible anaphylactic deaths. Ante mortem tryptase interpretation differs from post mortem interpretation due to differing priorities, biochemical behaviours and capacity for follow-up. Additionally, post mortem tryptase sampling site, method and even cut-off levels are not standardised between facilities. This review of the literature investigates the existing research and recommendations on the use of post mortem tryptase in suspected anaphylactic deaths. Currently, autopsy recommendations suggest early sampling, standardised sampling technique with clamping of and aspiration from the femoral vein, and for the results to be interpreted within the wider autopsy and clinical context. Areas in need of further research include the effects of cytolysis on tryptase levels and studies to stratify differing tryptase levels based on type of death and anaphylactic trigger.

Postmortem Tryptase Level in 120 Consecutive Nonanaphylactic Deaths: Establishing a Reference Range as <23 μg/L

Postmortem tryptase is a useful biochemical test to aid the diagnosis of anaphylaxis. Multiple perimortem and postmortem factors have been documented to cause an elevation in postmortem tryptase level. One factor that was recently recognized to have an impact on postmortem tryptase level is correct sampling technique. A recent study recommended aspirating blood samples from a clamped femoral/external iliac vein to be used for reliable postmortem tryptase analysis. This study sampled 120 consecutive nonanaphylactic deaths in which all the peripheral bloods were sampled as recommended. Postmortem interval, resuscitation, different nonanaphylactic causes of death, sex, and age did not show any statistical significant relation to postmortem tryptase level in Student t test, Pearson correlation, and univariate and multivariate analyses. The mean (SD) postmortem tryptase level was 8.4 (5.2) μg/L (minimum, 1.0 μg/L; maximum, 36.1 μg/L; median, 7.3 μg/L). Using nonparametric methods, the postmortem tryptase reference range in nonanaphylactic death was established as <23 μg/L (97.5th percentile).

The effects of different sampling techniques on peripheral post mortem tryptase levels: a recommended sampling method

Different sampling techniques can impact on post mortem tryptase levels. A previous study demonstrated significantly lower femoral post mortem total tryptase levels in samples collected via transcutaneous aspiration compared with directly sampling during internal examination. However, an outlier with high tryptase level was noted in one transcutaneous aspiration sample. This 6-month prospective study compared total post mortem tryptase levels between 21 paired aspirated venous and arterial femoral blood samples, and 19 paired aspirated and cutdown femoral venous blood samples in non-anaphylactic deaths only. No statistical differences were demonstrated between the different sampling methods. However, four outlier cases with higher tryptase levels in aspirated arterial and femoral cutdown samples compared with aspirated venous femoral samples were noted. The reasons for the outliers may be due to the bloods collected from these two methods being contaminated by central arterial and venous blood with high tryptase levels respectively. None of the aspirated venous femoral post mortem tryptase levels were above recognized post mortem tryptase cutoff to diagnose anaphylaxis. This study recommends aspirating blood samples from a clamped femoral/external iliac vein for post mortem tryptase analysis should be defined as the gold standard. Further study using the recommended sampling method on post mortem tryptase levels in non-anaphylactic and anaphylactic cases is warranted.

Decline in 2 Serial Postmortem Tryptase Measurements Beyond 72 Hours After Death in an Antibiotic-Related Anaphylactic Death

Anaphylaxis can be difficult to diagnose in the postmortem setting. Postmortem tryptase is a widely used ancillary test in aiding the diagnosis in which an elevation supports a death from anaphylaxis. Postmortem tryptase can be difficult to interpret, and the effects of postmortem kinetics are not fully understood. Clinically, mast cell tryptase returns to baseline 24 to 72 hours after an anaphylactic stimulus. We report another anaphylactic death from antibiotic administration in which 2 serial postmortem total tryptase measurements at 3 days (72 hours) and 6 days (144 hours) after death declined from 522 μg/L to 300 μg/L (baseline, 5.6 μg/L). The declination appears to be slower than what is expected in the clinical setting. This case highlights yet another example of the difficult and complex interaction of postmortem interval on postmortem tryptase, especially in an anaphylactic death. We suggest that early blood sampling and serial tests be performed if possible in suspected anaphylactic death.

Post mortem tryptase cut-off level for anaphylactic death

Serum mast cell tryptase is used to support the diagnosis of anaphylaxis. The recommended clinical cut-off for total tryptase (<11.4μg/L) appears unsuitable in the post mortem setting due to largely unknown processes which result in significantly elevated levels in these samples. Consequently there is no widely accepted tryptase cut-off level for diagnosing an anaphylactic death. This 5-year retrospective study compared total tryptase levels in post mortem femoral blood in anaphylactic deaths and control. Univariate and multivariate analysis was used to assess the relative contribution of other factors (age, gender, post mortem interval, and presence of resuscitation) on post mortem tryptase levels. Nine anaphylactic deaths and 45 controls were identified. Receiver-operating characteristic (ROC) curve analysis identified an optimal cut-off of 53.8μg/L, with sensitivity of 89%, and specificity of 93%, for total post mortem tryptase in femoral blood to diagnosis anaphylaxis. No other factors showed any statistical significant contribution to post mortem tryptase elevation. Femoral total post mortem tryptase level of 53.8μg/L and above is a useful ancillary test in diagnosing an anaphylactic death.