Immunohistochemical examination of the lungs in infant death cases using antibodies against milk components

To examine the use of immunohistochemical staining with antibodies against milk components for detection of aspirated milk on lung sections, eighteen infant death cases were investigated. Immunostaining was performed with anti-human alpha lactalbumin, anti-human IgA, anti-human milk fat globulin 1, and anti-cow whey antibody. Reactivity with each antibody was examined, and semi-quantitative examinations were performed to compare the amount of aspirated milk using anti-human alpha lactalbumin antibody. Materials in the alveoli or bronchioli on lung sections suspected to be aspirated milk showed the most sensitive and clearest reaction with anti-human alpha lactalbumin antibody. Of the eighteen cases, ten cases showed positive reaction with this antibody. The amount of aspirated milk varied widely in each case. In conclusion, immunohistochemical staining with antibodies against human milk components, especially anti-human alpha lactalbumin antibody, can detect small amounts of milk. Using this method, we were able to compare the relative amount of aspirated milk among cases.     

Toxicology and sudden infant death

One hundred thirty cases of sudden infant death occurring in Wayne County, Michigan, (population 2.7 million) were analyzed for possible drugs. The toxicological protocol has been outlined. Six cases were found to be positive, and in five of these the drugs found had been prescribed for a variety of illnesses. In one case methadone was found in the blood of an infant whose mother was undergoing methadone treatment for drug addiction, the drug being transmitted through breast milk. In none of the 102 cases of sudden infant death syndrome (SIDS) included in the study did the toxicological results affect the diagnosis. In our study, toxicological analyses never contradicted an initial diagnosis of SIDS, and, therefore, we feel that this diagnosis should be made promptly based on investigative and autopsy findings.     

Oronasal blood in sudden infant death.

Oronasal secretions are observed frequently in sudden infant death syndrome (SIDS), but overt blood is uncommonly reported. The literature on oronasal blood in sudden infant death is limited. The goal of this study was to determine the frequency of oronasal blood in sudden infant deaths and to examine possible causative factors. Oronasal blood was described in 28 (7%) of 406 cases of sudden infant death. Oronasal blood could not be attributed to cardiopulmonary resuscitation in 14 cases, including 10 (3%) of 300 cases of SIDS, 2 (14%) of 14 accidental suffocation cases, and 2 (15%) of 13 undetermined cases. Eight of the 10 infants in cases of sudden infant death were bedsharing: 5 with both parents, 2 between both parents. The infant in 1 SIDS case was from a family that had had three referrals to Child Protective Services. Oronasal blood not attributable to cardiopulmonary resuscitation occurs rarely in SIDS when the infant is sleeping supine in a safe environment. Bedsharing may place infants at risk of suffocation from overlaying. Oronasal blood observed before cardiopulmonary resuscitation is given is probably of oronasal skin or mucous membrane origin and may be a sign of accidental or inflicted suffocation. Sanguineous secretions that are mucoid or frothy are likely of remote origin, such as lung alveoli. The use of an otoscope to establish the origin of oronasal blood in cases of sudden infant death is recommended.     

Fatal Aspiration of Barium Sulfate in a Case of Myasthenia Gravis: A Case Report and Review of Literature

Barium contrast radiography is a usual procedure performed for detecting lesions of the digestive tract using barium sulfate on X-ray irradiation. The aspiration of barium contrast is an uncommon but well-documented complication occurring accidentally during examinations of the upper gastrointestinal system using contrast media. Certain conditions that affect the anatomical and functional integrity of the oropharynx and esophagus can be predisposing factors. Barium is an inert material that can cause symptoms varying from an asymptomatic mechanical obstruction to severe respiratory distress that can result in death when aspirated. Sudden death due to aspiration of barium is rarely reported in the literature. We report a case of a 50-year-old female who suddenly developed difficulty in breathing, followed by loss of consciousness during barium swallow procedure due to aspiration of barium contrast. She could not be revived and died within a few minutes of the episode. The predisposing factor was the weakness of the muscles of deglutition due to myasthenia gravis. We also reviewed the literature available on cases resulting from the aspiration of barium sulfate during the barium study procedures. We considered the factors like the age, indications, the distribution of barium in the lungs, clinical presentation, the period of survival, and cause of death. We came across only four cases of death within 24 h following the aspiration of barium. This case report and review of literature emphasize the importance of consideration of predisposing factors before conducting barium contrast radiography and also the possibility of sudden death.     

A comparison of respiratory symptoms and inflammation in sudden infant death syndrome and in accidental or inflicted infant death

Upper respiratory infection and pulmonary inflammation are common in sudden infant death syndrome, but their role in the cause of death remains controversial. Controlled studies comparing clinical upper respiratory infection and inflammation in sudden infant death syndrome with sudden infant deaths caused by accidents and inflicted injuries (controls) are unavailable. Our aim was to compare respiratory inflammation and upper respiratory infection within 48 hours of death and postmortem culture results in these two groups. A retrospective analysis of upper respiratory infection and pathologic variables in the trachea and lung of 155 infants dying of sudden infant death syndrome and 33 control infants was undertaken. Upper respiratory infection was present in 39% of sudden infant death syndrome cases and 40% of control cases. Upper respiratory infection was more likely to have occurred in association with more severe lymphocytic interstitial pneumonitis when sudden infant death syndrome cases and control cases were combined ( P=.04). Proximal and distal tracheal lymphocytic infiltration was more severe in control cases than in sudden infant death syndrome cases ( P=.01 and.01, respectively). Lymphocytic infiltrations of the bronchi, bronchioles, and pulmonary interstitium were similar between groups. Bronchial associated lymphoid tissue was more prominent in control cases ( P=.04). Cultures were positive in 80% of sudden infant death syndrome cases, 78% of which were polymicrobial. Among control cases, 89% were positive, with 94% being polymicrobial. This study confirms that microscopic inflammatory infiltrates in sudden infant death syndrome are not lethal.     

Virological analysis in the diagnosis of sudden children death: a medico-legal approach

Infections are considered to be an important cause of unexpected death in children. It has also been assumed that respiratory viruses are involved in the genesis of sudden infant death syndrome (SIDS). The Spanish National Institute of Toxicology and Forensic Sciences act as the forensic reference centre for Spain. We analyse the experience of this centre in the virological study of 64 cases of sudden children death where viral serology, virological cultures, herpesviruses polymerase chain reaction (PCR) and electron microscopy were performed. According to pathological findings, death could only be attributed to an adenovirus infection in one amygdalitis with upper airways stenosis and asphyxia. Human herpes virus 6 (HHV-6) was detected by PCR in one case with pathological findings characteristic of SIDS. Recent infection by respiratory syncytial virus (RSV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were also detected. Meanwhile, 85.9% of the cases yielded negative viral results. Twenty-eight infants were finally categorised as SIDS. Pathological findings of infection were detected in 12 patients despite the negativity of viral analyses. Although viral infection is an uncommon cause of sudden children death, a complete microbiological investigation will help to solve the puzzle of SIDS. Definitive guidelines for microbiological analyses need to be updated whilst new pathogens are discovered or new techniques are implemented in order to clarify unsolved cases.     

Sudden infant death from atelectasis due to amniotic fluid aspiration

An infant girl, whose hands showed lobster-claw deformity, was found dead in her bed at 17 days of age. Macroscopic and microscopic examination of the lungs showed fatal atelectasis. The alveolar spaces were filled with fluid, epithelial cells, and squamous debris. These were the constituents of amniotic fluid aspirated before birth. The present case suggested that some sudden unexpected deaths in early infancy are delayed deaths caused by amniotic fluid aspiration.     

The role of environmental factors in the causation of sudden death in infants: two cases of sudden unexpected death in two unrelated infants who were cared for by the same babysitter

We report two cases of sudden unexpected death in two unrelated African American female infants, 2 months and 4 months old. Both infants were attended to by the same babysitter in the same apartment and died 39 days apart in the same bed and in the same bedroom. The autopsy of the first infant revealed sudden unexplained death in an infant. Toxicologic analysis for carbon monoxide (CO) was not performed because it was not suspected. When the second infant died, investigation into the ambient air quality within the apartment revealed high levels of CO emanating from a poorly ventilated and defective hot water heater, which was located across a hallway from the bedroom where the two babies died. CO saturation levels in the postmortem blood samples of the two babies were elevated and were similar (13% and 14%). Nicotine and cotinine were not detected in the blood sample of the two infants. Cherry-red livor mortis was absent. Acute CO intoxication was determined to be the underlying cause of these two unexpected deaths. These two cases underscore the need to integrate ambient air analysis and postmortem CO analysis as routine components of the comprehensive death investigation of infants who die suddenly and unexpectedly.     

Toxicologic analysis in cases of possible sudden infant death syndrome: a worthwhile exercise?

The diagnosis of sudden infant death syndrome (SIDS) is one of exclusion. At the Department of Forensic Medicine, Westmead Hospital, toxicologic analysis is performed as part of the postmortem examination of all apparent SIDS deaths. The results for the 5-year period January 1, 1994, to December 31, 1999, were audited to determine whether such routine testing was worthwhile. During this time there were 117 cases with a history consistent with SIDS. Drugs were detected in 19 (16%) of these cases. In 1 case, death was attributed to the finding of methadone. The presence of methadone was regarded as a possible contributing factor to death in a further 2 cases. The presence of possible methadone toxicity had not been expected from the history given before the examination in these 3 cases. In 114 cases there was a suitable sample for alcohol testing; in no case was alcohol detected. In 13 cases the postmortem examination revealed an anatomic cause of death (including 3 cases consistent with whiplash/shaken baby/impact head injury), which excluded a diagnosis of SIDS. In conclusion, routine toxicologic testing in all possible cases of SIDS death supplements the postmortem examination in excluding cases of non-SIDS.     

Longitudinal evaluation of immunohistochemical findings of milk aspiration: an experimental study using a murine model

To examine the longitudinal change of pathological findings of the lung and other organs in milk aspiration, an experimental study using a murine model was carried out. Either 0.5 or 1.0 ml cow's milk was instilled into the trachea of rats. From immediately after to 14 days after instillation, the animals were sacrificed, and the lungs, liver, kidneys, and spleen were removed. The results of immunostaining with anti-human α lactalbumin antibody indicated that not only the lung but also the kidney and spleen showed a positive reaction against the antibody over time. Experimentally aspirated milk was detectable in alveoli until 2 days after instillation. It was also detectable in renal tubules from 1 to 6h after instillation. Macrophages containing granules of aspirated milk were observed in splenic red pulp from 3h to 14 days after instillation. Detection of aspirated milk in other organs except the lung would be clear evidence of intravital milk aspiration and would suggest previous or recurrent milk aspiration.     

Pulmonary siderophages and unexpected infant death

It has been proposed that the presence of siderophages in the lungs of infants who die unexpectedly should be considered a marker of a previous hypoxic event, which may preclude a diagnosis of sudden infant death syndrome. The authors retrospectively reviewed all infant deaths (<1 year old) going to autopsy at the Denver Office of the Medical Examiner from January 1999 to January 2001. Lung sections were stained with Prussian blue, and siderophages were counted in 20 high-power fields per lobe sampled. Cell counts were performed by two independent pathologists who were blinded to history and cause of death, with good reproducibility. Iron stain results were then categorized by average number of siderophages per 20 high-power field (category 1 = <5, category 2 = 5-100, category 3A = 100-500, category 3B = >100 in a single lobe, category 4 = >500). The results were subsequently correlated to case history, autopsy findings, and cause/manner of death. Forty-three cases were reviewed. The causes of death included sudden infant death syndrome (16), asphyxia (5), undetermined (6), and other (16). Those deaths were categorized by the above criteria as follows: category 1. (32), category 2. (6), category 3. (4), and category 4. (1). All sudden infant death syndrome deaths were in category 1. Categories 1 and 2 also included deaths in which hypoxia might have been present before death because of such factors as pneumonia and congenital heart disease. Categories 3 and 4 included a known homicidal asphyxia in which repeated episodes of intentional smothering were documented, 2 probable asphyxias, 1 nonaccidental trauma, and 1 undetermined. All 5 cases had questionable circumstances surrounding the death of the infant. Pulmonary siderophages were described in only 1 of the 43 autopsy reports. It was concluded that pulmonary siderophages can be markedly increased in cases of repeated asphyxia. Siderophages may also be increased in cases where hypoxia may have been present for another reason, but not to the same degree. Siderophages are not increased in sudden infant death syndrome. Because iron-laden macrophages often are not recognized on routine examination with hematoxylin and eosin staining, iron stains may be helpful in the evaluation of infant deaths. If siderophages are present in increased amounts without an obvious explanation, further investigation is warranted.     

An autopsy case of an infant with Joubert syndrome who died unexpectedly and a review of the literature

The present report describes the unexpected death of a 6-month-old female infant who had been clinically diagnosed with Joubert syndrome. This is a relatively rare congenital neurological disorder characterized by hypoplasia/aplasia of cerebellar vermis, which transmits information from the body to the cerebellum, and is associated with respiratory dysfunction, abnormal eye movements, and developmental delay. The infant was found dead in bed and the immediate cause of death was determined as aspiration of vomit which may have been induced by a neurological disorder related to hypoplasia of the cerebellar vermis. These findings, together with a review of previous clinical case reports, suggest that Joubert syndrome should be considered as a predisposition to sudden unexpected death in infants mainly due to aspiration or complicated infection.     

Infant death scene investigation and the assessment of potential risk factors for asphyxia: a review of 209 sudden unexpected infant deaths

At the Wayne County Medical Examiner Office (WCMEO) in Detroit, Michigan, from 2001 to 2004, thorough scene investigations were performed on 209 sudden and unexpected infant deaths, ages 3 days to 12 months. The 209 cases were reviewed to assess the position of the infant at the time of discovery and identify potential risk factors for asphyxia including bed sharing, witnessed overlay, wedging, strangulation, prone position, obstruction of the nose and mouth, coverage of the head by bedding and sleeping on a couch. Overall, one or more potential risk factors were identified in 178 of 209 cases (85.2%). The increasing awareness of infant positions at death has led to a dramatic reduction in the diagnosis of sudden infant death syndrome at the WCMEO. This study suggests that asphyxia plays a greater role in many sudden infant deaths than has been historically attributed to it.     

Axonal injury in young pediatric head trauma: a comparison study of β-amyloid precursor protein (β-APP) immunohistochemical staining in traumatic and nontraumatic deaths

We tested the independent utility of β-amyloid precursor protein (β-APP) immunohistochemical staining as evidence of brain trauma in the deaths of young children. Blinded reviewers retrospectively reviewed immunostained brain tissues from homicidal deaths, age-matched control cases without evidence of trauma, as well as cases of sudden infant death syndrome (SIDS). The reviewers correctly identified five of the seven cases with documented inflicted head trauma. However, one of seven age-matched control cases and one of 10 SIDS/sudden unexplained death in infancy (SUDI) cases demonstrated staining patterns similar to those seen in cases of inflicted trauma. We discuss these cases and the circumstances surrounding them with the intent to explain the difficulties associated with immunohistological interpretation of axonal injury. Although the utility of β-APP is quite powerful if not confounded by global hypoxic-ischemic injury, ultimately, β-APP studies should be only one piece of information in the determination of cause and manner of death.     

Laryngeal basement membrane thickening is not a reliable postmortem marker for SIDS: results from the Chicago Infant Mortality Study.

It has been suggested that laryngeal basement membrane (LBM) thickening is a pathognomonic postmortem marker for sudden infant death syndrome (SIDS) and is not seen in other causes of explained sudden infant death. To test this hypothesis, we evaluated longitudinal sections of the right hemilarynx taken through the midpoint of the true vocal cord from 129 SIDS cases and 77 postneonatal sudden infant death controls. Using a five-point semi-quantitative scale, maximum LBM thickness (LBMT) for SIDS cases and controls was not statistically different (mean, 2.39 + 0.69 and 2.40 + 0.77, respectively). Likewise, scores based on the average thickness along the entire basement membrane (i.e., "average" score), were not found to be different between SIDS cases and controls. Average and maximum LBMT increased with age in both SIDS cases and controls and were not different between SIDS cases and controls within each age interval. Similar trends in the distribution of maximum and average LBMTs were found between black and Hispanic SIDS and controls; the number of white/non-Hispanic infants was too low for meaningful comparisons. Maximum and average LBMTs were not different in SIDS cases and controls exposed to environmental tobacco compared with unexposed infants. The LBMTs also increased significantly with body weight and length in both SIDS cases and controls. Finally, there were no differences in LBMT in infants intubated prior to death compared with those who were not intubated. From these data, we conclude that LBMT is not pathognomonic of SIDS, is present or absent with equal frequency in SIDS and controls, increases with postnatal age, and does not correlate with passive smoke exposure. Therefore, LBMT should not be used to diagnose SIDS.     

Cosleeping and sudden unexpected infant deaths in Kentucky: a 10-year retrospective case review

This retrospective case review investigates modifiable risk factors in sudden unexpected infant deaths, including those attributed to sudden infant death syndrome, and examines the impact of cosleeping with adults or siblings. The study examines sudden unexpected infant deaths from 1991 to 2000 in the state of Kentucky, excluding homicides and deaths from identifiable natural causes. Meta-analysis provides a cosleeping prevalence control in normal infants. Based on the findings described herein, we conclude that cosleeping may represent a risk factor in sudden unexpected infant deaths and that a full scene investigation, including whether the infant was cosleeping, should be sought in all cases of sudden infant death.     

Sudden infant death syndrome: Histological studies on adrenal gland and kidney

Histological observations were made on the adrenal glands and kidneys in ten cases of sudden infant death syndrome (SIDS). The amount of fetal cortex was excessive in the adrenal glands and many glomeruli of fetal form were observed in the kidneys. These findings suggest that the adrenal glands and the kidneys in SIDS cases are more or less immature in development. The immature development in these organs, especially in the adrenal glands, was considered to play a role in the cardiac or respiratory mechanisms in SIDS.     

Cytomegalic inclusion disease of the salivary glands in sudden infant death syndrome

The parotid gland and/or the submandibular gland in SIDS cases (180 from Berlin und 75 cases from Hamburg) were examined by means of HE staining, immunohistochemical analysis, in situ hybridization and electron microscopy. The SIDS cases were taken from the last 10 years; the age of the children ranged from 2 weeks to 1 year. Typical cytomegaly inclusion bodies were recognized in 10% (18 cases from Berlin; more girls than boys) and 7% (6 cases from Hamburg; more boys than girls). Our files indicate that the frequency of CMV infection was not age-dependent within the first 12 months of life. Using immunohistochemical analysis and in situ hybridization, virus substances were detected in cytomegal cells as well as in morphologically uninfected cells. The literature on the clinical and epidemiological aspects of cytomegaly indicates that a localized CMV infection of the salivary glands does not sufficiently explain the sudden death of these infants; however, it should be emphasized that cytomegaly can influence the immunological status of the organism.     

Cytomegalovirus-induced pneumonia and myocarditis in three cases of suspected sudden infant death syndrome (SIDS): diagnosis by immunohistochemical techniques and molecularpathologic methods

Immunohistochemical and molecularpathologic techniques have improved the diagnosis of myocarditis as compared with conventional histologic staining methods done according to the Dallas criteria. Additionally, immunohistochemistry and in situ-hybridization are able to demonstrate viral infection, e.g. cytomegaloviruses in salivary glands and lungs, locations both known to be involved in cytomegalovirusinfection. However, in many cases of proved cytomegalovirusinfection the cause of death remains unclear. We report on three children younger than 1-year of age, who died suddenly without prodromal symptoms. Their deaths were attributed to SIDS (sudden infant death syndrome). In situ-hybridization, immunohistochemical (LCA, CD45R0, CD68, MHC-class-II-molecules, E-selectine) and molecularpathologic investigations (PCR), however, suggested that death was caused by a cytomegalovirus-induced pneumonia or myocarditis. In the future, these methods should be used for investigating cases with suspicion of SIDS.