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Pulmonary myelomonocyte subtypes in drowning and other causes of death
B Brinkmann1, M A Hernandez, B Karger
1Institute of Legal Medicine, University of Münster, Germany.
Abstract:
Three immunohistochemically different myelomonocytic subtypes, i.e. MRP8, MRP14 and 27E10 were quantitatively evaluated in the intraalveolar, alveolar-interstitial and alveolar-intracapillary lung compartments. Lung sections from 5 major groups with defined causes of death, i.e. drowning and death during immersion (DI), cerebral/intracranial haemorrhages (CH), sudden cardiac deaths (SCD), hanging and throttling (HT) and immediate trauma deaths (ITD) were stained and the positive cells counted. The results show clear differences of the cell numbers on average. Among the different compartments the intracapillary cell count exhibits the highest numbers. If the cell counts are compared to the different causes of death, DI shows the highest values and ITD the lowest. The individual values, however, show considerable variations in all compartments and especially in the low cell count range. Within the DI group two subgroups can be differentiated, one having low and the other one having high cell numbers. This can be due to the type of agony, i.e. drowning versus immersion/hydrocution, or to resuscitation attempts or to a combination of both factors.
Insights
Myelomonocytic subtypes in lung tissues varied by cause of death, with drowning (DI) showing higher cell counts than immediate trauma deaths (ITD). Cell counts differed across lung compartments, with intracapillary regions showing the most cells.
Area of Science:
- Forensic Pathology
- Immunohistochemistry
- Cellular Biology
Background:
- Myelomonocytic cells play roles in inflammation and immune response.
- Quantitative analysis of these cells in lung compartments can provide insights into physiological and pathological processes.
- Different causes of death may lead to distinct cellular responses in lung tissues.
Purpose of the Study:
- To quantitatively evaluate three myelomonocytic subtypes (MRP8, MRP14, 27E10) in distinct lung compartments.
- To compare cell counts across these subtypes and compartments in relation to five major causes of death.
- To investigate potential variations within specific death categories, such as drowning and death during immersion (DI).
Main Methods:
- Immunohistochemical staining of lung sections for MRP8, MRP14, and 27E10.
- Quantitative counting of positive cells within intraalveolar, alveolar-interstitial, and alveolar-intracapillary compartments.
- Analysis of lung tissues from five defined cause-of-death groups: DI, cerebral/intracranial hemorrhages (CH), sudden cardiac deaths (SCD), hanging and throttling (HT), and immediate trauma deaths (ITD).
Main Results:
- Significant differences in myelomonocytic cell numbers were observed on average across the different causes of death.
- The alveolar-intracapillary compartment exhibited the highest cell counts.
- Drowning and death during immersion (DI) cases showed the highest overall cell counts, while immediate trauma deaths (ITD) showed the lowest.
- Considerable individual variations in cell counts were noted across all compartments, particularly in lower cell count ranges.
- Within the DI group, two subgroups with distinct low and high cell numbers were identified, potentially related to the specific drowning mechanism or resuscitation efforts.
Conclusions:
- The quantitative distribution of myelomonocytic subtypes in lung compartments varies significantly with the cause of death.
- Alveolar-intracapillary localization is a prominent site for these cells.
- DI cases present a distinct cellular profile compared to other causes of death, with intra-group heterogeneity suggesting contributing factors.
- These findings contribute to understanding post-mortem cellular changes and their forensic implications.