IMMUNOHISTOCHEMICAL CHARACTERIZATION OF ALVEOLAR MACROPHAGES AND PULMONARY GIANT-CELLS IN FATAL ASPHYXIA

It is in dispute whether the occurrence of numerous alveolar macrophag es and in particular pulmonary giant cells in cases of fatal asphyxia is associated with agonal activation and proliferation. The nature of these alveolar cells was investigated in selected fatalities with prot racted final oxygen lack using immunohistochemistry (APAAP method) and a semi-quantitative graduation. The study included opiate-involved de aths (n = 22), fatal strangulations (n = 10) and a control group of su dden cardiovascular deaths (n = 10). Positive immunohistochemical reac tions were observed with the monoclonal antibodies PG-M1 (general mark er of macrophages, detection of nearly 100% of pulmonary macrophages a nd giant cells in all subgroups) and 25 F 9 (late stage inflammation m arker, detection of pulmonary macrophages/giant cells in 70%/50% of op iate-involved fatalities, 70%/20% of strangulations and 40%/30% of con trol cases). The antibodies LN-4 (macrophages), 27 E 10 (early stage i nflammation marker), AMH 152 (activated macrophages) and MIB 1 (prolif eration marker) did not react with these cell populations. Conclusions : pulmonary giant cells and numerous alveolar macrophages are not rest ricted to asphyxia. Their appearance is not of pathognomonic value for this diagnosis. Both cell types seem to be of heterogeneous nature (d ifferent functional state) as only one marker was expressed by all cel ls. The results do not suggest prefinal immigration, mobilization or p roliferation of alveolar cells, but rather point to a longer pre-exist ence of macrophages and giant cells in pulmonary tissue (25 F 9 as lat e stage inflammation marker positive).