The infiltration of 'primed' neutrophils into multiple organs due to physical abuse to the elderly: An immunohistochemical study

The infiltration of ‘primed’ polymorphonuclear neutrophils into multiple organs has been reported in cases of traumatic or hemorrhagic shock. Since multiple injuries are usually observed in cases of physical abuse of the elderly, we investigated neutrophil infiltration into the heart, lung, liver and kidney in cases of abused elderly individuals using immunohistochemistry for myeloperoxidase (MPO). In addition, we examined the expression of molecules associated with neutrophil infiltration, including P-selectin as the adhesion molecule and IL-8 as the chemotactic factor. The number of neutrophils in the physically abused elder cases was increased significantly, particularly in the lung and liver, compared with that of control cases of sharp instrument injury, single fatal blunt injury and polytrauma. In addition, P-selection expression in the endothelium and the presence of IL-8-positive cells (mainly macrophages) in the lung and liver of abuse cases were significantly greater than those in control cases. In contrast, the number of MPO-, P-selectin- and IL-8-positive cells in cases of multiple organ failure (MOF) due to various causes was significantly greater than that in abuse cases. It is known that primed neutrophils accumulation may undergo MOF by ‘activation’ due to secondary insults. Thus, our results suggest that MPO immunostaining can distinguish cases of elderly physical abuse from non-abuse and MOF cases. In addition, our results indicate that MPO is a potential diagnostic marker for elder physical abuse, and that P-selectin and IL-8 may be useful for a more accurate diagnosis. Finally, our results also suggest that elder cases of physical abuse may be in a primed stage of MOF, and are at risk of falling into MOF by various secondary insults including those following abuse.