Defective neutrophil chemotaxis resulting from thermal injury: restoration of directed migration by increasing Boyden chamber filter pore size.

Decreased chemotaxis of burn patient neutrophils has been observed in many studies. This study attempts to analyze the basis of this defect by determining the effect of filter pore size on chemotaxis, utilizing the Boyden chamber technique. Directed migration of burn patient neutrophils, as compared to normal controls, was greatly decreased when 3.0-micron filters were used. When 8.0-micron filters were used, however, the directed migration of burn patient neutrophils was identical to that of the normal controls. These findings indicate that the failure of burn patient neutrophils to undergo directed migration using Boyden chambers is not due to an inability to migrate toward a chemoattractant. Our data suggests that when utilizing the Boyden chamber technique to measure chemotaxis, the failure to give a normal response should not necessarily be interpreted as a chemotactic defect. In fact, mechanical impediments may play a major role in the decreased migration.