Neutrophil delivery to wounds of the upper and lower extremities

Clinical observations and experimental evidence indicate that wounds of the lower extremity are more susceptible to infection than are wounds located elsewhere on the body. The details of this regional relative immunoincompetence are not described. In this initial study of regional inflammatory response, neutrophil delivery to standard wounds of the upper and lower extremities was measured in 15 human volunteer subjects using a quantitative skin-window technique. Neutrophil delivery proved to be relatively deficient in the lower extremity. Neutrophil delivery (mean +/- SEM) was significantly lower to the lower-extremity wounds (5,890 +/- 590 cells per cubic millimeter) than to the upper-extremity wounds (16,600 +/- 1,680 cells per cubic millimeter). This lower neutrophil response may be a part of the lower extremity's increased susceptibility to infection. Further functional study of regionally collected neutrophils may provide more details of differences in regional inflammatory response. The mechanisms underlying these differences remain undescribed.