Human monocyte chemotaxis: a quantitative in vivo technique.

This report describes a new quantitative technique for evaluating monocyte chemotaxis to a site of superficial epidermal abrasion. Micro-acrylic chambers containing 50% Zymosan activated autologous serum were separated from a 5-mm diameter epidermal abrasion by 2 Nucleopore filters which entrapped migrating monocytes but allowed free neutrophil migration. Monocytes were specifically identified by alpha napthyl acetate esterase activity. Monocytes accumulated within the filters by 4 hr and maximized at 16 and 20 hr. This technique is superior to previous skin chamber techniques in the high yield of monocytes and in specific histochemical identification of monocytes. In contrast to the Rebuck window, it does not generate attractants and has greater reproducibility. This technique will be useful in the study of diseases characterized by monocytic infiltrates, in contrasting the function of peripheral blood monocytes to those available in the skin, and in testing the effects of drugs, immunodeficiency and infection on monocyte function in vivo.