Function of exudate neutrophils from skin in psoriasis

Human neutrophils harvested from skin chambers containing autologous serum in psoriatic patients were compared with peripheral blood neutrophils by examining migration, phagocytosis, and oxidative activation. Random migration was reduced in exudate cells, whereas the chemotactic response to yeast-activated serum was evident not only in blood neutrophils, but also in exudate cells. The metabolic activation of exudate neutrophils, when stimulated with formyl-methionyl-leucyl-phenylalanine and measured as chemiluminescence, was enhanced by 50-400% compared to blood neutrophils. The chemiluminescence response to phorbol myristate acetate was on the other hand reduced to 35%. In the phagocytic assay, using C3bi- and IgG-opsonized yeast particles, exudate neutrophils from non-psoriatic healthy controls showed enhanced uptake of C3bi-coated yeast compared to blood neutrophils. In psoriatics, the blood neutrophils showed enhanced C3bi-mediated phagocytosis compared to non-psoriatic control cells. No further increase in C3bi-mediated phagocytosis was then seen in exudate cells from these patients. IgG-mediated phagocytosis was in contrast to C3bi similar between blood and exudate neutrophils in psoriatics and non-psoriatic controls. These experiments show that during exudation priming of different receptor-mediated processes can occur. However, no significant difference was observed between different functional capacities in exudate neutrophils from psoriasis patients and non-psoriatic controls.