AbstractThe chemotactic activity for neutrophils and monocytes was examined in the sera of psoriatic patients and healthy controls using a Boyden chamber method. There were no significant differences in neutrophil chemotactic activity between the sera of psoriatic patients and healthy controls. However, the monocyte chemotactic activity of psoriatic serum was lower than that of control serum. Furthermore, there was a significant increase in the monocyte chemotactic activity of psoriatic sera after heat treatment (42°C, 1 hr).These results suggest that psoriatic serum has a defect of monocyte chemotaxis which can be corrected, in part, by heat treatment