Neutrophil recruitment in skin window chambers--activation by complement.

Complement was studied in skin window chambers, a human model of neutrophil recruitment in acute aseptic inflammation. Autologous plasma activated by the alternative pathway served as attractant; control chambers were filled with a balanced salt solution or with non-activated plasma samples. Neutrophil accumulation during a 24-hour period was consistently enhanced by activated complement in all of 15 healthy volunteers. Control chambers showed negligible cell counts. Reference assays revealed 1) consumption of the centrally placed complement component, C3, 2) generation of chemotactic activity as assessed in Boyden chambers by the standard complement activation procedure. Simultaneously obtained responses to activated complement in skin window chambers and in the Boyden assay of chemotaxis showed a highly significant, positive correlation. Our results demonstrate that the biological capacity of complement includes stimulation of neutrophil migration during simulated in vivo conditions and thus extends previous observations in animals.