RvE1 reduces CD18 expression on PMNs and monocytes in whole blood. Human whole blood was incubated (30 minutes, 37°C) with RvE1 (30 nM) or vehicle alone then stained with anti-CD18 for flow cytometry. (A) Representative fluorescence histograms of CD18 expression on PMNs and monocytes with RvE1. Numbers on plots are the mean fluorescence intensity of CD18-positive PMNs or monocytes. (B) RvE1 reduces CD18 surface expression on human PMNs (■) and monocytes () compared with vehicle. Results are expressed as percentage reduction in control MFI (means ± SEM from 3 to 6 healthy donors). *P < .05; **P < .005; ***P < .001.