Adherence to cultured endothelial monolayers and transendothelial migration by patient and control neutrophils. Endothelial monolayers (HUVECs) prepared as described were overlaid with neutrophils in adhesion chambers. After 500 seconds, % adherence to the monolayers was determined. After 1000 seconds, the proportion of adherent neutrophils that migrated across the monolayers was determined by phase contrast microscopy. Adherence of the patient's neutrophils in this system was modestly impaired compared with controls but transendothelial migration was severely impaired (P < .05; n = 3), consistent with the CD11/CD18 dependence of the latter process. Error bars indicate SEM.