Neutrophil adhesion to endothelial cells. The adhesion of¹¹¹Indium-labeled neutrophils from the patient and 2 normal donors, without (▪) or with () anti-CD18 antibody, to monolayers of normal endothelial cells (HUVEC) was studied in 2 ways. Neutrophils were activated with fMLP (10⁻⁶ mol/L) or PMA (2 μg/mL) and added to unstimulated endothelium or unstimulated neutrophils were added to endothelium stimulated with TNF- (2 ng/mL) for 4 hours or 24 hours. Neutrophils bound to the endothelium per well was determined. Control indicates the adhesion of unactivated neutrophils to unstimulated endothelial cells. In these multiple conditions, adhesion of the patient’s neutrophils to endothelium did not differ significantly from that of the normal donors. These data are representative of 3 experiments done in duplicate or triplicate in which the patient was compared with 2 normal donors and in which different normal donors were used in each experiment.