Relationship between neutrophil Mac-1 surface expression and stimulated Mac-1-dependent adherence to KLH-coated glass for the patient's PMNs. As described in “Patients, materials, and methods,” neutrophils from the patient were treated with a range of suboptimal concentrations of fMLF from 0.1 to 6.0 nM. Cells from each stimulation condition were divided into 2 separate aliquots, and one was stained to quantitate Mac-1 surface sites (A). The other was subjected to a second fMLF stimulation at 10 nM, then assayed for % adhesion to KLH-coated glass (B). (C) The strong quantitative relationship by linear regression analysis (R = 0.971) between the number of Mac-1 sites before the second stimulus and % adherence after the second stimulus.