Stimulated adherence to KLH-coated glass, homotypic aggregation, and oxidative burst in response to opsonized zymosan particles by patient versus control neutrophils. (A) Neutrophils stimulated with 10 nM fMLF were assayed for adherence to KLH-coated coverslips in adhesion chambers as described. Results are expressed as the percentage of neutrophils that adhered to the KLH-coated surface (% adherence). Error bars indicate SEM. The patient's values are diminished to about 20% of those for control (P < .05; n = 3). Homotypic aggregation (B), measured as the recruitment of single neutrophils into doublets, triplets, and larger aggregates (% recruitment of singlets) was measured by flow cytometry of fixed aliquots from a stirring suspension of neutrophils at successive time intervals after addition of 1.0 μM fMLF. Markedly impaired aggregation was observed for the patient's cells compared with controls. Two additional assays yielded similar results. The patient's neutrophils were compared with those from a healthy adult control in an assay that measured the oxidative burst of the cells in response to iC3b-opsonized zymosan particles, using a lucigenin-dependent chemiluminescence assay that measures superoxide release (C). The patient's cells exhibited a moderately reduced oxidative burst in response to opsonized zymosan particles compared with the other subjects, with the area under the chemiluminescence (CL) curve for the patient achieving approximately 57% of the control value. Treatment of PMNs with the anti-Mac-1 mAb 60.1 virtually eliminated the response to opsonized zymosan for both patient and control PMNs. Two additional experiments comparing the patient's neutrophils with those from a healthy control yielded similar results.