CF patients have increased circulating monocyte- and neutrophil-platelet aggregates and increased platelet responsiveness to ADP and TRAP compared with healthy controls. Whole blood from CF patients and healthy controls was incubated with or without agonist and analyzed for (A) monocyte-platelet aggregates and (B) neutrophil-platelet aggregates. Data are mean ± SEM; n = 18. ^*P < .05 versus healthy controls. ⁺P < .01 versus healthy controls.