Neutrophils from patients with sepsis and patients with RA demonstrate increased Siglec-9-mediated cell death susceptibility. (A) Blood neutrophils from patients with sepsis and joint fluid neutrophils from patients with RA appeared to be primed in vivo. Additional in vitro priming with GM-CSF had no effect on these inflammatory neutrophils. Results of 20-hour cultures are shown (control individuals: n = 6; septic shock neutrophils: n = 5; joint fluid RA neutrophils: n = 4). ^**P < .01. (B) Cytoplasmic vacuolization associated with inflammation. (Left) Sepsis blood neutrophils following 15-hour anti-Siglec-9 mAb treatment alone in vitro. (Right) Neutrophils from fresh RA joint fluids. Neutrophils were stained with Giemsa-May-Grünwald (Diff-Quik). Original magnification, × 1000.