Uptake of BTHS neutrophils by human monocyte-derived macrophages. Freshly purified control granulocytes (fresh) and granulocytes from the same donor after overnight culture with more than 70% annexin-V binding (cultured) were incubated with human monocyte–derived macrophages for 30 minutes, and the percentage of phagocytizing macrophages was estimated as described in “Patients, materials, and methods” (▪). Freshly purified granulocytes from a BTHS patient with more than 60% annexin-V binding were used to compare with the control granulocytes (□). Uptake of cultured apoptotic BTHS granulocytes was similar compared with cultured control cells (not shown). Results shown (mean ± SD) are representative of experiments performed on different occasions with cells from 4 control individuals and 3 patients in total.