Correlation between FCGR3B CN and neutrophil function in a family. (A) No significant differences in superoxide anion production between family members with 0, 1, and 2 copies of FCGR3B were observed after Fc receptor–independent stimulation with GM-CSF, fMLP, or PMA (two-way ANOVA, P = ns). Mean and SEM from two independent experiments are shown. (B) Quantification of neutrophil adhesion to IgG-coated glass slides after 4 min of flow at a shear stress of 0.1 Pa in the FCGR3B-null individual and her single-copy daughter relative to the three CN control. (C) Percentages of neutrophils with bound, antibody-opsonized, Alexafluor-labeled ovalbumin after 10 min at 4°C, for family members with 0, 1, and 2 copies of FCGR3B. Mean and SEM are shown for triplicate repeats of one experiment that is representative of two. (D) Percentages of neutrophils with bound and internalized, antibody-opsonized, Alexafluor-labeled ovalbumin after 10 min at 37°C, for family members with 0, 1, and 2 copies of FCGR3B. Mean and SEM are shown for triplicate repeats of one experiment that is representative of two (the same experiment is shown in C). P values in C and D refer to one-way ANOVA with a post test for linear trend. (E) sFcγRIIIb in serum, as measured by ELISA, increases with FCGR3B CN in patient A's family (letters correspond to individuals shown in Fig. 1 B).