Scatter plot showing mean fluorescence intensities of rhodamine 123 after repeated stimulation with batch B1 (ANCA IgG titer 1:32) and batch A1 (ANCA IgG titer 1:1024), respectively, employing varying IVIg concentrations (0.25, 2.5, and 25 mg/mL) and incubation times (60 ○, 80 ▿, 100 ⋄, 120 ▵, and 150 □ min). With both preparations, a dose-dependent effect of IVIg on granulocytic H202 production was seen.