Local administration of CD16A-Ig at the inflammatory site blocked reversed passive Arthus reaction in mice with or without complement depletion. (A) The mice (n = 3) were injected intradermally with PBS (site 1), or various concentrations of CD16A-Ig (0 μg/mL at site 2, 5 μg/mL at site 3, 25 μg/mL at site 4, and 50 μg/mL at site 5) along with rabbit anti-Ova antibody in PBS, immediately after which ovalbumin with 1% Evan blue was injected through the tail vein. To deplete the complement, mice were twice injected intraperitoneally with cobra venom factor before the initiation of RPA. After 3h the mice were euthanized, and the dorsal side of the skin was photographed for analysis. The figure shows 3 representative mice. (B) Quantitative analysis of RPA. The dermal lesion, seen blue in the photographs, was quantified using ImageJ and KaleidaGraph softwares for groups with or without CVF treatment. Data are presented as mean plus or minus the SD from 3 individual mice. *P < .01, **P < .001.