Fig. 1.
Effects of intravenous (i.v.) immunoglobulin G (IVIgG) on airway inflammation and hyperresponsiveness. (a) Ovalbumin (OVA)-sensitized mice received i.v. administration of rabbit IgG (IgG, 0·1–1000 µg), 1000 µg of IgM, F(ab′)2 or mouse IgG (m-IgG) 1 day before OVA challenge (OVA/OVA) and total cells and eosinophils in bronchoalveolar fluid (BALF) were quantified. (b) Schedules of rabbit IgG administration were compared. The number of total cells and eosinophils in BALF were measured in mice administered with rabbit IgG (1000 µg) before and after OVA challenge. (c) The level of plasma OVA-specific IgE in OVA-challenged mice was compared. (d) Airway hyperresponsiveness (AHR) was assessed using body plethysmography. At 24 h after the last challenge, increased enhanced pause (Penh) in response to inhaled methacholine were measured. The effects of IgG administration on AHR to methacholine were expressed on the Y-axis as relative values of Penh to baseline. *Significant differences (P < 0·05) versus naive mice. †Significant differences (P < 0·05), versus phosphate-buffered saline (PBS).