RICIN INCREASES IGE LEVELS AND AIRWAY INFLAMMATION BUT NOT HYPERRESPONSIVENESS IN THE RAT

The effect of ricin treatment on IgE levels and airway inflammation ha s been examined in ovalbumin (OA)-sensitized rats. Ricin augmented the total IgE titre and caused about a 10-fold increase in the antigen-sp ecific IgE titre. Repeat antigen challenges (every second day) with an OA aerosol increased the number of eosinophils and neutrophils in bro nchoalveolar lavage fluid and produced airway hyperresponsiveness (AHR ) 24 h after the third challenge. Ricin pretreatment caused a signific antly larger influx of eosinophils, neutrophils and lymphocytes into l avage fluid, but there was no further increase in AHR. The present stu dy demonstrates that ricin augments IgE production and the inflammator y response, but that AHR is unrelated to the number of infiltrating in flammatory cells.