INDUCTION OF TYPE-IV HYPERSENSITIVITY TO CONTACT ALLERGENS IN GUINEA-PIGS BY IN-VITRO HAPTENIZED ALLOGENIC PERITONEAL-EXUDATE CELLS

The induction of type IV hypersensitivity to contact allergens in guin ea pigs has been studied by using allogenic peritoneal exudate cells ( >90 % macrophages), which had been incubated primarily in vitro with d initrochlorobenzene, formaldehyde, potassium dichromate, nickel II sul phate or para-aminobenzoic acid. In these guinea pig sensitization exp eriments Freund's complete adjuvant was used. In all haptens investiga ted the sensitization rates of the presented method were parallel to t he known contact allergenicity in humans and, apart from the potassium dichromate results, comparable with those of the guinea pig maximizat ion test. Because of its alternative immunization procedure, in which only few or no allergen molecules escape the effective presentation pa thway, the authors conclude that this method could be developed into a predictive test assay for the evaluation of the contact allergenicity of water-soluble substances.