PULMONARY HYPERSENSITIVITY TO HEXYL ISOCYANATE-OVALBUMIN AEROSOL IN GUINEA-PIGS

The antigenicity of hexyl isocyanate was evaluated using the guinea pig animal model of hapten-specific respiratory hypersensitivity previously described. Animals were sensitized by daily inhalation of hexyl isocyanate-ovalbumin (H-OA) aerosol, exposure chamber concentration 12 μg/liter. Pulmonary hypersensitivity, assessed by increased respiratory rate, was produced exclusively toward the hexyl isocyanate (hapten) portion of the sensitizing antigen. Passive cutaneous anaphylaxis tests and gel diffusion analyses revealed the presence of antibodies having specificity toward the haptenic groups. Hapten-specific IgE antibodies were also identified. No reactions were detected between antibodies and antigen conjugates prepared with p-tolyl isocyanate or phenyl isocyanate. This report of respiratory hypersensitivity and cytophilic antibody production in animals exposed to hexyl isocyanate antigen aerosol alerts one to the possibility of hypersensitivity reactions in workers exposed to vapors of hexamethylene diisocyanate (HDI). © 1979.