Toluene diisocyanate–induced reverse passive cutaneous anaphylaxis caused by IgG antibody

Abstract

Toluene diisocyanate (TDI)-induced asthma is a complex lung disease not easily classified as immunologic in pathogenesis. In one study IgE antibodies were demonstrated in approximately 92% of patients. 1 Other studies reported a much lower incidence of IgE antibodies present in subjects (15% to 19%). 2 A reactive airways dysfunction syndrome has also been described, for which no immunologic mechanism has been found? Elevated levels of IgG antibodies have been correlated with isocyanate-induced asthma. 4 Classically, IgG antibodies are not associated mechanistically with extrinsic asthma. However, in vitro analysis has shown that IgG antibodies could activate haptenized basophils. 5 We postulated that IgG antibodies might activate mast cells modified by isocyanate haptenization. Such a phenomenon might have a correlation with certain human cases of TDI-induced asthma. In this study we attempted to determine whether IgG antibodies could generate a reverse passive cross-species cutaneous anaphylactic reaction against TDI.