Immunological investigation of individuals with toluene diisocyanate asthma.

Thirteen subjects who experienced only the expected irritant respiratory and ocular effects from occupational exposure to toluene diisocyanate (TDI) were compared with eight workers who appeared clinically to be sensitized to this substance, as manifested by the prompt development of asthmatic symptoms on exposure to minute concentrations of TDI. In an attempt to document an immunological response to TDI in the latter group, several conjugates of TDI with human serum albumin were prepared. Gel diffusion, leucocyte histamine release, PCA in guinea-pigs, passive haemagglutination, passive transfer (P-K) and a few direct skin tests all failed to show antibodies to TDI. In lymphocyte culture, however, TDI–human serum albumin complexes produced stimulation of lymphocytes from seven of the eight subjects suspected of being sensitized and none of the controls.