Hypersensitivity pneumonitis induced by toluene diisocyanate: sequelae of continuous exposure. Ann Intern Med

A 41-year-old automobile paint sprayer showed the clinical features of hypersensitivity pneumonitis 1 week after he had begun to work with paint materials containing toluene di-isocyanate. His symptoms began 6 to 8 hours after exposure to the agent and spontaneously disappeared by the next morning. He had diffuse, fine reticulonodular shadows on a chest roentgenogram and a restrictive impairment of pulmo-nary function. Immunoglobulin G antibody to toluene di-isocyanate-human serum albumin was present in bronchoal-veolar lavage fluid and sera; IgA antibody was present only in bronchoalveolar lavage fluid. Also, the patient had sensi-tized bronchoalveolar lymphocytes to toluene diisocyanate-human serum albumin. The histologic findings suggested hy-persensitivity pneumonitis. The results of bronchoalveolar lavage, which was repeated on four separate occasions, showed lymphocytosis and a predominance of suppressor-cytotoxic T cells. The findings from serial determinations of humoral antibodies showed no changes consistent with the results of clinical and laboratory studies. In contrast, blasto-genic responses of bronchoalveolar lymphocytes to toluene diisocyanate markedly decreased, and the patient showed clinical improvement despite continued exposure to the agent