Radioallergosorbent testing of toluene diisocyanate-reactive individuals using p-tolyl isocyanate antigen.

Serum from 26 persons shown to react to provocative inhalation challenge with low concentration of toluene diisocyanate (TDI) was tested by radioallergosorbent test (RAST) using a p-tolyl isocyanate-human serum albumin (TMI-HSA) conjugate. Results were evaluated by the RAST ratio and by the mean +3 standard deviation methods. Positive results were obtained in 15% to 19% of TDI reactors, depending on the method of evaluation. These findings suggest that TDI asthma may be a complex syndrome with several types of reaction possible, including an IgE mechanism in some individuals, but they do not support the theory that TDI asthma is based solely on an immune mechanism. However, they do not disagree with the hypothesis that TDI reactivity may be mediated by a pharmacologic mechanism.