Antigens which detect IgE antibodies in workers sensitive to toluene diisocyanate

Two antigens, both containing tolyl groups, were compared for ability to detect IgE antibodies in workers hypersensitive to toluene diisocyanate. One antigen, formed by reaction of p-tolyl isocyanate with human serum albumin, detected antibodies in each of ten hypersensitive workers. A second tolyl antigen, formed by reaction of p-toluoyl chloride and human serum albumin, and therefore lacking isocyanate linkages, detected antibodies in seven of the ten workers. In RAST assays, sera from toluene diisocyanate-sensitive workers demonstrated higher binding to human serum albumin-coated control discs than did sera from non-sensitive workers. The significance of this binding in calculating tolyl-reactive antibody titres is discussed.