The laboratory evaluation of IgE antibody to metabisulfites in patients skin test positive to metabisulfites.

An immediate-type hypersensitivity reaction has been proposed as one possible mechanism in which metabisulfites (MBSs) cause reactions. As demonstrated with certain occupational chemicals, we proposed that MBS might conjugate with human proteins, such as human serum albumin, and then cause an immunologic response. Because we had identified no reactions to MBS at the Northwestern Allergy Service, we used sera from four patients reported elsewhere as having positive skin tests and positive oral challenges to sulfites. We attempted to demonstrate, both in vitro by ELISA and in vivo by passive cutaneous transfer to monkey, evidence for IgE-mediated hypersensitivity to MBSs. Our results demonstrated that there is evidence of IgE antibody by passive transfer for one patient studied, but no evidence of IgE antibody by ELISA to an MBS-albumin conjugate in any of the four patients. This study illustrates the complexities involved in the evaluation and mechanism of MBS-induced disease and the caution with which results must be interpreted.