Background: This study was designed to investigate the development of both cellular and humoral immune responses to gelatin in patients with vaccine-related immediate and nonimmediate reactions. Our purpose was to define the nature of the responses in the different clinical states.
Methods: Six patients with immediate reactions and 21 patients with nonimmediate reactions after inoculation of various live vaccines were studied. Measurement of gelatin-specific IgE was performed in all subjects. Gelatin-specific T-cell responses detected by an in vitro lymphocyte proliferation assay and by an assay for IL-2 responsiveness were investigated to compare the immune response in patients with the two types of reaction.
Results: All six patients with immediate reactions had IgE responses to gelatin, whereas none of the 21 patients with nonimmediate reactions had any anti-gelatin IgE. All of the six patients with immediate reactions and 17 of the 21 patients with nonimmediate reactions exhibited positive T-lymphocyte responses specific to gelatin.
Conclusions: Immediate and nonimmediate reactions are caused by different types of allergy to gelatin, and cell-mediated immunity to gelatin may play an important role in the pathogenesis of nonimmediate reactions.