Cross-reactivity patterns of T cells specific for iodinated contrast media.

Background: Approximately 3% of patients exposed to iodinated contrast media develop delayed hypersensitivity reactions.

Objective: We wanted to better understand the molecular basis of contrast media cross-reactivity.

Methods: Cross-reactivity was assessed by skin testing and measurement of T-cell activation (CD69 upregulation) and proliferation ((3)H-thymidine uptake, 5,6-carboxyfluorescein diacetate succinimidyl ester staining) of PBMCs, T-cell lines, and T-cell clones of 2 patients with delayed hypersensitivity reactions to iohexol and iomeprol, respectively.