Non-ionic iodinated contrast media related immediate reactions: A mechanism study of 27 patients

- Investigate mechanism of non-ionic iodinated contrast media related immediate reactions.
- Non-ionic ICM related immediate reaction may be a kind of mechanically heterogenous disease.
- BAT may be an elaborate approach to detect basophil activation and diagnose hypersensitivity.
- Combined detection could improve diagnostic sensitivity and accuracy for hypersensitivity.

The underlying mechanism of non-ionic iodinated contrast media-related immediate reactions was evaluated in this study. Patients presenting at least grade II immediate reactions after non-ionic iodinated contrast media injection were enrolled. Basophil activation was evaluated by flow cytometry. The plasma concentration of human terminal complement complex SC5b-9, as well as concentrations of serum chymase, tryptase, human mast cell carboxypeptidase A3, human prostaglandin D2, and total IgE were measured by enzyme-linked immunosorbent assay. The basophil activation percentage was significantly higher in the study group than in the control group (17.94 ± 21.06% vs 3.45 ± 1.49%). The plasma concentration of human terminal complement complex SC5b-9 and concentrations of serum chymase, human mast cell carboxypeptidase A3, prostaglandin D2, tryptase, and total IgE were also significantly increased (236.99 ± 318.21 vs 49.70 ± 30.41 ng/mL, 0.41 ± 0.49 vs 0.09 ± 0.06 ng/mL, 1.17 ± 0.67 vs 0.30 ± 0.17 ng/mL, 203.52 ± 137.27 vs 102.28 ± 48.72 pg/mL, 3.81 ± 0.22 vs 2.70 ± 0.16 ng/mL, 102.00 ± 51.84 vs 19.97 ± 2.75 ng/mL, respectively). Both mast cells and basophils were activated in non-ionic iodinated contrast media to mediate immediate hypersensitivity, and mast cells may be involved. Different mechanisms, including IgE-dependent, complement-dependent, and direct membrane effects, contributed to mast cell and basophil activation. Individual patients may use a single or combined mechanism involving single or combined mast cells and basophils. Immediate reactions following non-ionic iodinated contrast media injection may be a mechanically heterogenous disease.