Table 2. Results of basophil activation to metamizole and metamizole metabolites at different concentrations (0.25-2.5 mg/mL) expressed as stimulation index (SI) values.

Cut-off for considering positivity >1.80. MAA: 4-methylamino antipyrine; AA: 4-aminoantipyrine; AAA: 4-acetylamino antipyrine; FAA: 4-formylamino antipyrine.