Comparison of Basophil Activation Test and Skin Testing Performances in NMBA Allergy

Background: Neuromuscular blocking agents (NMBAs) are the main agents involved during perioperative immediate hypersensitivity. The etiological diagnosis (IgE-mediated allergy vs nonallergy) is linked to the clinical presentation together with tryptase and histamine levels and skin test results. The role of basophil activation test (BAT) needs to be better defined in this setting.

Objectives: To assess the role of BAT compared with the results of skin testing in 31 patients experiencing immediate NMBA hypersensitivity and compare skin test results and BAT performances in the identification of alternative NMBAs.

Methods: Histamine and tryptase levels were quantified. Anesthetic drugs, including NMBAs, were skin-tested. Basophil CD63 and CD203c expressions were measured in response to serial dilutions of the different NMBAs.

Results: Allergy and Nonallergy groups involved 19 and 12 patients, respectively. Circulating histamine and tryptase levels were significantly increased in allergic patients. In the Allergy group, while skin test results were positive in 100% (19 of 19) of the cases, BAT positivity to the culprit NMBA reached 78.9% (15 of 19) when combining CD63 and CD203c. NMBAs cross-reactivity was identified through skin testing and BAT in 36.8% (7 of 19) and 26.3% (5 of 19) of the cases, respectively. The concordance (culprit and cross-reactive NMBAs) between skin tests and BATs was between 73.6% (14 of 19) and 100% (19 of 19) for each NMBA. Negative skin-tested NMBAs were uneventfully used in 7 NMBA-allergic patients. In the Nonallergy group, skin test results were negative in 100% of the cases while BAT result was positive once (CD63 upregulation).

Conclusion: In our technical conditions, BAT does not replace skin testing in the assessment of NMBA allergy.