Published online: February 22, 2018
Neuromuscular blocking-agents (NMBAs) are the main agents involved in perioperative allergy in France. In the perioperative setting, NMBAs are used to improve anesthetic and/or surgical conditions. While the etiological diagnosis of NMBA immediate hypersensitivity (allergy versus non-allergy) is actually linked to the clinical presentation together with tryptase levels and skin tests results, the role of the basophil activation test (BAT) is still debated in this setting. BAT is based on the up-regulation of some markers (CD63 and/or CD203c) expressed at the basophil (a type of leukocyte) membrane upon ex vivo activation by the suspected drug. This blood test might add to the etiological diagnosis of immediate NMBA hypersensitivity and help to identify both cross-reactive and safe alternative NMBAs for further anesthetics. The use of BAT needs to be better defined in the assessment of NMBA immediate hypersensitivity however since skin testing is considered to be more sensitive than in vitro procedures.
In a recently published research article in The Journal of Allergy and Clinical Immunology: In Practice, Dewachter and coworkers investigated the performances of BAT in 31 patients experiencing perioperative allergic and non-allergic NMBA-induced immediate hypersensitivity occurring within 5 min after NMBA injection. The goals of this observational retrospective study were to 1) combine the analysis of the clinical history along with histamine/tryptase and specific serum IgE levels (quaternary ammonium ion and suxamethonium) and 2) investigate the diagnostic performances of BAT in the identification of the culprit and cross-reactive NMBAs using two activation markers (CD63 and CD203c) compared to skin testing. Another objective of this study was to evaluate the performances of both tests for predicting safe alternative regimens in NMBA-allergic patients for further anesthetics.
Nineteen patients (61%) were included in the Allergy group and 12 patients (39%) were included in the Non-Allergy group. There were no between-groups differences in the distribution of age and gender (p = 0.17). Suxamethonium was the most frequent NMBA involved in the allergic (79%) and non-allergic (58%) groups (p = 0.21). The authors found that the performances of BAT were globally satisfactory with a better sensitivity and specificity than measurements of specific IgE. Although demonstrating good sensitivity (80%) and specificity (91.7%), BAT did not however identify the culprit agent in 20% of NMBA-allergic patients and yielded divergent cross-reactivity results in almost 40% of the cases. In addition, combined CD63 and CD203c markers did not increase BAT sensitivity compared to CD203c only. Finally, the concordance between skin tests and BAT including the culprit and cross-reactive NMBAs was between 73.6% and 100% for each NMBA.
In this study, the authors showed that skin testing allowed provision of a diagnosis and also suggested safe alternative regimens, especially in NMBA-allergy. Thus, despite a previous documented NMBA-allergy, negative skin-tested NMBAs could be safely used during subsequent anesthetics in 7 patients from the group Allergy based on skin tests results only. The performances of BAT in the investigation of NMBA immediate hypersensitivity were globally satisfactory with a better sensitivity and specificity than measurements of specific IgE while not reaching the sensitivity and specificity of skin tests. The authors concluded that BAT cannot replace skin testing in the assessment of NMBA immediate hypersensitivity but might be a useful “screening” tool when skin tests are not available.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.