The Performance of Flowcytometry-Assisted Basophil Activation Tests in the Diagnosis of Drug-Induced Immediate- Type Hypersensitivity Reactions

Abstract

Background: Flowcytometry-assisted basophil activation tests (BAT) are useful in vitro diagnostic tools for drug-induced immediate-type hypersensitivity. Objective: The study aimed to perform a medical literature review on the perform‐ ance of CD63 BAT. Results: Seven studies for antibiotics, eleven for neuromuscular blocking agents (NMBAs), and 10 for nonsteroidal anti-inflammatory drugs (NSAIDs) were included. The reference standards such as history, skin tests, challenge tests, and/or IgE, along with the concentrations, varied among studies. The thresholds for BAT positivity varied from basophils in the range greater than 4–15%, a net percentage of activated baso‐ phils greater than 5% or a stimulation index ranging 1.76–1.85, to the use of more complex composite indexes for NMBAs. For antibiotics and NSAIDs, a stimulation index > 2 was generally chosen. BAT sensitivity for β-lactams was 33–55%, while specificity was 79–93.3%. For NMBAs, BAT sensitivity was 36–92%, while specificity was 93–100%. For NSAIDs, BAT sensitivity was 11.7–61% and specificity was 74–100%. Discussion: BAT for the diagnosis of drug hypersensitivity has good specificity, but only moderate sensitivity. Despite the shortcomings and the methodological differences in BAT, the potential benefits to avoid challenge tests and increase the allergologic survey sensitivity have led to their widespread use in the clinical practice and warrant their future standardization.