LPS in combination with amoxicillin increases BAT sensitivity to amoxicillin IgE‐mediated hypersensitivity

Abstract

β-lactams (BLs), and among them, amoxicillin (AX) are the most current prescribed antibiotics to treat bacterial infections,1 and their use is related to an increasing prevalence of drug hypersensitivity reactions (DHRs),2 being mainly immediate IgE-mediated, allergic reactions.3 The basophil activation test (BAT) is a currently accepted complementary in vitro tool to detect these reactions to BLs, however its sensitivity is far from optimal, ranging from 20% to 55%, with specificities of 90%–95%.4 This limitation can be explained, in part, by the small size of drugs that make them behave as haptens, and/or the need for other elements, that were present during the sensitization and/or acute phase of the reaction, and absent in the sample at resolution phase and, therefore, in the in vitro tests. In the context of BL intake during an infection, pathogen-associated molecular patterns (PAMP) can interact with Toll-like receptors (TLR) on immune cell surfaces to potentially stimulate proinflammatory cytokine production and contribute to basophil degranulation.5 In this study, we evaluated whether TLR ligand (TLR-L) interaction together to AX increased BAT sensitivity.