Dual intracellular staining of CD154 (CD40L) and cytokines at single-cell level: A novel aid to document immediate hypersensitivity to amoxicillin Actually, 11/15 (73%) patients demonstrated a positive CD154/IL-4 LAT (e.g. a net expression of CD154 and/or IL-4 higher than the respectively maximal values observed in tolerant controls). Keywords: amoxicillin; CD154; cytokines; flow cytometry; IFN- ; IL-4; immediate drug hypersensitivity EN amoxicillin CD154 cytokines flow cytometry IFN- IL-4 immediate drug hypersensitivity 679 682 4 06/09/23 20230601 NES 230601 Key messages Multichromatic flow cytometry enables simultaneous analysis of intracellular CD154, IL-4 and IFN- in drug-reactive T lymphocytes. In conclusion, flow-based combined analysis of intracellular expression of CD154, IL-4 and IFN- by AXE-reactive T lymphocytes is an attractive approach for safe diagnosis of immediate amoxicillin hypersensitivity reactions. [Extracted from the article]