The role of skin testing, drug challenge and IFN-γ ELISpot in delayed hypersensitivity to iodinated contrast media

Copaescu, AM; Chua, KYL; Mouhtouris, E; Holmes, NE; AlGassim, M; Al Otaibi, I; Stehlin, F; Isabwe, GAC; Tsoukas, C; Toupin, JF; Lee, D; Ben-Shoshan, M; Phillips, EJ; Trubiano, JA

Author(s): Copaescu, AM; Chua, KYL; Mouhtouris, E; Holmes, NE; AlGassim, M; Al Otaibi, I; Stehlin, F; Isabwe, GAC; Tsoukas, C; Toupin, JF; Lee, D; Ben-Shoshan, M; Phillips, EJ; Trubiano, JA;
Details: Publication Year 2025-08-14,Volume 21,Issue #1,Page 35
Journal Title: Allergy, Asthma, and Clinical Immunology
Publication Type: Research article
Abstract: BACKGROUND: The use of in vivo and ex vivo diagnostic tools for delayed hypersensitivity reactions (DHRs) associated with iodinated contrast media (ICM) is currently ill-defined. OBJECTIVE: To evaluate the role of in vivo and ex vivo diagnostic tools for DHRs occurring >6 h following intravenous low-osmolality ICM. METHODS: We conducted a prospective, multicenter, international cohort study. The patients were recruited from two tertiary care adult allergy clinics, Austin Health, Australia and the McGill University Health Centre, Canada. Eligible participants were adults who reported a DHR after receiving ICM. In vivo testing (skin testing and intravenous challenge) was performed to identify an alternative agent. Ex vivo testing using interferon-γ enzyme-linked ImmunoSpot assay was performed in four Australian patients to explore its diagnostic performance. RESULTS: The culprit ICM was identified by dIDT in 17/20 (85%) while in 3/20 (15%) a challenge was necessary to confirm delayed hypersensitivity. All patients with a positive dIDT to iohexol were positive to iodixanol (15/15; 100%) while 3/4 (75%), 3/4 (75%), 4/6 (67%), and 3/5 (60%) were positive to iopromide, ioversol, iopamidol, and iobitridol, respectively. Overall, 7/20 (35%) patients tolerated a challenge with an alternative ICM. The IFN-γ release assay was negative for the implicated ICM in 4 patients with confirmed DHR through a positive dIDT. CONCLUSION: dIDT allowed confirmation of T cell-mediated allergy to the implicated ICM in 85% of patients with a strong clinical suspicion of DHR and identification of non-cross-reactive ICM in 35% of patients. The IFN-y ELISpot was not useful in the four patients tested.
Publisher: BioMed Central
Keywords: Delayed hypersensitivity reactions; Drug reaction with eosinophilia and systemic symptoms; Ex vivo diagnostic tools; In vivo diagnostic tools; Iodinated contrast media; Maculopapular exanthema
Department(s): Infectious Diseases
Publisher's Version: https://doi.org/10.1186/s13223-025-00982-3
Open Access at Publisher's Site: https://doi.org/10.1186/s13223-025-00982-3
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2025-08-28 05:52:25

Last Modified: 2025-08-28 05:52:35