N. SuthumchaiY. SrinoulprasertP. ThantiworasitP. RerknimitrP. TuchindaL. ChularojanamontriT. RerkpattanapipatK. ChanprapaphW. DisphanuratP. ChakkavittumrongN. TovanabutraC. SrisuttiyakornC. SukasemJ. KlaewsongkramChulalongkorn UniversityKing Chulalongkorn Memorial Hospital, Faculty of Medicine Chulalongkorn UniversityFaculty of Medicine, Ramathibodi Hospital, Mahidol UniversityFaculty of Medicine, Thammasat UniversityFaculty of Medicine, Siriraj Hospital, Mahidol UniversityPhramongkutklao College of MedicineChiang Mai University2019-08-282019-08-282018-06-01Journal of the European Academy of Dermatology and Venereology. Vol.32, No.6 (2018), 992-99814683083092699592-s2.0-85043522994https://repository.li.mahidol.ac.th/handle/20.500.14594/46651© 2018 European Academy of Dermatology and Venereology Background: The lymphocyte transformation test (LTT) is a standard laboratory method to identify culprit drugs in patients with a history of drug-induced non-immediate hypersensitivity and is mainly performed during the recovery phase. The measurement of drug-specific interferon γ (IFN-γ)-releasing cells has been introduced to confirm culprit drugs, even during the acute phase of drug allergy. Objectives: This study aimed to evaluate the capability of the enzyme-linked immunospot assay (ELISpot) to detect drug-specific IFN-γ-releasing cells during the acute phase and the capability of LTT to identify culprit drugs during the recovery phase in patients presenting with severe cutaneous adverse reactions (SCARs). Methods: Peripheral blood mononuclear cells (PBMCs) from 23 SCAR patients were collected during the acute and recovery phases and assayed for drug-specific IFN-γ-releasing cells and lymphocyte proliferation, respectively. Results: Drug-specific IFN-γ-releasing cells were detectable in 73.9% of SCAR subjects (55.6% and 85.7% in patients who were and were not taking systemic steroids, respectively), whereas LTT results were positive in 52.2% of SCAR subjects. The frequencies of drug-specific IFN-γ-releasing cells were significantly higher in patients with positive LTT than in those with negative LTT (260.1 ± 110.0 and 46.6 ± 20.7 cells/106 PBMCs, P = 0.01). A significant correlation between the results of the IFN-γ ELISpot assay and LTT was demonstrated (r = 0.65, P value <0.01). Conclusion: The IFN-γ ELISpot assay could be a useful tool to identify culprit drugs in SCAR patients when culprit drug identification is urgently needed during the acute phase of drug allergy.Mahidol UniversityMedicineArticleSCOPUS10.1111/jdv.14890