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Evaluated the Diagnostic Utility of Interferon-Gamma Enzyme-Linked Immunospot (ELISPOT) Assays in 117 Patients with Non-Immediate Drug Hypersensitivity Reactions
Saturday, March 5, 2016
South Exhibit Hall H (Convention Center)
Suda Punrin, Pattarawat Thantiworasit, MSc, Pungjai Mongkolpathumrat, Jettanong Klaewsongkram, MD
Rationale: To evaluate the diagnostic utility of Interferon (IFN) -gamma Enzyme-linked Immunospot (ELISPOT) assay in non-immediate drug hypersensitivity reactions (DHR). 

Methods: Medical records of patients who were diagnosed non-immediate DHR and underwent ELISPOT at our hospital between 2012 and 2015 were retrospectively examined.

Results: Total 117 individuals were included (mean age 53 years, range 7-97), most were in-patients. Sixty-six (56.4%) were female. Thirty (25.6%) were immunocompromised. One-third concurrently received systemic corticosteroids. For the clinical entities, 46(39.3%) subjects experienced severe cutaneous adverse reactions and 43(36.8%) had maculopapular exanthems (MPE). In the majority of cases, ELISPOT was performed with multiple implicating medications simultaneously and within a month after symptom onset. Number of drug-specific IFN-gamma secreting cells was analyzed by incubating PBMCs with culprit or alternative drugs, and more than 20 spot-forming cells/106(PBMCs) was considered positivity. Entirely, sixty-nine agents had been tested. Majority were antibiotics, allopurinol, anticonvulsants, anti-tuberculosis, non-steroidal anti-inflammatory drugs (NSAIDs) and radiocontrast media. Among those investigated, 45(38.5%) patients yielded a positive test. Proportion of positive outcomes was 62.5% in acute generalized exanthematous pustulosis, 50% in acute interstitial nephritis, 41.8% in MPE, 40.0% in drug rash with eosinophilia and systemic symptoms and drug-induced hepatotoxicity, 35.2% in Stevens-Johnson syndrome, 33.3% in delay urticaria and angioedema, 25% in fixed drug eruption, and 16.7% in toxic epidermal necrolysis. Subsequently, 41(35%) persons underwent drug provocation test. Of which resulted in the sensitivity, specificity, positive predictive value, negative predictive value of 50%, 95.1%, 77.8% and 84.8%, respectively.

Conclusions: IFN-gamma ELISPOT could be potentially applied in management of DHR.