In vitro released interferon-gamma in the diagnosis of drug-induced anaphylaxis.

A 17-year-old Japanese male was referred with acute urticaria and anaphylaxis after the administration of PL (salicylamide, acetaminophen, anhydrous caffeine and promethazine methylene disalicylate) and Bufferin (aspirin and dialminate) for headache and a high grade fever. The results of prick test, patch test and drug-induced lymphocyte stimulation test with PL and Bufferin were all negative. The patient's peripheral blood mononuclear cells (PBMC) were cultured with or without PL for 72 hours, and the activity of interferon-gamma (IFN-gamma) in the culture supernatant was measured with EIA. A significantly high level of IFN-gamma was detected in PBMC from the patient, but very little in those from healthy control subjects with a history of exposure to PL. This finding may indicate the presence of drug-specific IFN-gamma producing T cells in patients with an anaphylactic shock reaction to medication. Assays that measure the drug-induced IFN-gamma production may thus be a useful diagnostic tool not only for identifying delayed-type hypersensitivity (DTH) to drugs, but also for predicting anaphylactic shock reaction to drugs.