Increased in vitro release of interferon-gamma from ampicillin-stimulated peripheral blood mononuclear cells in Stevens-Johnson syndrome.

Stevens-Johnson syndrome (SJS) was diagnosed in a 39-year-old woman, treated with ampicillin (4000-8000 mg daily), phenytoin (250 mg daily), and furosemide (20-40 mg daily) for 25, 21, and 20 d, respectively, before the appearance of the eruption. The lymphocyte stimulation test with the MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay on ampicillin, phenytoin, and furosemide showed a low value of stimulation index, which indicated negative reactivity. An in vitro IFN-gamma release test was conducted on the patient with SJS and on two healthy controls. IFN-gamma release increased by 52% following the in vitro challenge of the patient's peripheral blood mononuclear cells (PBMCs) with 15 microg/ml of ampicillin, but not with phenytoin or furosemide. Neither of the controls experienced increased IFN-gamma release. In the present case, increased in vitro IFN-gamma release was observed on ampicillin-stimulated PBMCs, which may indicate the role of ampicillin as the drug responsible for the induction of SJS, and may imply the role of IFN-gamma in the pathogenesis of SJS.