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.