Figure 1
The patient's antibody (1:5 dilution) reacted with normal platelets in the present of acetaminophen glucuronide, but not acetaminophen or acetaminophen sulfate. Washed platelets (5 × 106) were combined with patient serum in the presence or absence of 0.4 mM acetaminophen or the metabolite indicated in a final volume of 50 μL. After incubation for 1 hour, the platelets were washed in the presence or absence of the indicated drug or metabolite (0.2 mM). Bound human IgG was detected by the addition of FITC goat (Fab′)2 anti-human IgG (H+L) (1:200; Jackson Immunoresearch, West Grove, PA). No reaction occurred with normal serum under same conditions. Abscissa indicates mean platelet fluorescence intensity in arbitrary units.
