Fig. 2. Time course of antiaprotinin immunoglobulin (Ig)G antibody concentrations in three patients experiencing an anaphylactic reaction to aprotinin treatment. Notably, patients 1 and 2 had a repeat reexposure to aprotinin treatment during the study, and the data from the first (uneventful) treatment are included in the figure. For comparison, the mean IgG antibody concentrations in other patients with detectable antibody concentrations are also presented. IgG concentrations were measured using an enzyme-linked immunosorbent assay.