The significance of preformed aprotinin-specific antibodies in cardiosurgical patients

Acute hypersensitivity reactions are serious complications of reexposure to aprotinin. Previous contact via infusions or fibrin tissue adhesives can i nduce specific antibodies. In this study, we aimed to elucidate the preoper ative prevalence of aprotinin-specific antibodies in patients scheduled for cardiac operations. Sera of 520 consecutive cardiosurgical patients were c ollected preoperatively and screened retrospectively for aprotinin-specific IgG using a standard enzyme-linked immunosorbent assay (ELISA). Positive s era were analyzed also for aprotinin-specific IgA (ELISA) and IgE (fluoresc ence enzyme immunoassay). The histories of all patients were reviewed with focus on aprotinin preexposure. Of 520 patients, 22 (4%) had specific IgG O nly three of these had a documented aprotinin preexposure. Of 448 patients exposed to aprotinin intraoperatively, 15 had preformed specific antibodies . The only patient presenting with severe anaphylaxis was positive for both IgG and IgE, and had a recent IV preexposure in cardiovascular surgery. Th e presence of aprotinin-specific IgG alone seems not to induce adverse reac tions on exposure. Exposure history alone is not sensitive enough to identi fy patients with aprotinin-specific antibodies. Implications: Anaphylaxis o n IV reexposure to aprotinin is a medical emergency. The clinical significa nce of preformed aprotinin-specific IgG remains questionable, whereas prefo rmed IgE was present in the only patient who suffered from severe anaphylax is on reexposure to aprotinin. Preformed antibodies are not reliably predic ted by exposure history.