The significance of preformed aprotinin-specific antibodies in cardiosurgical patients.

UNLABELLED: Acute hypersensitivity reactions are serious complications of reexposure to aprotinin. Previous contact via infusions or fibrin tissue adhesives can induce specific antibodies. In this study, we aimed to elucidate the preoperative prevalence of aprotinin-specific antibodies in patients scheduled for cardiac operations. Sera of 520 consecutive cardiosurgical patients were collected preoperatively and screened retrospectively for aprotinin-specific IgG using a standard enzyme-linked immunosorbent assay (ELISA). Positive sera were analyzed also for aprotinin-specific IgA (ELISA) and IgE (fluorescence enzyme immunoassay). The histories of all patients were reviewed with focus on aprotinin preexposure. Of 520 patients, 22 (4%) had specific IgG. Only 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. The presence of aprotinin-specific IgG alone seems not to induce adverse reactions on exposure. Exposure history alone is not sensitive enough to identify patients with aprotinin-specific antibodies. IMPLICATIONS: Anaphylaxis on IV reexposure to aprotinin is a medical emergency. The clinical significance of preformed aprotinin-specific IgG remains questionable, whereas preformed IgE was present in the only patient who suffered from severe anaphylaxis on reexposure to aprotinin. Preformed antibodies are not reliably predicted by exposure history.