[Allergic risk of aprotinin]

To analyse the risk of anaphylactic reaction with the administration of aprotinin, either by i.v. route or as a biological sealant application and to propose updated guidelines in accordance with current data of the literature.

Search in the Medline data base of articles in French, English and German, published since 1960, using following key words: aprotinin, allergy, anaphylaxis.

All categories of articles on this topic have been selected.

Articles have been analysed for history, incidence and mechanisms of anaphylactic reactions, symptomatology, factors of risk, diagnosis and precautions of use.

Aprotinin is widely used for decreasing preoperative bleeding, especially in cardiac and orthopaedic surgery. This heterologue protein can cause anaphylactic reactions in 0.5 to 5.8% of patients, depending of the inclusion criteria. They are mediated by IgG and IgE antibodies. Aprotinin has also a direct, non specific, histaminoliberation effect. The clinical presentation includes various degrees of severity, up to cardiac arrest. Documented factors of risk are a previous parotinin administration, 15 days to 6 months before, and intolerance to beef meat, white of egg, cheese and milk. The immediate biological diagnosis is obtained on assessing the degranulation of basophiles (histamine) and mastocytes (tryptase), as well as the concentration of anti-aprotinin antibodies (RAST IgE), with a test of inhibition. The secondary assessment, six weeks later, includes prick-tests and intradermoreactions if the former are negative. The mean precaution consists to search factors of risk at preanaesthetic assessment. The predictive value of systematic prick-tests has not yet been validated. Anti H1 and anti H2 premedication is inefficient. A test dose can trigger a severe reaction.

Considering a significant anaphylactic risk, aprotinin administration becomes only licit after a careful evaluation of the benefit-risk ratio.