[Importance of in vivo and in vitro studies of leukotrienes. Application to the particular instance of aspirin].

The major role played by leukotrienes in the inflammatory reaction is today clearly demonstrated. These newly-formed mediators show powerful pro-inflammatory activities and their release from various cell types may be induced by agonists including the allergens. Therefore, leukotriene levels in biological fluids may represent a reliable image of the local or systemic inflammatory reaction and their release in vitro after incubation of the blood leukocytes in the presence of a specific allergen is today widely used for allergy diagnosis. Leukotrienes metabolism is deeply involved in aspirin intolerance or so-called pseudo allergy and, in spite of that the exact mechanism involved is still unknown, leukotriene release in vitro by ASA in the presence C5a represent the first reliable test for this diagnosis. The results of the recent clinical trials concerning the activity of anti-leukotrienes in vivo have led to a real therapeutic hope.