PASSIVE ANTIBODY TRANSFER ON HUMAN-LEUKOCYTES - APPLICATION TO SMALL ANIMAL ALLERGY DIAGNOSIS BY FLOW-CYTOMETRY

Animal allergy diagnosis is based mainly on clinical history, skin tes ts and, at least for dogs, specific IgE antibodies. The quality of ant i-canine IgE antibodies is variable and monoclonal antibodies have bee n recently characterized. The allergen panel tested in humans and in d ogs is similar except for flea and for Staphylococcus. Allergen-induce d basophil activation may be measured by the release of mediators such as histamine and leukotriene C4 and by the expression of the CD63 mar ker on basophil membrane. This latter method is based on the flow cyto metric analysis of leukocyte suspensions after double anti-IgE FITC, a nti-CD63 PE labelling of human basophils, and has been validated for a ero-allergens, food allergens, venoms and several drugs for human alle rgy diagnosis. After having demonstrated that, in the dog, anaphylacti c antibodies were capable of binding to human basophil high-affinity r eceptors for IgE, we went up a flow cytometric method for animal aller gy diagnosis based on passive sensitization of human basophils. Prelim inary results obtained by this method for allergens such as house dust mite or pollen were very encouraging. This method is faster and less expensive than the methods based on mediator release but is still depe ndent on the availability of fresh human leukocytes. This method may r epresent a new sensitive and specific method for animal allergy diagno sis.