In vivo and in vitro study of antigens and allergens in pollen extracts of Graminaceae.

The standardization of the diagnostic and immunotherapeutic products plays an even more definite role in allergology. The investigations performed in the last few years allowed to attain the purification and characterization of the allergenic extracts, both from the allergenic and antigenic viewpoint, implementing the most sophisticated techniques. The identification of the allergens in the extracts is of primary importance in the standardization and purification of the allergens themselves. The allergenic activity may be determined both in vitro and in vivo and the combination of the two techniques allows reaching a higher reliability in the assay. The Authors thought it very timely to verify the reliability of the in vivo and in vitro assays by employing four allergenic extracts of Graminaceae pollens, due to their importance in the allergological field. Phleum, Lolium, Cynodon, Anthoxanthum, were selected for the investigations. The extracts were also characterized by immunoprecipitation techniques. The results allowed to state that good results may be obtained by the in vivo assay (prick test) of allergenic extracts, with a precision comparable to that obtainable with the RAST inhibition, even using a restricted sample of allergic patients. It was ascertained that it is possible to express the allergenic activity versus a reference extract (Phleum). The three extracts (Anthoxanthum, Cynodon, Lolium), for which good antisera were obtained, were antigenically characterized, by means of CRIE and CIE, and the major allergens were identified.