Allergenic activity of fractions of cocksfoot (Dacylis glomerata) pollen

A cocksfoot (Dactylis glomerata) pollen extract has been fractionated by isoelectric focusing in polyacrylamide gel, the separated components extracted from the gel and assayed by three methods: prick tests in human skin, RAST and PCA tests in monkey skin. Prick testing in human skin showed that subjects responded differently to the separated components, indicating the presence of more than one antigenic determinant, and a profile of antibody activity against each fraction could be constructed. In general, good agreement was observed between RAST profiles and skin test profiles, although some patients who gave positive skin tests lacked circulating IgE and consequently did not give a RAST profile or a monkey PCA. These studies emphasize the current difficulty in attempting to isolate a single pure allergen from cocksfoot which can be used either diagnostically for the detection of pollen allergy, or for the standardization of diagnostic extracts.