Comparison of the allergenicity and Ole e 1 content of 6 varieties of Olea europaea pollen collected during 5 consecutive years

Background Numerous varieties of Olea europaea have been described in Mediterranean countries. Objective To investigate the immunochemical characteristics of 6 varieties of Olea europaea collected during 5 consecutive years. Methods The varieties Carrasqueno, Manzanillo, Acebuche (wild olive), Hojiblanco, Picual, and Nevado were analyzed. Pollen samples from each variety were collected for 5 consecutive years from the same cultivars by trained personnel. The antigenic and allergenic profiles of these extracts were evaluated by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot using the serum of 29 O europaea -allergic individuals. Ole e 1 was measured using enzyme-linked immunosorbent assay and purified Ole e 1 and rabbit polyclonal antibodies. Allergenic potency was determined using enzyme-linked immunosorbent assay inhibition and is expressed in histamine equivalent prick units per gram of raw material. Results Hojiblanco and Acebuche had the lowest mean ± SD Ole e 1 content in the 5 years (0.045 ± 0.029 and 0.059 ± 0.031 μg/μg of freeze-dried material, respectively). The variety with the highest mean ± SD Ole e 1 content was Picual (0.19 ± 0.075 μg/μg). Hojiblanco had the lowest total biological potency throughout the study. A positive correlation was obtained between rainfall in the winter months and total allergenicity of the 6 varieties. Conclusions The different varieties of O europaea pollen demonstrated great differences in allergenic potency and Ole e 1 content. These differences were maintained throughout the study, suggesting that they are due to genetic differences intrinsic to the varieties, although certain climatic effects may also play a role.