Variability of Ole e 9 allergen in olive pollen extracts: relevance of minor allergens in immunotherapy treatments.
BACKGROUND
Clustered severe adverse reactions to immunotherapy with olive pollen extracts have been occasionally reported in areas where olive trees are extensively grown. Allergic patients from these areas, in addition to the major olive pollen allergen Ole e 1, frequently recognize a recently described allergen, Ole e 9.


OBJECTIVE
We aimed to develop an immunoassay to measure Ole e 9 concentration and to study the variability of this allergen in olive pollen extracts.


METHODS
Monoclonal antibodies (mAb) to Ole e 9 were produced from mice immunized with the pure allergen. One of these mAbs was used to develop a sandwich ELISA with an anti-olive pollen extract rabbit serum as the tracer. Olive pollen batches from several suppliers were analyzed using this method. These batches were also analyzed for Ole e 1 content and biological activity.


RESULTS
A 10-fold variation between the extreme values was found for the biological activity of the batches analyzed. Ole e 1 concentration showed a 25-fold variation. Variability of Ole e 9 concentration was extremely high, up to 161 times. The ratio Ole e 1/Ole e 9 varied in a range from 0.6 to 390.4.


CONCLUSIONS
The availability of a mAb-based ELISA for Ole e 9 made it possible for us to detect an important source of variability in olive pollen batches. This variability may be the cause of outbreaks of adverse reactions in the course of immunotherapy treatments, which have sometimes been observed among olive-allergic patients living in areas with very high levels of airborne olive pollen.
Duffort
Oscar
O
Departamento de Investigación y Desarrollo, ALK-ABELLO, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, España.
Palomares
Oscar
O
Lombardero
Manuel
M
Villalba
Mayte
M
Barber
Domingo
D
Rodríguez
Rosalía
R
Polo
Florentino
F
D000485:Allergens / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000737:chemistry* / Q000276:immunology; D000918:Antibody Specificity; D052179:Antigens, Plant; D002846:Chromatography, Affinity; D003888:Desensitization, Immunologic / Q000009:adverse effects*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D031658:Olea / Q000737:chemistry* / Q000276:immunology; D010936:Plant Extracts / Q000737:chemistry; D010940:Plant Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D011058:Pollen / Q000009:adverse effects / Q000276:immunology; D001617:beta-Glucosidase / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification
D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D010936:Plant Extracts; D010940:Plant Proteins; C433244:OLE9 protein, Olea europaea; D001617:beta-Glucosidase