Determination of allergenic load and pollen count of Cupressus arizonica pollen by flow cytometry using Cup a1 polyclonal antibody.
BACKGROUND
There is an increase in the incidence of pollen related allergy, thus information on pollen schedules would be a great asset for physicians to improve the clinical care of patients. Like cypress pollen sensitization shows a high prevalence among the causes of allergic rhinitis, and therefore it is of interest to use it like a model of study, distinguishing cypress pollen, pollen count, and allergenic load level. In this work, we use a flow cytometry based technique to obtain both Cupressus arizonica pollen count and allergenic load, using specific rabbit polyclonal antibody Cup a1 and its comparison with optical microscopy technique measurement.


METHODS
Airborne samples were collected from Burkard Spore-Trap and Burkard Cyclone Cupressus arizonica pollen was studied using specific rabbit polyclonal antibody Cup a1, labeled with AlexaFluor(®) 488 or 750 and analysed by Flow Cytometry in both an EPICS XL and Cyan ADP cytometers (Beckman Coulter(®) ). Optical microscopy study was realized with a Leica optical microscope. Bland and Altman was used to determine agreement between both techniques measured.


RESULTS
We can identify three different populations based on rabbit polyclonal antibody Cup a1 staining. The main region (44.5%) had 97.3% recognition, a second region (25%) with 28% and a third region (30.5%) with 68% respectively. Immunofluorescence and confocal microscopy showed that main region corresponds to whole pollen grains, the second region are pollen without exine and the third region is constituted by smaller particles with allergenic properties. Pollen schedule shows a higher correlation measured by optical microscopy and flow cytometry in the pollen count with a P-value: 0.0008 E(-2) and 0.0002 with regard to smaller particles, so the Bland and Altman measurement showed a good correlation between them, P-value: 0.0003.


CONCLUSIONS
Determination of pollen count and allergenic load by flow cytometry represents an important tool in the determination of airborne respiratory allergens. We showed that not only whole pollen but also smaller particles could induce allergic sensitization. This is the first study where flow cytometry is used for calculating pollen counts and allergenic load.
Unidad de Alergia de Clínica Dr. Lobatón, S.L., Cádiz, Spain; Cátedra Externa "Inmunología y Alergia"-UCA-Asociación para la Investigación en Ciencias de la Salud. Dr. Pedro Lobatón.
Francisco Moreno
FM
Benítez
Antonio Letrán
AL
Camacho
Alfonso
A
del Cuvillo Bernal
Pedro Lobatón Sánchez
PL
de Medina
Francisco J
FJ
García Cózar
Marisa Espinazo
ME
Romeu
D000485:Allergens / Q000032:analysis* / Q000276:immunology; D000906:Antibodies / Q000276:immunology; D052179:Antigens, Plant / Q000276:immunology*; D029781:Cupressus / Q000276:immunology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D052638:Particulate Matter / Q000032:analysis*; D010940:Plant Proteins / Q000276:immunology*; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology
D000485:Allergens; D000906:Antibodies; D052179:Antigens, Plant; C419643:Cup a 1 protein, Cupressus arizonica; D052638:Particulate Matter; D010940:Plant Proteins
Cupressus arizonica; allergenic load; allergy; flow cytometry; pollen count